extensive_survey_camp.pdf

EXTENSIVE SURVEY PROJECT

1. INTRODUCTION This extensive survey project is conducted to acquire a practical knowledge and application of theory and over come the difficulties that could arise in field during surveying. We also learn the use of different survey instrument and to develop the team spirit at work. It also helps to develop the confidence in handling of survey project. We conducted survey for a new tank project, Highway project, water supply scheme and sewerage project. This survey is conducted at S.S Ghati located at Honnenahalli which is 56 Km away from Bangalore. 1.1 Objects of Extensive Survey Camp: In order to acquire a sound knowledge of both theory and in practical way and also the difficulties that could arise during surveying. The object of this survey project is as follows:1. To impart training in the use of survey instruments instruments and to acquire a comprehensive idea of the project. 2. To train the students under difficult and realistic situation of the surveying project. 3. To develop develop team spirit in practical work. work. 4. To impart confidence confidence in the management management of the survey survey project.

DEPARTMENT OF CIVIL ENGINEERING

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R.V.C.E, BANGALORE


1.2 Technical aspects of a project: The design and construction of any project such as dam, road alignment requires a thorough investigation of the site as regards to its stability and feasibility. The preliminary investigation starts from the reconnaissance reconnaissance work, study of top sheets, proposal of alternate sites etc. The second stage work of investigation investigation includes the survey work at the site in order to collect the data necessary for the design of project elements, preparation of drawings, estimates etc. the office work is confined to the designs, drawings and estimates of the project. 1.3 Historical background of the place: The famous Sri.Ghati Subramanya temple is located at the limit of Honnenahalli of Doddaballapura taluk, Bangalore district. It is 56 km. away from Bangalore with good transportation facilities from all round the corners of the state The temple comes under the jurisdiction jurisdiction of Muzrai of Revenue department. The temple is an ancient one, which is believed to be 80 years old. The famous cart festival festival including cattle cattle fair is also held every every year. 2.0 STUDY OF TOPO SHEET This sheet gives the topographical topographical features of the locality like alignment of a railway line, roadway, streams and its distributaries and permanent structures located in that locality. This map helps in selecting the site for a new tank and also gives clear picture of transportation to the proposed area in proposed site for the transportation of men and material for their construction. From this we can know the approximate catchment area of site. This map has to be study before reconnaissance survey.


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2.1 Calculation of yield at site. The catchment catchment area of proposed New Tank determined determined from the toposheet toposheet is 14 Km2. The rainfall rainfall of a bad year is always always taken as 2/3 2/3 of mean amount of rainfall. Average annual rainfall for Doddaballapur area from Meteorological department data is 80 cms. Bad year rainfall is 2/3 of

80cm = 53cms. 53cms.

Runoff coefficient is usually assumed as 15 % to 20% Assuming as 20% Annual Yield = 20 x 53cm = 10.6 cms 100 Yield from catchment (14X10 6) x 10.6 cum/year 100 = 1.48 X 106 cum/year.


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3.0 INTRODUCTION FOR IRRIGATION Irrigation may be defined as the process of artificially supplying water to soil for rising crops. India is basically an agricultural country and its economy depends to a great extent on the agricultural output.

Water is

evidently the most vital element in the plant life. Water is normally supplied to the plants by nature through rains. However, the total rainfall in a particular area may be either insufficient or ill timed. In order to get the maximum yield, it is essential to supply the optimum quantity of water and to maintain correct timing of watering. This is possible only through a systematic irrigation system that is Collecting water during the periods of excess rainfall and releasing it to the crop as and when required. The need for irrigation can be summarized in the following four points: Less rainfall: When the total rainfall is less than that needed for the crop, artificial supply of water is necessary.

In such a case, irrigation system should be

developed at the place where more water is available and then, the means to convey water to the area where there is deficiency. Non-uniform rainfall: The rainfall in a particular area may not be uniform throughout the crop period. During the early periods of the crop rains may be there, but no water may be available at the end, with the result, that either, the yield may be less or the crop may wither. But the accumulated or stored water during the excess rainfall period may be supplied to the crop during the period when there may be no rainfall, but there is a need for watering.


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Commercial crop with additional water: The rainfall in a particular area may be just sufficient to raise the usual crops, but more water may be necessary for raising commercial or cash crops, in addition to increasing the annual output by adopting multiple cropping patterns distributed throughout the year. Controlled water supply: By constructing a proper distribution system, the yield of crop may be increased. Application of water to the soil by modern methods of irrigation serves the following purpose: 

It adds water to the soil to supply moisture essential for the plant growth.



It washes out all diluted salts in the soil.



