Quick r Wall 20 Users Guide

QuickRWall User’s Guide Retaining Wall Design Software

Version 2.01.0006

Copyright (c) 2003-09 Ensoltech, Inc. All rights reserved.

QuickRWall is a proprietary computer program of Ensoltech, Inc. Although every effort has been made to ensure the accuracy of this program and its documentation, neither Ensoltech nor Integrated Engineering Software shall be held liable for any mistake, error, or misrepresentation in, or as a result of the usage of, this program and/or its documentation. The results obtained from this program should not be substituted for sound engineering judgment.

S ALES /S UPPORT Integrated Engineering Software 519 E. Babcock St. Bozeman, MT 59715 406-586-8988 (sales) [email protected] www.iesweb.com

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QuickRWall 2.01.0006 User’s Guide

CONTENTS

Contents 1 Overview 1.1 Introduction . . . . 1.2 License . . . . . . 1.3 Disclaimer . . . . 1.4 Requirements . . . 1.5 Installation . . . . 1.6 Technical Support 1.7 Limitations . . . .

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2 Menu Commands 2.1 File Menu . . . . . . . . . . . . . . . . . 2.1.1 New . . . . . . . . . . . . . . . . 2.1.2 Open . . . . . . . . . . . . . . . 2.1.3 Save . . . . . . . . . . . . . . . . 2.1.4 Save As... . . . . . . . . . . . . . 2.1.5 Print Report... . . . . . . . . . . . 2.1.6 Print Full Page Drawing... . . . . 2.1.7 Preview Report... . . . . . . . . . 2.1.8 Preview Full Page Drawing... . . 2.1.9 Print Setup... . . . . . . . . . . . 2.1.10 Create DXF File... . . . . . . . . 2.1.11 [Recent Files] . . . . . . . . . . . 2.1.12 Exit . . . . . . . . . . . . . . . . 2.2 View Menu . . . . . . . . . . . . . . . . 2.2.1 Toolbar . . . . . . . . . . . . . . 2.2.2 Status Bar . . . . . . . . . . . . . 2.3 Project Menu . . . . . . . . . . . . . . . 2.3.1 Add Load Case... . . . . . . . . . 2.3.2 Remove Load Case... . . . . . . . 2.3.3 Project Information... . . . . . . . 2.3.4 Set Defaults... . . . . . . . . . . . 2.4 Design Menu . . . . . . . . . . . . . . . 2.4.1 Choose Footing Reinforcement . 2.4.2 Choose Stem Reinforcement . . . 2.4.3 Position Key To Embed Stem Bars 2.4.4 Set All Embedment Lengths . . . 2.4.5 Set All Lap Splice Lengths . . . . 2.4.6 Set Bar Cutoff Lengths . . . . . . 2.4.7 Design Preferences . . . . . . . .

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2.5

2.6

CONTENTS

Options Menu . . . . . . . . . . . . . . . . . . . . 2.5.1 Units... . . . . . . . . . . . . . . . . . . . . 2.5.2 Preferences... . . . . . . . . . . . . . . . . . 2.5.3 Concrete Load Combinations... . . . . . . . 2.5.4 Masonry Load Combinations... . . . . . . . . 2.5.5 Stability Load Combinations... . . . . . . . . Help Menu . . . . . . . . . . . . . . . . . . . . . . 2.6.1 Contents... . . . . . . . . . . . . . . . . . . 2.6.2 Iesweb.com — Update QuickRWall 2.0 . . . 2.6.3 Iesweb.com — Customer Center . . . . . . . 2.6.4 Iesweb.com — FAQ Answers . . . . . . . . 2.6.5 Iesweb.com — Email IES Technical Support 2.6.6 Software License... . . . . . . . . . . . . . . 2.6.7 About QuickRWall 2.0... . . . . . . . . . . .

3 User Inputs 3.1 Criteria Inputs . . . . . . . . . 3.1.1 Design Code . . . . . . 3.1.2 Assumptions . . . . . . 3.1.3 Stability Criteria . . . . 3.1.4 Geotechnical . . . . . . 3.2 Load Case Inputs . . . . . . . . 3.2.1 General . . . . . . . . . 3.2.2 Backfill . . . . . . . . . 3.2.3 Water in Backfill . . . . 3.2.4 Passive Pressure @ Toe . 3.2.5 Surcharge (Uniform) . . 3.2.6 Surcharge (Line/Strip) . 3.2.7 Uniform Lateral Load . 3.2.8 Stem Axial Load . . . . 3.2.9 Seismic Loading . . . . 3.3 Wall (Footing/Stem) Inputs . . 3.3.1 General . . . . . . . . . 3.3.2 Material . . . . . . . . . 3.3.3 Footing Geometry . . . 3.3.4 Heel Reinforcement . . 3.3.5 Toe Reinforcement . . . 3.3.6 Transverse Reinf. (S&T) 3.3.7 Key . . . . . . . . . . . 3.3.8 General . . . . . . . . . 3.3.9 Geometry . . . . . . . . 3.3.10 Reinforcement (Flexural) 3.3.11 Reinforcement (S&T) . 3.3.12 Sections . . . . . . . . . 3.4 Stem Section Inputs . . . . . . 3.4.1 General . . . . . . . . . 3.4.2 Masonry Block . . . . . 3.4.3 Reinforcement . . . . .

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4 Forces on the Wall

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CONTENTS

4.1

Overview . . . . . . . . . . . . . . . 4.1.1 Forces Used for Stem Design 4.1.2 Multiple Load Cases . . . . . 4.2 Backfill Pressure . . . . . . . . . . . 4.3 Water Pressure . . . . . . . . . . . . 4.4 Passive Pressure @ Toe . . . . . . . 4.5 Uniform Surcharge . . . . . . . . . . 4.6 Line/Strip Surcharge . . . . . . . . . 4.7 Seismic Loading . . . . . . . . . . . 4.8 Wall Weights . . . . . . . . . . . . . 4.9 Soil Weights . . . . . . . . . . . . . 4.10 Bearing Reaction . . . . . . . . . . . 4.11 Friction . . . . . . . . . . . . . . . .

5 Checks 5.1 Stability Checks . . . . . 5.1.1 General Notes . . . 5.1.2 Checks Performed 5.2 Stem Checks . . . . . . . 5.2.1 General Notes . . . 5.2.2 Checks Performed 5.3 Toe Checks . . . . . . . . 5.3.1 General Notes . . . 5.3.2 Checks Performed 5.4 Heel Checks . . . . . . . 5.4.1 General Notes . . . 5.4.2 Checks Performed

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Chapter

1

Overview

1.1

Introduction

Thank you for choosing QuickRWall. This software package has been created to assist the engineer in the design of retaining walls. Use of this program can save countless hours in the calculations and documentation associated with retaining wall design. The software has been designed so that you may quickly become productive with very little training, but by reading through this manual and other associated documentation you should be able to resolve any questions that may arise during program use.

1.2

License

Use of this software program is strictly governed by the license agreement that is displayed during the install process. This program is the copyrighted property of Ensoltech, Inc. and is provided for the exclusive use of each licensee. Additional licenses may be obtained exclusively through Integrated Engineering Software. You may copy the program for backup purposes and you may install it on any computer allowed in the license agreement. Distributing the program to coworkers, friends, or duplicating it for other distribution violates the copyright laws of the United States. Future enhancements and technical support for this product depend on your cooperation in this regard.

