Study On The Prediction And Precipitation Scheme Of The Water Surge In A Parking Lot In Qingdao Intercity Track

Along with the development of national economy,underground space engineering is built in large quantities,in the construction process of deep Foundation pit of construction engineering,it is often necessary to reduce the groundwater level to a certain depth,so as to make the bottom of the foundation pit anhydrous and easy to construct.How to ensure the safe and efficient construction of underground engineering,the development of waterproofing and drainage design and construction plan is particularly important,so the correct prediction of foundation Pit Water inrush,effective control of surface and groundwater infiltration has become the focus of engineering construction.There are many methods used to predict groundwater inrush water,such as hydrogeological comparison method,stable well flow analysis method,unsteady flow analysis method,water inrush curve equation method,water equalization method,analytical method,numerical method,etc.,the above method has advantages and disadvantages for the prediction of water inrush in Foundation Pit aquifer.Based on the detailed survey of geology and groundwater filling,diameter and discharge conditions in the study area,this study uses analytic method and numerical simulation method to predict groundwater inrush in Foundation pit aquifer.The concrete conclusions are as follows:(1)The types of groundwater in the study area are divided into bedrock fractured water,the fourth system pore water and tectonic fractured water.In the middle of the field of powder clay distribution,groundwater has micro-pressure.The aquifer in the field is poor in water,the permeability coefficient of bedrock is 0.054-0.14m/d,and the joint fracture belongs to the torsional closed fracture of the study area,which is fractured by the fault of the field,and the fault is broken by the fracture of the north eastward pressure torsional Rice cliff,and there is no hydraulic connection between the southern section of the Fault and the northern section.(2)The field zoning is divided into 10 residential areas,using Chukayev formula to calculate the water inrush 307.3m3/d of the Foundation pit,in order to ensure the safety of the project,take the safety factor 1.5,determine the final water inrush for 461.07 m3/d.In extreme cases,the water inrush is 486.87m3/d.According to the numerical simulation of groundwater,the water inrush before the foundation pit support is 258m3/d,taking the safety factor 1.5,and determining the final water inrush is 387m3/d.After the support,the total water inrush of the foundation Pit is m3/d,in order to ensure the safety of the project,take the safety factor 1.5,determine the final water inrush for 180m3/d.(3)According to the analysis of the results of numerical simulation of groundwater,the foundation pit basement in the study area is located in the bedrock,and there will be no surge of pit bottom.The effect of foundation pit precipitation on the surrounding area is mainly uneven settlement.The cast-in-place pile and rotary jet pile are arranged for supporting and stopping water during construction,and the influence of precipitation on the surrounding area is reduced.