It reduces the hazard of soil piping.

3.1 BASIC PRINCIPLES OF IRRIGATION Duty: Duty represents the irrigating capacity of a unit of water.

It is the

relation between the area of a crop irrigated and the quantity of irrigation water required during the entire period of growth of that crop. For example, if 3 cumecs of water supply is required for a crop sown in an area of 5100 hectares, the duty of irrigation water will be 5100/3 = 1700 hectares/cumec, and the discharge of 3 cumecs will be required throughout the base period.


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Delta: Delta is the total depth of water required by a crop during the entire period from the day of sowing to harvesting. For example, if a crop requires about 12 watering at an interval of 10 days and a water depth of 10 cm in every watering then the delta for that crop will be 12x10 = 120 cm = 1.2 m.

If the area under that crop is A

hectares, the total quantity will be 1.2 x A = 1.2A hectare-meters in a period of 120 days. Crop period: Crop period is the time, in days, that a crop takes from the instant of its sowing to its harvesting. Base period: Base period for a crop refers to the whole period of cultivation from the time of first watering for sowing the crop, to the last watering before harvesting. The duty of water is reckoned in the following four ways: 

By the number of hectares that 1 cumec of water can irrigate during the base period, i.e., 1700 hectares per cumecs.



By total depth of water, i.e., 1.20 meters.



By number of hectares that can be irrigated by a million cubic meter of stored water. This system is also used for tank irrigation.



By the number of hectare meters expended per hectare irrigated. This is also used in tank irrigation.


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Relation between duty (D), delta (D) and base period (B) in metric system Let there be a crop of base period b days. Let one cumec of water be applied to this crop on the field for B days. Now, the volume of water applied to this crop during B days (V) V = (1x60x60x24)m3 = 86,400 (cubic meter) By definition of duty (D), one cubic meter supplied for B days matures D hectares of land. Therefore this quantity of water (V) matures D hectares of land or 104 D square meters of area. Total depth of water applied on this land = Volume/Area = 86,400 B/104 D meters = 8.64 B/D meters By definition, this total depth of water is called delta (D). Therefore D = 8.64 B/D meters Or D = 864 B/D cm. Where, D is in cm or m, B in days, and D is duty in hectares/cumec.


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Cultivable commanded area: The gross commanded area also contains unfertile barren land, alkaline soil, local ponds, villages and other areas as habitation. These areas are known as uncultivable areas. The remaining area on which crops can be grown satisfactorily is known as cultivable commanded area. The cultivable commanded area can be further classified as cultivable cultivated area and cultivable uncultivated area. Gross commended area: An area is usually divided into a number of watersheds and drainage valleys. The canal usually runs on the watershed and water can flow from it, on both side, due to gravitational action only up-to drainage boundaries. Thus in a particular area lying under the canal system, the irrigation can be done only up-to the drainage boundaries, which can be commanded or irrigated by a canal system. Cultivable commanded area: The gross commanded area also contains unfertile barren land, alkaline soil, local ponds, villages and other areas as habitation. These areas are known as uncultivable areas. The remaining area on which crops growth, including water consumed by accompanying week growth. Gross commanded area: An area is usually divided into a number of watersheds and drainage valleys. The canal usually runs on the watershed and water can flow from it, on both sides, due to gravitational action only up-to drainage boundaries. Thus in a particular area lying under the canal system, the irrigation can be done only up-to the drainage boundaries.

The gross commanded area is

thus the total area lying between drainage boundaries, which can be commanded or irrigated by a canal system.


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Consumptive use: Consumptive use of water by a crop is the depth of water by a crop is the depth of water consumed by evaporation & transpiration during the crop growth, including water consumed by accompanying weed growth. 3.2 INVESTIGATION FOR A NEW TANK PROJECT The design and construction of any dam whether earthen masonry or concrete has to be preceded by a thorough investigation to select the most suitable and economical site. The thoroughness of the investigation depends upon the size of the project. 3.3 PRELIMINARY INVESTIGATION Before taking up a detailed survey of project, it is essential to carry out considerable reconnaissance work.

The topo sheet study of the probable

project area gives possible sites in that area and the catchment area of the site.

This reconnaissance survey was carried out by us the day before we

started the actual survey.

During this survey, we decided the site for the

construction of bund, weir & canal alignment.

Using chain or tape rough

data regarding the level and the length of the dam are collected.

