Abstract: The deep-water foundations are required in various large bridge construction projects. As an efficient temporary cofferdam structure for the deep-water foundation construction, the double sheet pile wall cofferdam has received wide applications. This paper presents a case history for the numerical simulation of a cofferdam under different working conditions, water tables and water velocities by using a three-dimensional finite element software. The following conclusions can be obtained: The deformation and stress in the cofferdam after the dewatering are much greater than it was fully inserted in the mudline, but the cofferdam strength meets code requirements. At the beginning of the dewatering, the maximum deformation concentrates at the middle portion of the cofferdam. The location of the maximum deflection gradually moves downward with the increase of dewatering.

Key words: double sheet pile wall cofferdam, numerical simulations, groundwater, deformation