1.3

Disclaimer

With any technical software package, there will be concerns about possible errors. We have worked very hard to ensure that this software is as accurate and robust as possible. Despite our best efforts, errors in software can and do occur. It is very important to manually inspect the results and ensure that they are consistent with sound engineering practice and judgement. This program has been designed with that end in mind, exposing calculations wherever possible so they are available for examination. It is the responsibility of the engineer to ensure the final design produced is reasonable and constitutes sound engineering practice. In no event shall Integrated Engineering Software, Inc. or

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CHAPTER 1. OVERVIEW

Ensoltech, Inc. be liable for any direct or indirect damages resulting from the use of this software or its related documentation.

1.4

Requirements

The software has relatively minimal system and hardware requirements: • • • • •

1.5

Windows 2000/XP/Vista 20 MB of hard disk space 64 MB of RAM Pentium processor 1024x768 screen resolution

Installation

Simply run the install program that comes on the CD or that you have downloaded from the IES website. The step-by-step wizard will guide you through the installation process.

1.6

Technical Support

Before you contact IES for support, please make sure you have taken full advantage of the readily available resources that are included with the software: • Carefully read through this users guide • Refer to the numerous help screens built into the software • If you have a question about a result displayed in a summary, be sure to check the full calculations that are displayed in the program and in the report. • Check the resources on the IES website. These can be accessed easily by going to the Help menu, iesweb.com submenu and choosing from the various options there. You should also make sure that you have the latest maintenance update for the software. These updates are free and can be obtained automatically by going to the Help menu, choosing iesweb.com, and then choosing Update QuickRWall. In this manner you can make sure that the issue you have a question about has not already been resolved. Integrated Engineering Software provides technical support for this program via email. The best way to send an email is to go to the Help menu, choose iesweb.com, then choose Email IES Technical Support.

1.7

Limitations

Following are situations that the program does not address in its current release. Please let us know if any of the items on this list (or not on this list) are of critical importance to you. Customer feedback is the #1 criteria in determining which features are added to future versions. • Segmental / MSE walls 6


• • • • • • • • • •

CHAPTER 1. OVERVIEW

Multi-level basement walls (multiple lateral supports) Soldier pile walls Rock anchors Walls without footings Walls on pile foundations Counterfort walls Buttress walls Strength design of masonry walls (currently only ASD) Sheet pile walls Multiple soil layers (other than a saturated layer beneath the water table)

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Chapter

2

Menu Commands

2.1

File Menu

These are the commands available on the File Menu.

2.1.1

New

Creates a new file without any projects.

2.1.2

Open

Opens an existing project file.

2.1.3

Save

Saves the current project file. If the file has not been previously saved and does not yet have a file name, a dialog will prompt for the file name.

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2.1.4

CHAPTER 2. MENU COMMANDS

Save As...

Saves the current project file, always prompting for a file name.

2.1.5

Print Report...

Prints a report containing a summary and/or details of the design calculations. A dialog appears first to allow you to specify which items are to be included in the report.

2.1.6

Print Full Page Drawing...

Prints a full page drawing of the wall.

2.1.7

Preview Report...

Previews a report containing a summary and/or details of the design calculations. A dialog appears first to allow you to specify which items are to be included in the report.

2.1.8

Preview Full Page Drawing...

Displays a preview of a full page drawing of the wall.

2.1.9

Print Setup...

Selects a printer and printer connection. Also allows you to choose portrait or landscape page orientation. This option is there because this is a standard dialog from Microsoft, but you should not select the landscape option. The report pages are not designed for it and will look funny.

2.1.10

Create DXF File...

Creates a DXF file that contains a fully dimensioned drawing of the wall. A dialog box will appear to allow you to specify the name and location of the file.

2.1.11

[Recent Files]

Opens the recently used project file with the displayed name.

2.1.12

Exit

Exits the program.

2.2

View Menu 9



These are the commands available on the View Menu.

2.2.1

Toolbar

Shows/hides the toolbar.

2.2.2

Status Bar

Shows/hides the status bar.

2.3

Project Menu

These are the commands available on the Project Menu.

2.3.1

Add Load Case...

Adds an additional load case to the project. Note that multiple load cases in this program are simply a way of applying a different set of unrelated, non-combinable loads. There is no support for combining different cases with various factors etc.; only loads within a single load case will be combined and factored. The multiple load case feature simply offers a way to consider different loading scenarios. Most projects will not require more than one load case.

2.3.2

Remove Load Case...

Brings up a dialog that allows you to remove a load case. You can only use this command when there is more than one load case, since it is required that there be at least one load case at all times.

2.3.3

Project Information...

Brings up a dialog that allows you to enter information for this specific project. This information is displayed in the header area of reports.

2.3.4

Set Defaults...

This command allows you to indicate that the current inputs are to be recorded as the default settings for future projects. A dialog will appear to allow you to specify which groups of inputs are to be saved. 10


2.4


Design Menu

These are the commands available on the Design Menu.

2.4.1

Choose Footing Reinforcement

This command will choose reinforcement for both the heel and the toe. It is best used after the width and thickness of the footing have already been set. The bars chosen will be governed by the current design preferences (see the Design Preferences command).

2.4.2

Choose Stem Reinforcement

This command will choose reinforcement for the stem. It is best used after the stem thickness has already been set. Currently this command only does basic sizing of bars at the base of the stem and does not deal with some of the more complicated scenarios, in particular the specification of bars for a multi-piece stem, restrained stem, or masonry stem. We are planning to improve this command considerably in a future version (please let us know if this is important to you). The bars chosen will be governed by the current design preferences (see the Design Preferences command).

2.4.3

Position Key To Embed Stem Bars

Creates a key (if there isn’t one already there) and positions it such that it provides development for the stem reinforcement, if it extends below the footing. The key is also positioned such that the bars can act as reinforcement for the key in case it is required (although the program does not perform calculations to test the adequacy of key reinforcement).

2.4.4

Set All Embedment Lengths

Calculates the required embedment lengths for the stem, heel, and toe bars, and lengthens the bars if they are too short. Note that in the case where the stem bars are hooked into the footing, this may cause the footing to be thickened in order to achieve the necessary development length for the hook (Ldh). Otherwise, the stem bars are allowed to stick out of the bottom of the footing, and it is left as a separate step for the engineer to either position a key to contain them (recommend the ’Position Key to Embed Stem Bars’ command above) or to hook them into the footing.

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2.4.5


Set All Lap Splice Lengths

Calculates the required lap length for all lap spliced bars and extends the lap length if required. Note that in some situations where there are no lapped bars, but potentially could be, the program will prompt you asking whether to lap the bars, and then set the proper length.

2.4.6

Set Bar Cutoff Lengths

Ensures that all bar cutoffs occur a sufficient distance past the point where the bars are required for flexure, and that cutoffs in a tension zone meet the applicable ACI requirements. Lengthens the cutoff bars if necessary. Note that in some situations where there are no cutoff bars, but potentially could be, the program will prompt you asking whether to cut off alternate bars, and then set them to the proper length.