The

preliminary investigation should include. 1. A rough levelling work to give the topography of the site. 2. A study of the rocky out crop and a few boring is done to note the nature of the foundation. 3. Availability of construction materials such as Earth and good quarry etc. 4. Nature and extent of land, roads, bridges, etc. that would be submerged by the construction of the dam. 5. Benefit the dam would give to the people. 6. Collection of hydrological data like rainfall, floods discharge etc. 7. Facility for discharging the floodwater. DEPARTMENT OF CIVIL ENGINEERING

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Keeping the above points in view, a thorough study was done were the final choice of the site was made. 3.4 FACTORS CONSIDERED FOR SELECTION OF SITE FOR EARTHEN DAM. The following topography and geological features affects the selection of site for earthen dam. 1. The water storage should be largest for the minimum possible height and length. The site should be located in a narrow valley. 2. Good impervious strata [foundation] should be available at moderate depth. 3. Good and suitable basin should be available. 4. Material for construction should be available locally. 5. There should be suitable site available for waste weir. 6. Value of the property and land likely to be submerged by the proposed dam should be sufficiently low in comparison with the benefit expected from the project. 7. Dam should be accessible in all season. 8. Overall cost of construction and maintenance is to be taken into After selection the site, final and precise investigation was carried out. In the present survey work it was assumed that a choice of site was made and the type of dam to be constructed is of earthen dam, with this assumption the detailed survey were carried out which includes . A. Longitudinal and cross section along the centre line of the bund. B. Block levels at the waste weir site. C. Water spread contours.


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3.5 FLY LEVELLING It is one type of method to determine the R.L of required point. This levelling work is carried from the nearby permanent B.M for example from a railway station or other permanent structure. In this project we established T.B.M near the bund. The field work is carried as follows: 1. Set the levels near the P.B.M and carry out temporary adjustment. 2. Keep staff on permanent B.M and take readings and enter it as back sight in the field book. 3. Take intermediate points towards the direction of required point is reached. 4. If the staff is invisible shift the level and note down the last reading as fore sight, after shifting the level and temporary adjustment take readings of that point and note down it as back sight. 5. Continue this procedure until the required point is reached. 6. The R.L of the point is determine by using these formula 1. P.C= P.B.M +B.S 2. R.L = P.C-I.S or P.C-F.S


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3.6 LONGITUDINAL SECTIONS & CROSS SECTIONS ALONG THE PROPOSED CENTRE LINE OF THE TANK BUND: Object: To obtain the Profile of the valley along the assumed center line of the 

dam. 

To estimate the quantity of earthwork for the proposed construction of the bund the following points should be considered:-

TOP WIDTH Top width of earth dam should be sufficient to keep the seepage line well within the body of dam. It should withstand earthquake and wave action. For small dams, top width is generally governed by minimum road way requirements. Top width of earth dam can be selected as per the following recommendations. 1. T = 0.2 x Z+3

for very low dams (<15 m)

2. T = 0.55 x (Sqrt Z) + 0.2 x Z

for height less than 30m

3. T = 1.65 x (Sqrt (Z + 1.5)

for height greater than 30m.

where Z is the max height of dam in metres. T = 0.55 x (Sqrt Z) + 0.2 x Z = 0.55 x (Sqrt 21.80) + 0.2 x 21.80 = 6.973m say 7.0 m


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FREE BOARD:Free board of an earth dam is the height provided above MWL/FRL upto TBL in order to prevent over topping of water due to wave action. “Minimum free board” is defined as vertical distance between max reservoir level and top of dam. The vertical distance between full reservoir level and top of dam is called “Normal free board”. The Minimum height of free board for wave action is 1.5hw where hw = max.ht. of wave. The wave height (hw ) in meters can be calculated according to 1. Molitor’ s

formulae (British Practice)

hw metres = 0.032 x Sqrt (V x F) + 0.763 – 0.271 x sqrt (Sqrt (F)) where F is fetch in kms and F<32 Kms Fetch is defined as the longest unobstructed distance for wind to blow from one edge of reservoir up to the dam on u/s side of the dam. (Fetch can be measured from capacity contour sheet) V is wind velocity in kms/hr. (The max wind velocity in any area is 60 kmph according to meteorological data) 1. Molitor’s formula hw = 0.032 x sqrt (v x F)+0.763-0.271 x sqrt (sqrt(F)) where F = fetch in kms and F<32kms F

= 0.32km

v = 40kmph hw = 0.673m ( hw )max = 1.5 x 0.673 = 1.01 m


so provide FB=1M

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Earth dams are classified into following. 1. Homogenous earth dam: A purely homogeneous earth dam is composed of single kind of material {Exclusive of the slope protection}.Shown below is a typical cross-section of a purely homogeneous type earth dam.

h

h/3

2. Zoned embankment type earth dam: It is the one in which the dam is made up of more than one material. The most common type of a rolled earth dam section is that in which a central impervious core is flanked by zones of material considerably more pervious. Shown below is a typical cross-section of a Zoned Embankment type earth dam.

