Retaining Structures and Excavations

Abstract

Structures that retain lateral forces from soil and/or water are composed of various materials, constructed by numerous procedures and methods, and are used for many purposes. In this chapter the manner of support is used to classify the different types of structures. Reinforced earth structures are not included, as that type of structure is covered in Chapter 21. The three means of support consist of restrained, gravity, and cantilever systems. Each support system has variations---the restrained system having the greatest number and cantilever the least. Gravity structures are far more numerous than the other two since they are used for the construction of many small structures such as soil-retaining walls. The largest retaining structures are of the gravity type. Restrained structures are prominent in the construction of waterfront facilities and excavations. Cantilever structures are the least used because they allow large deflections to occur. Combinations of support types are sometimes used.