Method for earth pressure in design of steel sheet pile cofferdam

In order to analyze the earth pressure acting on steel sheet pile cofferdam, the construction practice of deep-water foundation at Yinghe River Bridge of newly-built Fuyang-Lu’an Railway is investigated. Three-dimensional finite element model is established considering the interaction among steel sheet pile, internal bracing and soil layer. The values and change rules of earth pressure are analyzed during the construction process of steel sheet pile cofferdam. The results show that the surrounding soil does not reach limit equilibrium state during the construction process of steel sheet pile cofferdam. The value of earth pressure on the outer steel sheet pile cofferdam is between the active earth pressure and the static earth pressure, which is close to the static earth pressure. The value of earth pressure on the inner steel sheet pile cofferdam is between the passive earth pressure and the static earth pressure, which is close to the static earth pressure. The earth pressure on steel sheet pile is suggested to use the static earth pressure because it is difficult to accurately determined under working condition. The suggestion will make the design results be safer.