The Analysis On The Stability Of Tunnel Surrounding Rock In Fault Region

The stability of tunnel surrounding rock has long been a concern problem during tunnel excavation,and it will often encounter a variety of complex and adverse geological phenomenon,especially fault.If there is a fault section in tunnel excavation range,tunnel surrounding rock will be very unstable.Therefore,the stability analysis of tunnel surrounding rock in fault broken region can reduce various geological disasters,improve the efficiency tunnel excavation and safety protection level.The existence of fault destroy the continuity and integrity of the rock,makes the stress distribution around the fault is very different.During the tunnel excavation,the displacement field,the stress field,the crown displacement and the maximum unbalanced force will be changed.In this special geological conditions of tunnel excavation,the stress and displacement of surrounding rock can not get the analytical solution.With the development of computer technology,numerical methods are constantly updated and improved,all kinds of complex engineering problems can parsed by it.Thus appeared various numerical simulation software,become an important means to study rock mechanics.If the model is well established,and the initial conditions and boundary conditions are chosen properly and reasonably,calculated data by using numerical simulation analysis can be used as a reference.Paper is divided into two parts,the first part describes the current research status,introduce the engineering characteristics of faults,and quantitative study on the stability of tunnel surrounding rock in fault region.In addition,by using Elastic Mechanics Theory analysis the stress of tunnel surrounding rock in fault region,derived and summarized expression of stress and displacement of surrounding rock after tunnel excavation.The other part by using FLAC-3D numerical simulation software,Based on the new Qi Daoliang tunnel,to simulate the stress and displacement distribution of tunnel excavation in fault region.The above research has some reference value for the stability analysis of underground engineering tunnel surrounding rock.