关键词: 实体模型, 桩基, 盾构掘进, 压力控制, 振动, 转矩, 软硬不均地层, 风险控制

Abstract:

Obstacles such as pile foundations are frequently encountered during shield boring. In such case, the cutters and cutterhead of the shield would be jammed or even damaged, and the boring efficiency is probably low. As a result, a entity model of cutterhead direct cutting pile foundation of Red Line of Tel Aviv LRT project is established to simulate different layouts of cutting tools and different boring conditions, and analyze the influencing laws of shield boring parameters and cutting tool layout mode on failure mode of pile foundations and shield cutterhead. The analytical results show that during shield cutterhead cutting pile foundation, the optimum boring parameters of advancing rate, cutterhead rotation speed and torque are 3-5 mm/min, 1.0-1.2 r/min and 3 300-4 300 kN?m, respectively; and the number of disc cutter and cutting bit have some influence on the cutting of the pile foundations. The practice of pile foundation cutting by shield and the monitoring results demonstrate good effects, such as no cutterhead jamming and damage, have been achieved during shield cutting pile foundation by rationally adjusting relative parameters.

Key words: entity model, pile foundation, shield boring, pressure control, vibration, torque, heterogeneous ground, risk management