Worked examples of retaining wall design to bs8002. Seismic design of retaining wall is considerably complicated problem in which assumptions have to be considered in order to make indeterminable issue solvable employing theory of statics and differential calculus. Assume level backfill, no surcharge or seismic loading, active earth pressure and. An rc retaining wall 5 m high above foundation base has to retain earth with a horizontal surface at the top. Earth pressure p 8 earth pressure is the pressure exerted by the retaining material on the retaining wall. Worked example 2 design of concrete cantilever retaining walls to.
Consider the cantilever retaining wall with the cross section shown in the above figure a. This wall was designed to repair a roadside slipout. Digital canals retaining wall design software, quickwall, is a deceptively simple program that can design or check just about any retaining or basement wall in minutes. Assuming that the allowable bearing pressure of the soil is 120 knm 2, the. It utilized a slope correction factor for passive resistance, but ignored the possibility of the downslope moving away from the caissons, which it did sometime later. The approach is illustrated through an embedded sheet pile wall design example that has been used in literature for the evaluation of eurocode 7. Updated and expanded throughout, this new edition covers nearly every type of retaining strucutre. Active earth pressure or earth pressure pa and passive earth pressure p p. Lateral forces on retaining wallsence 454 assakkaf design of retaining walls the design of retaining wall must account for all applied loads. This design example focuses on the analysis and design of a tapered cantilever retaining wall including a comparison with model results.
The computation of each static and dynamic pressure acting on retaining wall need more research and site selection is becoming codified. Underpinning to be formed in continuous reinforced concrete. Design the cantilever wall and give approximate dimensions of heel, toe and base. The density of retained earth is 16 knm3 and angle of repose is 300. In minutes you can design or analyze nearly any configuration or loading condition for cantilevered, restrained, gravity, gabion, soldier pile, or segmental retaining walls. Usually the cantilever wall stem is of concrete block. Worked example to accompany mbie guidance on the seismic design of retaining structures for residential sites in greater christchurch version 2 november 2014. The following worked example is for a freestanding. Most common materials used for retaining walls are. To further understand the designed approach, here is a worked example of the design of the retaining wall. Design of retaining walls the design of retaining wall must account for all applied loads. Retaining walls provide an excellent example of the problems and processes associated with preliminary engi neering design and cost estimation. Design of the retaining wall structures on the m4 smart motorway.
The design process for a segmental retaining wall typically has a wall design engineer or site civil engineer responsible for the wall design envelope. It is not advisable to include the actual strength of the retaining wall. Drainage material the crushed rock, gravel or similar material placed behind a retaining wall to convey ground water away from the wall and foundations. They are not full detailed calculations such as might be prepared for a real wall design but are limited to the calculation of earth pressure and bearing capacity, showing how the. In this example, the structural design of the three retaining wall components is performed by hand. Retaining wall design rcc structures civil engineering.
Geotechnical engineers should be hired to evaluate the overall stability of the site. Some of the many types of gravity retaining walls were described in chapter 1. A n beal earth retaining structures worked examples 7 bs8002 bs8002 design table 1 soil saturated density 21. What is the design procedure for gravity retaining wall. Gravity walls depend upon bulk weight for stability, as opposed to a cantilevered retaining wall fixed to a foundation. Design and analysis of retaining walls 2 economical when the wall height exceeds 8m.
Wood shall not be employed in the construction of retaining walls. Basics of retaining wall design 10 editionth a design guide for earth retaining structures contents at a glance. Active earth pressure tends to deflect the wall away from the backfill. There are two main reasons quickwall has been the industry standard for two decades.
For example 1, in fact, the results would be identical. Infill material the soil material placed behind the retaining wall facing. This example is intended to be readily calculated by hand although a lot of structural spreadsheets and software such as prokon are available. Ce 437537, spring 2011 retaining wall design example 1 8 design a reinforced concrete retaining wall for the following conditions. The following worked examples have been prepared to illustrate the application of bs8002 to retaining wall design. Method statement for retaining wall work execution retaining wall work shall be taken up for a length of 10m to 20m to suit the site condition duly considering the safety aspect. As part of this project, seventeen retaining walls are required to support the associated ramp widening works and the installation and maintenance of the its. Worked examples presented at the workshop eurocode 7.
Hence they provide a lateral support to vertical slopes of soil that would otherwise collapse into a more natural shape. The requirements of a functional retaining wall include. Cantilever rc retaining wall 10 knm2 m 500 mm h 400 0. Bottomup walls are generally the most cost effective type. Basics of retaining wall design civil engineering community. Ce 433, fall 2006 retaining wall design example 1 8 design a reinforced concrete retaining wall for the following conditions. Cantilever retaining wall ouestion for the retaining wall and the profile shown below, calculate. W wheel wfill wsur k ft klf ft u u klf ft ft ft w l m w plf.
