An Analysis of Geotechnical Reports to Determine the Soil Bearing Capacity in Manila for the Design Of

An Analysis of Geotechnical Reports to Determine the Soil Bearing Capacity in Manila for the Design of Foundation

by

Gangcuangco, Dave Joseph V. Mosuela, Ericson M. Palatino, Carlo Dominic M.

A Thesis Submitted to the School of Civil, Environmental and Geological Engineering in Partial Fulfillment of the Requirements for the Degree of Bachelor of Science in Civil Engineering

Mapúa Institute of Technology December 2012

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ABSTRACT

Foundation is considered as the most critical part of the structure. It transmits the building load directly into the underlying soil. In this study, collection of existing soil investigation report was done. The data used came mostly from the Manila City Hall, specifically from the Office of the Building Officials. From the collected data, the most probable allowable soil bearing capacity of soil in the city of Manila is 71.94 kPa which was determined using statistical procedure. This study addresses what is the most economical and most efficient foundation to be constructed and it was found out to be isolated footing with tie beam or combined footing with tie beam for structures with less than five storey and pile foundation for structures with five storey and above. From this study, the soil composition of the city of Manila was found out to be mostly of silty sands and sand silt mixture. This study aims to guide civil engineers in designing the foundation in the City of Manila by providing the allowable capacity of soil. Aside from these, the study has designs of foundation for typical structures.

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TABLE OF CONTENTS

APPROVAL SHEET ............................................................................................................... iii ABSTRACT............................................................................................................................. iv TABLE OF CONTENTS .......................................................................................................... 4 LIST OF TABLES .................................................................................................................. vii LIST OF FIGURES ............................................................................................................... viii Chapter 1: INTRODUCTION................................................................................................... 1 1.1.Background of the Study ........................................................................................ 2 1.2.Statement of the Problem ........................................................................................ 2 1.3.Objectives of the Study ........................................................................................... 3 1.4.Conceptual Framework Model ............................................................................... 4 1.5.Significance of the Study ........................................................................................ 5 1.6.Scope and Limitations of the Study ..................................................................... 5-6 Chapter 2: REVIEW OF RELATED LITERATURE ............................................................. 8 2.1.Related Literature.................................................................................................... 8 Chapter 3: METHODOLOGY ................................................................................................ 12 3.1.Research Design.................................................................................................... 13 3.2.Research Subject and Locale ................................................................................ 14 3.3.Data Gathering Procedures ................................................................................... 15 3.4.Laboratory Test Done in a Subsurface Soil Investigation .................................... 16 3.4.1 Grain Size Analysis .................................................................................................... 16 3.4.2 Unified Soil Classification System ............................................................................. 17 3.4.3 Unconfined Compression Test .................................................................................. 17

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3.4.4 Determination of Natural Moisture Content ............................................................ 18 3.4.5 Atterbergs Limit ........................................................................................................ 19

Chapter 4: PRESENTATION OF DATA, ANALYSIS, AND INTERPRETATIONS ......... 21 4.1 Presentation of Data .............................................................................................. 22 4.2 Analysis................................................................................................................. 36 Chapter 5: DETAILED ENGINEERING DESIGN...………………………………………..41 5.1 Minor: Structural Engineering…………………………………………...............42 5.2 Minor: Construction Methods……………………………………………………88 Chapter 6:CONCLUSION ...................................................................................................... 96 6.1. Conclusions .......................................................................................................... 97 Chapter 7:RECOMMENDATION…...………………………………………………………98 7.1 Recommendations ................................................................................................. 99 ACKNOWLEDGEMENT……………………………………………………………….....101 REFERENCES ..................................................................................................................... 103 APPENDICES………………………………………………………………………………105 Appendix A. Design of Concrete Mix .................................................................................. 106 Appendix B. Minimum Design Load Requirements ............................................................ 110 Appendix C. Design of Singly Reinforced Beam ................................................................. 112 Appendix D. Design of Square Tied Concrete Column ....................................................... 115 Appendix E. Designof Isolated Square Footing ................................................................... 116 Appendix F. Computation of the soil properties from available borehole samples…….......119

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LIST OF TABLES

Table 3.A Descriptionof Soil Strength Based on Liquidity Index .......................................... 19 Table 3.B Typical Atterbergs Limit for Soils ......................................................................... 20 Table 3.C Summary of Concrete-Mix Parameters .................................................................. 88 Table A.1 Compressive Strength of Concrete for Various W/C ratio .................................... 88 Table A.2 Approximate Mixing Water Requirements for Different Slump and Maximum Size of Aggregates ............................................................................................................ 89

Table A.3 Volume of Coarse Aggregate per Unit Volume of Concrete ................................. 89 Table 4ASummary of Data Gathered ..................................................................................... 29 Table 4B. Summarized Probable Value of qu(allowable) in Every District ........................... 34 Table 4C.Most Probable Value of qa(allowable) in Manila ................................................... 36 Table 4D.Tabulated Soil Properties ........................................................................................ 38 Table 4E.Tabulated Data of SOil Bearing Capacities, Dimension of Footing,Rebars for Residential Occupancy .................................................................................................... 38 Table 4.F.Tabulated Data of SOil Bearing Capacities, Dimension of Footing,Rebars for Commercial Occupancy .................................................................................................. 39

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LIST OF FIGURES

Figure 1: Map of the City of Manila ....................................................................................... 22 Figure 2: Number of BoreholeLogs on Each District of Manila ............................................ 23 Figure 3: Geological Map of Manila ...................................................................................... 24 Figure 4: Comparison Chart of the Most Probable Value of Soil Bearing Capacity in Manila .............................................................................................................................. 25 Figure 5: Unified Soil Classification System Chart ................................................................ 30 Figure 6:Map of Manila with the Most Probable Value of Allowable Bearing Capacity ...... 35

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CHAPTER 1 INTRODUCTION

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Chapter 1 INTRODUCTION

Foundation is that part of a structure which transmits the building load directly into the underlying soil. The foundation is considered as the most important part of the structure. It is the one responsible in holding the weight of the structure and the building’s stability depends on it. The design of the foundation will be efficient and economical if the soil investigation was conducted accurately. For the soil investigation to be accurate, soil testing must be performed on site and in the laboratory. Generally, there are two types of samples: the disturbed and undisturbed samples. Disturbed samples are taken from cuttings produced by the drilling process using split spoon sampler while undisturbed samples are generally taken by cutting blocks of soil, or by pushing or driving tubes into the ground using shelby tube sampler. These samples can be obtained by means of boring, drilling and probing. After the samples were obtained, they are tested on site or in the laboratory to determine different soil parameters. From the previous researches, the mechanical properties of soil in Manila were not fully determined. There are no studies that provide the mechanical properties of soil which would be used in the design of the foundation.

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1.1 The Problem and Its Background Soil is the oldest and most complex engineering material and all structures are constructed in it. The mechanical properties of soil must be determined before designing and constructing the foundation. The mechanical properties of soil are shear strength and bearing capacity. To obtain the ultimate bearing capacity of the soil, Unconfined Compression Test could be performed in the laboratory using the unconfined compression apparatus while the shear strength could be obtained through the Direct Shear Test using the Direct Shear Apparatus in the laboratory. However, the actual mechanical properties of soil in the City of Manila are not familiar to civil engineers since not anyone of them have access to these data.

1.2 Statement of the Problem More specifically, this study answered the following questions: 1. What is the composition of the soil in the city of Manila? 2. What is the value of soil bearing capacity in different parts of Manila?

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1.3 Objective of the Study

This study aims to develop a map of Manila City using the collected data. a) To be able to determine the type of foundation in Manila by collecting soil investigation reports submitted to the City of Manila and soil investigations done by private companies. b) To identify and classify the composition of soil in Manila. c) To generalize the foundation in the City of Manila with respect to the number of storeys of structure. d) To develop a map of Manila City showing probable allowable soil bearing capacity based from soil investigation report conducted in the city of Manila.

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1.4 Conceptual Framework

Obtain soil investigation reports from public and private institutions

Arrange each data from different references into following breakdown: Location of the soil investigation report, number of storey and type of structure in the site, allowable soil bearing capacity at a particular site, and the Unified Soil Classification System (USCS) in the site

Compare

the

Unified

Soil Determine the most probable value of the allowable soil bearing

Classification System(USCS) in the soil investigation report to the

capacity using statistical procedure

geographic map of manila

Make a conclusion

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1.6 Significance of the Study

The study is a useful guide to civil engineers in designing the foundation in the city of Manila by providing the allowable capacity of soil. With the aid of this study, the engineer will have an idea on what type of foundation to be constructed. Also with this study, the engineer would know if the soil condition in the proposed site is appropriate for a proposed structure. For its academic purpose, this study can serve as a reference for civil engineering students to know the soil condition in a particular site. And for its technological purpose, this study helps technical and non-technical people on being familiar with the different tests that could be used in determining the properties of the soil.

1.7 Scope and Limitations

The study is a collection of data, particularly the soil investigation reports in the City of Manila. The data inside the soil investigation report are obtained by laboratory or field experiments established by the American Standard for Testing Materials (ASTM) and with the guidance of other trusted references regarding the soil properties. The City of Manila is where the study took place. Since conducting a soil investigation is expensive, the data used in this study are those data which are collected from previous soil investigation reports. This study is a guide to civil engineers on what type of foundation may be designed or constructed. The foundation which was designed was based from the loads presented in the NSCP 2010 and only the most loaded footing was designed. Geotechnical investigation must be performed on site upon construction since this study

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only serves as a reference. The study covers structures which are classified as low rise and medium rise since no soil investigation report was collected for high rise structures.

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CHAPTER 2 RESEARCH COMPONENT

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Chapter 2 REVIEW OF RELATED LITERATURE 2.1 Related Literature

The urgency for accurate information and adequate understanding of the geotechnical properties of the foundation of subsoil cannot be over emphasized. Geotechnical information are useful in ensuring that the effects of projects on the environment and natural resources are properly evaluated and mitigated where necessary (Nwankwoala et al., 2009). The study of Nwankwoala et al.(2009) shows that on the determination of the properties of soil it would be appropriate to estimate a type of foundation to the subsoil. The estimation of soil strength indices is required for the design of foundations, retaining walls, and pavements in civil engineering applications (Freudlund &Vanapali, 2002). These indices are also essential in assessing the stability of slopes and soil, and can be used to construe the ability of a soil to withstand stresses and strains associated with naturally occurring instances of: increased pore pressure, cracking, swelling, development of slickensides, leaching, weathering, undercutting, and cyclic loading (Duncan & Wright, 2005). The difficulty and in some cases the high cost of attaining the soil strength indices has led to many researchers seeking correlations with easily measured soil index properties (Eid, 2006). Several empirical procedures have been developed over the years to predict the shear strength of soils, particularly unsaturated soils. Drained residual strength was shown to correlate with clay content as well as type of clay minerals (Stark & Eid, 1997).

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The unit of soil to withstand a shear stress is a derivative of the measurement of soil shear strength.. Specifically, research efforts have focused on determining correlations between the residual friction angle of soils and soil parameters such as Atterberg limits, and clay fraction (Kaya &Kwong, 2007). The quaternary alluvium are consists of gravel, sand, silt and clay, in which it is loose and easily deformed by underground water. (Kilic, R. , Ulamis K, and Atalar C., 2006). Foundation designs must satisfy both strength and serviceability criteria. The soil beneath the foundations must be capable of carrying the structural loads placed upon it without shear failure and consequent settlements being tolerated for the structure it is supporting. Rupture surfaces are formed in the soil mass upon exceeding a certain stress condition. The angle of internal friction of soil is measured between the normal force and the resultant force within the soil column that is attained when failure just occurs in response to a shearing stress. Peak soil friction angle refers to the initial angle attained from the initial shearing phase, while the residual friction angle refers to the angle obtained following the initial failure of the soil sample. (Das, 1997).Bearing capacity failure on foundation occurs as the soil supporting the foundation fails in shear, which may involve general, local, punching shear mechanism (Bowles, 1988). The soil properties are not distributed randomly, but in a semicontinuous fashion. It has been observed that the performance of foundations is considerably affected by the inherent spatial variability of the soil properties (Griffiths and Fenton, 2001). To date, some researches have been undertaken investigating the probabilistic analysis of the settlement of foundations supported on single-layered soil profiles incorporating spatial variability (Griffiths et al., 2002). For footings, the geotechnical engineering practice regularly calculates the bearing capacity from input of

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assumed shear strength values and a series of relations that depend on these values directly and indirectly. The capacity is then divided by a factor of safety, normally ranging from 2.5 through 4 to obtain the allowable load or stress. For piles, the capacity of the pile toe is assumed to follow a bearing capacity formula (static analysis). However, it is generally thought that the capacity of a pile is so difficult to analyze that a static or dynamic test giving the capacity directly is necessary for a reliable design. (Coduto, D. P., 1994)

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CHAPTER 3 METHODOLOGY

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Chapter 3 METHODOLOGY 3. 1 Research Design

This study aims to classify the soil and determine a certain mechanical property called the allowable soil bearing capacity. This property is essential in the design of a foundation. From a soil investigation report, the soil could be classified by the unified soil classification system. In order to classify the soil, grain size analysis was done. Specific test for the mechanical property is also performed such as the unconfined compression test for the bearing capacity. The soil investigation reports that were acquired were from the different districts in the City of Manila. From the data gathered, a comparison was made about the classification of soil from the geologic map of Metro Manila obtained from Bureau of Mines and GeoSciences in Quezon City. The results are presented in table form containing the street, district, type of structure, allowable soil bearing capacity, proposed foundation, and soil classification.

