Walls can generally be grouped into gravity and nongravity types, with the category based on how load resistance is developed. All the above methods have been discussed with an example of typical counterfort retaining wall. Reinforced concrete cantilever retaining wall analysis and. Section showing counterfort retaining wall for bus parking area at m level. Review of ncma segmental retaining wall design manual for. The prefabricated concrete counterfort retaining wall s design strength moment and shear surpassed that of the existing system with an overall reduction in concrete volume of 57%. Design and detailing of retaining walls learning outcomes.
Examples of this include cip cantilever, mse and modular block walls. Designing a counterfort retaining wall includes following difficulties long procedure, iteration to get optimum value of a st weight of tension reinforcement and a c area of concrete is of. Wisdot regional staff determines the need for permanent retaining walls on highway. Drainage is an important aspect of any retaining wall project. The geotechnical failure modes, which need to be considered in the design of a counterfort retaining wall are i horizontal sliding along the base of the wall, ii the rotation about the toe of the wall overturning, and iii bearing capac. Counterfort retaining wall design excel jobs, employment.
Name 120106039 kaizer dave 120106045 kishan vyas 120106061 binoy patel internal guide. Design of retaining wall with counterfort according to aci 318 08. Ab engineering manual retaining walls allan block wall. Active earth pressure tends to variation of earth pressure deflect the wall away from the 5. Functions and parts of these retaining walls are discussed. Due to the wall height of 25 feet, the use of counterforts has proven itself to be a more economical solution. A counterfort retaining wall is similar to a cantilever wall that contains counterforts, or buttresses. These make the selection of appropriate retaining wall systems and their design more complex. Jun 21, 2018 counterfort retaining wall design example using asdip retain duration. Most common materials used for retaining walls are. Retaining counterfort wall design bending deep foundation. At regular intervals, however, they have thin vertical concrete slabs known as counterforts that tie the wall and the base slab together.
We stand for making engineering education a practical approach. Concrete retaining walls may be considered in terms of three basic categories. A vertical retaining wall 5 meters high retaining a sand with. The design of a counterfort retaining wall is similar in many respects to that of a cantilever retaining wall as far as computing overturning and sliding stability, bearing capacity, and soil. Located in gansu province china maijishan grottoes is an amazing example of ancient rock cave ar. 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. Retaining walls are designed to resist earth pressures exerted by only the weight of soil retained. Drainage material the crushed rock, gravel or similar material placed behind a retaining wall to convey ground water away from the wall and foundations.
It is a power point presentation on counterfort retaining wall. Within these groups many common variations exist, for example cantilever walls may have additional supporting ties into. 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. This construction video is the part 2 series of retaining wall design. The video includes brief calculation made for cantilever and counterfort wall. Retaining wall construction counterfort retaining wall design. For example, a fill wall, such as a prefabricated modular gravity wall, may be used to retain earth for a major highway cut. Design principles of totally prefabricated counterfort. Calculations per aci 31811, aci 53011, ibc 2012, cbc 20, asce 710. Ce 537, spring 2011 retaining wall design example 6 8 2. P a active earth pressure or earth pressure pa and passive earth pressure pp. Design of a counterfort retaining wall researchgate. Final duevel arema retaining wall design for the railroad.
Counterfort retaining wall design example using asdip retain. Design of retaining wall with counterfort according to aci. A counterfort retaining wall is a cantilever wall with counterforts, or buttresses, attached to the inside face of the wall to further resist lateral thrust. Traditionally, a constant factor of safety usually 1. Design principles of totally prefabricated counterfort retaining wall system compared with existing castin. This document is a stepbystep design example of a typical counterfort retaining wall using asdip retain. Infill material the soil material placed behind the retaining wall facing.
