强度折减应用于隧道群整体稳定性分析的判据比较

为了讨论隧道群稳定性问题中判据的适用性,针对采用强度折减理论中塑性区贯通、特征点位移突变与基于力和位移准则判断计算是否收敛3种较为广泛使用的判据加以比较。通过比较表明,计算收敛判据明显偏大,其他两种判据结果较接近。单独使用任何一种判据分析隧道群的稳定性均不合理,也不能较真实地确定安全系数。用基于力和位移准则判断计算是否收敛作为判据不适合隧道群的稳定性分析,而塑性区贯通与特征点突变两判据相结合作为综合判据可以较好地得到隧道群的安全系数。

Discussion on Criteria for Evaluating the Stability of Tunnels Based on the Strength Reduction Method

Strength reduction theory in the study of slope stability has been widely used,but it is less used in the study of tunnels stability,particularly there is no uniform understanding in the choice of criteria so far.In order to discuss the stability of tunnels along the applicability of the criterion,the three common used criteria,that is,plastic strain zone connection criterion,the criterion of abrupt change of the relationship between the displacement（or displacement increment） and the reduction coefficient at a certain characteristic location and the divergence criterion of numerical calculation,are compared.By comparison,it is showed the divergence criterion of numerical calculation is too large,the other＇s results are closer to each other.Using any of criteria in stability analysis of tunnels is unreasonable and can not be compared to determine the real safety factor.The divergence criterion of numerical calculation is not suitable for stability analysis of tunnels,while using plastic strain zone connection criterion,combining with the criterion of abrupt changing displacement of characteristics point,as a comprehensive criterion can be good for the factor of safety of tunnels stability.