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. An lshaped gravity and a piled wall options were considered during the detailed. Dr andrew bond director, geocentrix ltd chairman tc250sc7. Worked examples presented at the workshop eurocode 7. Geotechnical design dublin, 14 june, 20 support to the implementation, harmonization and further development of the eurocodes.
Basics of retaining wall design 10 editionth a design guide for earth retaining structures contents at a glance. Figure 1reinforced cantilever retaining wall detailing mortar cap or other, as desired bond beam. For design purposes, an equipment impact point load on the gravity block retaining wall face will be assumed at 30 inches 2. This document is published by the chief executive of mbie. This is not meant to be a final authority as each project has its own set of unique situations. Mcgrawhill international edition, 1997 may be referred. The horizontal distance, measured from the toe of the wall, is the greater of twice the height of the wall 2h or, the height of the projection from the tail of the reinforcement layers to the surface h e plus a distance equal to the length of the reinforcement l. Design of semi gravity retaining walls wec civilians. For masonry retaining wall, the depth of wall is raised along with height as masonry withstands the lateral pressure by its weight. A n beal earth retaining structures worked examples 7 bs8002 bs8002 design table 1 soil saturated density 21.
Each type of retaining wall has its own particular characteristics, which make it. The cantilever retaining wall shown below is backfilled with granular material having a unit weight. Retaining wall design criteria minimum factors of safety. Deflection generally governs design for cantilever walls more than 18 feet high. Sketches of the retaining wall forces should be considered to properly distinguish the different forces acting on our retaining wall as tackled in the previous article, retaining wall. Please note that the gravity wall chart provided has specific heights for specific site and soil conditions. The design of all retaining walls needs to consider, the soil profile, soil type, clay, gravel or sand, the final height of the wall and any loadings from driveways and nearby buildings, that will increase the design forces that the wall has to withstand. Assuming that the allowable bearing pressure of the soil is 120 knm. Drainage is an important aspect of any retaining wall project. Cantilever concrete retaining walls are commonly used for residential purposes, often as integral basement walls. Usually the cantilever wall stem is of concrete block. Design of the retaining wall structures on the m4 smart motorway.
What is the design procedure for gravity retaining wall. The safety factor against sliding minimum required f. Degree gravel and coarse sandy backfill soil 3336 medium to fine sandy backfill soil 2932 silty sand 2730 p max k a. Exposed faces of precast concrete retaining wall blocks shall be reasonably free of large chips, cracks, or stains when viewed from a distance of 10 feet. Worked example 1 design of cantilever pol retaining walls. It is not advisable to include the actual strength of the retaining wall. Figure 1 illustrates typical cantilever retaining wall detailing requirements. Design the primary force acting on a retaining wall is the pressure exerted by the retained material at the back of the.
Note that the slip surface is forced to slide just below the gravity wall. These are much less than the hydrostatic pressure exerted by water trapped behind the wall. Gravity retaining walls including concrete cantilever walls, mass masonry. In britain the vast majority of new drystone work is limited to construction, repair and conservation of freestanding field walls. Type of retaining wall failure to design retaining walls, it is necessary to know how wall can fail. Precast concrete retaining wall blocks shall be vertiblock units as produced by a licensed verti. Assume variation of water pressure below wall same as cp2 example. For details of other type the book foundation analysis and design by j. Figure 4 is a graph showing the frictional angle used along the slip surface. Mechanically stabilized earth mse retaining walls are growing in popularity. A n beal earth retaining structures worked examples 1. Retaining walls page 10 lateral soil pressure on retaining walls typical angle of internal friction for backfill soil soil type.
Similar to a gravity wall, a structure providing lateral support for a mass of soil that owes its. 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. Lateral forces on retaining wallsence 454 assakkaf design of retaining walls the design of retaining wall must account for all applied loads. Table 1 provides the order of precedence for reference documents and.
Retaining walls in theory and practice, a textbook for. The intent of this material is to communicate the best practices for design of segmental retaining walls srw as determined by allan block corporation based on 25 plus years of research, design and field experience. A slope above a retaining wall will add more pressure and weight, while slopes below the retaining wall may make the wall unstable due to sliding or erosion. Worked examples of retaining wall design to bs8002 the following worked examples have been prepared to illustrate the application of bs8002 to retaining wall design. Worked example 2 design of concrete cantilever retaining. Retaining wall design design examples and construction. Example 1 retaining wall designs using retaining blocks. The contract documents and contract requirements are discussed in.
Active earth pressure or earth pressure pa and passive earth pressure p p. Design and analysis of retaining walls 2 economical when the wall height exceeds 8m. Retaining wall is formed with masonry and reinforced concrete. To add a retaining wall, you must first have a terrain perimeter on your plan. Gravity retaining wall depends on its weight for resisting lateral earth force because it have a large weigh 2. How to choose the right retaining wall for your project. Retaining walls in theory and practice, a textbook for students. Where especially unfavorable soil conditions occur or where piling is required under a retaining wall, the assistance of an engineer is essential for design and construction. The report considers the role of numerical methods of analysis for the design and assessment of masonryfaced earth retaining walls. The load that presents the greatest problem and its primary concern is the lateral earth pressure induced by the retained soil.
