This session is not intended to teach concrete design, but more of an awareness of why things are the way they are. The retaining wall is fixed to the reinforced concrete slab foundation with a shear key for sliding resistance. 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. Worked example 2 design of concrete cantilever retaining. A retaining wall of wood is a slightly more aesthetic and in some cases, a cheaper alternative to masonry. Western bridge preservation partnership meeting phoenix, arizona may 1214, 2020. Surcharge large surcharge loads are induced on retaining walls in close proximity to track. Cantilever retaining walls can be precast in a factory or formed on site and considered economical up to about 25 ft in height. 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. Retaining blocks are among the easiest of constructional elements used for building retaining walls. A complete design should address each of these modes of failure where appropriate. Analyze the stability of the reinforced cantilever retaining wall as shown.
Detailed design and plan development the bridge design bureau is normally responsible for producing the final wall plans and specifications, based on the. Where the backfill is greater than 12 ft in height, such proposed walls shall be designed per a geotechnical investigation and report prepared by a licensed geotechnical engineer and shall. Basics of retaining wall design 10 editionth a design guide for earth retaining structures contents at a glance. Geotechnical investigation and analysis performed by the geotechnical section 3. There various parts of a retaining wall and design principles of these retaining wall components based on. Some easytoadopt retaining wall design ideas have been listed below. Cantilever retaining wall basic information part1 by parag kamlakar pal. Current retaining wall design procedures are summarized with emphasis on the prediction of lateral earth. The safety factor against sliding minimum required f.
Assuming that the allowable bearing pressure of the soil is 120 knm 2, the. Ce 537, spring 2011 retaining wall design example 1 8 design a reinforced concrete retaining wall for the following conditions. Engineering and design retaining and flood walls 1. The stem may have constant thickness along the length or may be tapered based on economic and construction criteria. Stability limit state a limit state of loss of static equilibrium of a structure or part thereof, when considered as a rigid body. Lateral forces on retaining wallsence 454 assakkaf design of retaining walls the design of retaining wall must account for all applied loads. Worked example 2 design of concrete cantilever retaining walls to. 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. Retaining walls in theory and practice, a textbook for students. Earthquake load the force exerted on the structure by earthquake action, acting on either or both the face of the retaining wall and any other structure supported by the retaining wall. Concrete masonry reinforced cantilever retaining walls. The focus of the guideline is the geotechnical aspects of retaining wall design.
Reinforced concrete wall design basics mike oshea, p. Cantilever retaining wall ouestion for the retaining wall and the profile shown below, calculate. Deflection generally governs design for cantilever walls more than 18 feet high. There various parts of a retaining wall and design principles of these retaining wall components based on different factors and material and methods of construction are discussed. The ab stones provide a nominal setback of twelve degrees from vertical. Learn more about reinforced retaining wall construction. Geotechnical design dublin, 14 june, 20 support to the implementation, harmonization and further development of the eurocodes. This is where geogrid comes in allan blocks reinforcement grid provides a simple solution by creating a solid structure with more resistance to soil pressure and surcharges for retaining walls under 6 ft.
Common design issues are described in the following sections. Lrfd design examples federal highway administration. Ce 437537, spring 2011 retaining wall design example 1 8 design a reinforced concrete retaining wall for the following conditions. Concrete masonry reinforced cantilever retaining walls edition e3, may 20 isbn 0 909407 56 8. Final duevel arema retaining wall design for the railroad. Retaining wall blocks can cost as much as several dollars per block, so even the slightest miscalculation can throw your project off budget. We believe that a twelve degree setback maximizes the leverage achieved by a battered wall, while providing a finished retaining wall that fulfills the.
Design of sheet pile walls using truline composite wall sections design methods and examples introduction this report presents the recommended structural capacities for truline composite wall sections and a summary of design methods commonly used to design cantilevered and anchored sheet pile structures. Tql 9 timber retaining walls for residential applications. They are composed of a light form of concrete that is further blended with aggregates to make the blocks sturdier. Examples of this include cip cantilever, mse and modular block walls. The load that presents the greatest problem and its primary concern is the lateral earth pressure induced by the retained soil. Any wall that sustains significant lateral soil pressure is a retaining wall.
