Random Search Method of Fracture Surface for Seismic Stability of Reinforced Retaining Wall

In order to determine the fracture surface location of the reinforced retaining wall, a polyline fracture surfaceform was proposed based on the horizontal slice method. The fracture surface of the reinforced retaining wall is viewed to be composed of several line segments, one connected with another in a plane at different lengths and angles. According to the mechanical equilibrium of horizontal soil strip under seismic action, the calculation formula of reinforcement forces related to fracture surface parameters is derived. The total force of the reinforcement is taken as the objective function, and the calculation is run in a way of a two-layer cycle. The outer layer is a cycle of the fracture point position of the horizontal filling behind the wall, and the inner layer is a random angular cycle. By comparing the total forces of reinforcement calculated in each outer cycle, the fracture surface corresponding to the maximum value is the critical fracture surface of the reinforced retaining wall. A calculation example is used to verify the calculation method of the polyline fracture surface, and the influential factors on the stability of the reinforced retaining wall are analyzed. The results show that the calculation method in which the polyline fracture surface is generated by the random angular method can obtain reasonable results without mathematical optimization, and the fracture surface location of the reinforced retaining wall is closer to the free face than the logarithmic spiral fracture surface. The increase in the internal friction angle of the fill reduces the total tensile force and the length of the reinforcement, which can enhance the internal stability of the reinforced retaining wall.