ABSTRACT
The shear strength of soils is an important aspect in many foundation engineering problems such as the bearing capacity of shallow foundations and piles, the stability of the slopes of dams and embankments, and lateral earth pressure on retaining walls. This chapter discusses the shear strength characteristics of granular and cohesive soils and the factors that control them. The results obtained from triaxial tests are widely used for the design of structures. However, under structures such as continuous wall footings, the soils are actually subjected to a plane strain type of loading, that is, the strain in the direction of the intermediate principal stress is equal to zero. The shear strength of cohesive soils can generally be determined in the laboratory by either direct shear test equipment or triaxial shear test equipment. A number of investigations have been conducted to determine the effect of temperature on the shear strength of saturated clay.
