Numerical Modeling and Analysis of Steel Sheet Pile Cofferdams, Considering the Construction Sequence

The construction of steel sheet pile cofferdams is a systematic project. Simplified construction sequences are widely used to facilitate the numerical modeling of cofferdams, while the mechanical behaviors of cofferdams with different construction sequences have yet to be understood. In the present study, finite element models of steel sheet pile cofferdams with different construction sequences were established, based on the temporary cofferdam of the Shenzhen–Zhongshan Link. The mechanisms of simplified construction sequences on bending moment were revealed by analyzing the displacements and contact press of steel sheet piles. The distribution of bending moment with elevation demonstrates the importance of the layered backfill process in numerical modeling. In addition, a finite element model of the cofferdam considering steady-state seepage was also established. The comparison of the hydrostatic pressure results and the bending moment results obtained by engineering experience and seepage analysis were discussed. The analysis results showed that the empirical method overestimated the maximum bending moment of the inner side of piles, which led to a more conservative design of the cofferdam. This work can serve as a reference for numerical modeling of steel sheet pile cofferdams and contribute to risk assessment in related engineering projects.