2.4.7

Design Preferences

This brings up a dialog that lets you specify some settings such as available bars sizes and preferred bar spacings. This helps to make the automatic design results as practical as possible.

2.5

Options Menu

These are the commands available on the Options Menu.

2.5.1

Units...

Brings up a dialog allowing to modify the units used for various different quantities.

2.5.2

Preferences...

Brings up a dialog that allows use control of various aspects of program behavior.

2.5.3

Concrete Load Combinations...

Brings up a dialog allowing you to add, modify, or remove load combinations or groups of load combinations used for concrete design. This is the command that allows adding custom load factors/combinations. Note that you should not change the factors for the built-in, code-defined load combinations. The program will load its own built-in values for these at startup every time and overwrite your changes. If you would like to have a modified copy of one of these built-in combination sets, change its name (e.g. change ’IBC 2003’ to ’IBC 2003 (a)’). In this example, the program will load up a ’fresh’ copy of ’IBC 2003’ at startup and also leave your modified version (’IBC 2003 (a)’). 12


2.5.4


Masonry Load Combinations...

Brings up a dialog allowing you to add, modify, or remove load combinations or groups of load combinations used for masonry design. You should avoid modifying the built-in combinations; see the ’Concrete Load Combinations’ topic for guidelines regarding this issue.

2.5.5

Stability Load Combinations...

Brings up a dialog allowing you to add, modify, or remove load combinations used for stability checks (sliding & overturning). You should avoid modifying the built-in combination(s); see the ’Concrete Load Combinations’ topic for guidelines regarding this issue.

2.6

Help Menu

These are the commands available on the Help Menu.

2.6.1

Contents...

Brings up the help dialog, which presents a tree-style display of the available help topics.

2.6.2

Iesweb.com — Update QuickRWall 2.0

Initiates the process of checking for an update and, if necessary, automatically updates the program from the IES website. Note that you must be connected to the Internet for this feature to work properly.

2.6.3

Iesweb.com — Customer Center

Opens a web browser window with the IES Customer Center web page. This location provides access to several problem-solving resources.

2.6.4

Iesweb.com — FAQ Answers

Opens a web browser window with the IES Frequently Asked Questions (FAQ) web page.

2.6.5

Iesweb.com — Email IES Technical Support

Creates a new email message, addressed to IES tech support, and attaches certain useful system information that helps IES diagnose the source of potential problems. This is the best way to contact IES regarding 13



technical support issues.

2.6.6

Software License...

Brings up a dialog where current license information can be viewed, or new license information can be entered.

2.6.7

About QuickRWall 2.0...

Displays a dialog with version number, copyright, and other related information.

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Chapter

3

User Inputs

3.1

Criteria Inputs

3.1.1

Design Code

These are definitions of the inputs in the ’Design Code’ group.

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CHAPTER 3. USER INPUTS

Building Code The governing building code for code checks.

Use ASD for Masonry Design This option causes masonry checks to be performed using ASD provisions, rather than strength design provisions.

Concrete Load Combs The source of the load combinations that will be considered when performing checks on the concrete components of the wall. The abbrevation ’Str’ indicates ’Strength’ (combinations for strength as opposed to allowable stress design).

Masonry Load Combs The source of the load combinations that will be considered when performing checks on a masonry stem. If the stem is constructed entirely of concrete this setting has no effect. The abbrevation ’ASD’ indicates ’Allowable Stress Design’ (as opposed to strength design combinations).

Stability Load Comb The source of the load combinations that will be considered when performing stability checks on the wall.

3.1.2

Assumptions

These are definitions of the inputs in the ’Assumptions’ group.

Restrained Against Sliding Check this option if there is an external restraint, such as a slab, that prevents the wall from sliding. This will cause the program to skip the sliding stability check.

Neglect Bearing At Heel This causes the bearing pressure beneath the heel to be ignored when computing the critical moment and shear for the heel check. Checking this is conservative, but can sometimes lead to unrealistically high design forces.

Use Vert. Comp. for OT Causes the vertical component of the backfill force to be included in the overturning check. This force helps to resist overturning.

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Use Vert. Comp. for Sliding Causes the vertical component of the backfill force to be included in the sliding check. The contribution shows up indirectly via an increased friction force. This force helps to resist sliding.

Use Vert. Comp. for Bearing Causes the vertical component of the backfill force to be included in the bearing pressure calculation. This will increase the total bearing reaction, but can decrease the maximum pressure by evening out the pressure distribution.

Use Surcharge for Sliding & OT Causes the applied surcharge over the backfill to help resist sliding and overturning.

Use Surcharge for Bearing Causes the applied surcharge over the backfill to contribute to the bearing pressure. This will increase the average bearing pressure, but can sometimes decrease the maximum value by evening out the overall distribution. Note that this will also affect the toe and (possibly) heel design, since the bearing pressure influences the design shear and moment for those components.

Neglect Soil Over Toe Causes the weight of the soil over the toe to be neglected for strength design of the toe. This setting does not affect stability checks.

Neglect Backfill Wt. for Coulomb Causes the weight of the backfill to be neglected when the Coulomb earth pressure theory is used. This option is provided to be consistent with the recommendations of some textbooks, but is not appropriate in many situations and should be used with caution.

Factor Soil Weight As Dead Causes soil weight to be given the dead load factor rather than the earth load factor.

Use Passive Force for OT Causes the resultant force force from passive pressure (if there is one) to be excluded from the overturning check. This may or may not be conservative based on the location of the resultant.

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Assume Pressure To Top When the Rankine method is used to calculate the lateral pressure from a cohesive (c = nonzero) soil, it can happen that the theoretical pressure distribution goes into tension towards the top of the wall. The programs normal response in this case is to simply assume zero pressure in that region, but this option allows you to specify (conservatively) that the pressure distribution is taken as extending all the way to the top of the wall. Note that this feature is meaningless when either the Coulomb pressure theory is selected or when the soil is cohesive (c=nonzero).

Extend Backfill Pressure To Key Bottom For walls that have a key beneath the footing, this option causes the various lateral pressures from the backfill side to extend to the bottom of the key, rather than just to the bottom of the footing.

Use USACE Method For Sliding Check Selecting this option causes the sliding factor of safety for sliding to be calculated differently. The passive soil force at the toe is used to reduce the sliding force prior to division by the resisting force, rather than being added to the resisting force. This approach is advocated by the US Army Corps of Engineers.

3.1.3

Stability Criteria

These are definitions of the inputs in the ’Stability Criteria’ group.

Required F.S. for OT The required factor of safety for overturning. If the option to specify different safety factors for seismic loading is chosen, then this factor will be used only for an overturning moment based on non-seismic loads.

Required F.S. for Sliding The required factor of safety for sliding. If the option to specify different safety factors for seismic loading is chosen, then this factor will be used only for a sliding force based on non-seismic loads.

Has Different Safety Factors for Seismic Allows you to specify different factors of safety (for sliding and overturning) that are used with seismic loading. If this option is chosen, the factors of safety will be separately calculated and checked for the seismic case and for the non-seismic case.

Seismic F.S. for OT The required factor of safety for overturning, where the overturning moment includes seismic loads.

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Seismic F.S. for Sliding The required factor of safety for sliding, where the sliding force includes seismic loads

Allowable Bearing Pressure The maximum allowable bearing pressure.

