双隧洞开挖过程中围岩稳定敏感因素分析

Analysis on Sensitive Factors of Surrounding Rock Stability during Double Tunnel Excavation

为了研究双隧洞开挖过程中围岩稳定的问题,以新疆某隧洞工程为依托,使用数值模拟双隧洞不同施工开挖方式的优劣、分析了影响隧洞围岩稳定的敏感因素。结果表明:上下台阶法开挖效果较好,围岩相对完整时开挖步骤适中可以提高围岩的稳定。隧洞埋深增加,围岩最大应力、位移、塑性值逐渐增大;围岩密度增加,围岩最大应力、塑性值缓慢增加,位移值逐渐减小;围岩粘聚力增大,围岩最大应力、位移值缓慢增加,塑性值逐渐减小。

In order to study the stability of surrounding rocks during the excavation of double tunnels,this paper takes a tunnel project in Xinjiang as the support,uses numerical simulation to analyze the advantages and disadvantages of different construction excavation methods of double tunnels,and analyses the sensitive factors affecting the stability of tunnel surrounding rocks.The results show that the upper and lower step method has a better excavation effect,and the appropriate excavation steps can improve the stability of surrounding rocks when the surrounding rocks are relatively complete.The maximum stress,displacement and plastic value of surrounding rock gradually increase with the increase of tunnel buried depth.As the density of surrounding rock increases,the maximum stress and plastic value of surrounding rock increases slowly and the displacement value decreases gradually.With the increase of cohesion of surrounding rock,the maximum stress and displacement of surrounding rock increase slowly and the plastic value decreases gradually.