TRANSITION FILTER

RIP RAP

ROCK TOE CORE


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3. Diaphragm Embankment type: This is a modification over the homogeneous embankment type, in which the bulk of the embankment is constructed of pervious material and a thin diaphragm of impermeable materials is provided to check the seepage. The diaphragm may be of impervious soils, cement concrete, bituminous concrete, or any other material, and may be placed either at the centre of the section as a central vertical core, or at the upstream face as a blanket. Shown below is a typical cross-section of a Diaphragm Embankment type earth dam.

DIAPHRAGM

PERVIOUS FOUNDATION

IMPERVIOUS


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RECOMMENDED SLOPES FOR SMALL HOMOGENEOUS EARTHFILL DAMS ON STABLE FOUNDATION: Cas e

Type

Purpose

Soil Classificati on

Upstream Slope

1)

Homogene ous or Modified Homogene ous

Detention or Storage

GW GP SW SP

Previous

Not suitable

2.5:1

2:1

3:1

2.5:1

3.5:1

2.5:1

GW GP SW

Previous

Not suitable

SP

3:1

2:1

GC GM SC

3.5:1

2.5:1

SM

4:1

2.5:1

GC GM SC SM

Downstream slope

CL ML CH MH 2)

Modified Homogene ous

Storage

CL ML CH MH


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RECOMMENDED SLOPES FOR SMALL ZONED EARTHFILL DAMS ON STABLE FOUNDTION:

Cas Type e

Purpos e

Shell Material Classification

Core Materials Classification

U/s slope

D/s slope

A

Zoned with “Minim um”

Any

Not critical, rock-fill; GW,GP,SW,SP

Not critical GC, GM, SC, SM, CL, ML, CH, MH

2:1

2:1

B

Zoned with “Maxim um” Core 1

Detenti on OR Storage

Not critical, rock-fill: GW,GP,SW,SP

GC,GM,

2:1

2:1

2.25:1

2.25:1

2.5:1

2.5:1

3:1

1:1

GC,GM

2.5:1

2:1

SC,SM

2.5:1

2.25:1

CL,ML

3.0:1

2.5:1

CH,MH

3.5:1

3.0:1

C

Zoned with “Maxim um” Core1

Storage

Not critical, rock-fill, GW,GP, SW,SP

SC,SM, CH,MH

CL,ML,

Note; 1. Minimum and maximum size cores shown in Fig: 2. CL and IH soils are not recommended for major portions of the cores of earth fill dams Pt soils are unsuitable. Though any one of the tables can be used for preliminary selection of the bund section the current practice has been in favour of Strange’s table.


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Core (Hearting): Core or Hearting is clay type of material provided mainly to prevent seepage through the body of the dam. The different types of clay silt for suitability of construction or core is provided in Table No.1 under the heading “Rolled Earth Dams.” Rip Rap or u/s Revetment is coarse material placed on the embankment to prevent erosion of soil is termed “Rip Rap” Rip Rap is of two types 1. 2.

Dumped Placed (also called “Pitching”)

The minimum weight of each rock for rip rap is calculated by using Iribarren – Hudson formula. '

W

3

K  S  h 

(  Cos 



3

Sin  )

3

( S 1)3 

W= Minimum weight of Rock to be placed on rip rap in kN. K’= A coefficient taken = 0.02  =

Specific weight of water =9.81 kN/m 3

S= Specific gravity of rip rap material ( 2.45 to 2.2)  =

Coefficient of friction of rip rap material (1 to 1.1)

h= effective wave height in meters, calculated using Sverdup – Munk formula h= 0.0045 x F

0.423

x U1.154

F= fetch in kilometer, U =wind velocity in kilometer per hour β= Angle of u/s slope made with horizontal. RIP rap is placed in layers. The innermost is the “cushion“acts as filter to prevent washing of the soil in the shell zone. It also prevents sinking of the coarse rock into the softened surface of the shell.


