Meitan kexue jishu (Jul 2023)
Calculation and system of support resistance of shield for contugous-multiple coal seams with coordinated mining
Abstract
Under the coordinated mining mode of close-multiple coal seams, due to the mining influence between coal seams, the roof structural characteristics are different after each coal seam extraction, so the calculation methods of support resistance shield of each coal seam are also different. In order to provide ideas for the setting load of shield determination in each coal seam, the calculation methods of the support capacity of shield in each coal seam is given by comprehensive use of theoretical analysis, system development and field measurement. The results show that: ①The voussoir beam, given load of loose body and voussoir beam with given load of loose body balance roof structure models after each coal seam extraction are established. Voussoir beam balance roof structure model is applicable to the coal seams extractions that are not affected by mining or are less affected by mining. Given load of loose body balance roof structure model is applicable to the coal seams extractions with a single roof stratum and is affected by the upper coal seam extraction. Voussoir beam with given load of loose body balance roof structure model is applicable to the coal seams extractions with multi-rock strata and within has a thick and hard lithology. At the same time, affected by the extraction of the upper coal seam, the rock stratum can still maintain continuity and integrity. ②The “overburden breaking and load evaluation system for close-multiple coal seams extraction” suitable for Kailuan Group is developed, and the recommended selection results of setting load of shield in each coal seam are put forward. Through the field measurement of support capacity of shield, the load utilization rate of shield in each coal seam is generally low and the load margin of shield is too large after using the empirical selection results of the setting load of shield. After adopting the recommended selection results of the setting load of shield in each coal seam, the load utilization rate of shield in each coal seam is significantly improved and the load margin of shield is significantly reduced.
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