Development of design graphs for cantilever and anchored steel sheet piles

Abstract

The purpose of this thesis was to develop graphs to simplify the design of steel sheet pile walls. There are two basic types of steel sheet pile walls: cantilever and anchored walls. For cantilevered walls, the pile is driven to a sufficient depth into the ground to become fixed as a vertical cantilever in resisting the lateral active earth pressure. This type of wall is commonly restricted to a maximum height of 15 ft. Anchored walls also derive support by passive pressure on the front of the embedment pile portion as the cantilever wall. Support is also contributed from the anchor tie rods near the top of the piling. This method is suitable for heights up to approximately 35 ft, depending on soil conditions. Four cases for sheet piles were analysed which included: Cantilever with granular backfill and grandular subsoil; Cantilever with granular backfill and cohesive subsoil; Anchored with granular backfill and grandular subsoil; and Anchored with granular backfill and cohesive subsoil.

A computer program was written in BASIC to aid in the trial and error solutions for individual sheet pile problems.

Design graphs were developed for the respective analytical expressions for pile embedment depth, bending moment and anchor force for various soil conditions and water levels. Hence, the graphs will greatly reduce the length of time required to size a sheet pile and improve the accuracy of calculations.