Study on optimization of protective coal pillar width on large mining height working face in western China
The size of protective coal pillars has always been a hot topic in research on mining under buildings,railways and waters.Its impact on the safety of surface buildings,especially under the conditions of large mining height and high-strength soft overburden thick coal seam mining in western China,needs to be further studied.Taking the 20119 working face in Yushuwan well field as an example,this study first determined the reasonable width of protective coal pillars through a combination of numerical simulation and probabilistic integration method and carried out an on-site verification.The results show that as the width of the coal pillar decreases,the horizontal movement of the surface along the X direction shows an inverted"S"trend,and the movement along the Y direction shows an inverted"U"trend,and that the maximum subsidence of the surface decreases with the decrease of the width of the pillar.Then,the probability integral method was used to predict the width of the protected coal pillar.The optimized width of the coal pillar was determined to be 180 m.Finally,the real-time monitoring of the on-site village was carried out and the results show that the values of surface subsidence and inclination meet the requirements of the on-site construction,verifying the reasonableness of the protection of the coal pillar.
large mining height working facenumerical simulationprobabilistic integrationprotective coal pillar width
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