Abstract:

From YDK14+180 to YDK14+280 of a running tunnel on Line 7 of Shenzhen Metro, the shield bores close to the existing pile foundations of a bridge. In the paper, the influence of different shield attitudes on the pile foundations is analyzed by means of finite element program, so as to bring the disturbance to the pile foundations under effective control and to ensure the tunneling safety. Conclusions drawn are as follows: 1) Shield attitude has great influence on the pile foundations, therefore shield attitude should be well controlled during tunneling; 2) As the distance between the shield and the pile foundations reduces and the shield rolling angle increases, the impact of shield boring on the pile foundations grows; 3) When the distance between the shield cutterhead and the pile foundation is twice the tunnel diameter, the rolling of the shield shall be strictly controlled.

Key words: Shenzhen Metro, shield attitude, pile foundation, finite element analysis, deformation characteristics