Study on the failure depth of thick seam floor in deep mining

Aimed at the trend of water inrush disasters increasing annually with the mining depth above confined aquifers,based on the conditions of the fully mechanized workface in the deep mine,and according to the in-situ strain value of the mining face at different depth under the coal seam bed,it was determined the coal seam floor failure depth was between 18-20 m.This study analyzed the characteristics of coal seam floor failure through repeated calculations and gradual correction to model boundary conditions,based on the actual formation material in the study area to establish the geological model,which makes up for the disadvantages of coal seam mining stress that the field measurement result could not reflect.The coal seam floor failure depth was 20 m,and it revealed the characteristics of the mine pressure in mining coal floor when combining the in-situ strain measurement method with the numerical simulation method.