Abstract
The fault-crossing tunnel in high geothermal areas can be severely damaged under strong earthquake. In this paper, numerical models were established in Flac(3d) to investigate the thermal insulation and seismic effects under the strong earthquake when using highly damped composite structure. The results showed that the thermal insulation effect of the PC, the PC highly damped composite structure and the SFRC highly damped composite structure were almost the same, which the PC highly damped composite structure was slightly better. After applying the highly damped composite structure, the maximum and minimum principal stresses on the lining decreased, it showed that highly damped composite structure could enhance the seismic effect of tunnel. The safety factor of SFRC highly damped composite structure was 2.420, which was a 28.14% increase compared to PC. Based on numerical simulations, the thermal insulation and seismic effect of SFRC highly damped composite structure was better than other seismic measures. The research can provide a reference for the design of thermal insulation and anti-earthquake for fault-crossing tunnel under strong earthquake in high geothermal area.