| Water gushing in mines and its prevention and control has always been a hot and difficult point in underground mining.With the increasing demand for mineral resources,underground mining continues to develop deeper and more difficult,resulting in frequent occurrence of mine water inrush accidents.Insufficient research on the hydrogeological conditions of the mining area or wrong judgment is one of the main reasons for the mine water inrush.Therefore,fully studying the hydrogeological conditions of the mining area,effectively predicting the amount of water inflow in the pit,and formulating an effective water control plan are the basic criteria for water control in underground mines.The Panlong lead-zinc mine in Wuxuan County,Guangxi is adjacent to the Datengxia Water Conservancy Project.After the completion of the Datengxia Water Conservancy Project,the water level of the Qianjiang River will reach 61.5m,which is 20～30m higher than usual.As a result,the hydrogeological conditions of the mining area have also undergone major changes.This paper takes the Panlong lead-zinc mine as the research object.Based on the data collection and field investigation,according to the characteristics of the mining area’s geology,hydrogeology,and fault structure,it deeply analyzes the change law of the hydrogeological conditions in the mining area,and comprehensively analyzes the hydrogeological comparison method and Visual MODFLOW numerical simulation predicts the water inflow volume of the mine in the middle of each mining section,and then proposes a proposal to build a hanging curtain on the east and west sides of the mining area.Through this study,the following conclusions can be drawn:（1）The hydrogeological features of the mining area are that the north and south sides are water-resisting boundaries,of which the south side is the Yujiang Formation（D1y）mudstone,the north side is the Ertang Formation（D1e）marlstone.The east side is the boundary of fixed water head（Qianjiang water level）,the west side are the boundary of free water supply（F2fault）.This mining area is located in the groundwater system（area II）of the central mining area,basically forming a complete hydrogeological unit.（2）The karst development in the mining area is mainly above the elevation of-120m.Therefore,the development degree of underground karst in the mining area is divided into:the karst development zone above 0m elevation is relatively strong development zone.The 0～-120m elevation section is the medium development zone.The-120～-500m elevation section is a weakly developed zone.Below the-500m elevation,the karst is basically undeveloped.（3）The numerical simulation of Visual MODFLOW shows that the water inflow will increase by about 1500 m3/d for each deepening of the mining area.Among them,the mine water inflow in the middle section of-270m is 16399 m3/d,and the numerical simulation results are basically consistent with the actual mine water inflow.After the reservoir is impounded,the water inflow volume of the mine at the lowest-800m middle mining section is 39635 m3/d,an increase of about 9500 m3/d compared with that before impoundment.After the Datengxia Dam is impounded,it will affect the east and west sides of the mine at the same time.（4）According to the goal of 50%water blocking rate in the mining area,this study proposes the water control plan in the mining area:build a hanging curtain on the east and west sides of the mining area.The main design indicators are:（1）The curtain shoulder of the north wing of the east-west curtain is placed on the lower Devonian Ertang Formation（D1e）waterproof layer,and the curtain shoulder of the south wing is placed on rests on the lower Devonian Yujiang Formation（D1y）waterproof layer,2m above the bedrock surface,the elevation of the bottom surface of the curtain is set to-125m.（2）The length of the east curtain（downstream of the Qianjiang River）is 1308m,there are two rows of grouting holes,arranged in a plum blossom shape,with a row spacing of 3m and a hole spacing of 6m.The west curtain（47 Exploration Line）length 1296m,one row of grouting holes,the hole distance is 8m.This article can provide a reference for the prevention and control of the mining area water,and it can also provide reference for the water in the similar mining area prevention and control,which has certain reference and significance. |
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