Cantilever walls

Assuming a cantilever wall with height h, length 1 and thickness t is acted on by a unit horizontal force, the following is obtained ... 

The dynamic behavior of L-shaped cantilever walls was explored by means of 1-g shaking table testing. The aim of the experimental investigation is to better understand the soil-wall dynamic interaction problem, the relationship between design parameters, stability safety factors and failure mechanisms, and the validation of the seismic Rankine theoretical model. The test series were conducted to the Bristol Laboratory for Advanced Dynamics Engineering (BLADE), University of Bristol, UK. Details on the experimental hardware, materials, configurations and procedure are provided in the ensuing. 

Greco VR (2001) Active earth thrust on cantilever walls with short heel. Can Geotech J 38(2) 401 09... 

Retaining systems, such as cantilever walls, are widely used worldwide for serving various purposes in structures and infrastructures (embankments, bridges, ports, etc). In the chapter by Tsompanakis (Chapter 29) the dynamic interaction of the retaining walls with the retained soil and the retained structures is investigated. This so-called phenomenon of dynamic wall-soil-structure interaction (DWSSI) is a rather... 

The most frequently used types of retaining structures in highway, transportation, and railroad projects consist of cantilever walls, tiehack walls, soil nail walls, and mechanically stabilized embankment (MSB) walls. The overall design objective of these retaining structures is to resist lateral soil pressure forces. 

Cantilever retaining walls can be any cantilever structure used to resist the active lateral soil pressure in topography fill, and cut locations. Usually, the common wall height (H) limits for cantilever walls in transportation projects is 30-40 ft (9.14-12.2 m). For wall heights greater than 30 ft (9.14 m), various other types of retaining walls usually have more economical advantages compared to cantilever walls. 

Gravity walls are part of the cantilever wall category. Common shapes of concrete cantilever walls are upside down T and L shapes. Gravity walls are usually a massive volume of concrete and the retaining effects mainly depend on the self-weight. Most gravity walls are constructed by using solid concrete or other means of confined box system fill with heavy materials. 

The soil nail can also be used to effectively tie back other retaining wall systems. The soldier pile wall with soil nail tie back is a good example of a combined system. Any tie back mechanism would provide additional effective resistance for different types of cantilever walls. 

A well-accepted simplified process for cantilever wall systems is to use the equivalent liquid density kj to determine the lateral soil pressure on the wall stem. The soil density is typically in the range of 120-150 pounds per cubic feet (pcf) (1.9-2.4 T/m ). Figure 10.2 shows a simplified load distribution diagram for typical retaining wall. 

Various types of retaining structures are adopted for different applications. Over the time, the classical gravity rigid retaining walls evolved into reinforced concrete cantilever walls (e.g., sheetpiles), with or without buttresses and counter forts (Fig. 2). These were then followed by a variety of crib- and bin-type walls. All these walls are externally stabilized walls or conventional gravity retaining walls. 

Masomy acceptance criteria (in Annex C) are quantified in terms of wall drift - in common with ASCE 41 for flexure-controlled walls, but in contrast to ASCE 41 for shear-controlled walls for which strength criteria apply. For flexure-controlled walls, drift hmits are given in terms of the slenderness ratio of width to the height of the point of contraflexure, which gives limits similar to those given in ASCE 41 for fix-fix boundary conditions of wall piers but doubles the limits for cantilever walls (mapping the limit states as discussed for steel). 

Conventional gravity and cantilever wall systems made from masonry and concrete resist lateral earth pressure by virtue of their large mass. They act as rigid units and have served the industry well for centuries. These mechanically stabilized earth (MSE) walls, which have geotextile reinforcement (Fig. 15.20), are flexible compared with conventional gravity structures. 

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