Shaking Table Tests on Seismic Response of Tunnel with Longitudinal Cracking Lining

In order to study the influence of longitudinal cracks in the lining of double track tunnel of high speed railway on the seismic safety of the structure, a large-scale shaking table model test was carried out on class IV surrounding rock in accordance with the Code for design of railway tunnel (TB 10003—2016). The test adopted an improved static-dynamic coupling shear model box to analyze the response rules of seismic strain and structural internal force of tunnel lining, taking into consideration three influencing factors including the tunnel buried depth, the cracking position and the cracking form of lining. The test results showed that under the action of seismic shear wave, the failure mode of the shallow tunnel is tension failure, while that of the deep tunnel is compression failure, both of which occur at the arch waist. The peak acceleration of input wave of the shaking table was 0.8g and 0.9g, respectively, when the crack-free lining was damaged at the two buried depths. Cracks in vault and sidewall have little influence on seismic response of tunnel, while the cracks at the arch waist have significant effect. Under the shallow and deep buried conditions, the peak acceleration of the input wave of the shaking table was 0.5g and 0.6g, respectively, when the lining with cracks at the arch waist was damaged. For deep-buried tunnels, compared with the normal section cracks, inclined section cracks at the arch waist will speed up the deformation of lining structure after failure but have little influence on the critical value of failure acceleration.