In aspects of often used reduction coefficient of lining external water pressure in tunnel water inflow estimation and hydrotechnical tunnel,this paper analyzes lining external water pressure calculation of rich water segment of tunnel under "limited drainage" via simplified model,and discusses the implementation of "limited drainage" so to conclude some useful conclusions for design reference.

Analysis of interaction between surrounding rock and lining in high water-level tunnels with controlled drainage;

Analysis of mechanical character of surrounding rock with controlled drainage in mountain tunnels;

Pigovian tax and amount of exhausting restriction can help to internalize the external environment pollution,but it only effective when controlling pollution cost is lower than environment cost,and the effect of the amount of exhausting restriction is not so good as pigovian tax.