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3.2 Research Design Framework

Gather Related Literature

Collect Soil Investigation Reports

Analyse Information

Classify the soil

Determine Bearing Capacity

Propose Type of Foundations

Determine Suitable Type of Structures

Design of Foundation

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3.2 Research Subject and Locale

The City of Manila, known as Maynila for the Filipinos, is the capital city of the Philippines and one of the cities that make up the greater metropolitan area of Metro Manila. Manila is the center of government in the country and one of the central hubs of a thriving metropolitan area home to over 12 million people as of NSO 2010 Census. It is located on the shores of Manila Bay just west of the geographical center of Metro Manila, also known as the National Capital Region (NCR), which lies on a peninsula between Manila Bay and Laguna de Bay in southern Luzon. The city is one of 17 cities and municipalities which form the metropolitan area. The geography of Manila reveals that the city is on the eastern shore of Manila Bay. Manila apart from the Manila City encompasses seven cities and nine towns. The City of Manila is approximately 38.3 square kilometers and is located on the west coast of the Philippine island of Luzon. Manila is the capital of Philippines and is also an important commercial, industrial and cultural center. The geography of Manila also reveals that the Pasig River divides the city into two sections -The Intramuros (the old city) and the Ermita (important government buildings and the hotels) and the new section on the northern bank (http://www.manila.gov.ph/, March 5, 2012).

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3.3 Data Gathering Procedures

There were 55 soil investigation reports gathered from the City of Manila. From these reports, the soil classification, bearing capacity, and the proposed type of foundation were determined. There are numerous tests performed in the laboratory for the complete subsurface exploration such as unified soil classification system, unconfined compressive strength of cohesive soil, particle size analysis of soils, liquid limit of soils, plastic limit and plasticity of soils, moisture content of soils, unconfined compressive strength of intact rock cores, and specific gravity of soils.

3.4 Laboratory Test Done in a Subsurface Soil Investigation

In a soil exploration report, several tests must be performed in laboratory or at the site. These test are ASTM D422 (Grain Size Analysis of Soil), ASTM D4318 (Atterbergs Limit), ASTM D2216 (Determination of Natural Moisture Content of Soil), ASTM D2488

(Unified

Soil

Classification

System),

ASTM

D2166–06

(Unconfined

Compression Test)

3.4.1 Grain Size Analysis (ASTM D422)

Soil was passed through a series of sieves, the weight of soil retained on eachsieve determined and recorded. For each sample analyzed, a gradation curvewas drawn based on the percent finer by weight. The distribution of particlesizes larger than No. 200 sieve (retained on the No. 200 sieve) is determinedby sieving, while the distribution of particle sizes smaller than the No. 200 sieve is determined by a sedimentation process, using a hydrometer. 23

3.4.2 Unified Soil Classification System (ASTM D2488)

Soils seldom exist in nature separately as sand, gravel, or any other single component. Usually they occur as mixtures with varying proportions of particles of different sizes. Each component contributes its characteristics to the mixture. The USCS is based on the characteristics of the soil that indicate how it will behave as a construction material. In the USCS, all soils are placed into one of three major categories. They are coarse-grained, fine-grained and highly organic. The USCS further divides soils that have been classified into the major soil categories by letter symbols, such as S for sand, G for gravel, M for silt, and C for clay. A soil that meets the criteria for a sandy clay would be designated (SC). There are cases of borderline soils that cannot be classified by a single dual symbol, such as GM for silty gravel. These soils may require four letters to fully describe them. For example, (SM-SC) describes a sand that contains appreciable amounts of silt and clay.

3.4.3 Unconfined Compression Test (ASTM D2166– 06)

The unconfined compression test is an important method of determining the shear strength of cohesive and semi-cohesive soil. In the unconfined compression test, the sample is placed in the loading machine between the lower and upper plates. Before starting the loading, the upper plate is adjusted to be in contact with the sample and the deformation is set as zero. The test then starts by applying a constant axial strain of about 0.5 to 2% per minute. The load and

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deformation values are recorded as needed for obtaining a reasonably complete loaddeformation curve. The loading is continued until the load values decrease or remain constant with increasing strain, or until reaching 20% (sometimes 15%) axial strain. At this state, the samples are considered to be at failure. For each applied load, axial unit strain can be computed by dividing the specimen’s change in height by its initial height. The value of the initial height is given by the deformation dial reading, provided that the dial is set to zero initially. As the load is applied to the specimen, its cross-sectional area will increase by a small amount. For each applied load, the cross-sectional area can be computed by dividing the initial area of the specimen to the quantity one subtracted by the axial unit strain. Each applied load can be determined by multiplying the proving ring dial reading by the proving ring calibration factor, and the load per unit area can be computed by dividing the load by the corresponding cross-sectional area. The largest value of load per unit area at fifteen percent strain, whichever is secured first, is taken to be the unconfined compressive strength and the cohesion is taken to be half of the unconfined compressive strength.

3.4.4 Determination of Natural Moisture Content of Soil (ASTM D2216)

The water content of soil is determined as the ratio, expressed in percentage of the mass of pore water to the given mass of the solid particles.

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3.4.5 Atterbergs Limit (ASTM D4318)

The test method covers the determination of the liquid limit, plastic limit, and plasticity index of soils that are defined as follows: Liquid Limit is the water content, in percent, at which a soil changes from plastic to liquid state. Plastic limit is the water contents of solid at which the soil changes from a solid to a semi-solid to a plastic state. Plasticity index is the range of water contents over which the soil deforms plastically and is defined by the equation: Plasticity index = Liquid Limit – Plastic Limit Liquidity Index is the ratio of the difference in water content between the natural water content of a soil and its plastic limit to its plasticity index and is defined by the equation: Liquidity Index =

    

Values of Liquidity Index

Description of soil strength

LI < 0

Semisolid State – high strength, brittle, sudden fracture is expected

0 < LI < 1

Plastic State – intermediate strength, soil deforms like a plastic material

LI > 1

Liquid State - low strength, soil deforms like a viscous fluid Table 3.A Description of Soil Strength Based on Liquidity Index

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Soil Type Sand Silt Clay

Liquid Limit (%)

Plastic Limit (%) Plasticity Index Nonplastic 40 30 – 20 25 – 10 – 16 40 -180 25 50 – 15 - 100 Table 3.B Typical Atterberg Limits for Soils

3.5 Presentation of Data

After the collection of data, the data were presented in a table form found at the next chapter of the study. The table is composed of the location of the conducted subsurface soil investigation, district, number of storeys of the structure as well as its purpose, the allowable soil bearing capacity of soil, and the proposed type of foundation as prescribed by the report. The most probable allowable soil bearing capacity of soil in each district and the most probable soil bearing capacity of soil in the City of Manila is tabulated. 3.6 Design of Footing

The footing for one storey residential, two storey residential, three storey residential, one storey commercial/industrial, two storey commercial/industrial, three storey commercial/industrial was designed using the most probable allowable soil bearing capacity of soil and the Ultimate Strength Design (USD) and with accordance with the National Structural Code of the Philippines (NSCP). The design of the footing is limited to these structures since these are the typical types of structure constructed in the city based on the subsurface soil investigation collected. Together with the design is the estimated amount of material to be used in the construction of the footing using the American

Concrete

Institute

(ACI)

method

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of

designing

for

concrete

mix.

CHAPTER 4 DATA PRESENTATION

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Chapter 4 PRESENTATION OF DATA, ANALYSIS AND INTERPRETATIONS 4.1 Presentation of Data

The location of each soil investigation samples are shown in Figure 1. In general, the soil classification in the City of Manila is found to be composed of silty sands and sand silt mixture for the upper layer and it is drawn in Figure 2.

Figure 1. Map of the City of Manila

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3 BOREHOLES

1 BOREHOLE 11 BOREHOLES 18 BOREHOLES

1 BOREHOLE

3 BOREHOLES

3 BOREHOLES 1 BOREHOLE 2 BOREHOLES 1 BOREHOLE

6 BOREHOLES

4 BOREHOLES 1 BOREHOLE

Figure 2. Number of Borehole Logs on Each District of Manila

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Figure 3. Geological Map of Manila(Source: Mines and Geosciences Bureau)

It is the geological representation of the city of Manila in which it provides the information necessaryto make decisions about constructionand infrastructure design in earthquake-prone areas. The map also indicates the type of formation in Manila such as it contains quaternary alluvium that mainly consists of gravel, sand, silt and clay, in which it is loose and easily saturated by ground water.

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MPV per District vs MPV of Manila ty ic 80 a70 p a C60 g n ir 50 a e 40 B li o30 S le 20 b a w10 lo l A0 V P M

District

MPV of Allowable Soil Bearing Capacity per District MPV Allowable Soil Bearing Capacity of Manila

Figure 4. Comparison Chart of the Most Probable Value of Soil Bearing Capacity in Manila

The chart shows the relationship between the most probable values of the soil bearing capacity in each district with respect to the most probable value of soil bearing capacity of Manila. The method used in computing the most probable value is shown in the latter part of this chapter. The district of San Miguel has the farthest value compared to Manila and the other districts while the other district has a little variation compared to the value of Manila.

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Street

District

Purpose of Structure 3 Storey Residential 3 Storey condominium 3 Storey Residential 3 Storey Building with Deck 3 Storey Building with Deck 4 Storey Warehouse Building

qu (allowable)*

1882 C.M. Recto Avenue Solis Street

Quiapo

M.A. Guerrero Extension 068 Quirino Street

Tondo

2416 Callejon 1 Corner Fidel Street, Gagalangin Calle Gamban Corner Calle Guidote Balut

Tondo

1249 San Nicolas corner Tindalo Streets 1227 Camba Street Extension

Tondo

75 kPa

Tondo

4 Storey Building 3 Storey Residential Apartment

Lot 20-C, Herbosa Street

Tondo

with Penthouse 3 Storey with Deck

401-C Interior 54 Perla Street

Tondo

Balintawak Street

Tondo

300 Pacheco Street

Tondo

1732 Tecson Street

Sta. Cruz

2140 Vision Street

Sta. Cruz

1525 Sulu Street

Sta. Cruz

Tondo

Tondo

Tondo

Proposed Foundation Isolated Footing with Tie Beam Isolated Footing with Tie Beam Isolated Footing with Tie Beam Isolated Footing

USCS

72 kPa

Isolated Footing with Tie Beam

SM

72 kPa

Strip or Continuous Footing with Tie Beam Isolated Footing with Tie Beam Isolated Footing with Tie Beam

SM

Combined Footing with Tie Beam Combined Footing with Tie Beam Pile Foundation with Tie Beam

SM

75 kPa 75 kPa 57.46 kPa 72 kPa

72 kPa

75 kPa

SM SM SM SM

SM SM

3 Storey Residential with Deck 5 Storey Residential with Deck 3 Storey Residential with Roof

72 kPa

72 kPa

Continuous Footing with Tie Beam

SM

4 Deck Storey Commercial 3 Storey Residential

75 kPa

SM

2 Storey with Deck and

72kPa

Isolated Footing with Tie Beam Isolated Footing or Combined Footing with Tie Beam Isolated Footing with Tie Beam

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72 kPa

72 kPa

SM

SM

SM

SM

Lot 19 Block 2 Makisig Street

Sta. Mesa

2604 Benito Street

Sta. Mesa

419 Alegria Street

Sta. Mesa

Estrada Street

Sta. Ana

Br. Manuel Carreon Street

Sta. Ana

2265 Calabastro Street

San Andres Bukid

Aqua Marina Street

Penthouse 3 Storey Residential Apartment with Deck

72 kPa

Isolated Footing or Combined Footing with Tie Beam

SM

3 Storey Residential 3 Storey Residential 3 Storey Building with Deck 3 Storey Residential Building 3 Storey Building

86.19 kPa

Isolated Footing with Tie Beam Isolated Footing with Tie Beam Isolated Footing with Tie Beam

SM

72 kPa


SM

72 kPa

SM

3 Storey Building with Deck 3 Storey Residential

72 kPa

Sta. Maria Street

San Andres Bukid Pandacan

2279 Linceo Street

Pandacan

Mendoza Guanzon Corner Isidro Mendoza Street Lot 59 Block 35, Antipolo Street 1415 A. Maceda Street 1238 Miguelin Street

