Simplified Theoretical Prediction for Lateral Deformation of a Diaphragm Wall Using the General Third-Order Plate Theory

Abstract

The diaphragm wall is widely used in deep excavation engineering to guarantee the safety of the foundation pit and surrounding environment during excavation. An accurate prediction of the lateral deformation of the diaphragm wall is the basis of the design and optimization of the diaphragm wall structure. In this paper, we apply the third-order shear deformation plate theory to develop an analytical method for predicting the lateral deformation of the diaphragm wall to take into account the effects of shear stress distributed along the thickness direction on the lateral deformation. By using the Pb-2 Ritz method, combined with the minimum potential energy concept, the analytical solution for the deformation of the diaphragm wall is obtained under certain simplifications. Three types of boundary conditions for the bottom side of the diaphragm wall are considered to meet different geological conditions. The proposed method is verified by comparing the results predicted in this study with the monitoring data obtained from the practical pit engineering of Dinggong south road metro station of Metro Line 2 in Nanchang, Jiangxi province, China. Finally, the effects of the thickness and the embedded depth of the diaphragm wall and the lateral support patterns are analyzed, and the optimized design parameters for the diaphragm wall are also suggested. The proposed method can theoretically provide preliminary parameter optimization guidance for the design and construction of a diaphragm wall.