The Numerical Simulation Analysis About Foundation Pit Water Inflow In Karst Region

In guizhou karst region, due to the heterogeneity of the karst aquifer, karst aquifer system complexity of infiltration and seepage field, large dynamic range etc.There will be a larger error with foundation pit water inflow forecast and construct water level. A sudden rise ooze water will be happen when some of the basement engineering in construction process. Not only make the basement floor, the ground beam deformation and failure, and water inflow forecast than prospecting several times and even more, cause great difficulty in governance. This Guojijiayuan district 3#basement garage in anshun water accident investigation and complementary investigation, on the basis of karst hydrogeological conditions in the study area is analyzed. Through porous pumping test, find out the groundwater seepage field characteristics of foundation pit, the numerical simulation method and experience method for foundation pit karst water inflow to calculate. Take the following understanding:?1? The study area is located in the north east to F₂ pressure shear fault and the north west of press F₅ shear fault nearby, where to Anshun group of the second paragraph?T₁a²? dissolved pore- soluble gap aquifer. To the west of the aquifer to F₅ water-blocking faults formed water boundary, south east of F₂ fault resistance water to form water boundary, north to the east for the groundwater recharge area, for the infinite boundary. Overall flow from north east south west groundwater runoff,groundwater enrichment region is located in the area.?2? Exploration drilling and porous pumping test show that :?1?Groundwater burial form natural condition is half under pressure, the Q S curve is diving;?2?Permeability coefficient ZK6^ZK2?north east? and ZK6^ZK4?north west?in the directionof permeability coefficient were 2.29m/d,1.98m/d, renderingnot uniformity;?3?Underground water level of 1351.87 m, pumping test maximum drawdown of 13.21 m, the maximum yield of 3551.52 m³/d;?4?Original during the engineering investigation due to did not find out the karst groundwater seepage characteristics of foundation pit accident.?3? In identification, on the basis of groundwater seepage field characteristics in the study area, the karst hydrogeological conditions generalized processing. Visual Modflow software is adopted to establish the two-dimensional steady flow numericalmodel based on finite difference method, the simulation results objectively reflect the characteristics of the karst seepage field of foundation pit?basement?, provide the basis for correctly predicting water inflow and construct water level.?4? Numerical model method and experience method of foundation pit in karst water inflow forecast, and puts forward Suggestions on the basement of ooze water governance.In this paper, using the finite difference method for the first time two dimensional steady flow numerical simulation method analyzes the region in Guizhou karst seepage characteristics and water inflow forecast of foundation pit, which has some new insights, karst foundation pit seepage analysis for the region and water inflow prediction provides a reference model.