Pandacan

3 Storey Apartment 3 Storey Office/ Warehouse 3 Storey with Deck 3 Storey Residential 3 Storey Residential/

Isolated or Combined Footing with Tie Beam Combined Footing with Tie Beam Isolated or Combined Footing with Tie Beam Isolated Footing with Tie Beam Isolated Footing with Tie Beam Isolated Footing with Tie Beam Isolated Footing with Tie Beam Isolated Footing with Tie Beam

SM

Isolated or Combined Footing with Tie Beam Combined Footing with Tie Beam

SM

Sampaloc Sampaloc Sampaloc

Lot 20-A Florentino Corner Metrica Streets

Sampaloc

Adelina Street

Sampaloc

Apartment Building 3 Storey with Roof Deck

3 Storey with Deck

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72 kPa 72 kPa

57.46 kPa

72 kPa 75 kPa

75 kPa 72 kPa 72 kPa

72 kPa

72 kPa

SM SM

SM

SM

SM

SM SM

SM

Lot 17-A Block 3 Kundiman Street

Sampaloc

3 Storey Residential

72 kPa

751 Sisa Street

Sampaloc

75 kPa

1416 Maceda Street

Sampaloc

Lot 7 Extremadura Street 1152 E. Quintos Street Lot 54 Bolck 11,918 A. Maceda Street

Sampaloc

Lot 50 Block 20 M. Fuente Street

Sampaloc

Santisima Street

Sampaloc

3 Storey Building with Deck 3 Storey Residential 3 Storey Residential 3 Storey Residential 4 Storey with Deck Commercial/ Residential Building 3 Storey Residential Building 4 Storey with Deck

Lot 33 A&B P. Florentino corner J. Marzan Streets PIY Margal Street

Sampaloc

Fajardo corner Don Quijote Streets

Sampaloc

940 A. Leyte Del Sur Street 688 Domingo Santiago Street 528 Madrid Street

Sampaloc

Sampaloc Sampaloc

Sampaloc

Sampaloc Binondo

San Nicolas Lot no. 5-C-9-A, Matienza Street

San Miguel

Sto. Cristo

San Nicholas

4 Storey Commercial Building 3 Storey Residential 4 Storey Residential/C ommercial 3 Storey with Deck 3 Storey with Roof Deck 3 Storey Residential with Roof Deck 3 Storey Residential with Deck 5 Storey with Mezzanine and Penthouse 35

Combined Footing with Tie Beam Combined Footing with Tie Beam Isolated Footing with Tie Beam Isolated Footing with Tie Beam Isolated Footing with Tie Beam Isolated Footing with Tie Beam

SM

78.57 kPa


SM

72 kPa

Combined Footing with Tie

SM

72 kPa 72 kPa 72 kPa 72 kPa

71.80 kPa

72 kPa 72 kPa

99 kPa 70 kPa 72 kPa

Beam Isolated Footing with Tie Beam

SM

SM SM SM SM

SM

Isolated Footing with Tie Beam Isolated Footing with Tie Beam

SM

Isolated Footing with Tie Beam Isolated Footing with Tie Beam Isolated Footing

SM

SM

SM SM

with Tie Beam 57.46 kPa

Mat Footing

SM

72 kPa

Pile Foundation

SM

Lot 10 Block 7 interior P. Gil

Paco

1565-F Valentina street Phase 14 lot 3 block 3 Acropolis subd. P.H. Guazon

Paco

Lot 2 Block 3 road Lot I Acropolis Manila Paz Mendoza Guanzon

Paco

Lot 4-C Peñafrancia street

Commercial Building 3-storey with roof deck

72 kPa

3-storey with roof deck 3-storey residential

72 kpa

4-storey residential 3-storey residential

75 kPa

Paco

4-storey with roof deck

57.46 kPa

Lot 4 Anak bayan street Lot 448 Leyte street

Malate

3-storey residential 3-storey residential

72 kPa

Lot 1, Block 3 Leveriza Urban Bliss

Malate

1739 F.T. Benitez Street

Paco

Paco

Malate

72 kpa

75 kPa

72 kPa

4 Storey 72 kPa Building with Deck Malate 3 Storey 72 kPa Residential Building Table 4A. Summary of Data Gathered

Combined/Isolat ed with grade beam Isolated footing with tie beams Isolated footing with tie beams

SM

Isolated footing with tie beams Isolated/Combin ed footing with tie beams Continuous footing with tie beam Isolated footing with tie beams Isolated footing with tie beams

SM


SM


SM

The table shows the lists of districts in Manila which the soil investigation was performed. Its shows the number of storey as well as its purpose, allowable soil bearing capacity, type of foundation recommended, and the Unified Soil Classification System (USCS).

*qu (allowable)-Allowable soil bearing capacity

36

SM SM

SM

SM

SM SM

Figure 5. The Unified Soil Classification System Chart

37

In conducting a soil investigation the soil composition is classified using the USCS chart. In this chart the typical description of the soil can be seen as well as the letter symbol which is indicated at every depth of the borehole. It is subdivided into two major divisions which are the coarse grain soil and fine grain soil.

The following table shows the probable value of the allowable soil bearing capacity in each district. Where N is the number of soil investigation report collected on the district. The probable value of qu was computed by using the formula

District : Binondo qu(allow)

N

qu*N

72

1

72

1

72

Prob. Value

of qu

72

District: Malate qu(allow)

N

qu*N

72

4

288

4

288

Prob. Value of qu

72

District : Paco qu(allow)

N

qu*N

75

2

150

72

3

216

57.46

1

57.46

6

423.46

Prob. Value of qu

70.57667

38

 

District : Pandacan qu(allow)

N

qu*N

75

1

75

72

1

72

57.46

1

57.46

3

204.46

Prob. Value of qu

68.15333

District: Quiapo qu(allow)

N

qu*N

75

1

75

1

75

Prob. Value of qu

75

District: Sampaloc qu(allow)

N

qu*N

75

2

150

72

12

864

78.57 71.8

1 1

78.57 71.8

90

1

90

70

1

70

18

1324.37

Prob. Value of qu

73.57611

District: San Andres qu(allow)

N

qu*N

72

2

144

2

144

Prob. Value of qu

72

District: San Miguel qu(allow)

N

qu*N

57.46

1

57.46

1

57.46

Prob. Value of qu

57.46

39

District: San Nicolas qu(allow)

N

qu*N

72

1

72

1

72

Prob. Value of qu

72

District: Sta. Ana qu(allow) 72

N 2

qu*N 144

2

144

Prob. Value of qu

72

District: Sta. Cruz qu(allow)

N

75

1

qu*N 75

72

2

144

3

219

Prob. Value of qu

73

District: Sta. Mesa qu(allow)

N

qu*N

72

2

144

86.19

1

86.19

3

230.19

Prob. Value of qu

76.73

District: Tondo qu(allow)

N

qu*N

75

3

225

72

7

504

57.46

1

57.46

11

786.46

Prob. Value of qu

71.49636

40

District

Probable Value of qu(allowable)

Binondo

72

Malate

72

Paco

70.57667

Pandacan

68.15333

Quiapo

75

Sampaloc San Andres

73.57611 72

San Miguel

57.46

San Nicolas

72

Sta. Ana

72

Sta. Cruz

73

Sta. Mesa

76.73

Tondo

71.49636

Table 4B. Summarized Probable Value of qu(allowable) in Every District

The probable value of the allowable soil bearing capacity is then used to compute for the probable value of the allowable soil bearing capacity of the City of Manila as presented in the next table. The most probable value was computed using the formula

. 

41

`

71.4963

73 73.57611

72 72

76.73

75

70.57667

68.15333

72

72 72

Figure 6. Map of Manila with the Most Probable Value of Allowable Bearing Capacity

42

District Binondo Malate Paco Pandacan Quiapo Sampaloc

Prob. Value of qu (kPa) 72 72 70.57666667 68.15333333 75 73.57611111

Area(hectares) 66.11 259.58 278.69 166 84.69 513.71

San Andres 72 San Miguel 57.46 San Nicolas 72 Sta. Ana 72 Sta. Cruz 73 Sta. Mesa 76.73 Tondo 71.49636364 Most prob. 71.94343597 kPa Table 4C. Most Probable Value

168.02 91.37 163.85 169.42 309.01 261.01 865.13

Prob. Value*Area 4759.92 18689.76 19669.01123 11313.45333 6351.75 37796.78404 12097.44 5250.1202 11797.2 12198.24 22557.73 20027.2973 61853.64907

of qa(allowable) in Manila

4.2 Analysis

All data collected almost came from the Manila City Hall, office of the building officials in particular, while other data came from private institutions. From the data gathered, soil investigation reports were collected from the different districts of the city. It was then tabulated in terms of address, district, proposed type of structure, allowable soil bearing capacity, recommended type of foundation, and USCS (Unified Soil Classification System). The soil bearing capacity in each district is determined using the data collected. These values can be computed with the use of Terzaghi’s bearing capacity divided by the factor of safety. But in order to use the Terzaghi’s bearing capacity equation, the soil’s cohesion and the soil’s angle of internal friction should be known. These can be obtained by laboratory test such as Unconfined Compression Test (UCT) and Direct Shear Test.

43

The allowable bearing capacity of soil is needed to design for the foundation of the structure and it’s foundation type depends on the load passed by the structure. These loads may differ with the type of use of the structure (e.g. commercial, residential, industrial, etc.). Based from Table 1, the type of foundation which is recommended in the City of Manila is shallow foundation for structures with 4-storey and below while pile deep foundation for structures with 5-storey and above without considering the 2

occupancy type of the structure which was verified from the data of EM A Partners and Co. In some instances, because of the weak bearing capacity of soil and heavy load carried by the structure, there are four storey structures which are required to be rested on deep foundation. Shallow foundation may be made of isolated footing and combined footing if the area of the site is limited while deep foundation is mainly made up of piles. Since the numbers of soil investigation reports gathered are not equal in every district as well as the areas for each district, statistic procedure was done to compute for the most probable value of the allowable soil bearing capacity on each district and on Manila. The most probable value of the allowable soil bearing capacity of Manila can be taken as 71. 94 kPa.

44

NUMBER OF SAMPLES

PROPERTY 1 2 3 w.c.(%) 15.4 7 19.7 3 Moist density(kg/ cm ) 2.447 2.606 1.859 3 Dry density(kg/ cm ) 2.12 2.436 1.553 Dry unit weight(kN/ m3) 20.7972 23.89716 15.23493 Moist unit weight(kN/ m3) 24.00507 25.56486 18.23679 Void ratio 0.496342 Moist unit weight(kN/ m3) 20.95518 Table 4D. Tabulated Soil Properties

4 6.3 1.618 1.522 14.93082 15.87258

5 14.7 1.595 1.391 13.64571 15.64695

The table shows the tabulated data of a specific soil sample in which its shows some of the soil properties needed in designing a structure. The data are gathered by the field density test for the determination of in-site unit weight and moisture of backfill used. There were 5 samples taken and by oven drying and the sand replacement method the moisture content, moist and dry densities were then gathered. The formula in the determination of necessary soil properties are used to determine the required unit weights and void ratio. The computed moist unit weight is used in the design of the foundation since the unit weight of soil is vital factor in designing. Occupancy: Residential No. of Dimension of storey Square Footing Rebars A.S.B.C.(qa) E.S.B.C.(qeff) U.S.B.C.(qu) 1 71.94 kPa 37.6335 kPa 36.7411 kPa 3.2x3.2x0.3 m. 11 2 71.94 kPa 37.4389 kPa 37.266 kPa 4.5x4.5x0.35 m. 21 3 71.94 kPa 37.2443 kPa 36.1848 kPa 5.6x5.6x0.45 m. 30 Table 4E. Tabulated Data of Soil Bearing Capacities, Dimension of Footing, and Rebars for Residential Occupancy

45

Occupancy: Commercial No. of Dimension of storey Square Footing Rebars A.S.B.C.(qa) E.S.B.C.(qeff) U.S.B.C.(qu) 1 71.94 kPa 37.5038 kPa 35.8232 kPa 4.1x4.1x0.35 m. 17 2 71.94 kPa 37.2443 kPa 37.1381 kPa 5.7x5.7x0.45 m. 36 3 71.94 kPa 37.0496 kPa 37.0137 kPa 7x7x0.525 m. 54 Table 4F. Tabulated Data of Soil Bearing Capacities, Dimension of Footing, and Rebars for Commercial Occupancy The table shows the bearing capacities, dimension of isolated square footing, and the required number of reinforcing bars for footing. The allowable soil bearing capacity was computed using most probable value method to compute the probable soil bearing capacity of Manila from the available data from city engineer’s office of Manila. The value of the allowable bearing capacity used in the design process is 71.94 kPa since it is the most probable value of bearing capacity, and then the effective soil bearing capacity is calculated by subtracting the effective pressure due to concrete and overburden soil to the allowable bearing capacity. The effective bearing capacity is used for the determination of the dimension of isolated square footing with the total unfactored dead load as the axial load. The design thickness of the footing is gathered by computing the effective depth of the footing, and then by adding the 150% of the rebar diameter and concrete cover of 75 mm for structural elements exposed to earth. The design of the isolated square footing was done using the ultimate strength method with the help of the NSCP to be provided by the proper codes especially in design. Referring to the table, the effective bearing capacity of the soil lessens as the number of storey increases and also the assumed thickness of the footing affects the value of the effective bearing capacity. The ultimate bearing capacity of the soil varies from the load imposed as well as the dimension of the square footing, and it is noticeable from the