Req’d Bearing Location The required position of the bearing pressure resultant beneath the footing.

3.1.4

Geotechnical

These are definitions of the inputs in the ’Geotechnical’ group.

Wall Friction Angle The wall friction angle is a measure of the friction between the wall and the mass of retained soil. It is only used if the lateral backfill pressure is calculated via the Coulomb method.

Friction Coefficent This coefficent is a measure of the friction beneath the bottom of the footing and the soil below. It is the ratio of the maximum friction force over the total vertical force.

3.2

Load Case Inputs

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3.2.1


General

These are definitions of the inputs in the ’General’ group.

Name The name of this load case.

3.2.2

Backfill

These are definitions of the inputs in the ’Backfill’ group.

Backfill Depth The height of the backfill surface, measured from the point where it contacts the wall stem down to either the subgrade surface (over the toe), the footing top, or the footing bottom, depending on the setting of the ’Measured From’ field.

Measured From Specifies how the backfill depth will be specified. The ’Lower Grade’ option represents the measurement used in previous versions of QuickRWall, where the retained height was always specified as the distance between upper and lower grades.

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Slope The slope of the backfill with the horizontal. You can either enter the angle directly or enter a ratio (e.g. 3:1).

Unit Weight (gamma) The unit weight or density of the backfill material.

Analysis Type Specifies the method that will be used to calculate the lateral pressure from the backfill. The Rankine and Coulomb methods are earth pressure theories that account for internal soil friction, whereas Equivalent Fluid Pressure (EFP) simply treats the soil as a fluid with a specified density.

Friction Angle (phi) The internal friction angle (phi) of the backfill material. Note you will not see this option in the event that you have chosen the option to use equivalent fluid density; it is not needed in that case.

Cohesion (c) The cohesion of the backfill material. Note you will not see this option in the event that you have chosen the option to use equivalent fluid density; it is not needed in that case.

Equiv. Fluid Density The equivalent fluid density of the backfill material. Note you will only see this option in the event that you have chosen the option to use equivalent fluid density; it is not needed otherwise.

3.2.3

Water in Backfill

These are definitions of the inputs in the ’Water in Backfill’ group.

Has Water in Backfill Whether to consider the effects of a water table in the backfill.

Water Table Depth The depth of the water table, measured from the top of the footing.

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Water Unit Weight The unit weight of the water in the backfill.

Saturated phi-sat The saturated internal friction angle (phi) of the backfill beneath the water table. Note you will not see this option in the event that you have chosen the option to use equivalent fluid density; it is not needed in that case.

Saturated Weight gamma-sat The saturated unit weight or density of the portion of the backfill beneath the water table.

3.2.4

Passive Pressure @ Toe

These are definitions of the inputs in the ’Passive Pressure @ Toe’ group.

Analysis Type Specifies the method that will be used to calculate the lateral passive pressure from the soil in front of the toe. The Rankine and Coulomb methods are earth pressure theories that account for internal soil friction, whereas Equivalent Fluid Pressure (EFP) simply treats the soil as a fluid with a specified density. You can also neglect this pressure entirely.

Friction Angle (phi) The internal friction angle (phi) of the soil in front of the toe. Note you will not see this option in the event that you have chosen the option to use equivalent fluid density; it is not needed in that case.

Cohesion (c) The cohesion of the soil in front of the toe. Note you will not see this option in the event that you have chosen the option to use equivalent fluid density; it is not needed in that case.

Equiv. Fluid Density The equivalent fluid density of the soil in front of the toe. Note you will only see this option in the event that you have chosen the option to use equivalent fluid density; it is not needed otherwise.

Unit Weight (gamma) The unit weight or density of the soil in front of the toe.

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Apply Only To Key Whether to apply passive pressure only to the key. Otherwise the pressure will be applied to the entire burial depth, less that which has been ignored.

Soil Depth To Ignore The depth of material over the toe to ignore when calculating the passive pressure. This must be less than or equal to the burial depth of the footing, or to the depth of the key bottom if there is a key. A higher value is more conservative.

3.2.5

Surcharge (Uniform)

These are definitions of the inputs in the ’Surcharge (Uniform)’ group.

Surcharge Type Specifies whether there is a uniform surcharge over the backfill, and whether that surcharge is specified directly as a pressure, or as additional depth of backfill.

Surcharge Pressure The surcharge pressure on top of the backfill.

Add’l Backfill Depth The specified additional depth of backfill from which the surcharge pressure will be calculated.

3.2.6

Surcharge (Line/Strip)

These are definitions of the inputs in the ’Surcharge (Line/Strip)’ group.

Type Choose either a line or a strip surcharge on the backfill. A line surcharge is applied at a specified distance from the wall and has units of force per unit length of the wall. A strip surcharge is applied over a finite width at a specified distance from the wall and has pressure units.

Depth The depth below the backfill surface at which the line or strip surcharge is applied. This is useful, for example, if there is a buried footing in the backfill. This depth is measured from the backfill surface at the point where it contacts the wall, not the sloped surface (if the the backfill is sloped).

23



Distance From Stem If a line surcharge is applied, this is the lateral distance from the point where the backfill surface contacts the stem to the point at which the line load is applied. If a strip surcharge is applied, this is the lateral distance from the point where the backfill surface contacts the stem to the start of the strip surcharge pressure.

Width This is the width of the strip surcharge pressure. This input is not available for a line surcharge.

Pressure The magnitude of the strip surcharge (pressure).

Force The magnitude of the line surcharge (linear force).

3.2.7

Uniform Lateral Load

These are definitions of the inputs in the ’Uniform Lateral Load’ group.

Apply Lateral Pressure To Stem Choose this option if you would like to manually specify a lateral pressure on the stem.

Magnitude The magnitude of the manually specified lateral pressure on the stem. The pressure acts in the same direction as the backfill pressure, as indicated on the diagram.

Top Bound The distance from the top of the stem to the top of the lateral pressure distribution.

Bottom Bound The distance from the top of the stem to the bottom of the lateral pressure distribution.

Load Source The load source for the uniform lateral pressure.

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3.2.8


Stem Axial Load

These are definitions of the inputs in the ’Stem Axial Load’ group.

Has Axial Load on Stem This option allows you to specify a vertical, downward force on the top of the stem, with an optional eccentricity.

Dead Load The magnitude of the dead load component of the axial force.

Live Load The magnitude of the live load component of the axial force.

Eccentricity Enter the eccentricity of the stem load. Only positive eccentricities are allowed (move the load out towards the end of the toe). The eccentricity is measured from the center of the top of the stem.

3.2.9

Seismic Loading

These are definitions of the inputs in the ’Seismic Loading’ group.

Has Backfill Seismic Load This option applies a lateral force from the mass of backfill due to earthquake effects.

Kh The horizontal seismic coefficient, which is the horizontal earthquake acceleration component divided by the acceleration due to gravity.

Kv The vertical seismic coefficient, which is the vertical earthquake acceleration component divided by the acceleration due to gravity.

Friction Angle (phi) The internal friction angle (phi) of the backfill soil, as used in seismic calculations. This is usually specified in the ’Backfill’ inputs and cannot be modified here, but if the backfill pressure is calculated via EFP 25



(Equivalent Fluid Pressure) or at-rest, then phi must be entered here.

