Experimental Investigation of Load-Bearing Mechanism of Underwater Mined-Tunnel Lining

A series of model tests were performed to investigate the load-bearing mechanism a mined railway tunnel lining under water pressure. To characteristics different types linings, fully closed pressure exerting device for noncircular section was invented. large-scale test (1:30) combined and soil pressures conducted mechanical characteristics, deformation, stress distribution, crack development process, failure mode underwater mined-tunnel lining. The results indicated that high-speed Class IV surrounding rock with design speed 350 km/h, both drainage waterproof controlled by small eccentric compression two conditions. One had only pressure, other variable constant key sections controlling instability bottom wall inverted arch. ultimate head 49 m, 78 m. In comparison lining, could significantly improve water-pressure resistance. Thus, loads 30 60 m are recommended structures, respectively.