Analytical solution for longitudinal seismic response of long tunnels in homogeneous stratum
YU Haitao1,2, WANG Qi2, LIU Tao3
1. Key Laboratory of Geotechnical and Underground Engineering of Ministry of Education, Tongji University, Shanghai 200092, China; 2. Department of Geotechnical Engineering, Tongji University, Shanghai 200092, China; 3. Shanghai Huangpu River Crossing Facility Investment Construction Development Co., Ltd., Shanghai 200335, China
Abstract Long tunnel in homogeneous stratum was studied, which was simplified to a beam on elastic foundation. Soil-structure interaction was simulated by normal and tangential spring. Analytical solution of longitudinal seismic response was derived by solving governing differential equations. Through the analysis of the analytical solution of the internal force response, the calculation method of the maximum internal force response required for the longitudinal seismic design was put forward, which could be used to calculate the most unfavorable longitudinal response of long tunnel. On the basis of numerical calculation, the correctness of the analytical solution was verified. In addition, the analytical solution could intuitively give the correlations among the key parameters. Through parametric analysis, influence laws of incident angle, incident wavelength and relative stiffness ratio on longitudinal seismic response of tunnels were obtained. Analysis showed that as the wavelength of incident wave increased, the bending moment response first increased and then decreased, and the shear force and axial force response decreased. If the incident angle increased from 0° to 90°, the shear response decreased, while the bending moment and axial force first increased and then decreased. As the relative stiffness ratio increased, internal force response was reduced, but the displacement response of the structure and the deformation of tunnel structure would appear larger, which should be considered in the structural design. On this basis, a reasonable design and calculation method of longitudinal seismic response analysis of long tunnels was put forward, which could provide guidance for longitudinal seismic design of long tunnels.
YU Haitao,WANG Qi,LIU Tao. Analytical solution for longitudinal seismic response of long tunnels in homogeneous stratum[J]. Hazard Control in Tunnelling and Underground Engineering,
2020, 2(1): 34-41.