3.3

Wall (Footing/Stem) Inputs

Name The name of this wall. It is useful to give walls meaningful names to distinguish them from other stored walls.

3.3.1

General


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Burial Depth The distance from the lower grade surface to the bottom of the footing.

3.3.2

Material

These are definitions of the inputs in the ’Material’ group.

Rebar Fy The specified yield stress of the reinforcing bars. This value will also be used for the stem unless the option ’Material Properties Different Than Footing’ is chosen for the stem.

Concrete f’c The specified compressive strength of the concrete. This value will also be used for the stem unless the option ’Material Properties Different Than Footing’ is chosen for the stem.

Unit Weight The density, or unit weight, of the material (concrete) used to construct the footing. This value will also be used for the stem unless the option ’Material Properties Different Than Footing’ is chosen for the stem.

3.3.3

Footing Geometry

These are definitions of the inputs in the ’Footing Geometry’ group.

Footing Thickness The thickness of the footing (heel and toe).

Heel Length The length of the heel as measured from the base of the stem.

Toe Length The length of the toe as measured from the base of the stem.

3.3.4

Heel Reinforcement

These are definitions of the inputs in the ’Heel Reinforcement’ group.

27



Has Heel Reinforcement You can uncheck this box to specify that there is no reinforcement for the heel, for example when the heel is extremely short.

Embedment Type The manner in which the heel reinforcement is embedded in the rest of the wall. The bars with either extend straight the full width of the footing, extend straight a specified distance past the junction with the stem, or will hook downward. The hook option can be necessary when the toe is too short for the heel bars to be developed by extending straight into the toe. Note that in practice, it may be necessary to tilt these bars, since the footing may not be thick enough to accommodate the required hook extension.

Heel Bar Size The size of the heel reinforcing bars.

Heel Bar Spacing The center to center spacing of the heel reinforcing bars.

Heel Bar Ld The distance that the heel bars extend into the footing past the base of the stem (the critical section for flexure).

Heel Bar Cover The clear cover between the heel bars and the top of the heel.

3.3.5

Toe Reinforcement

These are definitions of the inputs in the ’Toe Reinforcement’ group.

Has Toe Reinforcement You can uncheck this box to specify that there is no reinforcement for the toe, for example when the toe is extremely short.

Embedment Type The manner in which the toe reinforcement is embedded in the rest of the wall. The bars with either extend straight the full width of the footing, extend straight a specified distance past the junction with the stem, or will hook up to become stem reinforcement. If the hook option is chosen, there will be no separate inputs

28



for specifying the toe bars; they will be consistent with the bars at the base of the stem.

Toe Bar Size The size of the toe reinforcing bars.

Toe Bar Spacing The center to center spacing of the toe reinforcing bars.

Toe Bar Ld The distance that the toe bars extend into the footing past the base of the stem (the critical section for flexure).

Toe Bar Cover The clear cover between the toe bars and the bottom of the toe.

3.3.6

Transverse Reinf. (S&T)

These are definitions of the inputs in the ’Transverse Reinf. (S&T)’ group.

Footing Has Transverse (S&T) Bars Whether or not the footing has transverse (shrinkage temperature) reinforcement, top and bottom.

Transverse Bar Size The size of the footing transverse (shrinkage temperature) reinforcing bars.

Transverse Bar Spacing The maximum center to center spacing of the footing transverse (shrinkage temperature) reinforcing bars. The actual detailed bar spacing may be slightly less, as the program will evenly distribute the bars over the footing width.

3.3.7

Key

These are definitions of the inputs in the ’Key’ group.

29



Has Key Use this option to indicate that the wall has a shear key in order to help with sliding resistance.

Key Depth The depth of the shear key, measured from the bottom of the footing to the bottom of the key.

Key Width The width of the shear key.

Key Position The position of the shear key beneath the footing. If ’Encase Bars’ is chosen, the key is positioned horizontally such that the stem bars will extend down into it, and such that they will also tend to reinforce the key.

Key Location The manually specified location of the shear key, measured from the left edge (toe) of the footing to the left edge of the key. This entry is only available if ’Key Position’ is set to ’Specified’.

3.3.8

General


Stem Type Whether the stem will be composed of multiple pieces of differing thicknesses.

Height This governs the height of the stem, measured from either the footing bottom, footing top, the backfill surface, depending on the setting of the ’Measured From’ field.

Measured From Specifies how the stem height will be specified. The ’Backfill Surface’ option will cause the same behavior used in QuickRWall 1.5, where the stem height is always set relative to the backfill depth.

30



Bars Developed @ Top By checking this option you indicate that the bars that extend to the top of the stem are developed by some external means that is not directly specified in the program. This is necessary when there is an eccentric axial load applied to the top of the stem, since there will in that case be a moment at the top of the stem. Without development of the bars at the top, there would be no moment capacity there, and so the stem would be considered inadequate.

Has Lateral Support (Restrained Wall) This option allows you to specify a lateral support on the stem. This is frequently used to model the ’basement wall’ or ’restrained wall’ condition. Choosing this option changes the available inputs for reinforcement, since the different applied moment caused by the support will require reinforcement at different locations.

Support Top Offset Specifies the position of the lateral support, as measured from the top of the wall. Leave this value at zero to have the support at the top.

Stem Base Is Pinned When there is a lateral support, you have the option of treating the stem-footing connection as pinned.

Material Properties Different Than Footing Check this box to enter different concrete material properties for the stem than for the footing. If this box is not checked, the properties entered for the footing will also be used for the stem.

Rebar Fy The specified yield stress of the reinforcing bars in the stem.

Concrete f’c The specified compressive strength of the concrete in the stem.

Unit Weight The density, or unit weight, of the material (reinforced concrete/masonry) used to construct the stem.

3.3.9

Geometry

These are definitions of the inputs in the ’Geometry’ group.

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Stem Top Thickness The thickness of the stem at its top. If the wall is not tapered, this will be the constant thickness from top to bottom.

Tapered Check this box to taper the stem.

Extra Thickness @ Toe The amount by which the bottom of the stem is thicker than the top on the toe side. This will be zero if the stem is not tapered on the toe side.

Extra Thickness @ Heel The amount by which the bottom of the stem is thicker than the top on the heel side. This will be zero if the stem is not tapered on the heel side.

3.3.10

Reinforcement (Flexural)

These are definitions of the inputs in the ’Reinforcement (Flexural)’ group.

Reinforcement Layout This setting determines whether there will be one or two curtains of reinforcement in the stem, and the position for cases where there is just one curtain.

Vertical Bar Size The size of the main vertical reinforcing bars.

Vertical Bar Spacing The center to center spacing of the vertical reinforcing bars.

Vertical Bar Embedment The manner in which the stem reinforcement is embedded in the footing. The bars can either extend straight down into the footing (and possibly into the shear key, if there is one), or hook into the heel, or hook into the toe, in which case they also serve as toe reinforcement.

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Vertical Bar Ld The distance the main vertical bars in the stem extend into the footing (when they aren’t hooked).

