长壁工作面基础板结构模型及其来压规律

MODEL FOR STRUCTURE OF FOUNDATION PLATE INLONGWALL FACE AND RULES OF ITS WEIGHTING

首次将长壁工作面支承老顶的直接顶与煤层分别视为弹性、弹塑性、粘弹性及粘塑性基础，将老顶视为弹性薄板，亦即将老顶及其基础（直接顶与煤层）分别视为４种统一的空间结构模型，并采用薄板弯曲边界元法分别与弹性、弹塑性、粘弹性及粘塑性边界元法耦合，对前述空间模型进行了求解，结果表明：老顶断裂后，各断裂岩板之间仍处于联锁咬合状态，形成了咬合板结构；随着基础从弹性向粘塑性过渡，老顶的断裂位置与煤壁间的距离以及顶板下沉率将增加，而应力集中系数、初次来压动载系数、周期来压动载系数及老顶与基础系统的反弹量将减小．

The immediate roof and coal which support the main roof in a longwall face are regarded separately as elastic,elasto plastic,visco elastic and visco plastic foundation,and the main roof is regarded as an elastic plate.That is,the main roof and its foundation (immediate roof and coal seam) are regarded respectively as four united spatial structural models.The boundary element method for bent thin plates combines individually with elastic,elasto plastic,visco elastic and visco plastic boundary element method to solve the above mentioned models.The results show that when the main roof fractures,all the fractured rock plates are still in an interlocking gripping state which forms as engaged plate structure.In the transitional period of the foundation from elastic to visco plastic state,the distance between the fracture of the main roof and coal seam and roof convergence rate increase,and the stress concentration factor,the dynamic coefficient of primary weighting,the dynamic coefficient of periodic weighting and the amount of reverse elastic movement of the main roof and foundation system decrease.