Abstract:

The metro 11 line shield tunnel passing through the Suzhou River, will impact on the security of flood wall for Suzhou River. The pile foundation relative to shield tunnel was raised and a “double span” portal frame was adopted to ensure the appliance of shield tunnel. Not only the security of flood wall is assuring, but the space for shield tunnel is adequate to the demand. The diversity in the stress and deformation construction of flood wall with shield tunnel or not, was analyzed by constitutive model built on the finite element method. Before shield tunnelling the deformation of bed plate foundation is consistent in it of continuous beam, both the middle part of long pile and the top part of short pile are detected in the extrorse deformation; and the stress rule of the whole structure accord with inherent characteristic of the portal frame. After shield tunneling the deformation of bed plate foundation is similar to it before shield tunnelling; the maximal deformation lies in the middle part of the tunnel upside. By contraries, after shield tunnelling both the middle part of long pile and the top part of short pile are detected in the introrse deformation. The deformation of long pile is in the form of bending deflection, and the maximal deformation lies in the neighborhood of the tunnel axle wire, the deformation of short pile is in the form of rigid body deformation; the maximal deformation lies in the bottom of itself. The theoretical settlement calculated approximates to the practical settlement tested; it is shown that the influence on the deformation of the flood wall by shield tunnelling is of controllable condition.

Key words: flood wall, shield tunnel, deformation, numerical simulation, ground loss