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The following table gives the dimension of riprap as a function of wave height. Max. Wave height

Minimum rip rap Thickness

Min thickness of cushion

Fine

Thickness

0 to 1.5

300mm

150mm

150mm

1.5 to 3.0

150mm

150mm

150mm

> 3.0m

600mm

150mm

150mm

Cut off wall When river bed is having thick stratum of sand, an impermeable structure is constructed within the stratum to reduce seepage through the foundation. There are two types of cut off wall: 1) If the bottom of the cut off wall permeates into the impermeable layer then cut off is called positive cut off wall. This type has the advantage of reducing seepage loss, but the disadvantage of increasing neutral stress due to water thus decreasing the factor of safety of slope – stability on u/s side. 2) If the bottom of cut off wall does not permeate into loose stratum completely, cut off is called “ Partial cut off wall” The Minimum bottom width of cut off wall is 4m, side of at least 1:1 or flatter slope may be provided in case of overburden. ½:1 or ¼:1 may be provided in soft rock and hard rock respectively. It also prevents seepage, erosion, and mass, instability, boiling and piping. Internal drainage system: The drainage system consists of two components. a) b)

Protective filter which is in contact with core. The conduits, which collect & dispose off seepage water.


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Minimum thickness of protective filter is provided as follows Thickness for given head (M) Filter Material 0 to 22m

22 to 46m

46 to 92m

Fine sand

150mm

300mm

450 mm

Coarse sand

200 mm

450 mm

650 mm

Gravel

300mm

600 mm

750mm

Rock toe/ toe drain

The toe drain is placed at D/s side toe of each dam. In small dams only drains are provided. In large dams embankment will be saturated below the phreatic line. And tow drain acts as a disposal zone of the drainage water. Its height varies from 5% of dam height (above tail water level), with external drainage system, to as much on 20% in small dams with no internal drains. The Rock toe designed like protective filter except for the gravel zone. The top width of rock toe will have the dimension same as of berm.


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3.7 WATER SPREAD CONTOUR: This survey is necessary to draw the capacity contours by the help of witch the storage levels of the tank are fixed. This can be carried out by the following methods. 1. One set of levels is taken along the course of the river on the up stream and another set at right angle to it at the widest region and counters are interpolated. 2. The F T L counter is traced directly and cross section at suitable intervals are taken across this until F T L on the other side is reached. The lowest point of main valley is met and the contours’ are interpolated 3. The entire water spread is covered by block leveling and any number of contours is interpolated. Of the above three methods the third method is most accurate but it is tedious. Any of the above methods may be adopted depending upon the degree of the accuracy required and the size of the project. Calculation of the storage capacity of reservoir: Areas of successive contours are measured using planimeter or by constructing squares.

If A1, A2, A3 … An, are the areas of successive contours, H being the contour interval, then by Prismoidal rule. The storage capacity can be calculated. Using Prismoidal rule V=

H

3

( A1  An)  4( A2  A4  A6  ......) 2( A3  A5  A7  .......) cubic meter. A = in sqm.


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CAPACITY OF RESERVOIR BETWEEN RL'S-793.000 & RL'S-808 (F.T.L) V=H/3((A1+An)+4(A2+A4+A6+...)+2(A3+A5+A7+...))

H/3

0.333333333

(A1+An)

17.02498046

4(A2+A4+A6+...)

173.222217

2(A3+A5+A7+...)

67.210416

858192.04 cum 85.82

ha-m

3.8 BLOCK LEVELS AT THE WASTE WEIR SITE. WASTE-WEIR: Similarly, as in case of all dam reservoir projects, tanks are provided with arrangements for spilling away the excess water that may enter in to the tank, to avoid over – topping of the tank bund. These escape arrangements may be in the form of a surplus escape weir or waste weir, provided in the body or at one end of the tank bund. The weir is a masonry weir with its top level equal to the Full tank level (F.T.P). When the tank is full up to its FTL and extra water comes in and discharges over the waste weir. The capacity of the weir is so designed that the water level in the tanks does not exceed the maximum water level (M.W.L). The top of the bund will be kept at a level so as to provide suitable freeboard this M.W.L. A detailed survey at the waste weir site is necessary to design the body wall of waste weir, the approach and draft channel and other protective works and to arrive at the cost of their work.

In choosing the site for waste weir the

following points must be borne in mind:1. A saddle disconnected from the tank bund is the best site for a surplus work. 2. The natural ground surface at the weir site should be approximately at F.T.L.


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3. The height of body wall must be minimum possible and should be located as far as possible in cutting. 4. The soil should be hard both at the weir site and along the draft channel. 5. There should be natural diversion to lead the water safely from the bund. 6. Cost of protective work should be minimum.

