摘要
深部高地应力、层间软弱夹层(结构面)等复杂应力环境下复合煤(岩)巷道围岩变形严重,底鼓问题尤为突出。针对某矿-830水平大巷复合区域岩巷底鼓大变形技术难题,梳理了复合岩巷现场变形破坏特征,分析了围岩破坏力学机制。结合滑移线场理论建立底鼓力学模型,推导了底板破坏半径R0的显式解析式,并借助ZDY钻孔窥视仪对围岩内部损伤裂隙发育程度进行量化表征。建立UDEC数值计算模型反演了原支护下复合岩巷围岩应力、裂隙发育特征以及位移分布规律,综合分析了复合岩巷底鼓变形机理。结果表明:高地应力、邻近岩石极限强度差异大、底板岩性差、底板无支护或弱支护是复合岩巷产生底鼓大变形的根本性原因。结合现场调研及数值模拟分析结果,基于“固底–强帮”整体支护、“强–弱–强”组合承载圈分梯次加固底板的控制思路,提出了一种“全断面锚索+预制块反底拱”锚注联合支护技术应用于复合岩巷底鼓返修实践中。现场监测结果表明,巷道返修60 d内底鼓缓慢变形直至趋于稳定,最大底鼓量约为67.9 mm,相比原支护条件下底鼓变形量降低了95%,大大降低了巷道重复返修的可能性,确保了该矿煤炭资源安全高效开采。
Under the complex stress environment of deep high ground stress and interlayer weak interlayer(structural surface),the deformation of the surrounding rock of composite coal(rock) roadway is severe, and the floor heave is particularly prominent. In view of the technical difficulties in the large deformation of the floor heave in the complex region of-830roadway in a mine, the deformation and failure characteristics of the roadway are investigated, and the failure mechanics mechanism of the surrounding rock is analyzed. Based on the theory of slip-line field, a mechanical model for the floor heave is established and is used to derive an explicit analytical formula for the failure radius of the floor(R0). With the help of ZDY borehole peeper, the development degree of damage cracks in the surrounding rock is quantified. The UDEC numerical calculation model is established to inverse the stress of the surrounding rock, fracture development characteristics and displacement distribution laws of composite rock roadway under the original support, and the deformation mechanism of floor heave of composite rock roadway is comprehensively analyzed. The results show that the high ground stress, large difference in the ultimate strength of adjacent rock, poor lithology of floor, no support or weak support of floor are the fundamental causes of deformation of the floor heave in composite rock roadway. Considering the results of field investigation and numerical simulation analysis, based on the control idea of “solid bottom-strong side” overall support and “strong-weak-strong” combined bearing ring to strengthen the floor plate step by step, a combined support technology of “full-section anchor cable + precast block inverted-arch” is proposed and applied to the repair practice of the floor heave of composite rock roadway. The field monitoring results show that the floor heave deforms slowly until it becomes stable within 60 days of roadway repair, and the maximum floor heave is about 67.9 mm, which is 95% lower than that under the original support conditions, greatly reducing the possibility of repeated repair of roadway and ensuring the safe and efficient mining of coal resources in the mine.
作者
张栋
柏建彪
闫帅
王瑞
孟宁康
王共元
ZHANG Dong;BAI Jian-biao;YAN Shuai;WANG Rui;MENG Ning-kang;WANG Gong-yuan(State Key Laboratory of Coal Resources and Safe Mining,China University of Mining&Technology,Xuzhou 221116,China;School of Mines,China University of Mining&Technology,Xuzhou 221116,China)
出处
《岩土工程学报》
EI
CAS
CSCD
北大核心
2022年第9期1699-1709,I0011,I0012,共13页
Chinese Journal of Geotechnical Engineering
基金
国家自然科学基金项目(52074239)。
关键词
复合岩巷
底鼓
全断面锚索
预制块反底拱
锚注联合支护
composite rock roadway
floor heave
full-section anchor cable
precast block reverse arch
bolt-grouting combined support
