高水位隧道衬砌临界水头数值计算

选取2种典型隧道断面,对其所能承受的极限水头值进行分析。计算结果表明:1对设计时速250 km/h的客专双线隧道,当衬砌厚度分别为t=30 cm、50 cm时,素混凝土衬砌均不能承担任何水压力荷载,C30钢筋混凝土衬砌能承受的极限水位分别为11.2 m、34.2 m;2对设计时速200 km/h的单线铁路隧道,当衬砌厚度分别为30 cm、50 cm、60 cm时,素混凝土衬砌能承受的极限水头分别为0 m、1.0 m、5.5 m,C30钢筋混凝土衬砌能承受的极限水头分别为26.0 m、55.2 m、73.5 m;3隧道形状对所承受的极限水头值有较大的影响,单线铁路隧道比客专双线隧道更有利于承受水压力;4对于高水位隧道,应该采取"以堵为主,限量排放"的措施,降低衬砌水压力,使设计既安全又经济。

Numerical calculation of high water head tunnel on critical water pressure

In this paper, two kinds of typical tunnel section is chosen for analyzing the critical water pressure of high water head tunnel by numerical calculation method. The calculation results show that: (1) For the design speed 250km/h double-line tunnel, when the lining thickness is respectively 30, 50cm, plain concrete lining is not liable for any water pressure load, and C30 reinforced concrete lining can withstand respectively 11.2m, 34.2m water head load. (2) For the design speed 200km/h single track railway tunnel, when the lining thickness is respectively 30m, 50m, 60cm, plain concrete lining can withstand respectively 0m, 1m, 5.5m, and C30 reinforced concrete lining can withstand respectively 26m, 55.2m, 73.5m water head load. (3) The tunnel shape has great influence on critical water head, single-track railway tunnel can bear greater critical water pressure than double-track tunnel. (4) For high water head tunnel, according to new concept of water control in tunnel, the amount of water inflow should be limited.