Research On Seismic Dynamic Response And Seismic Measure Of Tunnel Crossing Active Fault Zone

China is an earthquake prone country in the world.In recent years,a large number of cities in China continues to expand underground space construction,and the safety problem of underground structures has attracted more and more attention.At home and abroad,the research on anti-seismic measures of tunnel structure is more thorough,but when the tunnel crossing fault zone,especially the active fault zone,the anti-seismic measures effect is not ideal.During the earthquake,the dynamic response characteristics of the tunnel passing through the active fault zone are not clear,while the tunnel structure crossing the active fault area does not form systematic damping measures.The damping measures of the tunnel structure needs to be further studied.Via numerical simulation and shaking table model test,this dissertation revealed the tunnel lining’s dynamic response characteristics and the damping effect of different seismic measures at seismic active fault zone conditions.The main results are as follows:(1)The BP neural network algorithm based on MATLAB software is applied to optimize the proportion of similar materials,so that the test time of similar material matching is greatly reduced,and the result of proportion is more accurate.(2)Through the shaking table model test and numerical simulation,the internal force(moment and axial force)and stress characteristics of shallow tunnel in active fault zone are analyzed,and the seismic response characteristics of shallow tunnel crossing active fault zone are obtained.(3)In the shaking table model test,the tunnel with construction defects(insufficient thickness of the arch lining)is simulated,and the internal force(moment and axial force)and stress characteristics are compared with the defect free tunnel,and the dynamic response of the tunnel is analyzed.(4)Combined with the shaking table model test data and numerical calculation results,the corresponding damping measures(shock-absorbing joints,shock-absorbing layers)for the tunnel are analyzed,and the damping effect of the shock-absorbing joint,Shock-absorbing layers and the combination of them is compared and evaluated.