A Research On The Tactical Technology To Protect And Emit Limited The Groundwater Of Chun Tian Men Long Tunnel

With the quick development of domestic traffic engineering and the develop-the-west strategy,the construction of tracffic engineering has transferred to the western region from the eastern coastal areas.The landform of the west is very complex,the karst landform has a wide distribution,so that the construction of tunnels in karst areas is increasing day and day,and the engineering geological calamity caused by karst also endangers the construction and operation of tunnels.The situation of heavy water bursting and high water pressure is quite obvious when crossing abundant water of karst zone.So it's really very very important to study the technology of waterproof and drainage,so and the governance of the geological disasters caused by karst tunnel flooding.Groundwater effects it a lot during the tunnel construction process.In past many engineering applications,people usually deal with the groundwater according to the principle of “base on drainage”.It means,they reduce the external water pressure on lining to guarantee the safty of the structure.But as time goes on,this way will not only lower groundwater level and break the balance of water resources.But also destroy the ecological environment and affect the production and living water of the surrounding residents.So,it's quite important to adopt the principle of “To drain for water drainage”to deal with groundwater.This article is relying on the project “Nanchuan-Liangjiang New Area expressway ChunTianMen long tunnel” and combining the investigation data of it's hydrogeologic condition,the results are as follows:(1)According to the analysis of grouting theories,materials,technologies and so on,the specific grouting materials and technologies can be confirmed.The innovation of karst declogging can be divided into “YRTF” four levels on the basis of the amount of gushing water(2)Optimized scheme design of grouting test and the specific treatment of karst water inrush disaster are supposed on the basis of previous studies.(3)The numerical simulation of 3 different anti-hydraulic pressure lining structures in engineering is putting into execution by using MIDAS/GTS,and the external hydraulic pressure of different anti-hydropressure structures has been got,which can provide the reference basis for the follow-up studies.(4)According to ANSYS MIDAS/GTS,the stress analysis of karst water bursting onthe secondary lining structure of the most unfavorable place in rich water segment under the different thickness of grouting reinforcement of ChunTianMen Tunnel has been imitated,so that the optimum value of the thickness of structural grouting circle could be confirmed.It turned out that when the water pressure is 1.0MPa,the best thickness of reinforcing circle is 1.5m;when the water pressure is 1.5MPa,the best thickness of reinforcing circle is 2.0m;when the water pressure is 2.0MPa,the best thickness of reinforcing circle is 2.5m;when the water pressure is 2.5MPa,the best thickness of reinforcing circle is 3.0m.(5)The reciprocal relation curve of the thickness of grouting circles,external water pressure on lining,displacement,surrounding rock and permeability coefficient of grouting circles has been inferred.Combined with the practical situation and previous experience of the engineering,the displacement design of ChunTianMen Tunnel has been finished,it's 5 m3/(m·d).According to the basic theoretical study,the limited emission design and the construction technology of ChunTianMen Tunnel has been confirmed.