46

table 4F. The number of rebars was computed using the formulas for beam design and then checked if the actual spacing follows the required by the code, and the number of bars increases as the storey increases. The same analysis for the commercial occupancy since the imposed loads only changes

47

CHAPTER 5 DETAILED ENGINEERING DESIGN

48

MINOR: STRUCTURAL ENGINEERING DESIGN OF A TYPICAL ISOLATED FOOTING

Design method: Ultimate Strength Design method Type of structure: One-storey residential with roof deck Design parameters: Slab thickness: 100mm. (minimum slab thickness for two-way slab) Unit weight of plain concrete: 23.55 kN/m

3

Concrete compressive strength, f`c = 21MPa Reinforcing bar tensile strength, fy = 275MPa Main reinforcing bar diameter (for beam and column) = 20 mm. Stirrups and ties = 10 mm. (Main bar < 32 mm.) Concrete cover: Beam = 40 mm. Column = 40 mm. Footing = 75 mm. (Exposed to earth) Minimum design loads: Superimposed dead load: Slab self-weight = γconc.(slab thickness) = 23.55(0.1) =2.355kPa Dead load: Ceiling loads: Wood furring with suspension = 0.12kPa Gypsum board(15mm. thick) = 0.12kPa Flooring load: Flat tile on 25mm. mortar =1.1kPa Partition load allowance = 1kPa

49

Total dead load = 2.34kPa Live load: Residential = 1.9kPa Total live load = 1.9kPa Load combination: w = 1.2DL+1.6LL = 1.2(2.34) + 1.6(1.9) = 8.674kPa Short span = 5m Long span = 5m

  =   = 1≥0.5, Two-way slab       m ) =   ) = 14.46kN/m Uniform distributed load transfer formula =   Span ratio, m =

2

*For a middle singly reinforced beam loads from slabs are the most critical. W = 2(14.46) = 28.92kN/m, Factored load alone Beam design:

Beam width, b = 5% of span (design assumption) = 5%(5000mm) = 250mm. Height, H = 2b (design assumption) = 2(250mm) = 500mm. Beam self-weight = γconc.(Cross sectional area of beam) = 23.6(0.25x0.5) = 2.944kN/m

 =   =79.6427kN-m     =  =  = 0.037833

Moment at support = ρ BALANCE

ρ MAX = 0.75 ρ BALANCE = 0.75(0.037833) = 0.028375 ρ MIN =

 =  = 0.005091  

Assume ρ = 0.6 ρ MAX = 0.6(0.028375) = 0.017025 ω=

 =  = 0.222943 



50

Ru = ω f`c(1-0.59 ω) = 0.222943(21)[1-0.59(0.222943)] = 4.06597 MPa Let d=1.75b 2

2

Mu = Φ Rub d -> 0.9 Rub d = 79.6427kN-m b = 231.686276 = 250 mm.

d = 405.450983 = 425 mm. H = d + Concrete cover(40 mm.) + d(strirrups) + 0.5d(Main bar) = 425 + 40 + 10 +0.5(16) = 483 mm. H = 500 mm. *check design beam self-weight over actual beam self-weight Actual self-weight = 23.55(0.5)(0.25) = 2.94375 kN/m Design self-weight = 2.94375 kN/m Actual self-weight = Design self-weight OK! Number of main reinforcing bars As = ρbd = 0.017025(250)(425) = 1808.877273 mm

2

 =  = 314.1592654 mm     N=  =  = 6 bars   Reaction at support =  =  = 93.28177kN Ab =

2

Design of Columns:

Imposed axial load on column at 2nd level: 4(reaction at support) Pu(Axial load) = 373.1271 kN

51

Pu = 0.8ϕ(0.85f`c(Ag-As)+fyAs) , for tied column ϕ = 0.65 As = ρAg, Assume ρ = 0.04 As = 0.04Ag Pu = 0.8ϕ(0.85f`c(Ag-0.04Ag)+fy(0.04Ag)) 373.1271 kN = 0.8(0.65)(0.85(21) (Ag-0.04Ag)+275(0.04Ag)) Solving for Ag, Ag = 25502.99 mm2 For square column Ag = B2 = 25502.99 B = 159.7 mm = 175 mm. Design of isolated footing:

qa = 71.94 kPa, most probable value of allowable soil bearing capacity of Manila 3

γsat = 20.955 kN/ m , Assuming ground water table at near natural ground line (N.G.L.) Total axial load = Total axial load(from column) + self-weight (column + pedestal), pedestal height = Df - t Total axial load = 373.1271 + 2.163656 + 1.009706 Total axial load(Ultimate) = 376.2283 kN Total axial load(Unfactored) = Total axial load(unfactored from column) + self-weight (column + pedestal)

Total axial load(Unfactored) or service loads= 212.3731 kN Initial dimension of footing qa =

    

71.94 kPa =





52

B = 1.8 m., initial dimension of footing Thickness of footing, t = 300 mm. assumption verification needed on one-way shear (beam shear) and two-way shear (punching shear) qeffective = qa – qconcrete - qsoil qeffective = 71.94 – 23.55(0.3)- 20.955(1.6-0.3) qeffective = 37.6335 kPa qeffective =

    

37.6335 kPa =

 



B = 3.2 m., design dimension

qu =

  

qu = 36.74105 kPa Check against beam shear Vu = qu(Dimension)(d-x), x is the face length from column face to edge of dimension Vu = 36.74105(3.2)(d-1512.5)N

 ,     Vc =



Vc =

, for shear



Vu = Vc 36.74105(3.2)(d-1512.5)N =

  

d = 81.014 mm.

53

Chech against punching shear

 – (Column dim.+ d)) Vu = 0.3674105(  - (175+d) )N   ,  , for shear Vc =  Vu = qu(

2

bw = 4*( Column dim.+ d) Vc =

      



Vc = Vu

      

=

0.3674105(

 - (175+d) ) 2

d = 174.24 mm. = 175 mm.

t = d + 1.5Dbar +75 mm. t = 175 + 1.5(20) +75 mm. t = 300 mm, OK

Number of main bars

Mu =

 

Mu =

 



, treated as cantilever beam



Mu = 134.48 kN-m Mu = Φ Rub d2 134.48x106kN-m = 0.9Ru(3200)(175)

54

Ru = 1.5247 MPa ρ MIN =

 =  = 0.005091  

ρ=

     )  

ρ=

      )  

ρ = 0.0058 < ρ MIN, OK As = ρbd As = 0.0058(3200)(175) As = 3250.22 mm2

 =  = 314.1592654 mm     N=  =  = 11 bars  S=   S=  Ab =

S = 303 mm. > 100mm. OK

55

2

DESIGN OF A TYPICAL ISOLATED FOOTING

Design method: Ultimate Strength Design method Type of structure: Two-storey residential with roof deck Design parameters: Slab thickness: 100mm. (minimum slab thickness for two-way slab) Unit weight of plain concrete: 23.55 kN/m 3 Concrete compressive strength, f`c = 21MPa Reinforcing bar tensile strength, fy = 275MPa Main reinforcing bar diameter (for beam and column) = 20 mm. Stirrups and ties = 10 mm. (Main bar < 32 mm.) Concrete cover: Beam = 40 mm. Column = 40 mm. Footing = 75 mm. (Exposed to earth) Minimum design loads: Superimposed dead load: Slab self-weight = γconc.(slab thickness) = 23.55(0.1) =2.355kPa Dead load: Ceiling loads: Wood furring with suspension = 0.12kPa Gypsum board(15mm. thick) = 0.12kPa Flooring load: Flat tile on 25mm. mortar =1.1kPa Partition load allowance = 1kPa Total dead load = 2.34kPa

56

Live load: Residential = 1.9kPa Total live load = 1.9kPa Load combination: w = 1.2DL+1.6LL = 1.2(2.34) + 1.6(1.9) = 8.674kPa Short span = 5m Long span = 5m


2



 =   =79.6427kN-m     =  =  = 0.037833


ρ MAX = 0.75 ρ BALANCE = 0.75(0.037833) = 0.028375

ρ MIN =

 =   = 0.005091

Assume ρ = 0.6 ρ MAX = 0.6(0.028375) = 0.017025 ω=

 =  = 0.222943 



57

Ru = ω f`c(1-0.59 ω) = 0.222943(21)[1-0.59(0.222943)] = 4.06597 MPa Let d=1.75b Mu = Φ Rub d2 -> 0.9 Rub d2 = 79.6427kN-m b = 231.686276 = 250 mm.


2

 =  = 314.1592654 mm     N=  =  = 6 bars   Reaction at support =  =  = 93.28177kN 2

Ab =

nd

Design of Columns(2 Floor):


58

Pu = 0.8ϕ(0.85f`c(Ag-As)+fyAs) , for tied column ϕ = 0.65 As = ρAg, Assume ρ = 0.04 As = 0.04Ag Pu = 0.8ϕ(0.85f`c(Ag-0.04Ag)+fy(0.04Ag)) 373.1271 kN = 0.8(0.65)(0.85(21) (Ag-0.04Ag)+275(0.04Ag)) Solving for Ag, Ag = 25502.99 mm2 For square column Ag = B2 = 25502.99 B = 159.7 mm = 175 mm. Design of Columns(1st Floor):

Column self-weight Column height = 3 m. W = γconc(Volume of column) = 23.55(3)(0.175) 2 = 2.164 kN Pu(Axial load carried by ground floor column) = 2.164 kN + 2(373.1271 kN) = 748.4 kN 748.4 kN = 0.8(0.65)(0.85(21) (Ag-0.04Ag)+275(0.04Ag)) Solving for Ag, Ag = 51153.86 m m2 2

For square column Ag = B = 51153.86 B = 226.17 mm = 250 mm.

59

Design of isolated footing


γsat = 20.955 kN/ m , Assuming ground water table at near natural ground line (N.G.L.) Total axial load = Total axial load(from column) + self-weight (column + pedestal), pedestal height = Df - t Total axial load = 748.4178 + 4.415625+ 1.803047 Total axial load(Ultimate) = 754.6365 kN Total axial load(Unfactored) = Total axial load(unfactored from column) + self-weight (column + pedestal) Total axial load(Unfactored) or service loads= 426.926 kN Initial dimension of footing qa =

    

71.94 kPa =





B = 2.5 m., initial dimension of footing Thickness of footing, t = 375 mm. assumption verification needed on one-way shear (beam shear) and two-way shear (punching shear) qeffective = qa – qconcrete - qsoil qeffective = 71.94 – 23.55(0.375)- 20.955(1.6-0.375) qeffective = 37.4389kPa qeffective =

    

37.4389 kPa =

 



B = 4.5m., design dimension

60

qu =

  

qu = 37.266 kPa Check against beam shear Vu = qu(Dimension)(d-x), x is the face length from column face to edge of dimension Vu = 37.266 (4.5)(d-2125)N

 ,     Vc =



Vc =

, for shear



Vu = Vc 37.266 (4.5)(d-2125)N =

  

d = 115.36 mm. Chech against punching shear

 – (Column dim.+ d)) Vu = 0.37266( - (250+d) )N   ,  , for shear Vc =  Vu = qu(

2


     



Vc = Vu

      

=

0.37266(

 - (250+d) ) 2

61

d = 246.128 mm. = 250 mm.

t = d + 1.5Dbar +75 mm. t = 250+ 1.5(20) +75 mm. t = 375 mm, OK

Number of main bars

Mu =

 

Mu =

 






Mu = 378.628 kN-m Mu = Φ Rub d2 378.628 x106kN-m = 0.9Ru(3200)(175) Ru = 1.4598 MPa ρ MIN =

 =  = 0.005091  

ρ=

     )  

ρ=

      )  

ρ = 0.00569 < ρ MIN, OK As = ρbd As = 0.00569(4500)(250) As = 6399.68 mm

2

62

 =  = 314.1592654 mm     N=  =  = 21 bars  S=  S =   Ab =

S = 216.5 mm. > 100mm. OK

63

2


Design method: Ultimate Strength Design method Type of structure: Three-storey residential with roof deck Design parameters: Slab thickness: 100mm. (minimum slab thickness for two-way slab) Unit weight of plain concrete: 23.55 kN/m 3 Concrete compressive strength, f`c = 21MPa Reinforcing bar tensile strength, fy = 275MPa Main reinforcing bar diameter (for beam and column) = 20 mm. Stirrups and ties = 10 mm. (Main bar < 32 mm.) Concrete cover: Beam = 40 mm. Column = 40 mm. Footing = 75 mm. (Exposed to earth) Minimum design loads: Superimposed dead load: Slab self-weight = γconc.(slab thickness) = 23.55(0.1) =2.355kPa Dead load: Ceiling loads: Wood furring with suspension = 0.12kPa Gypsum board(15mm. thick) = 0.12kPa Flooring load: Flat tile on 25mm. mortar =1.1kPa Partition load allowance = 1kPa Total dead load = 2.34kPa

64

Live load: Residential = 1.9kPa Total live load = 1.9kPa Load combination: w = 1.2DL+1.6LL = 1.2(2.34) + 1.6(1.9) = 8.674kPa Short span = 5m Long span = 5m


2



 =   =79.6427kN-m     =  =  = 0.037833


ρ MAX = 0.75 ρ BALANCE = 0.75(0.037833) = 0.028375

ρ MIN =

 =   = 0.005091

Assume ρ = 0.6 ρ MAX = 0.6(0.028375) = 0.017025 ω=

 =  = 0.222943 



65

Ru = ω f`c(1-0.59 ω) = 0.222943(21)[1-0.59(0.222943)] = 4.06597 MPa Let d=1.75b Mu = Φ Rub d2 -> 0.9 Rub d2 = 79.6427kN-m b = 231.686276 = 250 mm.


