端部约束作用下巷旁支护体承载与破坏规律研究  

Study on bearing and failure laws of roadside support influenced by end restraint

作　　者：李国栋[1] 曹树刚[1] 杨红运[1] 

机构地区：[1]重庆大学煤矿灾害动力学与控制国家重点实验室,资源及环境科学学院,重庆400044

出　　处：《采矿与安全工程学报》2016年第4期706-712,共7页Journal of Mining & Safety Engineering

基　　金：国家自然科学基金项目(51474039,51404046);重庆大学煤矿灾害动力学与控制国家重点实验室自主课题项目(2011DA105287–ZD201302);重庆市研究生科研创新项目(CYS15007)

摘　　要：为了预测不同端部条件及不同煤层倾角下巷旁支护体的变形和破坏规律,利用FLAC3D构建巷旁支护体模型,通过试算法,获得模型内聚力和内摩擦角随塑性剪切应变的折减函数关系,使数值模型与充填材料在物理压缩试验中获得的应力-应变关系和破坏规律一致。基于该种赋值条件,对巷旁支护体在不同端部条件下的变形破坏规律进行研究,获得以下结论：无端部约束下,峰前支护体内的应力分布近似均匀,可自由侧向变形,且倾角对支护体进入塑性时的峰值载荷大小没有明显影响;存在端部效应时,支护体的峰值承载能力有所提高,并将在侧向产生非均匀变形。在端部约束条件下,随着倾角的变化,支护体的破坏形式不同：当倾角为0°-10°时,呈现多重剪切破坏;10°-25°时,呈现双裂隙的剪切破坏;〉25°时,边界单元呈现摩擦剪切破坏。此外,在倾角作用下,存在端部约束时,在支护体的锐角处应力集中程度最高,在进行支护设计时应补强支护。In order to acquire the regularity of deformation and destruction of the support in gob-side entry retaining, FLAC3 D has been used to build the model of roadside support. By using trial method, the reduction function relationship between cohesion of the model and interior angel and plastic sheer strain has been obtained, which helped to ensure that the stress-strain relationship gained from numerical model and filling materials in the physical compression test is consistent with the fracture law. Based on such parameters, the deformation and destruction characteristics under different end constraints and inclination angles have been analyzed. The main conclusions are as follows. Without end restraint, the stress distribution within support before peak is approximately uniform with unlimited lateral deformation, and the dip angle does not have obvious impact on the peak load before plasticity. With end constraints, the peak stress of support increases a little and lateral inhomogeneous deformation occurs. The destruction forms of the support differ according to different angles： when the angle is between 0° and 10°, multiple shear failure occurs; when it is between 10° and 25°, the double crack shear failure is produced; when it is greater than 25°, the top-bottom boundary friction shear failure presents. Additionally, due to the slope of coal seam, with end restraints, the stress concentration of sharp angle is higher, so it should be reinforced during supporting.

关 键 词：沿空留巷 巷旁支护体 破坏规律 数值模拟 

分 类 号：TD325[矿业工程—矿井建设]