软土区盾构刀盘扭矩分析及对地表变形影响

Analysis of torque of shield cutter head and its influence on surface deformation in soft soil region

依托杭州地铁2号线某盾构区间段工程,提出适合杭州软土地区的土压平衡盾构机刀盘扭矩计算方法,并进行盾构掘进时地表变形与刀盘扭矩的相关性影响现场试验。研究结果表明:软土区刀盘扭矩可由7个计算影响因子组成,计算得到的理论最大扭矩与实测最大扭矩相差10%,吻合度较高;开挖面正上方的瞬时隆沉和刀盘扭矩与单环排土量的比值M呈正相关,即在扭矩一定的情况下,地表变形随着单环排土量的减少逐渐由沉降转变为隆起。

Based on the project of Hangzhou Metro Line 2, a calculation method of torque of cutter head for the soft soil region was put forward. The correlation between surface deformation and the torque of cutter head in shield tunneling was tested. The result indicates that the torque of cutter head in soft soil region can be composed of seven influential factors. The calculated theoretical maximum torque is about 10% larger than the measured maximum torque. Furthermore, a positive correlation is found between the instantaneous surface deformation at the top of the excavation face and the ratio of the torque of cutter to the single ring excavated soil M. In the case of a certain torque value, the surface deformation is gradually changed from settlement to uplift with the reduction of the amount of the single ring excavated soil.