复合地层土压平衡盾构掘进参数模拟分析研究

复合地层特别是软硬交互地层的盾构掘进参数模拟与预测理论及方法研究,目前还处于薄弱阶段。基于Terzaghi松动土压力模型与CSM(科罗拉多矿业学院)模型,对广州地铁3号线大石—汉溪区间不同风化程度混合岩地层的土压平衡盾构掘进表现分别进行模拟分析,结果基本符合实际的掘进表现,但在贯入度大于20 mm/r的硬岩掘进情况下推力及扭矩模拟值与实际值存在较大正负差异。针对这种正负差异情况,分析可能产生的原因。通过对软硬交互复合地层的盾构受力分析,模拟计算在软硬地层各占50%情况下的推力与扭矩值,结果表明,总推力和扭矩的模拟值均在实际值范围内,验证了采用的综合考虑软土和硬岩模拟分析结果的复合地层掘进参数模拟分析方法的有效性。

Simulation Analysis on Boring Parameters of EPB Shield in Complex Strata

The simulation and prediction of shield boring parameters in complex strata are still in weak positions. The boring performance of EPB shields in the complex strata in Dashi-Hanxi running tunnel on No. 3 line of Guangzhou Met- ro is simulated and analyzed by means of Terzaghi loose soil pressure model and CSM model. The simulation results coincide with the actual boring performance, except that there are great differences between the simulated thrust and torque values and the measured values when boring in hard rocks with 20 mm/r penetration rate. The causes for the differences are analyzed. The thrust and torque when boring in complex ground with soft and hard rocks are calculated. The simula- tion results show that the simulated total thrust and torque are within the range of the measured values. The effectiveness of the mentioned simulation and calculation method is verified.