CALCULATION METHODOLOGY FOR ACTIVE EARTH PRESSURE UPON RETAINING WALL TRANSLATIONAL MOVEMENT

Deformation of the retaining wall is one of the important factors influencing the dimension and distribution of earth pressure. In this study, on the basis of Coulomb's earth pressure theory, a hyperbolic mechanical model is used to describe the mechanical properties of soil. The mechanical behavior characteristics of the deformation and stress state of nonsynchronous behaviors on the fractured surface are considered. Then, the static equilibrium of the wedge of soil pressure calculation method has been set up upon the deformation of the retaining wall. The evolution characteristics of the soil pressure of sandy and cohesive soil with the deformation of retaining wall are analyzed. The earth pressure of sandy soil decreases sharply first and then slowly tends to a constant value with the increase of retaining wall deformation. When the deformation δ of retaining wall reaches (1‰~5‰)H, most areas on the broken surface of sandy soil enter the stress state of a post-failure zone, and the soil pressure changes little with the deformation. It is reasonable to take the earth pressure corresponding to the deformation value as the main earth pressure. The clay earth pressure decreases sharply first and then increases with the increase of retaining wall deformation, and finally reaches the constant earth pressure value. It is dangerous to design the retaining wall according to Coulomb’s theory for clay soil. The retaining wall should be designed according to the actual design deformation value or the corresponding earth pressure value satisfying the deformation length failure rate of 95%. The calculated results are compared with the Coulomb’s earth pressure, and the results are consistent. However, the corresponding deformation of retaining wall is different. This method can provide a reference for calculating earth pressure of retaining wall deformation.