Design of Surplus Weir or Waste Weir: Ryve’s formula: Qmax = CM2/3 C: Ryve’s Coefficient = 10.1 M: Catchment area = 14KM2 Discharge Qmax = 58.67 m3/Sec Assuming it as broad crested weir. Discharge Q = 1.022 LH3/2 H : Head over the weir

= (MWL - FRL) = 1 m

L : Length of weir L= (58.67/1.022) = 57.40m say 60m

3.9 CHANNEL ALIGNMENT


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A canal is provided on the downstream side of the bund, taking off from the sluice points at a gentle bed slope. This is the paths along which water stored in the tank is supplied to the command area for the purpose of irrigation.Based on the alignment, canals are classified as: a) Ridge or watershed canal b) Side slope canal c) Contour canal In contour canals, gravity flow of water is made use of to irrigate the area on the lower side, down to the valley whereas in ridge canals irrigation is possible on either sides of the canal. A contour canal has been provided for the proposed bund. Its alignment is similar to the figure shown below.


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Channel alignment is meant to estimate the cost of the channel and cross drainage works, and also to determine the gross command area. The following points were kept in view while aligning the channel. 1) The channel should as far as possible be aligned in a straight line. 2) A channel in embankment is less desirable when compared to a channel in cutting. 3) A channel should be aligned as a ridge channel wherever possible but the main channels are usually aligned as contour channels. 4) There should be as few cross drainage work as possible. If cross drainage is necessary then channel should cross the valley or the river at a point where the width is least and the foundation soil is good for the cross drainage works. 5) If there is only one channel, the channel should preferably be aligned on the flank opposite to the one where the waste weir is located.

Calculation of Ground level for starting channel alignment

Sluice level

:

807.000 m

Full supply depth of water

:

0.430 m ( According to Channel design)

Free board

:

0.320 m (Assumed)

Ground level

:

807.750 m @ 0 chainage.

Calculation of actual gross command area: The area enclosed between center line of bund, the mother valley and the final alignment is defined as gross command area. This area can be calculated by using Planimeter or by constructing squares.


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Design of Channel Section:

Determination of Irrigable area:

The yield of catchment has been found to be 1.48 X 106 cum Assuming 10% for evaporation loss and 15 % of conveyance loss i.e., 25% as total loss in reservoir storage capacity. Volume of water available for irrigation is = 0.75 X 1.48 X 10 6 cum

= 1.11 X 106 cum Assuming average duty of 286 Hectares million cum for mixed crop pattern. Area that can be irrigated: 1.11 x 106 x 286 hectares 106

= 317.46 Hectares. Actual canal network provided for an area of 83.09hectares.

Longitudinal slope of channel

 f 5 / 3     1/ 2 3 9 2 S=  3340Q1 / 6 

Hence assumed slope of (1/2000) is correct.

3.10 PARTICULARS AND SALIENT FEATURES OF THE NTP

1. Place of the project

Sri Subramanya Ghati Doddaballpur Taluk, Bangalore district.

2. Distance from Bangalore

52 Km.

3. Nature of Project

New tank Project

4. Type of Bund

Earthen Bund.


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5. Bund 

Length of Bund

320 m



Deepest Streambed

792.800m



812.00 m.

T.B.L.



811.00 m.

M.W.L.

810.000 m. 

F.T.L. 19.20 m.

4. 

Max height of Bund

6. Length of Weir

60m

7. Capacity contour

85.82 hactare-m.

8. Canal 

Length of the Canal

330.00 m



Bed Width

0.300 m.



F.S.D.



Free Board

0.430 m. 0.320 m.

Earth work required for channel alignment : Area of channel section = 0.7875 m2. Length of channel


= 330 m.

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HIGHWAY PROJECT 4.1 HIGHWAY ALIGNMENT: The positioning or the laying out of the center line of the highway on the ground is called the alignment. The horizontal alignment includes the straight path, the horizontal deviations and curves.

Changes in gradient

and vertical curves are covered under vertical alignment of roads. A new road should be aligned very carefully, as improper alignment would result in one or more of the following disadvantages: 

Increase in construction cost



Increase in maintenance cost



Increase in vehicle operation cost



Increase in rate of accidents Once the road is aligned and constructed, it is not easy to change the

alignment due to increase in cost of adjoining land and construction of costly structures by the road side. Hence the importance of careful considerations while finalizing the alignment of a new road should be overemphasized. Requirements: The basic requirements of an ideal alignment between two terminal stations are that is should be: 

Short



Easy



Safe



Economical


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R.V.C.E, BANGALORE


4.2 Need for Highway Planning: In the present era, planning is considered as a pre-requisite before attempting any development program.

This is particularly true for any

engineering work, as planning is the basic need for highway development. Particularly planning is of great importance when funds available are limited in contrast to the amount required which would be very high. This is actually the most important problem that has to be addressed by the developing countries like India as funds have to be utilized in the best possible and economic way. 4.3 The objects of highway planning are as follows: 

To plan a road network for efficient and safe traffic operation, but at a minimum cost.



The cost of the construction, maintenance and renewal of pavement layers and the vehicle operation costs must be given due considerations.



