Method for evaluating loading capacity of complete bottom plate during under-pressure mining

Abstract

The invention discloses a method for evaluating the pressure-bearing capacity of a complete bottom plate mined under pressure. The method comprises the following steps: (1) determining the damage depth of the bottom plate; (2) determining whether a floor failure zone has affected an aquifer and causes unsafe mining or not, and otherwise, performing evaluation by adopting steps (3)-(8); (3) determining the position of a specific water-containing rock stratum, coring, and obtaining the porosity n of the water-containing rock stratum; (4) acquiring tensile strength values of the rock samples of the water-containing rock stratum, the overlying rock stratum of the water-containing stratum and the contact zone of the water-containing stratum and the overlying rock stratum; (5) obtaining a top plate water pressure value of the water-containing rock stratum; (6) solving the effective water pressure of the water-containing rock stratum; (7) solving effective tensile strength, and determining the minimum effective tensile strength; (8) calculating a water inrush safety coefficient e; the principle is simple, application is convenient, and evaluation results are more accurate.

Description

technical field [0001] The invention relates to the technical field of evaluation of the pressure bearing capacity of a coal seam floor, in particular to a method for evaluating the pressure bearing capacity of a complete floor under pressure mining. Background technique [0002] Water damage is one of the five major disasters in underground coal mining. Once it occurs, it often causes heavy casualties and property losses, mainly in the form of roof water damage, floor water damage, and old empty water damage. The channels for water inrush include natural channels, artificial channels, and disturbance activation. channel etc. The prevention and control of mine water hazards is relatively difficult, and the specific work is divided into two aspects: prevention and control. At present, the evaluation of water hazards in bottom-floor hydraulic mining mainly refers to the water inrush coefficient method in the "Detailed Rules for Prevention and Control of Water in Coal Mine". ...

AI Technical Summary

Problems solved by technology

At present, the evaluation of water hazards caused by floor pressure hydraulic pressure mining mainly refers to the water inrush coefficient method in the "Coal Mine Water Control Rules". Calculate the ratio of the water pressure of the floor aquifer to the thickness of the floor water-resisting layer, and evaluate the safety of the floor under pressure mining by comparing the threshold value of the water inrush coefficient stipulated in the "Detailed Rules for Water Prevention and Control in Coal Mine". This method is derived from experience , the evaluation conclusions are generally conservative, and the evaluation results are not accurate enough

Images