基于三维随机坍塌模型的软岩隧道掌子面抗震稳定性的可靠度分析（英文）

Reliability analysis for seismic stability of tunnel faces in soft rock masses based on a 3D stochastic collapse model

采用对数螺旋曲线构建了软岩隧道掌子面的牛角破坏模式,利用拟静力法将地震力引入到牛角破坏模式中,考虑岩体参数及荷载的随机性,建立地震效应下软岩隧道掌子面的三维随机坍塌模型。将极限分析上限法和响应面法有机结合,对软岩隧道掌子面的抗震性进行了可靠度分析。研究表明,支护力、地质强度指标、单轴抗压强度、岩体重度以及地震力对隧道掌子面的可靠度均有显著影响。尤其是水平地震力和竖直地震力的影响更不容忽视,否则会明显高估计算结果,但是在计算精度要求不高的条件下可以忽略其相关性的影响。

A new horn failure mechanism was constructed for tunnel faces in the soft rock mass by means of the logarithmic spiral curve. The seismic action was incorporated into the horn failure mechanism using the pseudo-static method. Considering the randomness of rock mass parameters and loads, a three-dimensional (3D) stochastic collapse model was established. Reliability analysis of seismic stability of tunnel faces was presented via the kinematical approach and the response surface method. The results show that, the reliability of tunnel faces is significantly affected by the supporting pressure, geological strength index, uniaxial compressive strength, rock bulk density and seismic forces. It is worth noting that, if the effect of seismic force was not considered, the stability of tunnel faces would be obviously overestimated. However, the correlation between horizontal and vertical seismic forces can be ignored under the condition of low calculation accuracy.