Study On The Mutual Influence For Chongqing Nanshan Tunnel And Overlying Tu Shan Lake

Along with our country economic development,the construction of infrastructure,especially roads,railways,road line selection would inevitably consider the tunnel across the mountain,for the deep mountain tunnel,if the underground water level is higher than the tunnel hole body height,the construction of the tunnel will have to consider the effects of groundwater,in the construction of urban road tunnel,inevitably near the surface water,and then if the tunnel construction revealed the channel between this kind of surface water with the conductivity of tunnel body,the water head height of surface water will provide sufficient dynamic conditions to the tunnel leakage even pour water inrush, resulting in water inrush, sudden mud or even collapse in the tunnel,bring huge difficulties to the tunnel construction,and if an unlimited drainage during tunnel construction will make the groundwater and surface water resources loss,seriously can lead to surface vegetation and water dried up and human life is dangerous. But because of the complexity of the underground space, the interaction mechanism law of groundwater,tunnel structure and tunnel surrounding rock is difficult to grasp, this paper takes chongqing nanshan tunnel with overlying Tu Shan lake as the research background,use theoretical analysis,experiment,numerical simulation and combined with the field monitoring measurement way,explore the mutual influence between nan shan tunnel with Tu Shan lake.In this paper,the main research contents are the following:① After the introduction of the tunnel excavation based on the influence of groundwater seepage mechanism,then using FLAC3 D software to simulate the tunnel excavation effect on seepage field of groundwater around the tunnel, when not considering the effect of stress field and considering the effect of stress field when.② Using the water tracer test to determine the relationship between the water leakage of Tu Lake and Nanshan tunnel excavation,the results show that there are at least three water conductive channels between Nanshan tunnel and and Tu lake reservoir after the excavation of Nanshan tunnel,and between the Great Lake and Small lake reservoir with weak links,the lake reservoir within the Great Lakes water weak links of Nanshan tunnel.③ Through the Tu lake reservoir water level monitoring data,combined with Chongqing surface water evaporation formula, estimated Tu lake reservoir water daily consumption,and compared Nanshan left tunnel daily water quantity monitoring data,taking of Nanshan tunnel excavation effect on the overlying coated lake reservoir evaluation,results show that the Tu small lake reservoir water loss is mainly due to the underground hydrologic connectivity after the excavation of Nanshan tunnel.④ The influence of reservoir leakage on tunnel excavation is simulated by FLAC2 D software,when there are different amounts of leakage passage between Tu lake reservoir and Nanshan tunnel,and different permeability coefficient of leakage passage between Tu lake reservoir and Nanshan tunnel.⑤ According to the Nanshan tunnel surge water gushing and Tu lake reservoir leakage,combined with tunnel engineering geological and hydrological conditions,proposed Tu lake reservoir leakage treatment measures and grouting scheme of Nanshan tunnel through wealthy Water District of karst.