Characteristics Of Karst Development And Prediction Of Water Inflow In The Middle Section Of 1800m In The Zengcaidong Lead-zinc Mining Area In Jianshui County, Yunna

Yunnan is rich in mineral resources.Karst development and water filling of mineral deposits are common problems in mining engineering.It is important to evaluate the inflow of mine roadway correctly to reduce the mining cost and ensure the safety of mine production.There are many layers of karst in the liecaidong lead-zinc deposit in jianshui county,yunnan,the carbonate strata are widely distributed,the structure of the mining area is developed,the hydrogeological conditions are complex,and the production and mining activities are greatly affected by the groundwater.The purpose of this work is to find out the characteristics of karst development of the deposit,divide the karst development zone,analyze the water-filling conditions of the mining roadway,determine the hydrogeological parameters,and finally predict the water inflow of the mine.The main understandings and conclusions are as follows:1.The study area belongs to the tectonic erosion landform of the shallow layer in the middle of the mountain.The outcrop strata are mainly carbonate rocks of the old formation,with the lithology of dolomite,limestone and argillaceous limestone.The type of deposit aquifer is direct-indirect water-filled karst fissure aquifer.2.Research in karst development,according to the data of drilling and the pumping test data,determine the various karst hydrogeological parameters of aquifer,the aquifer mining area into the period of old group,and the karst development zone are divided,old group mainly 4 belt of karst development,which will contain(every)layer is divided into13 sections.3.Numerical regression analysis was carried out on the development of karst depressions(sinkholes),the development of borehole fractures in underground holes,and the permeability tensor was determined on the basis of the descending funnel of pumping test.The conclusions obtained by the three methods were basically the same.When there are enough fissure data,the K value of permeability coefficient calculated by the fissure data can replace the K value calculated by pumping(injecting)water test.4.The stratified observation of multi-layer karst aquifer deposit in the mining area was conducted through the borehole stratified pumping test,and the changes of observed water level were recorded.The model was verified.By comparing and verifying three calculation methods,such as water balance method,large well method and numerical method,it is proved that the numerical method is more accurate in this study.The reasonable and accurate underground water flow model was established by using GMS software,and the final simulation predicted that the water inflow of the mine from the mine to the middle of 1800m in the future was 23931.37m~3/d.