This manual is intended primarily for retaining walls which will be subjected to hydraulic loadings such as flowing water, submergence, wave action, and spray, exposure to. I have to design a stepped retaining wall for 22m height. Water must not be allowed to build up behind the wall. Design of retaining wall with counterfort engineering. In such a case counterforts having trapezoidal section fixed at the base slab are provided at intervals of 1. This type of wall is economical to a height of about 8 m 25 ft. Reliability analysis of counterfort retaining walls.
As for this height, cantilever retaining wall is not recommended and counter fort retaining wall is not economical. Structural design of cantilever retaining wall is depend on separating each part of wall and design it as a cantilever, so its called cantilever r. The following figure shows theses different types of retaining walls. The retained material or backfill exerts a push on the structure and thus tends to overturn or slide it, or both. The cantilever retaining wall design involves two major steps. Retaining walls types details with analysis and design. Department of civil engineering design of reinforced concrete structure 2170607 counterfort retaining wall. Worked example 2 design of concrete cantilever retaining.
To further understand the designed approach, here is a worked example of the design of the retaining wall. The counterfort wall is more commonly used because it has a clean, uncluttered exposed face and allows for more efficient use of space in front of the wall. The load that presents the greatest problem and its primary concern is the lateral earth pressure induced by the retained soil. Design of retaining wall with counterfort according to aci 318 08 retaining structures hold back soil or other loose material where an abrupt change in ground elevation occurs. Results from pre vious large scale retaining wall tests and field studies are presented. W wheel wfill wsur k ft klf ft u u klf ft ft ft w l m w plf. Sep 20, 2017 design of retaining wall with counterfort according to aci 318 08 retaining structures hold back soil or other loose material where an abrupt change in ground elevation occurs. It is affixed with the inside face of the wall to also withstand lateral thrust.
The stem may have constant thickness along the length or may be tapered based on economic and construction criteria. Assuming that the allowable bearing pressure of the soil is 120 knm 2, the. The objective of this guideline is to provide information on retaining wall design in accordance with the city of nanaimo the city and the british columbia building code bcbc requirements. Design principles of totally prefabricated counterfort retaining wall. The ab stones provide a nominal setback of twelve degrees from vertical. The objective of retaining walls is to withhold the soil at a slope that is in excess of it would usually take on, generally at a vertical or near vertical position. The focus of the guideline is the geotechnical aspects of retaining wall design. These are much less than the hydrostatic pressure exerted by water trapped behind the wall. In minutes you can design or analyze nearly any configuration or loading condition for cantilevered, restrained, gravity, gabion, soldier pile, or segmental retaining walls. Counterfort retaining wall architecture britannica.
Cantilever concrete retaining walls are commonly used for residential purposes, often as integral basement walls. An example of a completed project is illustrated in figure 1. Relax with these backyard landscaping ideas and landscape design. Hence they provide a lateral support to vertical slopes of soil that would otherwise collapse into a more natural shape. Classification of retaining walls gravity wallmasonry or plain concrete cantilever retaining wallrcc inverted t and l counterfort retaining wallrcc buttress wallrcc this excel sheet introduce design of counterfort retaining wall according. Engineering and design retaining and flood walls 1. Contrary to suppliers statements, no single wall type solves all design issues. Cantilever retaining walls figure b are made of reinforced concrete that consists of a thin. Retaining wall design design examples and construction. This example is intended to be readily calculated by hand although a lot of structural spreadsheets and software such as prokon are available. This design manual contains information on many aspects of retaining. Types of reinforced concrete retaining wall and their parts. The system includes a precast base and a precast face, with counterforts that feature anchors for connection to the.
Counterfort retaining wall guidelines for design of counterfort retaining walls pillai and menon, 2009 are available at. Design steps and procedure of counterfort retaining wall is explained in this video. The national concrete masonry as sociation ncma recently adopted the term soilreinforced segmental retaining wall to identify this type of retaining wall system 4,p. The purpose of this article is for the reader to fully understand the principle behind it.
