Study On Stabilization And Construction Method For Highway Tunnel With Shatter Rock

With our country highway develops rapidly,a lot of tunnels constructed in shatter rock,but stability analysis and prevention measures of constructing tunnels in shatter rock lack the experience and could draw lessons from,so,there are to be a further study and improvement. This dissertation is base on the tunnel construction through the active Longmen Shan fault zone of GuangGan highway project.The wall rock of many GuangGan highway tunnels are shattered rock after the earthquake, whose main lithology is the weathered and strongly weathered phyllite with a lot of fault and broken wall rock.what’s more,the phyllite become very soft and weak after dipped with water and the tunnel Rock level is between class II-V, Which is very complex and changeable.During the construction of these tunnels, early support instability failure caused by large deformation and large landslides have Occurred several times.This dissertation first analyzed the basic characteristics of the shattered rock, summarized the variation of instability and analyzed the influencing factors and cause of shattered rock tunnel instability s, then studied the preventions measures of instability. The research method and research results are as follows:(1) Base on the rock along GuangGan highway, the rock situation revealed by the tunnel face and information research, we conclude the basic characteristics of surrounding rock injured by earthquake:the Longmen Shan fault zone northern section is obvious rubbroken; lots of the fault that is very broken.(2) By analysis of instability phenomena in the shattered wall rock conditions, the site of the monitoring data analysis, we think that the instability mainly behaves as a result of large deformation and slip collapse mainly landslides, location is mainly concentrated in the vaultand arch waist bit. A variety of law is clear and obvious characteristics, very typical.(3) Field test as the main method, joint numerical simulation and theoretical analysis, we summed up the impact factors of instability of construction of tunnels under the class formation conditions.and put forward the broken wall rock conditions and the groundwater is the key reasons of tunnel instability.(4) Base on the field data,and with the help of numerical simulation, we proof "four-step approach ", and "bassoon studio+catheter+grouting reinforcement" of the response measures is practicable.