摘要
为探究玻璃钢锚杆在软弱层直接顶板巷道的支护效果,以湖北肖家河磷矿为工程背景,对比管缝锚杆支护,开展两种锚杆支护的巷道收敛监测试验。监测数据表明,玻璃钢锚杆与管缝锚杆支护的软弱层直接顶板巷道的位移变形规律一致。同时,顶板厚度变化对锚杆支护效果具有显著影响。对此,利用数值模拟进一步探讨不同层状顶板厚度下2种锚杆的支护效果。结果表明,在顶板厚度变化条件下,与管缝锚杆相比,玻璃钢锚杆支护对顶板厚度变化的敏感程度相对较低,支护效果优于管缝锚杆。同时,玻璃钢锚杆支护效果受软弱层直接顶板厚度增大而呈现阶段性变化特征。随着顶板厚度增加,顶板沉降量呈现先线性增长后对数型增长的规律,巷道围岩塑性区占比呈现先增大再减小后趋于稳定的规律。通过对不同顶板厚度的玻璃钢锚杆和管缝锚杆轴向拉力值进行比较,揭示了玻璃钢锚杆支护效果更好的原因是玻璃钢锚杆能够在顶板厚度增加的情况下提供更大的轴向拉力。
The paper has done 2 kinds of convergence monitoring tests of bolts to compare the pipe-joint bolt supporting effect with that of the slit-wedge tubing bolt in the direct roof roadways in the weak strata by taking Xiaojiahe Phosphate Mine in Hubei as a case sample of engineering background. And,for the said purpose,we have done convergence monitoring tests of the 2 bolt ways to compare the support effects of the FRP bolt in direct roof roadways in the weak strata. The effects of the monitoring data show that the displacement and deformation regularity of the direct roof roadway in the weak layer supported by FRP bolt and by the pipe joint bolt proves consistent. At the same time,the change of the roof thickness has been found of significant impact on the effect of the support. To prove the effect,we have done numerical simulations to further the exploration by taking the roof settlement and the number of plastic zones of the surrounding rock as the reference to the simulation. The results of our simulation demonstrate that,under the condition of the roof thickness variation,the FRP bolt support to the roof thickness variation turns out to be less sensitive than that of the pipe joint bolt,and,therefore,the support effect it proves better than that of the pipejoint bolt. On the other hand,the FRP bolt support tends to be affected by the phased changes with the thickness increase of the direct weak layer roof. That is to say,with the increase of the roof thickness,its settlement tends to increase first linearly and then logarithmically. If the ratio of the plastic zone in the surrounding rock of the roadway increases first,then decreases,it can be said that the changing trend is stable and regular. And,furthermore,we have also traced the relation between the failure form of the roof and the thickness of the direct roof in the weak strata,and brought up forward the variation regularity of the bolt supporting effect,and have then made clear the comparative relation between the thickness of the roof and the length of the bolt in addition to the difference of the roof failure form under its different thicknesses. And,so,we have analyzed the axial tension extents of the FRP bolts and the slotted bolts under the different roof thicknesses,too,hencefore,confirmed that the FRP bolts can be expected to provide for greater axial tension to extrude the roof and maintain its stability with the increase of its thickness.Hence,the research results can be expected to serve as a technical reference for the application of FRP bolts in the direct roof roadway in the soft stratum.
作者
叶义成
陈虎
王其虎
周趾金
关炜
刘冉
YE Yi-cheng;CHEN Hu;WANG Qi-hu;ZHOU Zhi-jin;GUAN Wei;LIU Ran(School of Resource&Environmental Engineering,Wuhan University of Science&Technology,Wuhan 430081,China;Industrial Safety Engineering Technology Research Center of Hubei Province,Wuhan 430081,China;Yichang Mingxin Industry and Trade Co.,Ltd.Xiaojiahe Phosphate Mine,Yichang 443145,Hubei,China)
出处
《安全与环境学报》
CAS
CSCD
北大核心
2020年第3期913-919,共7页
Journal of Safety and Environment
基金
湖北省2017年安全生产专项(HBAJ(2017)-35)
湖北省自然科学基金项目(2017CFC831)。
关键词
安全工程
软弱层直接顶板
玻璃钢锚杆
支护
顶板厚度
管缝锚杆
safety engineering
weak layer direct roof
FRP bolt
support
roof thickness
slit wedge tubing bolt
