Floor Water Inrush Risk Evaluation And Mine Water Inflow Prediction In Donghuantuo Mine

The bottom of Donghuantuo mine is threatened by ordovician limestone water and has the risk of water inrush.Once water inrush accident happens,it will cause a lot of casualties and property loss.Therefore,it is necessary to evaluate the risk of water inrush and predict the water inflow before coal mining.Based on the analysis of geophysical,geochemical and drilling data of Donghuantuo mine,the hydrogeological conditions are summarized,and the factors of floor water filling and potential water filling channels are analyzed which concluded that the hydrogeological conditions is complex type.Numerical simulation is used to simulate the coal seam retrieval process and analyse to obtain the change law of waterproof layer property,the destruction process and the destruct law of floor under the influence of coal seam mining.Factor sets including coal seam conditions,mining conditions,aquifer performance and aquiclude performance were selected to establish a targeted index system for evaluating the risk of water inrush from 8 coal seam floor in Donghuantuo mine.Ten main control factors of permeability,water pressure,waterrichness,fault size,tectonic complexity,water barrier thickness,brittle plastic rock thickness ratio,coal seam thickness,coal seam depth of burial,and the depth of damage to the bottom slab were quantified and analyzed,and their high-low attribute were determined.Using analytic hierarchy processto determine the subjective weights of each factor.And using a new method of weighted rank and ratio method to combine the main control factor weights and performance attribute data,the data is graded to four grade intervals of safe,safer,more dangerous and dangerous.Using the powerful information presentation capabilities of GIS to present results.Seasonally decomposed the ARIMA model and compared with original model,the new seasonal decomposition model is found to be more accurate and effective.The new model is used to predict the water inflow of Donghuantuo Mine in the second half of 2022.The research results have great guilding significance to the actual normal production of mine.This article included 32 figures,36 tables and 85 references.