Construction Mechanical Response of a Shield Tunnel Adjacent to Existing Pile Foundation

More attention has focused on the issue of shield tunneling across existing pile foundation. The two-stage approach was conducted to propose the simplified calculation method of impact on adjacent existing pile foundation by shield tunneling in close range. The influencing law of existing pile was calculated based on a typical engineering example,as well as the result was analyzed and compared with the result which was calculated by three-dimensional numerical simulation. The results show that the maximum horizontal displacement of adjacent existing pile foundation caused by shield tunneling is4. 25 mm,and the corresponding bending moments,the shear forces are 1176. 09 k N·m and 505. 1k N respectively. The influencing scope of existing pile foundation caused by shield tunneling can be determined by 45° + φ /2 angular spread.Through the comparison with numerical calculation results,it is indicated that the method proposed in this work is feasible and it can be used to predict the perturbation of existing pile caused by adjacent shield construction.