The Analysis Of Seismic Dynamic Response Characteristics Of Coal Mine Roadway Structure

In recent years,a large number of widely distributed underground roadway have been formed along with coal mining in our country.There are inevitable many buildings above goaf.The instability and failure of roadway easily cause goaf subsidence which seriously threat to safe of buildings above the coal goaf.About 80% coal of china are distribution in meizoseismal area,but the seismic design codes and standards of roadway is not yet perfect.The roadway which coupled with complicated geological conditions of underground roadways(in-situ stress distribution and mechanical properties of surrounding rock)inevitably faced with damage of various load dynamic disaster.So how to guarantee the dynamic stability of coal mine roadway has become a problem that can not be ignored and the seismic dynamic stability of coal mine roadway especially became a inevitable topic of engineering design.Based on structural dynamics,the dynamic elastic-plastic mechanics and finite element analysis software ANSYS/LS-DYNA,this article research dynamic response and its change rule and its damage forms of coal mine roadway under seismic action by adopting combination of theoretical analysis and numerical simulation method.First of all,Based on plane strain finite element model,change of stress and displacement of roadway which is under action of unidirectional seismic wave is discussed.High stress concentration phenomenon which appear periodic is obvious and roadway is given priority to with shear deformation destruction when coal mine roadway is under horizontal seismic wave.Cyclical high stress concentration phenomenon mainly focus on roof,two waist and bottom of roadway and roadway cross section is given priority to with tension and compression deformation damage when coal mine roadway is under the action of vertical seismic wave when coal mine roadway is under the action of horizontal and vertical seismic wave,Peak stress of roadway is mainly concentrated in roof and waist of roadway and damage form is given priority to with deformation of tension compression and shear.what is more,the under the action of the dynamic response of bidirectional seismic wave is stronger than dynamic response of unidirectional wave.Secondly,This article study influence of different factors such as buried depth of roadway,cross section form of roadway,elastic modulus of lining,rock layers,types of seismic waves on the seismic dynamic response through comparison and analysis of stress distribution and measuring point displacement of roadway which is under different working conditions.It is found that stress response of roadway increases and displacement response decreased with the increase of buried depth,seismic performance of circular roadway is better than arch and rectangular roadway.It can slow the earthquake effects on roadway under a certain distribution of surrounding rock.Seismic damage of Tangshan is Stronger than EL and TAFE wave.The influence of elastic modulus of lining on seismic dynamic response of roadway is relatively small.Finally,Based on three dimensional numerical model of arch roadway,damage effect of arch roadway under action of earthquake is considered.This article discusses the dynamic response of arch roadway and its schedules change situation,the study found that high stress concentration mainly appears in arch roof and corner of roadway.Because of strong compression between roof and corner of arch roadway and surrounding rock,damage effect of roof and corner of roadway is obvious,the roof and corner of arch roadway should be as key to its dynamic disaster prevention and control.The seismic dynamic failure process of roadway is simulated by setting maximum tensile strain damage failure threshold of roadway unit.it is found that tensile damage firstly appear in arch and corner which cause the instability and collapse of whole roadway.