Numerical Simulation of Steel Sheet Pile Support Structures in Foundation Pit Excavation

Abstract

U-section steel sheet piles are widely used as support structures in bridge foundation pit excavation. Because of the reduced modulus action (RMA) effect of U-section steel sheet piles, it is difficult to balance structural safety and construction cost in engineering. In this paper, a case study of a foundation pit supported by U-section steel sheet piles in the middle and lower reaches of the Yangtze River was carried out. A three-dimensional FEM of the support structure was established and the RMA parameter analysis was conducted. According to the measured data, the RMA value was identified. Based on the RMA value, the support structure of the subsequent foundation pit was optimized and the deformation of the pile head was monitored during the excavation process. The measured deformation was in good agreement with the predicted value, verifying the feasibility of the inferred RMA value. Finally, to solve the uncertainty problem of the U-section steel sheet pile RMA in general situations, an optimization strategy for the design of the U-section steel sheet pile support structure was proposed.