2

 =  = 314.1592654 mm     N=  =  = 6 bars   Reaction at support =  =  = 93.28177kN 2

Ab =

rd



66

Pu = 0.8ϕ(0.85f`c(Ag-As)+fyAs) , for tied column ϕ = 0.65 As = ρAg, Assume ρ = 0.04 As = 0.04Ag Pu = 0.8ϕ(0.85f`c(Ag-0.04Ag)+fy(0.04Ag)) 373.1271 kN = 0.8(0.65)(0.85(21) (Ag-0.04Ag)+275(0.04Ag)) Solving for Ag, Ag = 25502.99 mm2 For square column Ag = B2 = 25502.99 B = 159.7 mm = 175 mm. Design of Columns(2nd Floor):

Column self-weight Column height = 3 m. W = γconc(Volume of column) = 23.55(3)(0.175) 2 = 2.164 kN Pu(Axial load carried by ground floor column) = 2.164 kN + 2(373.1271 kN) = 748.4 kN 748.4 kN = 0.8(0.65)(0.85(21) (Ag-0.04Ag)+275(0.04Ag)) Solving for Ag, Ag = 51,153.86 m m2 2

For square column Ag = B = 51153.86 B = 226.17 mm = 250 mm. st

Design of column( 1 floor):

Column self-weight

67

Column height = 3 m. 2

W = γconc(Volume of column) = 23.55(3)(0.250) = 4.416 kN Pu(Axial load carried by ground floor column) = 4.416 kN + 2.164 kN + 3(373.1271 kN) Pu(Axial load carried by ground floor column) = 1126 kN 1126 kN = 0.8(0.65)(0.85(21) (Ag-0.04Ag)+275(0.04Ag)) Solving for Ag, Ag = 51,153.86 m m2 For square column Ag = B2 = 76959 B = 277.41 mm = 300 mm. Design of isolated footing


γsat = 20.955 kN/ m , Assuming ground water table at near natural ground line (N.G.L.) Total axial load = Total axial load(from column) + self-weight (column + pedestal), pedestal height = Df - t Total axial load = 1125.96 + 6.3585+ 2.4374 Total axial load(Ultimate) = 1134.76 kN Total axial load(Unfactored) = Total axial load(unfactored from column) + self-weight (column + pedestal) Total axial load(Unfactored) or service loads= 643.191 kN Initial dimension of footing qa =

    

71.94 kPa =





68

B = 3 m., initial dimension of footing Thickness of footing, t = 450 mm. assumption verification needed on one-way shear (beam shear) and two-way shear (punching shear) qeffective = qa – qconcrete - qsoil qeffective = 71.94 – 23.55(0.45)- 20.955(1.6-0.45) qeffective = 37.2443kPa qeffective =

    

37.2443 kPa =

 




qu =

  

qu = 36.1848 kPa Check against beam shear Vu = qu(Dimension)(d-x), x is the face length from column face to edge of dimension Vu = 36.1848 (5.6)(d-2650)N

 ,     Vc =



Vc =

, for shear



Vu = Vc 36.1848 (5.6)(d-2650)N =

  

d = 139.907 mm.

69


 – (Column dim.+ d)) Vu = 0.361848( - (300+d) )N   ,  , for shear Vc =  Vu = qu(

2


      



Vc = Vu

      

=

0.361848(

 - (300+d) ) 2

d = 303.869 mm. = 325 mm.


Number of main bars

Mu =

 

Mu =

 






Mu = 711.502 kN-m Mu = Φ Rub d2 711.502 x106kN-m = 0.9Ru(5600)(325)

70

Ru = 1.33653 MPa ρ MIN =

 =  = 0.005091  

ρ=

     )  

ρ=

      )  

ρ = 0.00506 > ρ MIN, use ρ MIN As = ρbd As = 0.005091(5600)(325) As = 9265.45 mm2

 =  = 314.1592654 mm     N=  =  = 30 bars  S=   S=  Ab =

S = 187.241 mm. > 100mm. OK

71

2


Design method: Ultimate Strength Design method Type of structure: One-storey commercial with roof deck Design parameters: Slab thickness: 125mm. (minimum slab thickness for two-way slab) Unit weight of plain concrete: 23.55 kN/m 3 Concrete compressive strength, f`c = 21MPa Reinforcing bar tensile strength, fy = 275MPa Main reinforcing bar diameter (for beam and column) = 20 mm. Stirrups and ties = 10 mm. (Main bar < 32 mm.) Concrete cover: Beam = 40 mm. Column = 40 mm. Footing = 75 mm. (Exposed to earth) Minimum design loads: Superimposed dead load: Slab self-weight = γconc.(slab thickness) = 23.55(0.125) = 2.94375 kPa Dead load: Ceiling loads: Suspended steel channel system = 0.1 kPa Mechanical allowance = 0.2 kPa Gypsum board(15mm. thick) = 0.12 kPa Flooring load: Flat tile on 25mm. mortar =1.1kPa Partition load allowance = 1kPa

72

Total dead load = 5.464 kPa Live load: Commercial(reatail store) = 4.8 kPa Total live load = 4.8 kPa Load combination: w = 1.2DL+1.6LL = 1.2(5.464) + 1.6(4.8) = 14.237kPa Short span = 5m Long span = 5m

  =   = 1≥0.5, Two-way slab       m ) =   ) = 23.728 Uniform distributed load transfer formula =   Span ratio, m =

2

kN/m *For a middle singly reinforced beam loads from slabs are the most critical. W = 2(23.728) = 47.455 kN/m, Factored load alone Beam design:

Beam width, b = 6% of span (design assumption) = 6%(5000mm) = 300mm. Height, H = 2b (design assumption) = 2(300mm) = 600mm. Beam self-weight = γconc.(Cross sectional area of beam) = 23.55(0.3x0.6) = 4.329 kN/m

 =   =129.235 kN-m     =  =  = 0.037833



 =  = 0.005091  

Assume ρ = 0.6 ρ MAX = 0.6(0.028375) = 0.017025

73

ω=

 =  = 0.222943 



Ru = ω f`c(1-0.59 ω) = 0.222943(21)[1-0.59(0.222943)] = 4.06597 MPa Let d=1.75b Mu = Φ Rub d2 -> 0.9 Rub d2 = 129.235 kN-m b = 272.257 = 275 mm. d = 476.449 = 500 mm. H = d + Concrete cover(40 mm.) + d(strirrups) + 0.5d(Main bar) = 500 + 40 + 10 +0.5(16) = 483 mm. H = 575 mm. *check design beam self-weight over actual beam self-weight Actual self-weight = 23.55(0.575)(0.275) = 3.724 kN/m Design self-weight = 4.239 kN/m Actual self-weight

 Design self-weight OK!

Number of main reinforcing bars As = ρbd = 0.017025(275)(575) = 2340.9 mm2

 =  = 314.1592654 mm    =  = 8 bars N=    =  = 93.28177kN Reaction at support =   2

Ab =

Design of Columns: nd

Imposed axial load on column at 2 level: 4(reaction at support)

74

Pu(Axial load) = 597.122 kN Pu = 0.8ϕ(0.85f`c(Ag-As)+fyAs) , for tied column ϕ = 0.65 As = ρAg, Assume ρ = 0.04 As = 0.04Ag Pu = 0.8ϕ(0.85f`c(Ag-0.04Ag)+fy(0.04Ag)) 597.122 kN = 0.8(0.65)(0.85(21) (Ag-0.04Ag)+275(0.04Ag)) Solving for Ag, Ag = 40812.861 mm2 2

For square column Ag = B = 40812.861 B = 202.022 mm = 225 mm. Design of isolated footing

qa = 71.94 kPa, most probable value of allowable soil bearing capacity of Manila γsat = 20.955 kN/ m3, Assuming ground water table at near natural ground line (N.G.L.) Total axial load = Total axial load(from column) + self-weight (column + pedestal), pedestal height = Df - t Total axial load = 597.1215 + 3.5767+ 1.4903 Total axial load(Ultimate) = 602.1885 kN Total axial load(Unfactored) = Total axial load(unfactored from column) + self-weight (column + pedestal) Total axial load(Unfactored) or service loads= 455.0683 kN Initial dimension of footing qa =

     75

71.94 kPa =






    

37.5038 kPa =

 



B = 4.1m., design dimension

qu =

  

qu = 35.8232 kPa Check against beam shear Vu = qu(Dimension)(d-x), x is the face length from column face to edge of dimension Vu = 35.8232 (4.1)(d-1937.5)N

 ,   Vc =    Vc =



, for shear

Vu = Vc 35.8232 (4.1)(d-1937.5)N =

   76

d = 101.322 mm.


 – (Column dim.+ d))

Vu = qu(

Vu = 0.358232(

 - (225+d) )N   ,  , for shear Vc =  2


      



Vc = Vu

Vc =

      

=

0.358232(

 - (225+d) )N

d = 219.289 mm. = 225 mm.


Number of main bars

Mu =

 




           Mu =



Mu = 275.678 kN-m

77

2

Mu = Φ Rub d2 6

275.678 x10 kN-m = 0.9Ru(4100)(225) Ru = 1.4757 MPa ρ MIN =

 =  = 0.005091  

ρ=

     )  

ρ=

      )  

ρ = 0.00561 < ρ MIN, OK As = ρbd As = 0.00561(5600)(325) As = 5173.98 mm

2

 =  = 314.1592654 mm     N=  =  = 17 bars  S=   S=  Ab =

S = 245.6251 mm. > 100mm. OK

78

2


Design method: Ultimate Strength Design method Type of structure: Two-storey commercial with roof deck Design parameters: Slab thickness: 125mm. (minimum slab thickness for two-way slab) Unit weight of plain concrete: 23.55 kN/m 3 Concrete compressive strength, f`c = 21MPa Reinforcing bar tensile strength, fy = 275MPa Main reinforcing bar diameter (for beam and column) = 20 mm. Stirrups and ties = 10 mm. (Main bar < 32 mm.) Concrete cover: Beam = 40 mm. Column = 40 mm. Footing = 75 mm. (Exposed to earth) Minimum design loads: Superimposed dead load: Slab self-weight = γconc.(slab thickness) = 23.55(0.125) = 2.94375 kPa Dead load: Ceiling loads: Suspended steel channel system = 0.1 kPa Mechanical allowance = 0.2 kPa Gypsum board(15mm. thick) = 0.12 kPa Flooring load: Flat tile on 25mm. mortar =1.1kPa Partition load allowance = 1kPa

79



2



 =   =129.235 kN-m     =  =  = 0.037833



 =  = 0.005091  

Assume ρ = 0.6 ρ MAX = 0.6(0.028375) = 0.017025

80

ω=

 =  = 0.222943 





Number of main reinforcing bars As = ρbd = 0.017025(275)(575) = 2340.9 mm2


Ab =

rd

Design of Columns(3 floor): nd


81

Pu(Axial load) = 597.122 kN Pu = 0.8ϕ(0.85f`c(Ag-As)+fyAs) , for tied column ϕ = 0.65 As = ρAg, Assume ρ = 0.04 As = 0.04Ag Pu = 0.8ϕ(0.85f`c(Ag-0.04Ag)+fy(0.04Ag)) 597.122 kN = 0.8(0.65)(0.85(21) (Ag-0.04Ag)+275(0.04Ag)) Solving for Ag, Ag = 40812.861 mm2 2

For square column Ag = B = 40812.861 B = 202.022 mm = 225 mm. nd


Column self-weight Column height = 3 m. 2

W = γconc(Volume of column) = 23.55(3)(0.225) = 3.577 kN Pu(Axial load carried by ground floor column) = 3.577 kN + 2(597.122 kN) = 1197.82 kN 1197.82 kN = 0.8(0.65)(0.85(21) (Ag-0.04Ag)+275(0.04Ag)) Solving for Ag, Ag = 81870.184 m m

2

For square column Ag = B2 = 81870.184 B = 286.13 mm = 300 mm.

