When designing this type of retaining wall, sliding, bearing and overturning forces should be considered and tested. The report discusses the seismic design of gravity walls retaining granular backfill without pore water. Retaining walls and steep reinforced slopes chapter 730 1 retaining wall classifications retaining walls are generally classified as gravity, semigravity, nongravity cantilever, or anchored. The user is responsible for the final design and use of the cornerstone products. Therefore, they are usually not reinforced with steel. The semigravity wall is a modification of the gravity wall in which small. 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. Basics of retaining wall design 10 editionth a design guide for earth retaining structures contents at a glance. Retaining walls in theory and practice, a textbook for. Small gravity retaining walls concrete construction.
The fill should be granular in areas subject to freezing. Semi gravity retaining wall reduce the dimensions of the gravity retaining wall by using some reinforcement. Different types of retaining walls are used to retain soil in different places. Gravity walls are the earliest known retaining structures. Overturning is caused by the horizontal component of the resultant active earth pressure, p a, in the form of an overturning moment. Assuming that the allowable bearing pressure of the soil is 120 knm. Norfolk and tasman retaining walls au keystone retaining wall systems. These large wetcast blocks are like oneton lego blocks that interlock to create tall gravity retaining walls. Reinforced soil retaining wallsdesign and construction nptel.
An earth retaining structure can be considered to have the following types. These walls can be constructed with or without mortar. The wedge is defined as the soil which extends beyond the failure. Semigravity retaining wall reduce the dimensions of the gravity retaining wall by using some reinforcement. Hollow or solid concrete masonry units used in gravity retaining walls should meet the requirements of astm c 90 ref. Rather, support for the calculations is provided and a comprehensive help menu and design theory is a part of the package provided by recon. Prestressed retaining wall gravity walls reinforced gravity walls concrete cantilever. The following worked examples have been prepared to illustrate the application of bs8002 to retaining wall design. Retaining wall downslope and supporting dwelling foundations surcharge.
Retaining walls may be defined as a wall built to resist the pressure of liquid, earth filling, sand, or other granular material filled behind it after it is built. Built with the engineer in mind, reconwall is not a black box. A type of retaining wall which depends on its own weight alone to stand up is called a gravity retaining wall. This guide covers the design of segmental concrete gravity retaining walls. Conventional retaining walls gravity retaining structures stability depends on the self weight of the wall not economical for design semi gravity retaining structures minimum amount of reinforcement may be used in the wall to reduce the size of wall cantilever retaining walls reinforced concrete is used in wall design with thin stem and slab base. Presented in tabular form, the designs are for wall heights up to 10 feet, and for walls with ve r tical backs or with.
Design considerations a gravity retaining wall must have sufficient weight and width or be otherwise supported so that it does not overturn or slide forward due to external forces being exerted upon it. Pdf optimum design of gravity retaining walls using charged. A wall number is assigned as per criteria discussed in. The cantilever retaining wall shown below is backfilled with granular material having a unit weight. There are two checks to consider the stability of the retaining wall. The semigravity wall is a modification of the gravity wall in which small amounts of reinforcing steel are introduced. Design and analysis of retaining walls 2 economical when the wall height exceeds 8m. A retaining wall is a structure that retains holds back any material usually earth and prevents it from sliding or eroding away. The various wall types and their classifications are summarized in exhibits 7301 through 7306. Design principles for gravity retaining walls soil. Depending upon the site conditions, type of material to be.
The general features of behavior are illustrated by field experiences, results from laboratory model tests and. Cores of hollow units are typically filled to increase the weight of the wall. Concrete gravity retaining walls ma53 available from the concrete masonry association of. Worked example 2 design of concrete cantilever retaining. More detailed explanations of these elements are as follows. In 1990 the concrete masonry association of australia cmaa published masonry walling guide no 4 design for earth loads retaining walls, which set out a design methodology for earth retaining structures. One is the check for an overturning moment and the other one is the check for sliding. Ab engineering manual retaining walls allan block wall. Gravity retaining walls figure a are constructed with plain concrete or stone masonry.
This material is presented for the use of a qualified. Gravity wall design asd stone strong precast modular block this engineering section presents information for design of stone strong retaining walls in a gravity configuration using conventional procedures with safety factors. Gravity walls depend upon bulk weight for stability, as opposed to a cantilevered retaining wall fixed to a foundation. Some of the many types of gravity retaining walls were described in chapter 1. The weight of the retaining wall including the gravity loads within it plays a vital role in performing the stability check. Gravity walls are built with massive blocks that use a tongueandgroove system to lock together.