Cut Off Alternate Bars Choose this option to specify that every other bar is cut off and hence does not extend all the way to the top of the stem. If the lapped bar option is also chosen, this means that the (alternate) cutoff bars will not be lapped but will consist of the dowels extending up to the cutoff point.

Cutoff Length The distance from the base of the stem to the cutoff point for the cutoff bars.

Lap With Dowels Use this option to have the stem dowels lapped with other bars at the base of the stem. This might be every bar or every other bar depending on whether the ’cut off alternate bars’ option is chosen.

Lap Length The distance over which the bars are lapped. This is measured starting at the base of the stem.

Dowel Bar Size The size of the dowels that lap with the main vertical reinforcing bars.

Cover (backfill side) The clear cover between the stem bars and the outer surface of the stem on the backfill side.

Cover (toe side) The clear cover between the stem bars and the outer surface of the stem on the toe side (side opposite the backfill).

2nd Layer Bar Size The size of the vertical reinforcing bars in the second layer. The second layer is the one near the face of the wall furthest from the backfill (on the ’toe side’).

2nd Layer Bar Spacing The center to center spacing of the vertical reinforcing bars in the second layer.

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2nd Layer Bar Embedment The manner in which the 2nd layer stem reinforcement is embedded in the footing. The bars can either extend straight down into the footing (and possibly into the shear key, if there is one), or hook into the heel, or hook into the toe.

2nd Layer Bar Ld The distance the 2nd layer vertical bars in the stem extend into the footing (when they aren’t hooked). It is conceivable that this value will often be left at zero, since most loading configurations will not require positive moment capacity at the stem base.

3.3.11

Reinforcement (S&T)

These are definitions of the inputs in the ’Reinforcement (S&T)’ group.

Has Horizontal (S&T) Bars Whether or not the stem has horizontal (shrinkage & temperature) reinforcement.

Horizontal Bar Size The size of the stem horizontal (shrinkage & temperature) reinforcing bars.

Horizontal Bar Spacing The center to center spacing of the stem horizontal (shrinkage & temperature) reinforcing bars.

Same For Both Layers Whether or not the size and spacing of the horizontal reinforcement in the stem is the same for both layers of bars. De-select this option to specify separate bar size & spacing for the 2nd layer.

2nd Layer Horz Bar Size The size of the stem horizontal (shrinkage & temperature) reinforcing bars in the second layer.

2nd Layer Horz Bar Spacing The center to center spacing of the stem horizontal (shrinkage & temperature) reinforcing bars in the second layer.

34


3.3.12


Sections

These are definitions of the inputs in the ’Sections’ group.

Number of Stem Sections Specify the number of sections that make up the stem. Each section may have its own thickness and reinforcement.

3.4

Stem Section Inputs

3.4.1

General


Type This entry specifies whether this section of the stem will be constructed of concrete or masonry.

Height The height of this section of the stem.

Thickness The thickness of this section of the stem.

3.4.2

Masonry Block

These are definitions of the inputs in the ’Masonry Block’ group.

35



Masonry f’m The specified compressive strength of the masonry.

Block Thickness Thickness of the masonry block used in this section.

3.4.3

Reinforcement

These are definitions of the inputs in the ’Reinforcement’ group.

Bar Fs The allowable tensile or compressive stress in the reinforcement.

Bar Size The size of the reinforcing bars in this section of the stem.

Bar Spacing The center to center spacing of the reinforcing bars in this section of the stem.

Bar Position The bar position relative to the outer faces of the wall.

Bar Cover The clear cover between the bar and the nearest face. This input is not meaningful or visible if the bars are centered in the wall.

Embedment Above Distance the bars from this section extend into the section above. This input is not available for the top section.

Embedment Below Distance the bars from this section extend into the section below.

36



Base Embedment Type Determines the manner in which the bars that extend down from the bottom section are embedded into the footing.

37

Chapter

4

Forces on the Wall

4.1

Overview

The software allows loading the wall via the following sources: • • • • • • • • • • • •

4.1.1

Lateral pressure from the backfill Lateral pressure from water in the backfill Passive lateral pressure at the toe Surcharge on the backfill (uniform) Surcharge on the backfill (line/strip) Manually specified lateral pressure (e.g. from wind) Lateral pressure due to seismic loads Axial load on stem Weight of the wall Weight of the soil (backfill & soil above toe) Bearing reaction beneath the footing Friction between the footing and soil

Forces Used for Stem Design

For most of these loading types, the calculations will show a second set of results on the stem only, in addition to the initial set on the full wall. These stem-only forces are used for calculating the internal shears and moments for stem design.

4.1.2

Multiple Load Cases

If there are multiple load cases then there will be multiple sets of results for each of these loading types. When viewing the results (on the ’Analysis View’ tab), you can switch between load cases using the dropdown list at the bottom of the screen.

4.2

Backfill Pressure 38


CHAPTER 4. FORCES ON THE WALL

The retained backfill will exert a horizontal pressure on the wall. The backfill pressure can be arrived at in one of two ways: • Specified directly as an equivalent fluid pressure (EFP) • Calculated by the program using active earth pressure theory (Rankine or Coulomb) or at-rest earth pressure theory. When you specify an equivalent fluid pressure (EFP) you are telling the program directly what the pressure per unit depth is. This information might come from a geotechnical engineer or a soils report. This is a very simple calculation where the lateral pressure is calculated as if the backfill was a fluid with the given density gEFP. The resulting distribution varies linearly from a maximum value of gEFPH at the bottom of the footing up to zero at the top. When the program calculates the backfill pressure itself, it employs either Rankine active, Coulomb active, or at-rest earth pressure theory. Active earth pressure is most reasonable for a cantilever wall due to its tendency to displace somewhat in response to loading, hence allowing the backfill’s internal friction to engage in helping to restrain any further movement. Restrained walls are usually designed using at-rest pressure. If there is water in the backfill, the buoyant effect of the water will reduce the lateral pressure from the portion of the backfill that is below the water surface. The total lateral force over that portion, however, will increase when the pressure due to the water itself is considered (see following section).

4.3

Water Pressure

If there is water in the backfill, it will exert a lateral pressure on the wall. The magnitude of the pressure is determined by a simple hydrostatic calculation (pressure = depth multiplied by the unit weight of water). The unit weight of water defaults to 64 pcf but can be manually overridden by the user.

4.4

Passive Pressure @ Toe

The soil that is in front of the wall (over and in front of the toe) can also exert a pressure on the wall. The extent of this pressure will vary based on how much overburden you choose to neglect, whether a shear key is present, and on whether you opt to neglect the portion of the pressure above the bottom of the footing. This passive pressure contributes to sliding and (possibly) overturning resistance and can play an important role in ensuring the stability of the wall. Sometimes the fact that the soil in front of the toe gets disturbed during excavation, or other concerns, will cause concern over whether including a passive pressure contribution from that soil is reasonable. For this reason the program allows you to indicate that such pressure is to be excluded from the calculations. The passive pressure can either be calculated via Rankine passive theory, specified directly with an equivalent fluid density value, or neglected completely.