82

Design of isolated footing


    

71.94 kPa =





B = 3 m., initial dimension of footing Thickness of footing, t = 450 mm. assumption verification needed on one-way shear (beam shear) and two-way shear (punching shear) qeffective = qa – qconcrete - qsoil

qeffective = 71.94 – 23.55(0.45)- 20.955(1.6-0.45) qeffective = 37.2443kPa qeffective =

    

37.2443 kPa =

 



83


 

qu =



qu = 37.1381 kPa Check against beam shear Vu = qu(Dimension)(d-x), x is the face length from column face to edge of dimension Vu = 37.1381(5.7)(d-2848.5)N

 ,     Vc =



Vc =

, for shear



Vu = Vc

37.1381(5.7)(d-2848.5)N =

 


 – (Column dim.+ d)) Vu = 0. 371381( - (300+d) )N   ,  , for shear Vc =  Vu = qu(

2


      



Vc = Vu

84

      

=

 - (300+d) )N 2

0. 371381(

d = 316.725 mm. = 325 mm.


Number of main bars

Mu =

 

Mu =








Mu = 858.809kN-m Mu = Φ Rub d2 858.809x106kN-m = 0.9Ru(5700)(325) Ru = 1.5849 MPa ρ MIN =

 =  = 0.005091  

ρ=

     )  

ρ=

      )  

ρ = 0.00604 < ρ MIN, OK As = ρbd

85

As = 0.00604 (5600)(325) As = 11,198.2mm

2

 =  = 314.1592654 mm    =  = 36 bars N=     S=   S=  Ab =

S = 158 mm. > 100mm. OK

86

2


Design method: Ultimate Strength Design method Type of structure: Two-storey commercial with roof deck Design parameters: Slab thickness: 125mm. (minimum slab thickness for two-way slab) Unit weight of plain concrete: 23.55 kN/m 3 Concrete compressive strength, f`c = 21MPa Reinforcing bar tensile strength, fy = 275MPa Main reinforcing bar diameter (for beam and column) = 20 mm. Stirrups and ties = 10 mm. (Main bar < 32 mm.) Concrete cover: Beam = 40 mm. Column = 40 mm. Footing = 75 mm. (Exposed to earth) Minimum design loads: Superimposed dead load: Slab self-weight = γconc.(slab thickness) = 23.55(0.125) = 2.94375 kPa Dead load: Ceiling loads: Suspended steel channel system = 0.1 kPa Mechanical allowance = 0.2 kPa Gypsum board(15mm. thick) = 0.12 kPa Flooring load: Flat tile on 25mm. mortar =1.1kPa Partition load allowance = 1kPa

87



2



 =   =129.235 kN-m     =  =  = 0.037833



 =  = 0.005091  

Assume ρ = 0.6 ρ MAX = 0.6(0.028375) = 0.017025

88

ω=

 =  = 0.222943 





Number of main reinforcing bars As = ρbd = 0.017025(275)(575) = 2,340.9 mm2


Ab =

rd

Design of Columns(3 floor): nd


89

Pu(Axial load) = 597.122 kN Pu = 0.8ϕ(0.85f`c(Ag-As)+fyAs) , for tied column ϕ = 0.65 As = ρAg, Assume ρ = 0.04 As = 0.04Ag Pu = 0.8ϕ(0.85f`c(Ag-0.04Ag)+fy(0.04Ag)) 597.122 kN = 0.8(0.65)(0.85(21) (Ag-0.04Ag)+275(0.04Ag)) Solving for Ag, Ag = 40,812.861 mm2 2

For square column Ag = B = 40812.861 B = 202.022 mm = 225 mm. nd


Column self-weight Column height = 3 m. 2

W = γconc(Volume of column) = 23.55(3)(0.225) = 3.577 kN Pu(Axial load carried by ground floor column) = 3.577 kN + 2(597.122 kN) = 1,197.82 kN 1,197.82 kN = 0.8(0.65)(0.85(21) (Ag-0.04Ag)+275(0.04Ag)) Solving for Ag, Ag = 81,870.184 m m

2

For square column Ag = B2 = 81,870.184 B = 286.13 mm = 300 mm. st

Design of column( 1 floor): 90

Column self-weight Column height = 3 m. W = γconc(Volume of column) = 23.55(3)(0.300) 2 = 6.359 kN Pu(Axial load carried by ground floor column) = 6.359 kN + 3.577 kN + 3(597.122 kN) Pu(Axial load carried by ground floor column) = 1,801.3 kN 1801.3 kN = 0.8(0.65)(0.85(21) (Ag-0.04Ag)+275(0.04Ag)) Solving for Ag, Ag = 123,117.64 m m2 2

For square column Ag = B = 123,117.64 B = 350.881 mm = 375 mm. Design of isolated footing


     91

71.94 kPa =






    

37.0496 kPa =





B = 7 m., design dimension

 

qu =

 qu = 37.0137kPa Check against beam shear Vu = qu(Dimension)(d-x), x is the face length from column face to edge of dimension Vu = 37.0137 (7)(d-3498.5)N Vc =

 

Vc =

 

 , 

, for shear

Vu = Vc 37.0137 (7)(d-3498.5)N =

   92


 – (Column dim.+ d)) Vu = 0. 370137( - (375+d) )N Vu = qu(

2

Vc =

  

  , 

, for shear


      



Vc = Vu

      

=

0. 370137(

 - (375+d) )N 2

d = 385.793 mm. = 400 mm.


Number of main bars

Mu =

Mu =

 






Mu = 1585.6 kN-m 2

Mu = Φ Rub d

93

1585.6 x106kN-m = 0.9Ru(7000)(400) Ru = 1.57302 MPa ρ MIN =

 =  = 0.005091  

  ρ=      )       ) ρ=   ρ = 0.006 < ρ MIN, OK As = ρbd As = 0.006 (7000)(400) As = 16,791.9 mm2

 =  = 314.1592654 mm     N=  =  = 54 bars  S=   S=  Ab =

S = 128.868 mm. > 100mm. OK

94

2

MINOR: CONSTRUCTION METHODS Design of Concrete Mix (Using ACI Method)

Type I Angular

Portland Cement Type of Aggregate Max Size of Coarse Aggregates

19

mm

Max Density of Water

1000

kg/m3

Wt. of Cement Slump Unit Wt. of Coarse Aggregate.

40 25 to 50

kg/bag mm

1500

kg/m

Sand 2.8 2.08 3.0 1.3 Natural

Gravel 2.0 0 1.0 Angular

Fineness Modulus Sp. Gravity Moisture Content Absorption Type

Cement 3.2

I

3

Table 1.C: Summary of Concrete-Mix Parameters

1) Water-Cement Ratio

WATER CEMENT – RATIO

Absolute ratio by weight 0.35 0.44 0.53 0.62 0.71 0.80

NON-AIR ENTRAINED CONCRETE

Li/40 kg bag

kgf / sq.cm.

MPa

14.20

420.00

41.40

17.75 21.30

350.00 280.00

34.47 27.58

24.85 224.00 22.08 28.40 175.00 17.24 31.95 140.00 13.80 Table A.1: Compressive Strength of Concrete for Various Water Cement Ratios

95

Value

Strength (MPa)

W-C Ratio (L/40kg bag)

Upper Limit

22.08

24.85

Required

21.00

-

Lower Limit

17.24

28.4

 =  = 25.64 L/40 kg bag   2) Water Requirement Water, Li / cum of concrete of indicated max. size of aggregates Slump (mm)

9.5 mm

13 mm

19 mm

25 mm

38 mm

Ang

Rd

Ang

Rd

Ang

Rd

25 to 50

208

188

198

179

184

164

179

159

164

144

154

134

144

124

75 to 100

228

208

218

198

203

184

193

174

179

159

169

149

159

139

150 to 178 %Entrapped Air

243

228

228

208

213

193

203

184

188

169

179

159

159

149

2.5

2

1.5

Rd

1

Ang

Rd

76 mm

Rd

3

Ang

51 mm

Ang

Ang

0.5

TABLE A.2: Approximate Mixing Water Requirements for Different Slump and Maximum Size of Aggregates



Maximum Size of Coarse Aggregate = 19 mm



Type of Aggregate = Angular



Slump = 25 to 50mm



Water Requirement = 184 liters

3) Entrapped Air: (From Table E-4) 

Percent of Entrapped Air = 2%

96

Rd

0.3

4) Volume of Coarse Aggregate

Max. Size of coarse aggregate (mm) 9.5 13

Vol. of dry-rodded coarse aggregate per unit volume of concrete for different fineness modulus of sand

2.4 0.46 0.55 0.65

19

2.55 0.44 0.53 0.63

2.8 0.42 0.51 0.61

3 0.4 0.49 0.59

3.2 0.38 0.47 0.57

25 0.7 0.68 0.66 0.64 0.62 38 0.76 0.74 0.72 0.7 0.68 51 0.79 0.77 0.75 0.73 0.71 TABLE A.3: Volume of Coarse Aggregates per Unit Volume of Concrete



Maximum Size of Coarse Aggregate: 19 mm



Fineness Modulus of Sand = 2.8



Volume of Coarse Aggregates = 0.61

5) Number of bags per volume of concrete:

     N=  N=

N= 7.18 bags of cement 6) Absolute volume of cement |Vcement| =

 = 0.0897 m   

3

7) Absolute volume of water |Vwat| =

    = 0.184 m

3

8) Absolute volume of air = 1 x 0.02 = 0.02 97

9) Absolute volume of cement paste (|Vp|) Absolute volume of cement paste: Abs. Vol. of Cement + Abs. Vol. of Water + Abs. Vol. of Air Absolute Volume of Cement Paste = 0.0897 + 0.184 + 0.02 Absolute Volume of Cement Paste = 0.2937 10) Absolute volume of solid aggregates = 1 - Absolute Volume of Cement Paste = 1 – 0.2937 = 0.7063 11) Absolute volume of gravel:

                    = 0.4575 =    =

12) Absolute volume of sand: Absolute Vol. of Solid Aggregates – Absolute Vol. of Gravel Absolute volume of sand =0.7063 - 0.4575 Absolute volume of sand = 0.2488 A tabulated summary of computed values is shown below:

Material Cement Sand Gravel Water

Abs. Vol 0.0897 0.2488 0.4575 0.1840

Sp. Gr 3.20 2.08 2.00 1.00

Air

0.02

-

ϒH2O 1000.00 1000.00 1000.00 1000.00

Uncorrected Wt. (kg) 287.03 517.51 915.00 184.00

Corrected Wt. (kg) (required to find) (required to find) (required to find) (required to find)

-

Correcting the quantities of water, sand and gravel:

13) Field Moisture 

Field Moisture of Sand



Field Moisture of Gravel = 2.00 – 1.00 = 1%

= 3.00 – 1.30 = 1.70%

98

14) Correction of Weight of Sand and Gravel

) = 526.31 kg  ) = 925.15 kg = 915.00 (1 +  = 517.51 (1



Corr. Wt. of Sand



Corr. Wt. of Gravel

15) Corrected Quantity of Water

+

= 184 – [(526.31 – 517.51) + (925.15 – 915.00)] = 165.05 kg 16) Final Tabulated Results:

Material Cement Sand Gravel Water Air

Abs. Vol 0.0897 0.2488 0.4575 0.1840 0.02

Sp. Gr 3.20 2.57 2.50 1.00 -

ϒH2O 1000.00 1000.00 1000.00 1000.00 -

Uncorrected Wt. (kg) 287.03 517.51 915.00 184.00

Corrected Wt. (kg) 287.03 526.31 925.15 165.05

Volume of Concrete to Fill for One Storey Residential: Volume of Footing = 4.1m x 4.1m x 0.35m 3 Volume of Footing = 5.8835m Quantity of Concrete Proportions Considering Losses  

Where Absolute Volume of Concrete = 1 m Wt. of Cement

3

3

: 287.03 kg x 5.8835 mx 1.1

= 1857.62 kg

3 

Wt. of Sand Wt. of Gravel

: 526.31 kg x 5.8835 mx 1.1 3 : 925.15 kg x 5.8835 mx 1.1

= 3406.20 kg = 5987.43 kg



Wt. of Water

: 165.05 kg x 5.8835 m3x 1.1

= 1068.18 kg



Final Proportions Used: 

