4.1 Introduction

Stress analysis is necessary for the design of structural components，and deformation analysis aims at diagnosing the wall deflections and soil movements caused by excavation to protect adjacent properties.What will be introduced in this chapter is about wall bending moment.Bending moment and the shear is relevant to the choice of the appropriate type and dimension of retaining walls，and sometimes to the design of reinforcements.The differences in the profiles of the wall maximum bending moments as the excavation depth increases and the system response was governed by the movements in the underlying clay（Whittle and Hashash，1993）.The stress analysis methods for excavation include the simplified method and the numerical method，and the latter can be further classified into the beam on elastic foundation method and the finite element method，all of which will be introduced in this chapter.