4.5

Uniform Surcharge

The program allows you to specify a uniform surcharge in one of two ways:

39



• Specify a fictitious additional depth of backfill • Specify a uniform pressure on the backfill If an additional depth of backfill is specified, it is converted to a pressure internally and then lateral force calculations proceed using that pressure. The surcharge pressure results in a uniform lateral pressure on the wall, which is the vertical (surcharge) pressure multiplied by the lateral pressure coefficient. If Rankine or Coulomb active pressure was used for determining backfill pressure, K is the calculated Ka value for active pressure (similarly Ko for at-rest pressure). If EFP was used for backfill pressure, K is determined by dividing the weight of the backfill (gamma) by the specified equivalent fluid density.

4.6

Line/Strip Surcharge

You may apply either a line or strip surcharge on the wall. The corresponding lateral pressures are calculated using the methods outlined in the text Principles of Foundation Engineering by Braja M. Das, 3rd Edition. The exact equation used for a given loading is displayed in the output. This loading requires particularly complicated mathematical routines that can cause a noticeable delay in the software. If you notice such a delay after changing a parameter that affects the pressure (e.g. the retained height of backfill), this is normal.

4.7

Seismic Loading

The program applies a seismic load due to the weight of the backfill based on the Mononobe-Okabe method. The equations used to calculate the exact force are displayed in the program output. Take note when examining the pressure distribution on the stem. The theory gives two constraints: That the shape of the pressure distribution is an inverted triangle, and that the resultant acts at 0.6H from the bottom of the wall. Since these two conditions are mutually exclusive (resultant for a perfect triangular distribution would be at 2/3 or 0.667H from bottom) the program slightly modifies the distribution, increasing the bottom magnitude from zero such that the resultant drops to 0.6H. This is the pressure that is used when calculating stem moments.

4.8

Wall Weights

The wall weights are determined by dividing the wall into simple geometric pieces and calculating the weight for each piece. Each piece’s weight (per unit length of wall) is the area of the piece multiplied by the unit weight of the wall material.

4.9

Soil Weights

The soil weights are determined by dividing the backfill into simple geometric pieces and calculating the weight for each piece. Each piece’s weight (per unit length of wall) is the area of the piece multiplied by

40



the unit weight of the soil. This includes both the backfill behind the wall and the soil in front of the wall over the toe. The weight of the soil over the toe can be neglected if desired.

4.10

Bearing Reaction

The upward force (R) exerted by the soil against the footing is in reaction to the sum of all downward forces that act on the wall. The calculations displayed in the software show exactly what the various downward forces are. Note that the software also tabulates what contribution each load source (e.g. dead, live, etc.) makes to the total bearing reaction. This information may be of general interest, and also becomes important when factoring the bearing pressure and determining the sliding resistance due to friction, which is a function of this bearing resultant. The horizontal position at which R acts is determined by calculating the net moment of all the forces on the wall and dividing by R. See the program output for sample equations. Note that for a restrained wall the contribution of lateral forces to the overall moment is not added in directly; rather, their effect is reflected in the moment that is transferred to the footing at the base of the stem (Mstem). Knowing R and dR it is then possible to calculate the left and right bearing pressures beneath the footing. The formula used for this will vary based on whether the resultant R is located inside the middle third (full bearing) or outside the middle third (partial bearing). Again, the best illustration of this is to look at the program output.

4.11

Friction

The friction between the footing and the soil below is calculated by multiplying a user-specified coefficient by the total bearing reaction force. This is a fairly straightforward calculation, but there are complicating adjustments made when some portion of the bearing pressure was in reaction to certain load sources that should not be allowed to contribute to frictional resistance. These sources are: • Any live loads • Applied surcharge force (vertical) - (optional based on user setting) • Vertical component of backfill force - (optional based on user setting) If the bearing reaction contains contributions from any of these three sources, it will be reduced for the purposes of calculating friction. The printed report details how the calculations are adjusted to reflect this reduction.

41

Chapter

5

Checks

5.1

Stability Checks

5.1.1

General Notes

The following general notes apply to all stability checks: • The applied forces (calculated on the overall wall plus the backfill over the heel) used in stability checks are factored according the the load combination specified by the ’Stability Load Comb’ input on the Criteria tab of the Input View. The default combination has all factors set to 1.0 (unfactored). • Several of the options on the Criteria tab (Input View) under the ’Assumptions’ group affect stability checks. Make sure to examine these settings and ensure that they are correct for your particular project. • The results displayed by the software (Checks View, Stability tab) thoroughly illustrate the details of how the checks are performed. Refer to this output for a better understanding of the internal workings of these checks. • In the sliding check, the lateral support reaction (visible for restained walls) will be calculated based on the load combination used for stability checks (as selected on the Criteria tab). This is not necessarily the same as any of the strength combinations, so you should not expect the value shown to be the same as that displayed for strength design of the stem.

5.1.2

Checks Performed

These are the checks that are made to ensure stability.

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CHAPTER 5. CHECKS

Overturning Code References: • IBC 2003 1806.1 • IBC 2006 1806.1 Checks that the factor of safety against overturning is greater than or equal to the specified minimum allowable.

Sliding Code References: • IBC 2003 1806.1 • IBC 2006 1806.1 Checks that the factor of safety against sliding is greater than or equal to the specified minimum allowable.

Bearing Pressure Code References: • IBC 2003 1806.1 • IBC 2006 1806.1 Checks that the maximum bearing pressure (gross pressure) beneath the footing is less than or equal to the specified minimum allowable.

Bearing Eccentricity Code References: • IBC 2003 1806.1 • IBC 2006 1806.1 Checks that the bearing pressure resultant eccentricity (distance from footing center) does not exceed the allowable.

5.2

Stem Checks

5.2.1

General Notes

The following general notes apply to the stem checks: • The applied forces (e.g. backfill pressure) used to calculate the internal forces in the stem are illustrated on the Stem Forces tab of the Checks View. These forces are calculated independently from

43


CHAPTER 5. CHECKS

the forces on the overall wall; take note of the ’stem-only’ set of calculations on the Backfill tab and other tabs of the Analysis View. • The forces used in stem design are factored by the strength load combinations selected on the Criteria tab of the Input View, specifically the ’Concrete Load Combs’ and/or ’Masonry Load Combs’ inputs. • When viewing stem check results. note that most of the tabs in the Checks View display information for the selected load case, which is chosen by a drop-down list at the bottom of the window. If the stem contains both concrete and masonry, the window will show both the concrete load combination and best-matched masonry combination, and internal force graphs (moment/shear) will plot results for both combinations. • If the stem is unreinforced, ACI’s ’structural plain concrete’ provisions are used for design (ACI-318 Ch. 22).

5.2.2

Checks Performed

Specific code checks associated with the stem.

Moment Code References: • • • •

ACI 318-02 10.2, 10.3 ACI 318-05 10.2, 10.3 CSA-A23.3-94 Ch 10 CSA-A23.3-04 Ch 10

Checks the stem for flexural failure according to the selected design code. This check is performed at multiple critical locations along the height of the stem, depending on configuration and loading.

Shear Code References: • • • •

ACI 318-02 11.1.1, 11.3.1 ACI 318-05 11.1.1, 11.3.1 CSA-A23.3-94 11.3 CSA-A23.3-04 11.3

Checks the stem for shear failure according to the selected design code. This check is performed at multiple critical locations along the height of the stem, depending on configuration and loading. 44


CHAPTER 5. CHECKS

Max Steel Code References: • ACI 318-02 10.3.5 • ACI 318-05 10.3.5 Checks the stem for sufficient tensile strain at nominal strength. This is a ductility requirement that guards against over-reinforcement.

