The Behavior Analysis of a Cofferdam Constructed by Double Sheet Pile Wall Above Muck

This paper presents an investigation on the behavior of a cofferdam structure constructed by double sheet pile walls above the muck, which is used to construct the inner foundation for an immersed tube tunnel project in Guangzhou China. A detailed three-dimensional FEM model is formulated to simulate the whole processes, including the construction of the cofferdam and the excavation of the inner foundation. The strength reduction method is then adopted to calculate the safety factor of the cofferdam. In addition, the effects of the thickness of the filling sand is highlighted.