盾构机总推力反算滚刀法向破岩力探讨

Discussion on inverse calculation of normal force of rock breaking by disc cutter by total thrust of shield

分析了盾构机掘进过程的受力状况,建立了盾构机滚刀法向破岩力与掘进总推力之间的量化关系,提出了利用盾构机实测总推力反算滚刀破岩力的方法与步骤.以广州地铁三号线北延段盾构掘进工程为例,验证了本研究提出的方法,计算结果与Rostami预测值具有一致性,并指出反算法向破岩力的关键在于盾构机外壳与周围地层的摩阻力计算,取决于盾构机外壳所受压力的合理估算及盾壳与地层摩擦系数和侧压力系数的正确选取.

It is analyzed that the force conditions of shield machine in the process of shield tunneling, and the quantitative relationship between normal force of rock breaking by disc cutter and total thrust of shield tunneling has been established, and the methods and procedures on inverse calculation of normal force of rock breaking by disc cutter by using total thrust measured are presented. Taking the shield con- struction on North Extension Section of No. 3 Line of Guangzhou Metro as an example, the methods of in- verse calculation are verified, and the results suggest that the values of inverse calculation are consistent with the theoretical value calculated by prediction formula of Rostami. It is pointed out that the key of in- verse calculation of normal force of rock breaking by disc cutter lies in the calculation of friction resistance between shield shell and related stratum, depending on reasonable estimation of pressure applied on shield shell and correct selection of friction factor between shield shell and stratum, and lateral pressure coefficient.