摘要
Abstract
In order to study the adaptability of heap spraying technology to gob-side entry retaining,based on the engineering prac-tice of gob-side entry retaining in 11212-2 working face,the support body beside the gob-side entry of the heap spraying technology was studied by means of numerical simulation,physical test and theoretical analysis.The results are as follows:under the condition of roof cutting,the fracture characteristic of the surrounding rock on the roof of the support body is an inverted trapezoid.The sup-port resistance of the support body calcucated by a mechaincal model is 4.16 MPa.The numerical simulation shows that under the condition of roof cutting,the surrounding rock of the roof collapses sufficiently,and the broken edge of the surrounding rock on the upper part of the support body is similar to an inverted trapezoid,which verifies the rationality of the previous analysis.The sprayed concrete material has early strength,the 1 d strength reaches 12 MPa,the resistance increase speed is fast,and the 28 d strength reaches 40.6 MPa,the final strength is high and there is no strength loss.In the early stage,the support body is prone to lateral de-formation.After the steel mesh structure is built in,the lateral deformation is reduced by 78%.In the later stage,there are tension-compression stress areas and shear stress areas in the support body,which are prone to damage.The design has built-in tension steel bars and bolts are applied at the bottom.关键词
堆喷工艺/巷旁支护体/承载特性/沿空留巷/破坏特征Key words
heap spraying technology/roadside support body/load bearing characteristics/gob-side entry retaining/destruction fea-ture分类
矿业与冶金
