侧压力系数对节理岩体隧洞位移响应模拟研究

侧压力系数对隧洞围岩稳定性的影响较为显著,并且与隧洞的断面形式也有一定的关系.隧洞围岩位移变化量在一定程度上又反映了隧洞围岩的稳定性情况.本文建立了三种断面形式的节理岩体隧洞模型,分别对它们处于不同埋深、不同侧压力系数下的位移响应进行模拟分析,归纳出三种断面形式的隧洞在侧压力系数变化下的响应规律.通过算例总结可知,在同一侧压力系数下,埋深越大,隧洞关键点位移都会增大,在侧压力系数较大时,位移受埋深增加影响较显著；在同一埋深下,侧压力系数较小时,隧洞围岩位移受侧压力系数影响也较小,当侧压力系数较大时,隧洞围岩位移变化较明显；当埋深和侧压力系数均取最大值时,不同断面隧洞的最大位移关键点所处的位置不同.本文的模拟可以为不同埋深、不同侧压力系数下的隧洞选择断面形式提供参考,也可以为节理岩体隧洞开挖支护提供指导.

Simulation research on response of joint rock tunnel displacement under role of lateral pressure coefficient

The lateral pressure coefficient has greater influence on the stability of tunnel surround rock and also has certain relation with the section form of tunnel. While the stability of tunnel surround rock is reflected by its displacement to a certain extent. The paper established the joint rock tunnel model of three section forms, and simulated and analyzed the displacement response in different buried depth and lateral pressure coefficient respectively. The response rule of three section forms was obtained for these tunnels in the change of lateral pressure coefficient. Through example summary, the conclusions are that when the lateral pressure coefficient is identical, the bigger the depth of tunnel, the bigger the displacement of tunnel key point, and the displacement is strong impacted by the buried depth when the lateral pressure coefficient is big; In the same buried depth of tunnel ,the tunnel rock's displacement is slightly influenced by the lateral pressure coefficient when it is small, but the change of displacement is significant as the lateral pressure coefficient is larger; The critical points of the tunnel biggest displacement is located at different positions when the depth and lateral pressure coefficient are the biggest. The simulation in the context can provide reference for the choice of tunnel section form and guide for joint rock tunnel excavation and supporting.