破碎岩体中盾构施工掌子面安全系数计算方法研究

Calculation Method of Safety Factor of Shield Tunneling Face in Broken Rocks

为解决由于破碎岩体造成的盾构施工过程中隧道掌子面失稳破坏的风险,基于强度折减理论、修正椭球体理论和极限平衡安全系数理论,结合有限差分计算软件,提出一种破碎岩体中盾构施工掌子面安全系数计算方法,并对该计算方法的可靠性进行验证。研究结果表明:1)强度折减法适用于破碎岩体中盾构施工掌子面安全系数的计算;2)破碎岩体发育程度、掌子面支护压力对掌子面的安全系数影响很大。

The broken rock mass always causes instability and damage of tunneling face during shield construction.Therefore,a calculation method,based on strength reduction theory,modified ellipsoid theory,and limit equilibrium safety factor theory,is proposed for calculating the safety factor of shield tunneling face in broken rock mass using finite difference calculation method.The feasibility of the method is validated.The results show that:(1)The strength reduction theory is applicable for calculating the safety factor of shield tunneling face in broken rock mass.(2)The development of the broken rocks and support stress of tunneling face have a considerable impact on the safety factor.