Sufficient anchors need to be provided at the top of wall to carry this force. 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. Table 1 provides the order of precedence for reference documents and engineering design standards, applicable to the detail design of the retaining walls on. The safety factor against sliding minimum required f.
In minutes you can design or analyze nearly any configuration or loading condition for cantilevered, restrained, gravity, gabion, soldier pile, or segmental retaining walls. Chapter 14 retaining walls wisconsin department of transportation. The case of a rigid wall with inclined back face retaining reinforced cohesivefrictional backfill subjected to uniformly distributed surcharge load has been analyzed using limit equilibrium approach. It is not advisable to include the actual strength of the retaining wall. 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. Suggest suitable dimensions for the rc retaining wall example 1. Cantilever or restrained retaining wall calculations o r g a n iz a io n f. There are number of options that can be used in the case where reducing soil pressure is required for example decreasing retain earth height by regrading backfill earth surface, and landscape changing or pressing down drainage culvert at the wall back face. Optimum design of cantilever reinforced concrete retaining. Modes of failure as in all structural work, it is useful to look at the ways in which an mse wall might fail. The reinforced wall is a similar cost but when earth works are then considered, the inclined wall will be. Guidance on the seismic design of retaining structures for building.
In the numerical example height of stem is 3 m, yield strength of steel is 400 mpa, compressive strength of concrete is 25 mpa, elasticity modulus of steel is 200 gpa, specific. 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. For an additional 9 years he was a principal advisor to. Paul guyer is a registered mechanical engineer, civil engineer, fire protection engineer and architect with over 35 years experience in the design of buildings and related infrastructure. A n beal earth retaining structures worked examples. May 29, 2018 best practices for segmental retaining wall design 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.
Worked example 1 design of cantilever pol retaining walls. Intro to retaining walls and excavation support systems r. Design the reinforced concrete masonry cantilever retaining wall shown in figure 2. Infill material the soil material placed behind the retaining wall facing. Results from pre vious large scale retaining wall tests and field studies are presented. May 29, 2018 front wall profile view which depicts the location of geogrid reinforcement, elevation of top and bottom of wall and finished grade at bottom and top of wall. A castinplace cip concrete cantilever wall is an example and consists of a reinforced concrete stem and a base footing. Standard details for retaining walls santa cruz county. Worked example 1 version 3 design of cantilever pole retaining walls to resist earthquake loading for residential sites. Panel section markers depicting locations of design sections.
The height of both walls needs to be about 4 12 feet tall. The contract documents and contract requirements are discussed in. This design example focuses on the analysis and design of a tapered cantilever retaining wall including a comparison with model results. 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. Titling cantilever wall in grand rapids, michigan a tilt of 10o increases the load by 20% this problem likely exacerbated by undercutting of the footing by the grand river, at left. Limited guidance is available within the supporting documents to the building code for the design of. Special inspection is required as specified in the building code section 1704. 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. A n beal earth retaining structures worked examples 7 bs8002 bs8002 design table 1 soil saturated density 21. Retaining walls are as the name suggests any wall that is designed to retain any material. If you design retaining walls, you know its tedious and timeconsuming.
Worked example 1 design of cantilever pol retaining. Earth pressure p 8 earth pressure is the pressure exerted by the retaining material on the retaining wall. In order to avoid adversely affecting the structural integrity of the retaining wall each land owner has a responsibility to ensure the following including making builders or tenants aware. All design criteria specified by a soils or geologic report must be met by use of the standard detail for the wall.
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. From the menu, select terrain create terrain perimeter. Assuming that the allowable bearing pressure of the soil is 120 knm 2, the. Ce 437537, spring 2011 retaining wall design example 1 8 design a reinforced concrete retaining wall for the following conditions. The load that presents the greatest problem and its primary concern is the lateral earth pressure induced by the retained soil. It offers a number of retaining wall shapes and analyzes rc crosssections.
Ce 537, spring 2011 retaining wall design example 2 8 substituting eqn. Cantilever rc retaining wall 10 knm2 m 500 mm h 400 0. This input is a variable that can range from 20 lbs. Ab engineering manual retaining walls allan block wall. An introduction to retaining walls and excavation support systems j. They are composed of a light form of concrete that is further blended with aggregates to make the blocks sturdier. Wood shall not be employed in the construction of retaining walls. Worked example 2 design of concrete cantilever retaining walls to. Determine the factors of safety against sliding and overturning. Most common materials used for retaining walls are. The ab stones provide a nominal setback of twelve degrees from vertical. Retaining wall design guidelines allan block wall systems. For example 1, in fact, the results would be identical. 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.
The reinforced wall is a similar cost but when earth works are then considered, the inclined wall will be more economical. As numerical example, tlbo algorithm is performed on a retaining wall example and the results are compared with bbbc, pso and ihs approaches. I need to construct two retaining walls, one in my garden and one along side my driveway. The ten geotechnical design examples, prepared for the international workshop on the evaluation of eurocode 7 held in trinity college dublin on 31 st march and 1 st april 2005, are presented on. Usually the cantilever wall stem is of concrete block. Retaining wall design design examples and construction. Active earth pressure or earth pressure pa and passive earth pressure p p. Application of lateral earth pressure theories to design rankine theory. Note cables attached to wall and strung to a dead man anchor, outofview to right. Follow the design procedure in the background document.