1860 kg of cement



3410 kg of sand 99



5990 kg of gravel



1070 kg of water

Volume of Concrete to Fill for Two Storey Residential: Volume of Footing = 4.5m x 4.5m x 0.375m 3 Volume of Footing = 7.60m Quantity of Concrete Proportions Considering Losses 3



Where Absolute Volume of Concrete = 1 m



Wt. of Cement

: 287.03 kg x 7.60 mx3 1.1



Wt. of Sand

: 526.31 kg x 7.60 mx 1.1



Wt. of Gravel

: 925.15 kg x 7.60 mx 1.1



Wt. of Water

: 165.05 kg x 7.60 mx 1.1

= 2399.57 kg

3

= 4399.95 kg

3

= 7734.25 kg

3

= 1379.82 kg


2400 kg of cement



4400 kg of sand



7735 kg of gravel



1380 kg of water

Volume of Concrete to Fill for Three Storey Residential: Volume of Footing = 5.6m x 5.6m x 0.45m 3 Volume of Footing = 14.112m Quantity of Concrete Proportions Considering Losses  

Where Absolute Volume of Concrete = 1 m Wt. of Cement

3

3

: 287.03 kg x 14.112 mx 1.1 m3x 3

= 4455.62 kg



Wt. of Sand Wt. of Gravel

: 526.31 kg x 14.112 1.1 : 925.15 kg x 14.112 mx 1.1

= 8170.02 kg = 14361.29 kg



Wt. of Water

: 165.05 kg x 14.112 m3x 1.1

= 2562.10 kg




4456 kg of cement



8171 kg of sand 100



14365 kg of gravel



2565 kg of water

Volume of Concrete to Fill for One Storey Commercial: Volume of Footing = 4.1m x 4.1m x 0.35m 3

Volume of Footing = 5.8835m Quantity of Concrete Proportions Considering Losses 


3

3

= 1857.62 kg

3



Wt. of Cement

: 287.03 kg x 5.8835 mx 1.1



Wt. of Sand

: 526.31 kg x 5.8835 mx 1.1

= 3406.20 kg



Wt. of Gravel

: 925.15 kg x 5.8835 m3x 1.1

= 5987.43 kg



Wt. of Water

: 165.05 kg x 5.8835 m3x 1.1

= 1068.18 kg

Final Proportions Used:  

1860 kg of cement



3410 kg of sand 5990 kg of gravel



1070 kg of water

Volume of Concrete to Fill for Two Storey Commercial: Volume of Footing = 5.7m x 5.7m x 0.45m 3 Volume of Footing = 14.6205m Quantity of Concrete Proportions Considering Losses 3






Wt. of Cement

: 287.03 kg x 14.6205 m3x 1.1

= 4616.17 kg



Wt. of Sand

: 526.31 kg x 14.6205 m3x 1.1

= 8464.41 kg



Wt. of Gravel

: 925.15 kg x 14.6205 m x 1.1



Wt. of Water

3

= 14878.77 kg

3

= 2654.42 kg

: 165.05 kg x 14.6205 m x 1.1


4620 kg of cement



8465 kg of sand 101



14880 kg of gravel



2655 kg of water

Volume of Concrete to Fill for Three Storey Commercial: Volume of Footing = 7.0m x 7.0m x 0.525m 3 Volume of Footing = 25.725m Quantity of Concrete Proportions Considering Losses 3






Wt. of Cement

: 287.03 kg x 25.725 m3x 1.1



Wt. of Sand

: 526.31 kg x 25.725 mx 1.1



Wt. of Gravel

: 925.15 kg x 25.725 mx 1.1



Wt. of Water

: 165.05 kg x 25.725 mx 1.1


8125 kg of cement



14895 kg of sand



26180 kg of gravel



4671 kg of water

102

= 8122.23 kg

3

= 14893.26 kg

3

= 26179.43 kg

3

= 4670.5 kg

CHAPTER 6 CONCLUSION

103

Chapter 6 Conclusion 6.1 Conclusion

After the collection of data has been done it was found out that the best foundation to be used in the City of Manila for structure with less than 5-storey is isolated footing with tie beam and if the land area is limited then combined footing with tie beam must be use. In general the soil in the City of Manila has low bearing capacity which is underlain by weak, compressible and potentially liquefiable formation (sand) within the influence depth of the formation. The soil classification in the City of Manila obtained from the geotechnical report verifies the geological map of the Mines and Geosciences bureau which classified the soil as quarternary alluvium which is composed of mostly sand, silt, and gravel. It is suggested that for structure that have 5-storey and above pile foundation is highly recommended. The most probable value for the soil allowable bearing capacity of Manila is 71.94 kPa using the statistical procedures. In conducting a soil investigation, a soil classification is included and it was identified to be composed mostly of silty sands and sand silt mixture (more than half of

coarse fraction is smaller than no. 4 sieve) and partly inorganic silts micaceous or diatornaceous fine sandy or silty, elastic soils with liquid limit less than 50%. Since it has been identified that the soil bearing capacity in the city of Manila are almost the same in every district, the most suited type of structure to be constructed is residential structures. And if it is desired to have commercials or industrials structures deep foundation will be used.

104

CHAPTER 7 RECOMMENDATION

105

Chapter 7 Recommendation 7.1 Recommendation

This study utilizes available soil investigation reports that were available during the collection of data. Because of the limited resources, the researchers were not able to obtain reports from some districts like Ermita, Port Area, and Intramuros. Other districts have only one soil investigation report like Quaipo, San Andres Bukid, and San Miguel. It is suggested that further collection of data will be focused on these districts. There are other mechanical properties of soil that are needed in the design of foundation that were not included in this study. Further researches should consider the depth of water table, shear strength, angle of internal friction and other parameters. The design of the isolated footing in Manila is possible although based on the unified soil classification system the soil in Manila are composed mostly of silt particles in which affects the stability of isolated square footing. A strapped and wall footing type of shallow foundation is what is recommended for 3-storey structures and below floor levels, and pile foundation for 4-storey and above. It is advised that other cities should also have its geotechnical analysis especially cities where there are rapid infrastructure developments.

106

ACKNOWLEDGEMENT

107

ACKNOWLEDGEMENT

We dedicate this thesis to the Almighty Father, who gives us strength, knowledge and wisdom to finish this study. Our parents, for their unending support, who are our inspiration in doing the study. We would also want to thank Mr.Eduardo Guico who allowed us to have an access with the soil investigation reports passed on the Manila City Hall’s office of the building officials. Our sincerest thanks to our thesis adviser Engr. Flordeliza C. Villaseñor and our thesis coordinator Engr. Geoffrey L. Cueto. We would also like to acknowledge Engr. Vinci Nicolas R. Villaseñor for reviewing our thesis and giving us recommendations to improve our study, Engr. Ivan D.L. Marquez who acted us our second adviser who verifies our methodologies. We also want to thank other professionals who shared their knowledge to us namely Engr. Lewdan Ferrer and Engr. Jayson Lorenzo Manansala. In this thesis, there is nothing here that we possess as our own; they are all acknowledged in return to their respective studies, works and researchers, which became our inspiration for pursuing this thesis. Herewith now, we gave you this work of ours, the artifact that is the product of their knowledge, work of our hands, and the symbol of the researcher’s identity.

Regards from the Authors,

Dave Joseph V. Gangcuangco

Ericson M. Mosuela

Carlo Dominic M. Palatino 108

REFERENCES

109

REFERENCES

-

ASTM International, ASTM Standards in building codes: Specifications test methods, practices, Classifications, Terminology , Copyright ©2009 ASTM International, West Conshohocken, PA

-

Brown and G. Bally, “Land Capability Survey of Trinidad and Tobago. No. 4. Soils of the Northern Range of Trinidad ,” Government Printery, Port-of-Spain, 1967.

-

Budhu, Muni, “Soil Mechanics and Foundations”, John Wiley & Sons, Copyright © 2007

-

Coduto, D. P.,“Foundation design – Principles and practices”. Prentice Hall 796 p., Copyright © 1994

-

C.R.I. Clayton, M.C. Mathews, N.E. Simons, “Site Investigation”, Department of nd Civil Engineering, University of Surret, 2 Edition

-

G. Freudlund and S. K. Vanapalli, “Shear Strength of Unsaturated Soils,” Agronomy Society of America, 2002, pp. 329-361.

-

H. T. Eid, “Factors Influencing the Determination of Shale Classification Indices

and Their Correlation to Mechanical Properties ,” Geotechnical and Geological Engineering, Vol. 24, No. 6, 2005, pp. 1695-1713. -

http://www.dnr.mo.gov/geology/docs/gcwinter9.pdf. Retrieved August 8 2012

-

http://www.geotechdata.info/geotest/direct-shear-test. Retrieved March 5, 2012

-

http://www.geotechdata.info/geotest/unconfined-compression-test. Retrieved March 5, 2012

-

http://www.manila.gov.ph/localgovt.htm. Retrieved March 5, 201

-

J. M. Duncan and S. G. Wright, “Soil Strength and Slope Stability,” John Wiley & Sons, New York, 2005.

-

Kaya and K. P. Kwong, “ Evaluation of Common Prac-tice Empirical Procedures for Residual Friction Angle of Soils: Hawaiian Amorphous Materials Rich Colluvial Soil Case Study,” Engineering Geology, Vol. 92, No. 1-2, 2007.

-

Military Soils Engineering, FM 5-410, 23 December 92

110

-

National Structural Code of the Philippines (NSCP), C101-10, Volume I, Buildings, Towers, and Other Vertical Structures, Sixth Edition, 2010, Copyright©2010

-

S. K. Vanapalli, D. G. Fredlund, D. E. Pufahl and A. W. Clifton, “Model for the Prediction of Shear Strength with Respect to Soil Suction,” Canadian Geotechnical Journal, Vol. 33, No. 3, 1996, pp. 379-392.

-

W. Skempton, “4thRankine Lecture: Long-Term Stability of Clay Slopes,” Géotechnique, Vol. 14, No. 2, 1964, pp. 77-101.

-

Youdeowei, P. O. and Nwankwoala, H. O., “Studies on sub-soil characteristics of sand deposits in some parts of Bayelsa State, Eastern Niger Delta, Nigeria”, Institute of Geosciences and Space Technology, Rivers State University of Science and Technology, P. M. B. 5080, Nkpolu-Oroworukwo, Port Harcourt, Nigeria.

111

APPENDICES

112

APPENDIX A DESIGN OF CONCRETE MIX The ACI Method ( ACI 211.1-91)

1) Given the design compressive strength of concrete, fc’, identify the corresponding water-cement ratio. Interpolation might be needed. 2) Obtain the water requirement taking the following parameters: a) Type of Coarse aggregates (Angular/Rounded) b) Maximum Aggregate Size (MAS) c) Slump 3) From the corresponding water requirement, identify the percentage of entrapped air. 4) Use Table E-5 to identify the volume of coarse aggregates given the following parameters: a) Fineness modulus (sand) b) MAS 5) Number of bags of cement required N=

       

6) Absolute volume of cement |Vcement| = cement)

        

(Gc

=

sp.gr.

7) Absolute volume of water

|Vwat| =

  

8) Absolute volume of air = 1 x % entrapped (item 3) 9) Absolute volume of cement paste (|Vp|) = sum of items 6, 7 and 8 10) Absolute volume of solid aggregates = 1 - |Vp| 11) Absolute volume of gravel:

113

of

=

            12) Absolute volume of sand: = Absolute Vol. of Solid Aggregates – Absolute Vol. of Gravel Correcting the quantities of water, sand and gravel

13) Field Moisture (FM) = moisture content - absorption 14) Correction of Weight of Sand and Gravel Corr. = Uncorr. (1 +

 )

15) Corrected Quantity of Water



Corr. = Uncorr. – (Δs + Δg + Δ )



Δs, Δg, Δ = difference between the corrected and uncorrected weights of sand, gravel and air, respectively, 16) Tabulate Results (Sample Below): MATERIAL

Absolute Volume

Specific Gravity

Unit Weight of Water

Uncorrected Wt. (Col 2 x Col 3 x Col 4)

Sand Cement Gravel Water

17) Quantity Take-off (for filling a structural component)

Wt. of material =

       

V is the volume of the structural element required to fill. *Considering quantity losses, multiply the quantity of material by 1.1.

114

Corrected Wt.