This technical area provides method and procedural guidance concerning the selection, design, performance, specification, installation, quality assurancequality control, construction inspection, and contracting approaches associated with earth retaining structures for transportation. The design principles of gravity retaining walls are discussed below. Preface standards australia has published as 46782002 for the design of earth retaining structures, which include segmental concrete gravity retaining walls. Retaining structures i d i f it design of gravity walls eurocodes. Geotechnical design ith k d lgeotechnical design with worked examples 14 j d bli14 june, dublin scope of en 19971 section 9 retaining structures gravity walls walls of stone or ppglain or reinforced concrete having a base with or without a heel, ledge, or buttress the weight of the wall itself plays a significant role in the support of. Figure 4 is a graph showing the frictional angle used along the slip surface. The following parameters influence the design of the retaining wall. Adstir act s ss reverse as if necessary and fdeitfy by bl ock bor.
Gravity retaining walls gravity retaining walls are a basic design and rely on the mass of the wall to retain the earth behind. What is the design procedure for gravity retaining wall. The lateral forces from backfill is resisted by the weight of wall itself, and due to their massive nature, they develop little or no tension. Kousik deb,department of civil engineering,iit kharagpur. It is not intended as a textbook of soil mechanics or geotechnical engineering. However, retaining wallscanalsobeconstructed for aesthetic landscaping purposes. Retaining walls types details with analysis and design. Gravity retaining wall depends on its weight for resisting lateral earth force because it have a large weigh 2. Retaining wall block design and construction manual for building large block retaining walls. Gravity retaining structures stability depends on the self weight of the wall not economical for design semigravity retaining structures minimum amount of reinforcement may be used in the wall to reduce the size of wall cantilever retaining walls reinforced concrete is used in wall design with thin stem and slab base relatively economical for. Recon gravity retaining walls recon wall systems, inc. Pdf this study focuses on the optimum design retaining walls, as one of the familiar types of the retaining walls which may be constructed of stone. 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.
It is usually made of plain concrete and is used for walls up to approximately 10 ft in height. The selfweight of the srw system is either the weight. They depend on their own weight and any soil resting on the masonry. Design and detailing of retaining walls lecture will make student after this class be able to do the complete design and detailing of different types of retaining walls. Retaining walls types of retaining wallsstability of. Redirock standard retaining wall blocks started the large block retaining wall revolution back in 2000. Retaining wall development is described in section 11555 of the. Wisdot regional staff determines the need for permanent retaining walls on highway projects. Types of retaining walls gravity wall depends entirely on its own weight to provide necessary stability usually constructed of plain concrete or stone masonry plain concrete gravity wall height 3 m in designing this wall, must keep the thrust line within the middle. A gravity retaining wall is a retaining wall that can be built in a tight area where there isnt a lot of room to excavate. Design and detailing of retaining walls engineering books. Retaining wall definition and types of retaining walls. Gravity retaining wall ouestion a gravity retaining wall is shown below.
Integrate redirock standard blocks with the entire family of redirock products to create a seamless, structurally sound solution. Gravity walls the gravity wall figure 1a depends mostly on its own weight for stability. The use of horizontal layers of wire mesh as a horizontal tieback or soil reinforcement is discussed separately. Note that the slip surface is forced to slide just below the gravity wall. The wall to the right is 800mm wide and 1600mm high. The paper covers a theoretical approach in data acquisition needed for design of a retaining wall. The surcharge from the dwelling was assumed to be 5 knm 2 averaged across the active soil wedge for the gravity case and 4 knm 2 for the earthquake case. The procedure is more of a general summary and an appreciation of the role of subsurface exploration in geotechnical design. Retaining walls and chapter 730 steep reinforced slopes.
Figure 1 depicts the various components of a typical retaining wall, as discussed in this guideline. It is commonly required in the construction of hill roads, masonry dams, abutments and wings walls of bridges and so on. Gravity retaining wall design can be greatly simplified t h r ough the use of a series of sample designs deve l o p e d recently by the po r tland cement association pca. This manual presents the techniques used by allan block in our engineering practice to design retaining walls. Design and installation guidelines for retaining walls. It is designed so that to resist the material pressure of the material that it is holding back. Whereas, if bracing is in front of the wall and is in compression instead of tension, the wall is called buttress retaining wall. Retaining walls are usually built to hold back soil mass. Research article optimum design of gravity retaining walls.
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