Min Steel Code References: • • • •

ACI 318-02 10.5.1 ACI 318-05 10.5.1 CSA-A23.3-94 10.5.1 CSA-A23.3-04 10.5.1

Checks the toe for sufficient area of flexural reinforcement.

Base Development Code References: • • • •

ACI 318-02 12.2.3, 12.12 ACI 318-05 12.2.3, 12.12 CSA-A23.3-94 Ch 12 CSA-A23.3-04 Ch 12

Checks that the stem bars are sufficiently developed into the footing.

Lap Splice Length Code References: • • • •

ACI 318-02 12.15.1, 12.15.2 ACI 318-05 12.15.1, 12.15.2 CSA-A23.3-94 Ch 12 CSA-A23.3-04 Ch 12

Checks that the bar lap splices in the stem are long enough.

Lap Splice Spacing Code References: • ACI 318-02 12.14.2.3 • ACI 318-05 12.14.2.3

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CHAPTER 5. CHECKS

• CSA-A23.3-94 Ch 12 • CSA-A23.3-04 Ch 12 Checks that the transverse spacing between lapped bars does not exceed the limit (for noncontact lap splices).

Bar Cutoff Extension Code References: • • • •

ACI 318-02 12.10.3 ACI 318-05 12.10.3 CSA-A23.3-94 12.10.3 CSA-A23.3-04 12.10.3

Checks that cutoff bars extend a sufficient distance past where they are no longer needed for flexure.

Bar Cutoff Shear Code References: • • • •

ACI 318-02 12.10.5 ACI 318-05 12.10.5 CSA-A23.3-94 12.10.5 CSA-A23.3-04 12.10.5

For cutoff bars, checks that the shear does not exceed the allowable limit when bars are cut off in a tension zone.

Horz Bar Rho Code References: • ACI 318-02 14.3.3 • ACI 318-05 14.3.3 Checks that the horizontal bars in the wall meet the minimum reinforcement percentage (rho).

Horz Min Steel Code References: • CSA-A23.3-94 14.1.8.6 • CSA-A23.3-04 14.1.8.6 Checks that the horizontal bars in the wall meet the minimum area.

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CHAPTER 5. CHECKS

Horz Bar Spacing Code References: • • • •

ACI 318-02 14.3.5 ACI 318-05 14.3.5 CSA-A23.3-94 14.1.8.4 CSA-A23.3-04 14.1.8.4

Checks that the horizontal bars in the wall do not exceed the maximum spacing.

5.3

Toe Checks

5.3.1

General Notes

The following general notes apply to the toe checks: • The design shear force used for the toe is taken at a distance ’d’ from the base of the stem. • The design moment for the toe is not taken greater than the design moment at the base of the stem. • If the toe is unreinforced, ACI’s ’structural plain concrete’ provisions are used for design (ACI-318 Ch. 22). • When factoring the bearing pressure for heel and toe checks, the program calculates an average load factor based on the percentage contribution of each load source to the total bearing reaction.

5.3.2

Checks Performed

Specific code checks associated with the toe.


ACI 318-02 11.1.1, 11.3.1 ACI 318-05 11.1.1, 11.3.1 CSA-A23.3-94 11.3 CSA-A23.3-04 11.3

Checks the toe for shear failure according to the selected design code.

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CHAPTER 5. CHECKS



Checks the toe for flexural failure according to the selected design code.

Min Strain Code References: • ACI 318-02 10.3.5 • ACI 318-05 10.3.5 Checks the toe for sufficient tensile strain at nominal strength. This is a ductility requirement that guards against over-reinforcement.


ACI 318-02 10.5.1 ACI 318-05 10.5.1 CSA-A23.3-94 10.5.1 CSA-A23.3-04 10.5.1

Checks the toe for sufficient area of flexural reinforcement.

Development Code References: • • • •

ACI 318-02 12.2.3, 12.12 ACI 318-05 12.2.3, 12.12 CSA-A23.3-94 Ch 12 CSA-A23.3-04 Ch 12

Checks that the toe bars are sufficiently developed into the rest of the wall.

S&T Max Spacing Code References: • ACI 318-02 7.12.2.2 • ACI 318-05 7.12.2.2

48


CHAPTER 5. CHECKS

• CSA-A23.3-94 7.8.3 • CSA-A23.3-04 7.8.3 Checks that the shrinkage and temperature (transverse) steel spacing does not exceed the allowable limit.

S&T Min Rho Code References: • ACI 318-02 7.12.2.1 • ACI 318-05 7.12.2.1 Checks that the shrinkage and temperature (transverse) steel rho meets the minimum limit.

S&T Min Steel Code References: • CSA-A23.3-94 7.8.1 • CSA-A23.3-04 7.8.1 Checks that the shrinkage and temperature (transverse) steel area meets the minimum limit.

5.4

Heel Checks

5.4.1

General Notes

The following general notes apply to the heel checks: • The design moment for the heel is not taken greater than the design moment at the base of the stem. • If the heel is unreinforced, ACI’s ’structural plain concrete’ provisions are used for design (ACI-318 Ch. 22). • When factoring the bearing pressure for heel and toe checks, the program calculates an average load factor based on the percentage contribution of each load source to the total bearing reaction.

5.4.2

Checks Performed

Specific code checks associated with the heel.

49


CHAPTER 5. CHECKS


ACI 318-02 11.1.1, 11.3.1 ACI 318-05 11.1.1, 11.3.1 CSA-A23.3-94 11.3 CSA-A23.3-04 11.3

Checks the heel for shear failure according to the selected design code.



Checks the heel for flexural failure according to the selected design code.

Min Strain Code References: • ACI 318-02 10.3.5 • ACI 318-05 10.3.5 Checks the heel for sufficient tensile strain at nominal strength. This is a ductility requirement that guards against over-reinforcement.


ACI 318-02 10.5.1 ACI 318-05 10.5.1 CSA-A23.3-94 10.5.1 CSA-A23.3-04 10.5.1

Checks the heel for sufficient area of flexural reinforcement.

Development Code References: • ACI 318-02 12.2.3, 12.12 • ACI 318-05 12.2.3, 12.12

50


CHAPTER 5. CHECKS

• CSA-A23.3-94 Ch 12 • CSA-A23.3-04 Ch 12 Checks that the heel bars are sufficiently developed into the rest of the wall.

S&T Max Spacing Code References: • • • •

ACI 318-02 7.12.2.2 ACI 318-05 7.12.2.2 CSA-A23.3-94 7.8.3 CSA-A23.3-04 7.8.3

Checks that the shrinkage and temperature (transverse) steel spacing does not exceed the allowable limit.

S&T Min Rho Code References: • ACI 318-02 7.12.2.1 • ACI 318-05 7.12.2.1 Checks that the shrinkage and temperature (transverse) steel rho meets the minimum limit.

S&T Min Steel Code References: • CSA-A23.3-94 7.8.1 • CSA-A23.3-04 7.8.1 Checks that the shrinkage and temperature (transverse) steel area meets the minimum limit.

51

Quick r Wall 20 Users Guide

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