ROUNDED COARSE AGGREGATES % Sand of Maximum Total Net Water size Aggregate Content of coarse by (L / m3) aggregates Absolute mm (inch) Volume

ANGULAR COARSE AGGREGATES % Sand of Maximum size Total Net Water of Coarse Aggregate Content aggregates by (L / m3) mm (inch) Absolute Volume

13 (1/2 ") 51 199 13 (1/2 ") 56 214 19 (3/4 ") 46 184 19 (3/4 ") 51 199 25 (1") 41 178 25 (1") 46 192 38 (1 ½") 37 166 38 (1 ½") 42 181 51 (2") 34 157 51 (2") 39 172 76 (3") 31 148 76 (3") 36 163 152 (6") 26 131 152 (6") 31 146 Table A.0: Corresponding Properties of Round and Coarse Aggregates

WATER CEMENT – RATIO

Absolute ratio by weight 0.35

NON-AIR ENTRAINED CONCRETE

Li/40 kg bag

kgf / sq.cm.

MPa

14.20

420.00

41.40

0.44 17.75 350.00 34.47 0.53 21.30 280.00 27.58 0.62 24.85 224.00 22.08 0.71 28.40 175.00 17.24 0.80 31.95 140.00 13.80 Table A.1: Compressive Strength of Concrete for Various Water Cement Ratios

115

Water, Li / cum of concrete of indicated max. size of aggregates Slump (mm)

9.5 mm

13 mm

19 mm

25 mm

38 mm

Ang

Rd

Ang

Rd

Ang

Rd

25 to 50

208

188

198

179

184

164

179

159

164

144

154

134

144

124

75 to 100

228

208

218

198

203

184

193

174

179

159

169

149

159

139

150 to 178

243

228

228

208

213

193

203

184

188

169

179

159

159

149

3

2.5

2

1.5

Rd

1

Ang

Rd

76 mm

Rd

%Entrapped Air

Ang

51 mm

Ang

Ang

0.5

0.3

TABLE A.2: Approximate Mixing Water Requirements for Different Slump and Maximum Size of Aggregates

Max. Size of coarse aggregate (mm) 9.5 13

19 25 38 51

Vol. of dry-rodded coarse aggregate per unit volume of concrete for different fineness modulus of sand

2.4 0.46 0.55 0.65

2.55 0.44 0.53 0.63

2.8 0.42 0.51 0.61

3 0.4 0.49 0.59

3.2 0.38 0.47 0.57

0.7 0.68 0.66 0.64 0.62 0.76 0.74 0.72 0.7 0.68 0.79 0.77 0.75 0.73 0.71 TABLE A.3: Volume of Coarse Aggregates per Unit Volume of Concrete

116

Rd

APPENDIX B Minimum Design Load Requirements (Chapter 2, Section 203-205 of NSCP 2010 vol. 1)

The minimum design load is required for the design of a particular structural component of a vertical structure such as slabs, beams, columns, footings, and other structural components. The loads in particular of this study compose of live and dead loads with the help of the provisions on the code. Dead loads are consists of permanent weight imposed on the structural component and the self-weight of the structural component is considered, while the live loads are defined be the type of occupancy of the structure. Notation: DL = Dead load, includes imposed dead loads and self-weight. LL = Live load w = Loads coming from the slab to the beam. S = Short span of the slab. m = Ratio between the short span and long span of the slab.

203.3.1 Basic Load Combination w = 1.2DL+1.6LL, from NSCP 2010 chapter 2 section203-3(eq. B-1) Dead loads: 3

Unit weight of plain concrete, γconc.: 23.55 kN/m (from section 204-1) Ceiling loads: Wood furring with suspension = 0.12kPa (from section 204-2) Gypsum board(15mm. thick) = 0.12kPa (from section 204-2) Flooring load: Flat tile on 25mm. mortar =1.1kPa (from section 204-2) 117

Partition load allowance = 1kPa (from section 204.3) Live load: Residential = 1.9kPa

Span ratio, m =

   

m ≥0.5, Two-way slab m < 0.5, One-way slab Uniform distributed load transfer formula for two-way slab =

  

m2)(eq. B-2),

formula used to transfer the loads from slab to the supporting beam as a uniformly distributed load.

118

APPENDIX C Design of Singly Reinforced Concrete Beam using Ultimate Strength Design Method (Chapter 4, Section 410 of NSCP 2010 vol. 1)

The design method used on the structural components is the ultimate design method in which the code provides factors in designing a certain structural component. The loads from the slab including its weight would be imposed to the beam by the load transfer formula. Notation: w = Loads coming from the slab to the beam. S = Short span of the slab. m = Ratio between the short span and long span of the slab. b = Width of the beam. d = Effective depth of beam. H = Height of the beam. Φ = Reduction factor Ru = Coefficient of resistance. w=

   m ) (eq. C-1)  2

γconc. = Unit weight of concrete, kN/m 3 The self-weight of the beam is assumed by making its width to be a percentage of the beam span and the height would be twice the width; thus, in the latter part of the design the assumed section would be checked for verification if the assumption was right. Beam width, b = % of span (design assumption) Height, H = 2b (design assumption) Beam self-weight = γconc.(Cross sectional area of beam) The moment reaction at support is calculated by the given equation

119

Moment at support =

 , Moment at support with more than 2 span (eq. C-2, 

Section 408 of NSCP 2010) Balanced steel ratio condition in which the concrete and the reinforcing steel yields at the same time given a concrete strain of 0.003 and modulus of elasticity of steel to be 200 GPa. ρ BALANCE =

where

 (eq. C-3) 

 shall be defined in two cases (Section 410.3.7.3 of NSCP 2010):

 = 0.85, for concrete strengths ranging from 17 MPa – 28 MPa, and  = 0.85 – 0.05  , for concrete strength greater than 28 MPa, but not less than 0.65

Maximum steel ratio is given as 75% of the balanced steel ratio. ρ MAX = 0.75 ρ BALANCE (eq. C-4) Minimum steel ratio shall be the largest between the given:

ρ MIN =

 <  (eq. C-5)  

In design the actual steel ratio shall be a percentage of the maximum ratio and should not be less than the minimum steel ratio. ρ = % ρ MAX (eq. C-6) The reinforcement index is the ratio between yield strength of steel and concrete, also the value computed is used for determination of the coefficient of resistance. ω=

 (eq. C-7) 

Coefficient of resistance:

120

Ru = ω f`c(1-0.59 ω) (eq. C-8) Assume the effective depth of beam by setting a ratio between the effective depth and width of beam such that, d/b: d=1.5b to d=2b The ultimate moment is governed by the equation below. In which the calculated moment reaction from (eq. C-2, Section 408 of NSCP 2010) would be the same moment to be use. Mu = Φ Rub d2 (eq. C-9) Where: Φ = Reduction factor for flexure members For flexure, Φ = 0.9 (Section 409.4.2.1 of NSCP 2010) The designed beam height is calculated as, H = d + Concrete cover(40 mm.) + d(strirrups) + 0.5d(Main bar) (eq. C-10) The designed section must be compared to the assumed section to secure the stability of the designed beam. The required steel area is the area of reinforcing steel required for the beam with the actual steel ratio. As = ρbd (eq. C-11) The number of reinforcing steel is calculated by dividing the steel area by the area of a single reinforcing bar with the diameter of bar given and should be a whole number.

 (eq. C-12)  Where: N = number of reinforcing bars. N=

121

APPENDIX D Design of Square Tied Concrete Column using Ultimate Strength Design Method (Chapter 4, Section 410 of NSCP 2010 vol. 1)

The axial load to the column is calculated from the beam support reactions with the code provision from chapter 4 section 408 of NSCP 2010, Reaction at support =

 (eq. D-1, Section 408 of NSCP 2010)

The ultimate load that the column can carrie is governed by the (eq. D-2, Section 410.4.6.2 of NSCP 2010), and used also to determine the dimension and required steel for the concrete column. Pu = 0.8ϕ(0.85f`c(Ag-As)+fyAs) (eq. D-2, Section 410.4.6.2 of NSCP 2010) Where:Φ = Reduction factor for compressed member For compressed member Φ = 0.65 (Section 409.4.2.2 of NSCP) Ag = Gross area of column. As = Steel area. The steel ratio is the ratio between the area of steel and the gross area of the column. As = ρAg (eq. D-3) ρ= must range between 1%-8% (Section 410.10.1 of NSCP 2010) Then solve for the required area for the square tied column.

122

APPENDIX E Design of Isolated Square Footing using Ultimate Strength Design Method (Chapter 4, Section 415 of NSCP 2010 vol. 1)

The initial dimension of footing is solved by dividing the service load by the allowable soil bearing capacity of soil for the determination of the initial thickness of the isolated square footing. qa =

     (eq. E-1)

The assumed thickness would be governed by the formula, t = 20%B + 75 mm. Where: t = Assumed thickness of the footing. B = Least dimension of the footing. The effective soil bearing capacity is used to determine the actual or the designed dimension of the isolated square footing by dividing the factored load by the effective soil bearing capacity. qeffective = qa – qconcrete - qsoil (eq. E-2) Where: qeffective = Effective soil bearing capacity. qconcrete = Pressure applied by weight of concrete footing. qsoil = Pressure applied by weight of soil above the footing. qeffective =

 

(eq. E-3)

     (eq. E-4) Vc =

The beam shear on footings is governed by the formula from the code,



Where: Φ = Reduction factor for shear, Φ = 0.85

123

f`c = Concrete compressive strength. b = width of member that is perpendicular to the shear. d = Effective depth of member. Check against punching shear, because it is the most critical for most of the isolated square footing therefore the effective depth in punching shear should govern.

Vc =

  



(eq. E-5)

Where: Φ = Reduction factor for shear, Φ = 0.85 f`c = Concrete compressive strength. bw = Perimeter of the punched area, 4(d+B) d = Effective depth of member. H = Column dimension. The ultimate moment is governed by the equation below. In which the calculated moment reaction from (eq. C-2, Section 408 of NSCP 2010) would be the same moment to be use. Mu = Φ Rub d2 (eq. C-9) Where: Φ = Reduction factor for flexure members For flexure, Φ = 0.9 (Section 409.4.2.1 of NSCP 2010) The steel ratio is calculated with the given formula with Ru as a parameter.

ρ=

        (eq. E-6)  

The required steel area is the area of reinforcing steel required for the beam with the actual steel ratio.

124

As = ρbd (eq. C-11) The number of reinforcing steel is calculated by dividing the steel area by the area of a single reinforcing bar with the diameter of bar given and should be a whole number. N=



 (eq. C-12) 

Where: N = number of reinforcing bars. d = Main bar diameter. As =Steel area. The spacing should be checked to verify the computed number of rebars. S=

 (eq. E-7) 

Where: S = Spacing of rebars, S> 100mm. N = Number of rebars.

125

APPENDIX F Computation of the soil properties from available borehole samples

Given: Five samples of on-site soil specimens

PROPERTY w.c.(%) 3 Moist density(kg/ cm ) 3 Dry density(kg/ cm ) 3 Dry unit weight(kN/ m ) Moist unit weight(kN/ m3)

NUMBER OF SAMPLES 2 3 4 5 7 19.7 6.3 14.7 2.606 1.859 1.618 1.595 2.436 1.553 1.522 1.391 23.89716 15.23493 14.93082 13.64571 25.56486 18.23679 15.87258 15.64695

1 15.4 2.447 2.12 20.7972 24.00507

Unit weight(moist), γMOIST = mass densityMOIST*9.81kN/ m3 SAMPLE 1 3

3

3

3

γMOIST = 2.447*9.81 kN/ m = 24.005 kN/ m SAMPLE 2 γMOIST = 2.606*9.81 kN/ m = 25.565 kN/ m SAMPLE 3 3

3

γMOIST = 1.859 *9.81 kN/ m = 18.237 kN/ m SAMPLE 4

γMOIST = 1.522*9.81 kN/ m3 = 15.873 kN/ m3 SAMPLE 5 γMOIST = 1.595*9.81 kN/ m3 = 15.647 kN/ m3 Unit weight(dry), γMOIST = mass densityDRY*9.81kN/ m

3

SAMPLE 1 3

3

γDRY = 2.12*9.81 kN/ m = 20.7972kN/ m SAMPLE 2 3

3

γDRY = 2.436*9.81 kN/ m = 23.89716 kN/ m SAMPLE 3

126

3

3

3

3

3

3

γDRY = 1.553*9.81 kN/ m = 15.23493 kN/ m SAMPLE 4 γDRY = 1.522*9.81 kN/ m = 14.93082 kN/ m SAMPLE 5 γDRY = 1.391*9.81 kN/ m = 13.64571 kN/ m Average moist unit weight Average moist unit weight, γMOIST = Average moist unit weight, γMOIST =

      



3

Average moist unit weight, γMOIST = 19.86525 kN/ m Average dry unit weight Average moist unit weight, γDRY = γDRY =

 

       

Average moist unit weight, γDRY = 17.701164 kN/ m3

Determination of void ratio, e γDRY =





, taking Gs = 2.7 as average specific gravity of soil

17.701164 =





e = 0.496342

γsat

  

    = 

Saturated unit weight,γsat =

γsat = 20.95517733 kN/ m3

127

An Analysis of Geotechnical Reports to Determine the Soil Bearing Capacity in Manila for the Design Of

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