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