Research On Seepage Field And Water Gushing Characteristics Of Fault Zone In Erlang Shan Tunnel

For the past few years,with the rapid improvement of science and technology in China and constant progress made in the technique of tunnel construction,tunneling project develops toward large embedded depth,long tunnel line,complicacy of geology,frequently happened disasters,etc.among them,discharge disaster in tunnel that passed through fault zone has been one of the chief geographical disasters,and the casualties and economic loss it caused also ranked the top of tunnel geographical disasters of different kinds.Therefore,it is of important significance to test,study and analyze the change features of seepage field of fault zone that the water burst happens when tunnel passing through fault zone.This paper adopts the combination of these two methods of model experiment and numerical simulation,based on Erlang Mountain tunnel project of Yaan-Kangding expressway,the tunnel that passed through the fault zone is taken as the objective of study,and under the effect of self-weight stress field,it utilizes three materials of different physical characteristics,characteristic of the seepage field of fault zone will be studied when there is a discharge disaster in the tunnel.The main study content and conclusion are as follows:1.On the basis of material of field investigation,the growth characteristic of major fault and fault activity of tunnel site of Erlang Mount tunnel are analyzed and summarized,combining the formation lithology,the tunnel site is divided into four tectonic divisions,then study characteristics of the rock mass of each tectonic division;targeted with east slop and west slop of Erlang Mount,respectively study the water storage type and characteristic of these two hydrogeological units.2.Under the effect of self-weight stress field,it utilizes three materials of different physical characteristics to carry out model test,and studies the characteristic of seepage field of fault zone that the discharge disaster occurs when the tunnel passes through the fault zone,works out the change law of seepage field of fault zone when the tunnel's water burst with three materials and through comparative analysis,explores the relationship of change feature of seepage field of fault zone and osmotic coefficient of fault zone.3.The part of Erlang Mount tunnel passing through fault zone are carried out numerical modeling by adopting software of finite element analysis GeoStudio,and the result of numerical analysis and model experiment are analyzed comparatively,then the characteristic of seepage field of fault zone when the discharge disaster occurs can be found out,which will provide certain reference for the prevention and countermeasure of discharge disaster in the similar tunneling construction.