Possible modes of failure for freestanding concrete cantilever retaining walls are illustrated in cartoon fashion in figure x. This guide, segmental retaining walls best practices guide for the specification, design, construction, and inspection of srw systems, is published and maintained by the national concrete masonry association ncma since segmental retaining wall systems were first introduced in the 1980s, there has been a continuous evolution and. In such a case counterforts having trapezoidal section fixed at the base slab are provided at intervals of 1. 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. Design of cantilever sheet pile walls january 2015. Wisdot bridge manual chapter 14 retaining walls january 2019 147 14. The following parameters influence the design of the retaining wall. The vertical load of the soil, and whatever rests upon it, generates a horizontal force that the wall must resist. This video explains about how the forces acting on cantilever retaining wall and check for the factor of safety against sliding and factor of safety against overturning. For example, the buildings with shallow foundation may be taken as a uniform surcharge of 10kpa per storey. Example 8 cantilever wingwall design loads 6 21 design section b summary the abutment width along the skew, a 3. Design of sheet pile walls using truline composite wall sections design methods and examples introduction this report presents the recommended structural capacities for truline composite wall sections and a summary of design methods commonly used.
Building retaining walls requires simple mathematical knowledge and the skills to employ this. D ata sheet concrete retaining walls concrete retaining walls provide a durable solution that is required of a structure in contact. Gravity walls are the earliest known retaining structures. Introduction retaining wall is used to retain earth or other material in vertical or nearly vertical position at locations where an abrupt change in ground level. 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. Reinforced concrete cantilever retaining wall analysis and. 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. Retaining walls in theory and practice, a textbook for. They are built from solid concrete or rock rubble mortared together. Twall is a gravity retaining wall system, consisting of modular precast concrete units and select backfill. This program is intended as a preliminary design tool for design professionals who are experienced and competent in masonry design. Timber retaining walls for residential applications. Jul 19, 2016 mod01 lec23 design of retaining wall duration.
Consider the cantilever retaining wall with the cross section shown in the above figure a. This manual provides guidance for the safe design and economical construction of retaining and flood walls. Nhi course 081 load resistance factor design lrfd for highway bridge superstructures, design examples pdf, 7. Reinforced concrete cantilever retaining wall analysis and design. Izni syahrizal bin ibrahim faculty of civil engineering universiti teknologi malaysia email. Cantilever retaining wall reinforced concrete wall with small dimensions and it is the most economical type and the most common note. The following figure and design data section will serve as input for detailed analysis and design. A slope above a retaining wall will add more pressure and weight, while slopes below the retaining wall may make the. Worked examples presented at the workshop eurocode 7. The cantilever retaining wall shown below is backfilled with granular material having a unit weight. 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.
This design example focuses on the analysis and design of a tapered cantilever retaining wall including a comparison with model results. Retaining walls types details with analysis and design. For retaining wall design, the applicable train liveload surcharge is the cooper e80, which can be approximated as 1,880 pounds per square foot per foot psfft of rail. Design load is a vertical load of 40 lbft at an eccentricity of 4 inches outside the wall seismic design category a. Appendix a examples colorado department of transportation.
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. Types of retaining walls tieback wall tieback is a horizontal wire or rod, or a helical anchor use to reinforce retaining wall for stability one end of the tieback is secured to the wall, while the other end is anchored to a stable structure i. 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. 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 recommendations of bs8002 are applied in practice. Depending upon the site conditions, type of material to be. The system is a simple proven solution for grade separation on highway, bridge, railroad, water, commercial applications, and more. In this course you will find examples of the design of these walls and the principles which underlie those designs. 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. It is commonly required in the construction of hill roads, masonry dams, abutments and wings walls of bridges and so on. Cantilever concrete retaining walls are commonly used for residential purposes, often as integral basement walls.
Principles of retaining wall design the constructor. 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. In this example, the structural design of the three retaining wall components is performed by hand. 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.
However, retaining wallscanalsobeconstructed for aesthetic landscaping purposes. Assuming that the allowable bearing pressure of the soil is 120 knm. Example 1 retaining wall designs using retaining blocks. Retaining walls types, design, stability the construction.
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