Abstract：
Considering both protection of the ecological environment and optimum design of the lining structure, it is important to not only control ground water loss caused by tunneling, but also decrease the water pressure on the lining. By means of seepage analysis and numerical methods, a simple formula which shows a decreasing coefficient of water pressure is presented as follows: It is concluded that: 1) when the ground water head is higher than 60m, a waterproof lining is not suitable and an ideal drainage system should be set up with the lining; 2) instead of sealing the lining, ground grouting is an effective measure to limit water inflow from the ground; and 3) the thickness of the permeable layer behind the waterproof membrane is an important parameter for the drainage system.
2013, Vol. 50 