土压平衡盾构中顶进推力的计算分析

针对土压平衡盾构开挖过程中顶进推力难以确定的问题。采用理论计算与数值拟合相结合的方法,计算土仓和掘进面的等效压力,从而推导出隧道开挖所需的顶进推力。以实际工程为背景,利用ABAQUS在该顶进推力作用下地表沉降规律。结果表明:①该土仓与掘进面压力的计算方法适用于卵石地层;②盾构推进力为110 000 N时,开挖较为稳定;③监测与模拟的地表沉降值较为接近,两者之差小于2 mm。该研究对卵石地层中的盾构开挖具有一定的指导意义。

Calculation and Analysis of Propulsion Force of Earth Pressure Balance Shield

Contrapose construction problem that the EPB shield excavation process propulsion force is difficult to determine. The equivalent pressure of the chamber and the excavation face is calculated by the combination of theoretical calculation and numerical fitting, and then deduce the tunnel excavation required jacking thrust. In this paper, the typical of Line No.3 of Chengdu Metro is analyzed by means of ABAQUS software; and then the rules of ground surface settlement under the thrusting forces in simulated. The results show that: 1) The calculation method of earth chamber and pressure of excavation face applied to gravel stratum; 2) The excavation is more stable when the shield propelling force is 110000 N; 3) Surface subsidence monitoring and simulation is closer, the difference between them is less than 2mm. The resultes can provide guidance for Gravel Formation of shield excavation.