Pdf a new design method for retaining walls in clay. 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. Example 1 retaining wall designs using retaining blocks. A common example of a retaining wall in everyday life is basement walls, swimming pool walls, and landscape walls. The four different types of retaining walls that every. Worked example to accompany mbie guidance on the seismic design of retaining structures for residential sites in greater christchurch version 2 november 2014. To add a retaining wall, you must first have a terrain perimeter on your plan. Retaining walls in theory and practice, a textbook for students. Cantilever wall is an intuitive program for cantilever retaining walls design.
Assume variation of water pressure below wall same as cp2 example. The retaining wall retains less than 4 feet of material with or without a surcharge, unless the surcharge is caused by a building. The following worked examples have been prepared to illustrate the application of bs8002 to retaining wall design. 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. Also, the ground above the garden wall will not be level, it will slope upwards from the wall. Design of the retaining wall structures on the m4 smart motorway. 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.
Methods to prevent retaining wall distress and failures. It allows the user to model the real structure behavior using stages of construction, to calculate the deformation and pressures acting upon the structure. In order to promote public education and public safety, equal justice for all, a better informed citizenry, the rule of law, world trade and world peace, this legal document is hereby made available on a noncommercial basis, as it is the right of all humans to. Lateral forces on retaining wallsence 454 assakkaf design of retaining walls the design of retaining wall must account for all applied loads. A n beal earth retaining structures worked examples 1. Make sure to check your local authoritys regulations prior to starting the design of your retaining wall. Geotechnical design dublin, 14 june, 20 support to the implementation, harmonization and further development of the eurocodes. With the increasing regulatory demands for structurally sound precast retaining wall systems, it is critical for precast manufacturers to continually raise the bar on quality. The wall is braced top and bottom against lateral translation. Cantilever concrete retaining walls are commonly used for residential purposes, often as integral basement walls. Design requirements for retaining walls and associated structures retaining wall performance standards during design life 3. If this partition wall were part of an egress stairway, the importance factor would be 1. In this example, the structural design of the three retaining wall components is performed by hand. Retaining wall design example revised jim richardson.
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. Assume level backfill, no surcharge or seismic loading, active earth pressure and. That works adjacent to the retaining wall structure complies with the design parameters noted above. Worked examples of retaining wall design to bs8002. Hence they provide a lateral support to vertical slopes of soil that would otherwise collapse into a more natural shape. Worked example 2 design of concrete cantilever retaining. The book has a wealth of information on retaining walls but the material lacks a coherent structure. Ce 433, fall 2006 retaining wall design example 1 8 design a reinforced concrete retaining wall for the following conditions. However, the book does explain the basics of retaining wall design and lists incredible supplementary resources at the end of each chapter. For design purposes, an equipment impact point load on the gravity block retaining wall face will be assumed at 30 inches 2. Wall station data with corresponding elevation for exposed grade at top and bottom of wall i.
Basics of retaining wall design 10 editionth a design guide for earth retaining structures contents at a glance. Drainage material the crushed rock, gravel or similar material placed behind a retaining wall to convey ground water away from the wall and foundations. Retaining wall design outdoor retaining walls text. The design of retaining walls within these toe slump areas will require. The geo5 sheeting check program is used to make advanced designs of anchored or strutted sheet pile retaining walls also diaphragm, pile or soldier pile walls are supported. 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.
This may be set using derived mohr coulomb material type and entering multipliers for cohesion c0, c u and shear resistance tan. Retaining walls in theory and practice, a textbook for. The analysis considers the stability of an element of the failure wedge, which is assumed to develop in the reinforced earth mass adjoining the back face of wall. Foundation engineering retaining walls elements of retaining walls each retaining wall divided into three parts. Cantilever retaining wall ouestion for the retaining wall and the profile shown below, calculate. Retaining blocks are among the easiest of constructional elements used for building retaining walls. The material could be earth, water, anything else that needs to be retained. Here are a few illustrations of the most common types of failure. 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. Support and documentation for the geo5 software using standards and analysis settings inputting the geological. Cantilever or restrained retaining wall design calculations o r g a n iz a io n f. A new design method for retaining walls in clay article pdf available in canadian geotechnical journal 4.
Some easytoadopt retaining wall design ideas have been listed below. Underpinning to be formed in continuous reinforced concrete. To respond, successive editions have been updated, corrections made and additional materials added. Worked examples presented at the workshop eurocode 7. Precast concrete retaining wall systems, when manufactured and installed properly, will outperform and outlast systems consisting of competing materials. There are different types of retaining walls, and not all require a building consent. Before we discuss how to design retaining walls, i want you to. Examples of this include cip cantilever, mse and modular block walls. Other documents may provide more specific guidelines or rules for specialist structures and these may take precedence over this document.