盾构法隧道开挖对摩擦桩的影响

Effects of Shield Tunneling on Adjacent Friction Piles

通过数值仿真试验,分析了在均匀粘土地层条件下盾构法隧道施工引起摩擦单桩在不同桩洞距、注浆压力、桩土模量比等影响因素下侧摩阻力、变形、内力的变化规律,最后对摩擦双桩进行了分析,试验结果表明,开挖后桩身发生倾斜变形及明显的内力变化。对双桩的分析发现,存在一种正面的群桩效应,即开挖引起双桩的桩身内力比对应位置的单桩小,尤其体现在后桩上。

Numerical tests are carried out to analyze the response of both single piles and double piles due to shield tunneling. In the test of the single piles, a series of factors are considered, such as the distance from pile to tunnel centre, grouting pressure and the modular ratio of pile to soil. Results of the numerical tests indicate that the tilt deformations and the significant changes of internal forces are induced in adjacent piles after excavation. The numerical tests of the double piles show that there is a positive effect of group piles, that is, the internal forces of the double piles are smaller than bending moment that of the single piles in the relative location, especially incarnating in the back pile.