Shaft intake is lined with the reinforced concrete by making drainage holes so as to remove the exterior water with the aim of reaching optimizatioll design.

Study on the external water pressure of deep-lying tunnel in Jinping hydropower station;

Discussion on external water pressure value in tunnel design;

Study on external water pressure on lining of tunnel No 7 of south main of YRDP;

The result indicates that the lining s stress is different in consideration of external water load and not.

Up to now, the drainage and waterproof system design of most railway tunnels in China didn t consider the action of external water load, based on the principle of unlimited drainage, so a great number of railway tunnels have the problem of leakage water, some of which are very serious.