Retaining walls are structure used to retain soil, rock or other materials in a vertical condition. Example 11 castinplace concrete cantilever retaining wall 4 2020 summary of unfactored loads and moments resolve moments about point a see figure 1 typical section load combinations ev 1 ev 2 dc 2 dc 3 vehicular collision load 18. Pdf in the present study a counterfort earth retaining wall of 8 m. This design manual contains information on many aspects of.
Basics of retaining wall design 10 editionth a design guide for earth retaining structures contents at a glance. Retaining wall design design example 1 design a cantilever retaining wall t type to retain earth for a height of 4m. However, retaining walls can also be constructed for aesthetic landscaping purposes. 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. Within the last two years weve had contractors install over 220,000 sf of this product. Other articles where counterfort retaining wall is discussed. Download as xlsx, pdf, txt or read online from scribd. Pdf analysis of counterfort retaining wall with and without. If the height of earth to be retaining surpasses 5m, the bending moment established in the stem, heel and toe slabs are very huge which lead to greater depth of structural components and turn into expensive. There are another type of retaining wall called counterfort rw and is a. As an example, consider the retaining wall shown below, which supports a flat backfill load. Counterfort retaining wall utility concrete products. The following section presents the formulation reliability index or probability of failure vs. The big buddhas at maijishan maiji shan the cliff sides are riddled with niches and statues carved principally during the northern wei and zhou dynasties ad 386581.
Precast retaining walls are vibrated concrete structures for retaining soil. 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. In this video, you will learn various aspects of counterfort retaining wall along with the details of stability checks. Retaining counterfort wall design free download as pdf file. Counterfort retaining wall spreadsheet concrete design. Counterfort wall concrete design eurocode standards. Counterfort retaining wall guidelines for design of counterfort retaining walls pillai and menon, 2009 are available at optimal. Cantilever retaining wall design counterfort retaining wall. Counterfort retaining wall design example using asdip retain duration. Externally stabilized wall systems utilize an external. The safety factor against sliding minimum required f.
Aesthetic elements surrounding a particular retaining wall are key to public acceptance of a wall project. This gl pressure tends to deflect the wall outward. Reinforced concrete cantilever retaining wall analysis and design aci 31814 reinforced concrete cantilever retaining walls consist of a relatively thin stem and a base slab. The purpose of the counterforts is to reduce the shear and the bending moments. Lateral forces on retaining wallsence 454 assakkaf design of retaining walls the design of retaining wall must account for all applied loads.
Some common materials used for retaining walls are treated lumber, concrete block systems, poured concrete, stone, and brick. Design of retaining wall with counterfort and check of. 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. The base is divided into two parts, the heel and toe. 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. Rcc retaining wall design excel construction of rcc. Within these groups many common variations exist, for example cantilever walls may have additional supporting ties into the retained material. Retaining wall are generally used to retain earth or other material to maintain unequal levels on two faces.
This document is a stepbystep design example of a typical. Therefore, counterfort type retaining wall is recommended for greater heights. Retained height ft wall height above soil ft slope behind wall. Types of reinforced concrete retaining walls are cantilever retaining walls and counterfort retaining walls. This manual provides guidance for the safe design and economical construction of retaining and flood walls. It includes the design of counterfort retaining walls based on the ibc aci 318 provisions. 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. Worked example to accompany mbie guidance on the seismic design of retaining structures for residential sites in greater christchurch version 2 november 2014.
Usually the cantilever wall stem is of concrete block. Deflection generally governs design for cantilever walls more than 18 feet high. If you design retaining walls, you know its tedious and timeconsuming. The variation of different parameters involved can then given the idea on how each of the parameters affects stability and design of retaining walls. Cantilever retaining wall ouestion for the retaining wall and the profile shown below, calculate. Classification of retaining walls 7 counterfort gravity rw tshaped rw lshaped rw backfill backfill counterfort rw buttress. Oct 25, 2016 it is a power point presentation on counterfort retaining wall.
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