近距双线隧道浅埋暗挖施工过程中围岩整体稳定性分析

土体在长期自重应力作用下达到平衡,隧道在开挖过程中,开挖面土体应力释放,必将打破原有土体应力平衡.在新的应力场平衡过程中,土体颗粒位置发生改变,隧道围岩产生变形,当变形过大的时候,易于诱发工程事故,特别是在偏弱围岩近距双线隧道浅埋暗挖施工过程中,通过对其围岩变形的研究来合理分析隧道围岩的整体稳定性显得尤为重要.基于此,结合我国中部某市地铁2号线隧道施工工程实例,研究了双线隧道左右线隧道开挖过程中围岩的变形规律,得出近距隧道围岩变形的影响区域及最大变形值,其研究的方法及结论能够为类似工程设计及施工提供一定程度上的参考依据.

The Surrounding Rock Stability in Shallow Excavation Process of Close Bi-directional Tunnel

The soil reachs equilibrium under the long-time action of gravity stress,tunnel excavation. When soilexcavating,the face stress is released,which will break the balance of the original soil stress. In the new equilibriumprocess of stress field,soil particles position changes,and the tunnel rock deforms. When the deformation is toolarge,it is easy to induce engineering accidents. Especially in weak rock close-lane tunnel shallow constructionprocess,the rock deformation rational analysis on the overall stability of surrounding rock is particularly important.Based on this,combined with a city in the middle of Metro Line 2 of the tunnel construction project example,westudied the deformation process of two-lane tunnel excavation in rock around the tunnel line law. The close tunnelrock deformation affected area and maximum deformation values were obtained. Methods and conclusions of thestudy could provide a reference to a certain extent for the design and construction of similar projects.