A pre-mining impact risk pre-assessment method for isolated island working face

Abstract

The invention discloses a method for pre-assessing impact danger of an island working face before mining. The method comprises the steps of collecting related geological information of a to-be-assessed island working face; calculating theoretical evolution height of an overlaying rock and judging a key stratum according to the collected information, and correcting the evolution height of the overlaying rock according to whether the key stratum is broken or not; calculating a static load, a dynamic load and a static and dynamic combined superimposed stress on a coal body of the island working face; measuring uniaxial compressive strength of a coal seam and determining a critical impact load of the coal seam according to the uniaxial compressive strength; and comparing the static and dynamic combined superimposed stress with the critical impact load of the coal seam, and judging an impact danger level. Through laboratory and field actual measurement data, the impact danger of the island working face is assessed by quantitatively comparing the static and dynamic combined superimposed stress with the critical impact load, and the characteristics of the coal seam, the overlaying rock and goafs on two sides of the island working face are fully considered, so that the analysis is more reliable and more persuasive.

Description

technical field [0001] The invention relates to an impact risk pre-assessment method, in particular to an impact risk pre-assessment method based on the stress transfer mechanism of the overlying rock structure, which is suitable for whether the isolated island working face of a coal mine can be mined safely. Background technique [0002] In the early days of mines, strip mining and skip mining were mostly adopted based on safety considerations. This phenomenon is particularly prominent in the central and eastern mining areas of my country. Therefore, these mines generally have various forms of isolated island working faces: goaf on two adjacent sides, goaf on three sides, Two-sided goaf and fault cutting, three-sided goaf and fault cutting, etc. Due to the lack of mineral resources and other reasons in the later stage of mine mining, these legacy island working faces need to be mined. In recent years, with the increase of mining depth, the frequency and intensity of rock bu...

AI Technical Summary

Problems solved by technology

Most of the current impact risk assessment models are aimed at evaluating the impact risk during the mining of the working face, and there are few studies on the impact risk assessment of the working face before mining

Secondly, there are disagreements in the evaluation criteria and various indicators for judging impact instability, ignoring a large number of actual engineering conditions on site

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