预裂角度对柔模砼墙变形机理研究

Research on the deformation mechanism of flexible formwork concrete walls with different presplitting angle

针对锦界煤矿31116运输巷沿空留巷厚直接顶地质条件,建立应变软化与双屈服本构的数值模拟,对比研究了八组切顶卸压方案与未切顶方案,确定90°切基本顶为控制厚基本顶沿空留巷围岩稳定性的最佳方案。现场试验发现,巷道顶板下沉量在回采期间最大达650 mm,两帮最大移近量370 mm,数值模拟中切直接顶时顶板与煤柱帮最大变形量分别为48.8 mm和55.4 mm,切基本顶时顶板与煤柱帮最大变形量分别为38.8 mm和32.4 mm,说明数值分析结果准确可靠且沿空留巷技术可行有效。

According to the geological conditions of thick immediate roof of gob-side entry retaining as 31116 transportation roadway in Jinjie Coal Mine,a numerical simulation considering strain softening and double yield constitutive behavior was established.Eight sets of top cutting and pressure relief schemes were compared with the uncutting scheme,and the cutting main roof with an angle of 90°was determined as the optimal scheme for controlling the stability of the surrounding rock of the gob-side entry retaining with thick main roof.The practical test showed that the maximum subsidence of the roadway roof during the mining period was 650 mm,and the maximum displacement of the two sides of roadway was 370 mm.In numerical simulation,the maximum deformation of the roof and coal pillar sides when cutting the immediate roof was 48.8 mm and 55.4 mm,respectively,and the maximum deformation of the roof and coal pillar sides when cutting the main roof was 38.8 mm and 32.4 mm,respectively,which indicated that the numerical analysis results were accurate and reliable,and the technology of gob-side entry retaining was feasible and effective.