To arrive at a road system and lengths of different categories of roads, which could provide maximum utility and can be constructed within the available resources during the plan period under consideration.



To fix up date wise priorities for development of each road link based on utility as the main criterion for phasing the road development program.



To plan future requirements and improvements of road in view of anticipated developments.



To work out financing system.

4.4 Factors controlling alignment: For an alignment to be shortest, it should be straight between the terminal stations.

This is always not possible due to various practical

difficulties such as intermediate obstructions and topography. A shortest route may have very steep gradients and hence not easy for vehicle operation.

Similarly, there may be construction and maintenance


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R.V.C.E, BANGALORE


problems along a route, which may otherwise be short and easy. Roads are often deviated from the shortest route in order to cater for intermediate places of importance of obligatory points. A road which is economical in the initial construction cost need not necessarily be the most economical in maintenance or in vehicle operation cost.

It may also happen that shortest and easiest route for vehicle

operation may work out to be costliest of the different alternatives from construction view point. Thus it may be seen that an alignment can seldom fulfill all the requirements simultaneously hence, a judicial choice is made considering all the factors The various factors controlling the alignment of the highway are: 



Obligatory points Traffic



Geometric design



Economics



Other constructions In hilly areas, additional care has to be given for setting up the

alignment and the factors governing are as follows: 

Stability



Drainage



Geometric standards of hill roads



Resisting length

STEPS INVOLVED IN A NEW PROJECT REPORT 

Map Study



Reconnaissance Survey



Preliminary Survey



Location of Final Alignment



Detailed Survey


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R.V.C.E, BANGALORE




Materials Survey



Design



Earth Work



Pavement Construction

The following points may be kept in mind while aligning any type of road: 1. Cutting and embankment must be balanced. 2. Curves of larger radius should be used in no case; the radius of curves should be less than 16m. 3. A flat gradient as far as possible should be used, only when unavoidable conditions, the ruling gradient has to be given. 4. Super elevation has to be given for all the curves. 5. Transition curves should be provided between curve and a straight alignment. 6. Vertical curve should be provided whenever the gradient changes. 7. The alignment should be the most economical with economical with minimum drainage

crossing, so it should follow the ridge

GRADIENTS FOR ROADS IN DIFFERENT TERRAINS Terrain Plain or Rolling Mountainous & steep terrain with elevation more than 3000m above MSL Step terrain upto 3000m Height above MSL


31

Ruling Gradient 1/30 1/20

Limiting Gradient 1/20 1/16.7

Exception al gradient 1/15 1/14.3

1/16.7

1/14.3

1/12.5

R.V.C.E, BANGALORE


WIDTH OF ROADWAY FOR VARIOUS CLASSES OF ROADS SL No

Roadways width in meters Plain & Rolling Mountainous & Terrain Steep terrain

Road classification

1

National & State Highway a) Single lane b) Two lane Major District Roads a) Single lane b) Two lanes Other District Roads a) Single lane b) Two lanes c) Village Roads

2

3

12.00 12.00

6.25 8.60

9.00 9.00

4.75 --

7.50 9.00 7.50

4.75 -4.00

DESIGN SPEEDS t

Plain u mi ni M m

a ci fi g al

l

s d s

ni

a o R

n u oi C

NH&SH MDR ODR VR

R

100 80 65 50

g ni l u R

80 65 50 40

Rolling u mi ni M m

80 65 50 40

65 50 40 35

Mountain u g mi ni l ni u R M m 50 40 30 25

40 30 25 20

Steep u mi ni M g ni l u R

40 30 25 25

m

30 20 20 20

MINIMUM RADII OF ROADS f

Mountain o n

Plain

oi t d a a ci o fi

t

R s s C

NH&SH MDR ODR

g b

u

t

ul g ni

ul ni

o

al

VR

Rolling

l

o l

s u R

36 0 23 0 15 5 90

A

e

s R

b A

Area Not affected by snow t ul g ni o l s u b e R A e

Steep

Snow bound area t ul g ni o l s u b R A e

Area Not affected by snow t ul g ni o l s u b R A e

Snow bound area t ul g ni o l s u b R A e

23 0 15 5 90

23 0 15 5 90

15 5 90

80

50

90

60

50

30

60

33

50

30

60

33

30

14

33

15

60

30

20

33

23

20

14

23

15

60

60

45

20

14

23

15

20

14

23

15


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R.V.C.E, BANGALORE


DESIGN OF HORIZONTAL CURVE While undertaking the initial alignment of the new highway project , it was required that in the final alignment , we provide a smooth curve between 150 m chainage and 210 m chainage and another curve between 480m chainage and 540m chainage. we have designed the curve as follows. e+f= v^2/127 R; where e is the maximum super elevation that can be provided which is taken as 0.07, f is the maximum value of lateral friction which is equal to 0.15, v is the design speed taken as 40 kmph for other district roads, R is the radius of curve to be provided. Curve 1: (360 m to 420 m) 0.22= 40*40/(127*R) R req= 57.27 m R Provided = 200m. L= 104.55 m O0= 7.27 m

