Affiliation of Author(s):  土木与资源工程学院

Teaching and Research Group:  0201

Journal:  The 44th US Rock Mechanics Symposium and 5th U.S.-Canada Rock Mechanics Symposium

Funded by:  “８６３ ”计划

Abstract:  Compared with gentle dip long-wall fully-mechanized top-coal caving, workface length of top-coal caving for extra-steep-thick seam is short, so increasing section height of sub-level is one of the effective methods that can increase production. Meanwhile there are some challenges, such as low caving ratio, roof falling induced by local and large area collapse of top coal in workface, and injury induced by gas accumulation. After crack weakening of high section top coal for extra-steep seam (over 60º), broken top coal (granular medium) has obvious nonlinear movement characteristics. Geological occurrence environment and mining condition of excavation disturbed zone was thoroughly analyzed, based on simulation experiment results of large-scale 3D and coupling of top coal-water-gas, top coal after weakening was regarded as non-continuous medium, Particle Flow Code program was used to compare and analyze motion process and law of high section (30 m) top coal before and after weakening for extra-steep seam of Weihuliang coal mine. Mining experiment and monitor results show that water pre-infusion and pre-splitting blasting can improve top coal caving ability, symmetrical caving, relieve space for large area dynamic collapse of top coal, prolong motion time of noxious gases and escape it from mined out area to realize safe mining.

First Author:  苗胜军

Page Number:  1

Number of Words:  1

Translation or Not:  no