Cantilever or restrained retaining wall calculations o r g a n iz a io n f. Retaining wall construction retaining wall excel spreadsheet. Retaining walls are designed to resist earth pressures exerted by only the weight of soil retained. May 29, 2018 this design envelope is defined as follows. Assuming that the allowable bearing pressure of the soil is 120 knm 2, the. Reinforced masonry design requires that a groutreinforcement spacing be assumed. Semigravity retaining wall reduce the dimensions of the gravity retaining wall by using some reinforcement. Ce 437537, spring 2011 retaining wall design example 1 8 design a reinforced concrete retaining wall for the following conditions. Variations on the basic design, including curves, tiers, railings, stairs, walkways and the like are making them more and more attractive to designers and architects. Geotechnical design ith k d lgeotechnical design with worked examples 14 j d bli14 june, dublin contents of en 19971 section 9 retaining structures section 9 applies to retaining structures supporting ground i. Analysis of the stability of masonryfaced earth retaining walls.
Course objectives they seem to crop up everywhere, like cell phone towers. Abarac current retaining wall design procedures are summarized with emphasis on the prediction of lateral earth pressures using the coulomb and rankine earth pressure theories, and the equivalent fluid pressure method. Cantilever timber pole walls are probably the most commonly used form of. Two examples of seismic coefficient maps of the united states are shown in figures. In minutes you can design or analyze nearly any configuration or loading condition for cantilevered, restrained, gravity, gabion, soldier pile, or segmental retaining walls. Different types of retaining walls are used to retain soil in different places. This input is a variable that can range from 20 lbs. Ab engineering manual retaining walls allan block wall. Some of the many types of gravity retaining walls were described in chapter 1. The type of retaining wall retaining walls can be broadly divided into four main categories namely, gravity walls, cantilever walls, anchored walls, and reinforced soil or nailed walls.
Make sure to check your local authoritys regulations prior to starting the design of your retaining wall. These design methods are discussed in detail in allowable stress design of concrete masonry, tek 147a, and strength design of concrete masonry, tek 144a refs. The basic design precepts employed in cantilever walls include considerations of dead man tiebacks, taking active pressures to the bottom of the wall and considering any reductions in passive resistance for inclined slopes. Worked example to accompany mbie guidance on the seismic design of retaining structures for residential sites in greater christchurch version 2 november 2014. Creating a retaining wall home design software for diy. Norfolk and tasman retaining walls au keystone retaining wall systems. The grout spacing affects the wall weight, which in turn affects the seismic load. 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. Design of cantilever pole retaining walls to resist earthquake loading for residential sites.
Analysis of the stability of masonryfaced earth retaining. Ce 537, spring 2011 retaining wall design example 6 8 2. In general, they are used to hold back or support soil banks and water or to maintain difference in the elevation of the ground surface on each of wall sides. The recommendations and advice given in this document are given without liability on the part of tellus design ltd, elite precast concrete ltd or its employees.
Built with the engineer in mind, reconwall is not a black box. Rather, support for the calculations is provided and a comprehensive help menu and design theory is a part of the package provided by recon. If you are not sure of your site conditions we recommend being conservative with your retaining wall heights or use geogrid in your retaining wall. Drainage is an important aspect of any retainingwall project. The report discusses the seismic design of gravity walls retaining granular backfill without pore. Ce 437537, spring 2011 retaining wall design example 28 substituting eqn. Gravity retaining wall classical mechanics applied and. A n beal earth retaining structures worked examples. They are composed of a light form of concrete that is further blended with aggregates to make the blocks sturdier.
The wall is assumed to be located in the christchurch port hills. Water must not be allowed to build up behind the wall. Oct 23, 2012 ce 437537, spring 2011 retaining wall design example 18design a reinforced concrete retaining wall for slideshare uses cookies to improve functionality and performance, and to provide you with relevant advertising. Retaining walls such as mse walls with precast concrete panel facing that are susceptible to damage from vehicular impact shall be protected by a roadway barrier. Retaining blocks are among the easiest of constructional elements used for building retaining walls. W wheel wfill wsur k ft klf ft u u klf ft ft ft w l m w plf.
Cantilever retaining wall ouestion for the retaining wall and the profile shown below, calculate. 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. The design of the above retaining wall structures must consider all the constraints. Worked example 1 design of cantilever pol retaining. Avoid slopes greater than 3 to 1 without first consulting a local engineer. If you design retaining walls, you know its tedious and timeconsuming. Results from pre vious large scale retaining wall tests and field studies are presented. Whereas, if bracing is in front of the wall and is in compression instead of tension, the wall is called buttress retaining wall. Semi gravity retaining wall reduce the dimensions of the gravity retaining wall by using some reinforcement. Preface standards australia has published as 46782002 for the design of earth retaining structures, which. Retaining walls are useful for developing basement under ground level, wing walls of bridge and to sustain slopes in hilly terrain roads. Worked examples of retaining wall design to bs8002.
Some easytoadopt retaining wall design ideas have been listed below. However, retaining wallscanalsobeconstructed for aesthetic landscaping purposes. Because of their large mass, gravity retaining walls may not. Recon walls can be designed as either gravity retaining walls, which use the mass of the block to retain the soil, or as geogrid reinforced walls. From the menu, select terrain create terrain perimeter.
The ab stones provide a nominal setback of twelve degrees from vertical. Design of semi gravity retaining walls 1 a semi gravity retaining wall consisting of plain concrete weight 145 lbft. The following worked examples have been prepared to illustrate the application of bs8002 to retaining wall design. Earth pressure p 8 earth pressure is the pressure exerted by the retaining material on the retaining wall. Gravity walls depend upon bulk weight for stability, as opposed to a cantilevered retaining wall fixed to a foundation.
In this example, the structural design of the three retaining wall components is performed by hand. Gravity retaining walls tek 156 structural 1995 keywords. The bank of supported earth is assumed to weigh 110 lbft. We believe that a twelve degree setback maximizes the leverage achieved by a battered wall, while providing a finished retaining wall that fulfills the.