O30=4.72 m

O10 = 6.818m

o

40


O20 = 6.23 m

o50 = 0m

=3.180m

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R.V.C.E, BANGALORE


HIGHWAY PROJECT EARTH WORK CALCULATIONS

Chainage in

Filling area in

Cutting

sqm

area in sqm

m

remarks

0

0.180

0.00

A1

60

0.00

7.87

A2

120

1.32

0.00

A3

180

0.00

1.10

A4

240

0.320

1.89

A5

300

0.00

6.00

A6

360

0.00

5.59

A7

420

3.810

0.00

A8

480

0.00

5.4

A9

540

5.200

0.00

A10

600

3.600

0.00

A11

VOLUME OF EARTH WORK IN FILLING IN 'cum' V=H/3((A1+An)+4(A2+A4+A6+...)+2(A3+A5+A7+...))

20 0.00 36.04 3.28

H/3 (A1+An) 4(A2+A4+A6+...) 2(A3+A5+A7+...)

872cum


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R.V.C.E, BANGALORE


VOLUME OF EARTH WORK IN CUTTING IN 'cum' V=H/3((A1+An)+4(A2+A4+A6+...)+2(A3+A5+A7+...)) H/3

20

(A1+An)

0.000

4(A2+A4+A6+...)

59.88

2(A3+A5+A7+...)

25.76

1718.2 Balance earth required

846.2

cum cum

5.0 INTEGRATED ENVIRONMENTAL ENGINEERING PROJECT FOR S.S. GHATI. 1. Water Supply project: a) New source project (b) Augmentation scheme. c) Water treatment system d) Pumping system e) Distribution system. 2. Sewerage project: a) Sewerage system b) Sewage Treatment facility. 5.1 WATER SUPPLY PROJECT FOR S.S.GHATI. DATA: a) Geological b) Hydrological c)

Sanitary conditions


35

R.V.C.E, BANGALORE


d) Topography showing elevations of various points, density of population in various zones. This map helps in positioning intake works, treatment plant and type of system to be adopted for conveyance and distribution of water. e)

Legal data of lands

f) Public opinion.

FACTORS: Population P 2001, as per census = 4115; P 2020, assuming an annual increase of 1.9% = 6000. Per capita requirement: 175 lpcd is to be provided as per Indian standards. Q required=(6000 x 175)/(1000*24*60*60) = 0.0122 cumecs Assuming a peak factor of 3 Max. flow = 0.0122*3=0.0365 cumecs =3153.6 m3/day Proposing slow sand filter & chlorination for the treatment of water. Slow sand filters are designed for 100-200 lit/hr/m 2 Assuming 150 lit/hr/m2 Q max

Water surface area of filter =

Filtration rate

=

3153 .6 

150

876 m2

Propose 4 units of filter each of area 219 m 2. Assuming L/B ratio of 2.0 The dimensions of each filter: L x B = 219 2B x B = 219 B = 10.46 m, say B = 11.0 m, L = 22 m DEPARTMENT OF CIVIL ENGINEERING

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R.V.C.E, BANGALORE


Providing filter sand depth of 1 m, gravel depth varying from 30-75 cm say 50 cm, 50 cm free board and water depth of 1 m. Therefore Total depth = 1+1+0.5+0.5 = 3.0 m

Design of pump capacity

BHP

WQH 

75 c

W= 1000 kg/m3(unit weight of water)

where

Q = discharge m3/sec   c

 m x  p =

H = Head in m

= combined efficiency of pump and motor =

80%

Friction loss (hf) = flv 2 2gd = flQ2 12.1 d5 = ( 0.01 x 884 x 9460.82) (12.1 x .2255) hf = 15.19 m ‘Q’ for 8 hours pumping will be maximum flow rate x 3. Providing a pipe of 22.5 cm & adding 10% minor loss due to valves. ‘H’ = Suction head (3m) + Delivery head (13.12 m) + Friction loss (hf) = 4.316 m + 3.0 m = 23.436 m BHP = (1000 x 5043 x 23.436) (75 x .8) BHP = 7.6 KW


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R.V.C.E, BANGALORE

extensive_survey_camp.pdf

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