分级围岩下充填滞后时间优化及数值分析

Optimization and numerical analysis of filling lag time under graded surrounding rock

为研究合理采空区充填时间,基于蠕变理论,利用改进的西原正夫模型进行分析,确定最佳充填时间段;采用FLAC^(3D)软件进行采场及围岩三维模型构建,进行不同等级岩体在不同充填滞后时间下采场稳定性分析,确定不同等级围岩合理充填滞后时间。结果表明:1)采用充填采矿法进行矿体开采,可有效抑制围岩变形,并提高采场稳定性。2)Ⅲ、Ⅳ、Ⅴ级岩体条件下即采即充能使采场的变形达到最小,有效控制采场的变形。3)Ⅲ级围岩的充填滞后时间不应超80 h,Ⅳ级围岩的充填滞后时间不应超60 h,Ⅴ级围岩的充填滞后时间不应超30 h。

In order to study the reasonable filling time of goaf,based on creep theory,the improved Nishihara model was used to determine the best filling time.FLAC^(3D) software was used to build the 3D model of stope and surrounding rock,the stope stability of different grades of rock under different filling lag time was analyzed,and the reasonable filling lag time of different grades of surrounding rock was determined.The results indicated that:1)The filling mining method can effectively restrain the deformation of surrounding rock and improve the stope stability.2)Under the condition of gradeⅢ,Ⅳand V rock mass,the stope deformation can be minimized and effectively controlled.3)The filling lag time of classⅢsurrounding rock should not exceed 80 h,the filling lag time of classⅣsurrounding rock should not exceed 60 h,and the filling lag time of class V surrounding rock should not exceed 30 h.