【作者】 黄先伍；

【导师】 缪协兴；

【作者基本信息】 中国矿业大学 ， 固体力学， 2008， 博士

【摘要】 随着煤矿开采不断向深部延伸,其开采条件不断劣化,高地应力、高承压水、各种复杂地质构造等因素,使得煤矿井下巷道的维护与围岩变形控制变得越来越困难,岩体的流变特性表现得越来越突出,因而,岩体结构变形的时间相关性研究成为深部岩土工程中广泛关注的热点问题。本文针对深部煤矿巷道受力与稳定性特征及支护难题,从破碎岩石承压变形的时间相关性试验、局部支护下应力场的理论分析、渗流作用下巷道围岩应力场的弹塑性分析及变形的粘弹性分析、局部支护下巷道围岩稳定性的数值分析等方面对巷道围岩的应力场及变形场进行研究。论文取得的主要研究成果及创新点有:(1)基于破碎岩石的承压变形时间相关性试验,得到岩样在各级应力水平下孔隙度及其变化率的时间历程曲线;考虑渗流作用时孔隙水压的时间历程曲线;岩样孔隙度变化率与其关系曲线。给出了岩性、含水性、渗流作用对岩样变形时间相关特性的影响规律。(2)采用自然边界元法的数学理论及弹性力学理论推导了深埋巷道在无支护、整体平衡支护、局部支护、局部弱支护下围岩内应力函数的边界积分公式,进而得到了围岩内应力的解析解或半解析解。(3)应用弹塑性理论,得到了存在渗流作用时巷道围岩内的应力场、塑性区分布及巷道边界位移随孔隙水压的变化规律。采用K-V蠕变模型研究了巷道整体平衡支护下围岩与支护系统的粘弹性变形,得到了围岩与衬砌相互作用力及巷道边界位移及考虑渗流作用时巷道围岩径向位移随时间的变化规律。(4)利用数值模拟方法研究了整体弱支护及局部弱支护下巷道围岩应力场、塑性区分布及巷道顶板、底板、两帮位移等的时间相关特性,探讨了侧压系数、弱支护抗力及弱支护范围对巷道围岩稳定性的影响。同时,分析得到了底板承压水渗流作用下弱支护巷道围岩的应力场、渗流速度、塑性区分布、围岩变形等随孔压的变化规律。研究成果可为深部高应力软岩巷道的变形分析与稳定性控制等提供参考。更多还原

【Abstract】 With the increase of mining depth and mining intensity, the mining conditions are getting worse and worse. For example, high ground pressure, high confined water, various complicate geological structure, and so on, made the roadway maintenance and the deformation control of surrounding rock becoming more and more difficult and the rheological property of rock mass are becoming more and more obvious. So the study on time-dependent of the rockmass structure deformation becomes a hot issue concerned widely in deep geotechnical engineering. In this paper, According to the problem of the forced and stability characteristics of roadway and its support in deep coal mine, the stress field and the deformation field of the roadway surrounding rock are studied by the following aspects such as the experiment on the time-dependent deformation under pressure for broken rock, the theoretical analysis of the stress field under local supporting, the analysis on the elastic-plastic stress field and the visco-elastic deformation of roadway surrounding rock under the water flow, and the numeric analysis on the stability of roadway surrounding rock. The main research results and innovative points are as follows:(1) Based on the experiment of the time-dependent deformation of the broken rock under pressure, the time-history curves of the porosity and its variation rate, the pore pressure-time curves at every stress level under water flow and the curves of rock porosity-porosity variation are obtained. From these curves the effects laws of the lithology, the moisture state and the water flow on the property of time-dependent deformation are given.(2) Using the mathematical theory of the natural boundary element method and the elasticity theory, the boundary integral formulas for the stress functions of roadway surrounding rock with not any support, whole balance support, local support and local weak support on the deep roadway boundary are derived respectively, moreover, from the integral formula the analytic or semi-analytical solutions to the stress of surrounding rock are obtained.(3) Making using of the elastic-plastic theory, the laws of the stress field, plastic region distribution of surrounding rock and the boundary displacement of the roadway changing with the pore pressure are obtained. Using a K-V creep model, the visco-elastic deformation of surrounding rock- supporting system under the whole balance supporting is studied and the changing laws with time of the interactive force between the surrounding rock and liner supporting, the boundary displacement of the roadway and the radial displacement of the roadway surrounding rock under the water flow are obtained respectively.(4) Using numerical simulation methods, the stress field of the surrounding rock and the time-dependent properties such as the plastic distribution and the displacements of the roof, floor and two sides under the whole weak supporting and the local weak supporting are studied, accordingly, the effects of the lateral pressure coefficient, local supporting force and its area on the stability of the surrounding rock are investigated. In the same time, under the flow of the confined water in the floor, the changing laws with the pore pressure for the stress field of the surrounding rock under the local supporting, flow velocity, the plastic distribution and the deformation of the surrounding rock are also obtained.The research results can provide a reference for the deformation analysis and stability control of the deep soft rock roadway with high ground pressure.更多还原