For information into the basic concepts behind an allan block retaining wall design see page 18 of the ab spec book and. In such a case counterforts having trapezoidal section fixed at the base slab are provided at intervals of 1. Retaining wall design design examples and construction. Download limit exceeded you have exceeded your daily download allowance. The book has a wealth of information on retaining walls but the material lacks a coherent structure. Geotechnical design dublin, 14 june, 20 support to the implementation, harmonization and. The purpose of this article is for the reader to fully understand the principle behind it. Worked example 1 design of cantilever pol retaining. The safety factor against sliding minimum required f.
For example, in the cost index within the design table it can be noted that a 4m inclined block wall is 100 compared to 125 for a similar gravity block retaining wall. Apart from retaining the soil, retaining walls can also help protect against erosion on susceptible sites. The following design example briefly illustrates some of the basic steps used in the allowable stress design of a reinforced concrete masonry cantilever retaining wall. In home designer pro, a retaining walls height can be specified independent of the terrain by selecting and editing the wall in 3d views.
Pro v8i, the latest version, allows civil engineering individuals to analyze structural designs in terms of factors. To respond, successive editions have been updated, corrections made and additional materials added. Worked example 1 version 3 design of cantilever pole retaining walls to resist earthquake loading for residential sites. Suggest suitable dimensions for the rc retaining wall example 1. Design the reinforced concrete masonry cantilever retaining wall shown in figure 2.
The reinforced wall is a similar cost but when earth works are then considered, the inclined wall will be more economical. The ab stones provide a nominal setback of twelve degrees from vertical. If you design retaining walls, you know its tedious and timeconsuming. Whereas, if bracing is in front of the wall and is in compression instead of tension, the wall is called buttress retaining wall. Cantilever concrete retaining walls are commonly used for residential purposes, often as integral basement walls. Method statement for retaining wall work execution blogger. Worked example 2 design of concrete cantilever retaining. Usually the cantilever wall stem is of concrete block construction rising from an in situ concrete foundation. Pro is one of the most widelyused software for developing and analyzing the designs of various structures, such as petrochemical plants, tunnels, bridges etc. Ab engineering manual retaining walls allan block wall. The cantilever retaining wall shown below is backfilled with granular material having a unit weight. Assuming that the allowable bearing pressure of the soil is 120 knm. Council approval is often required for the design of retaining walls, when they are over a specified height, next to a boundary, or supporting a driveway or other structures. Basics of retaining wall design 9th edition design guide for earth retaining structures.
Examples of this include cip cantilever, mse and modular block walls. A wall for holding in place a mass of earth or the like, as at the edge of a terrace or excavation. We believe that a twelve degree setback maximizes the leverage achieved by a battered wall, while providing a finished retaining wall that fulfills the goal of more useable flat land. A n beal earth retaining structures worked examples.
Ce 537, spring 2011 retaining wall design example 2 8 substituting eqn. However, the book does explain the basics of retaining wall design and lists incredible supplementary resources at the end of each chapter. Make sure to check your local authoritys regulations prior to starting the design of your retaining wall. A retaining wall is a structure designed and constructed to resist the lateral pressure of soil, when there is a desired change in ground elevation that exceeds the angle of repose of the soil a basement wall is thus one kind of retaining wall. Determine the factors of safety against sliding and overturning. The wall is braced top and bottom against lateral translation. Ce 537, spring 2011 retaining wall design example 6 8 2. Modes of failure as in all structural work, it is useful to look at the ways in which an mse wall might fail. Special inspection is required as specified in the building code section 1704. Basic failure modes in addition to these basic modes of failure mse walls, especially tall ones, may fail globally. The total height of different types of retaining wall shall be cast in 2 or 3 pours, keeping the maximum height of pour of 2. The load that presents the greatest problem and its primary concern is the lateral earth pressure induced by the retained soil. Retaining wall design example revised jim richardson.
Component quality is important due diligence when a designer issues a design certificate a form 15 in queensland, the design is being certified against a specified criteria, for example as 4678, earth retaining structures code. To change the height of a retaining wall in home designer pro open the plan in which you would like to add a retaining wall, or create a new plan by selecting file new plan. Design and detailing of counterfort retaining wall when the height of the retaining wall exceeds about 6 m, the thickness of the stem and heel slab works out to be sufficiently large and the design becomes uneconomical. Expert system architecture for retaining wall design. Here are a few illustrations of the most common types of failure. Retaining walls are structure used to retain soil, rock or other materials in a vertical condition. In addition, the layout of the book and the examples themselves were disappointing. Retaining walls in theory and practice, a textbook for.
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