【作者】 张华磊；

【导师】 王连国；

【作者基本信息】 中国矿业大学 ， 工程力学， 2011， 博士

【摘要】 随着煤矿开采范围及开采强度的增大,跨采动压巷道的支护问题日益突出,特别是受多次动压影响的巷道,围岩变形破坏机理复杂,且控制十分困难,因此,对跨采动压巷道围岩变形破坏及控制机理进行研究,不仅具有重要的理论意义,而且具有重要的工程应用价值。为此,本文基于弹性力学,首次应用附加应力算法分析了采动支承压力在底板中的传播规律,并将采动支承压力与巷道围岩应力有机结合在一起,建立了跨采动压巷道的弹塑性力学模型,进而运用数值模拟、相似模拟等研究手段,系统分析了煤层群采动影响下巷道围岩变形破坏特征与控制机理,并将研究成果成功运用到跨采动压巷道支护的工程实践,其主要创新性成果主要体现在如下五个方面:(1)基于弹性力学半无限体理论,采用附加应力计算方法建立了采场底板应力分布的力学模型及采动支承压力传播的力学模型,分析了工作面回采过程中底板采动应力分布及传播规律,得到了工作面开采过程中支承压力诱导的底板下某一固定点的应力变化规律。(2)考虑底板采动应力与巷道围岩应力的耦合及岩石应力-应变软化特性,建立了跨采动压巷道的弹塑性力学模型,分析了上覆不同煤层工作面开采时巷道围岩的应力分布规律及巷道围岩变形特征,讨论了支护阻力与跨采动压巷道围岩变形之间的关系,给出了巷道应力及变形随工作面回采时的表达式。(3)借助数值模拟与相似材料模拟方法,分析了跨采动压巷道在煤层群采动时的稳定性特征,得到了巷道围岩应力、塑性区范围及变形规律等随不同的煤层群开采顺序、巷道与上覆工作面不同垂直距离、水平距离的变化规律。研究表明:自上而下的煤层群开采顺序更有利于底板巷道围岩的控制;巷道与上覆工作面水平距离、垂直距离越小时,受到的采动影响越大;巷道靠近工作面一侧拱腰处最先进入破坏状态,且破坏范围最大,是重点的围岩控制区域。(4)运用数值模拟与相似模拟研究了不同支护强度对跨采动压巷道围岩的控制作用,揭示了跨采动压巷道围岩的变形破坏特征,据此提出了“分阶段”支护理念,即根据上覆煤层不同的开采顺序,选用不同的支护方案。(5)针对淮北矿业股份有限公司海孜煤电跨采动压巷道支护存在的问题,提出了以注浆锚杆为核心的分阶段支护方案,通过现场长时间观测,结果表明该支护方案有效地控制了巷道围岩的剧烈变形,保持了巷道围岩的稳定,巷道安全性大大提高。更多还原

【Abstract】 With an increase in coal mining strength, supporting and maintaining the cross-mining roadway with dynamic pressure have become increasingly prominent, expecially the roadway affected by dynamic preeure many times. Its mechanism is so complex to support, therefore, to research mechanism and control of floor roadway with dynamic pressure not noly has important theoretical significance, but also has important application value. Therefore, based on elasticity, this paper firstly analyzes the spread laws of floor abutment pressure in mining by using additional stress algorithm and combines the mining abutment pressure with stress of surrounding rock. And the elastic-plastic model of cross-mining roadway with dynamic pressure is established. In addition, under the conditions of mining coal groups, the features of deformation fracture and mechanism of grading support are systematically analyzed by numerical simulation and analog simulation. And the results were successfully applied to engineering practice of supporting cross-mining roadway with dynamic pressure. The main innovative achievements are as follows:(1) Based on the theory of semi-infinite in elasticity, the mechanical models of floor stress distribution and floor abutment pressure transmission are established by using additional stress algorithm. The distributing and transmission laws of floor abutment pressure during the mining process are analyzed and the changing laws of stress at a fixed point under the floor induced by abutment pressure are obtained.(2) The coupling of floor abutment pressure and roadway rock stress is achieved. Base on this and tri-linear rock stress-strain softening property, this paper establishes an elastic-plastic mechanical model of cross-mining roadway with dynamic pressure and analyses the distribution and deformation laws of surrounding rock during mining different coal. The relationship between the support resistance and deformation of cross-mining roadway with dynamic pressure is discussed and the expressions of stress and deformation of surrounding rock during mining the coal face are obtained.(3) With the help of numerical simulation method and similar material simulation method, this paper analyses the stability characteristics of cross-mining roadway with dynamic pressure under the condition of mining coal groups. And the laws of surrounding rock stress, size of plastic zone and deformation with the different coal mining orders, vertical distances from roadway to overlying workface and horizontal distances are got. The results show that: the order of top-down coal mining is more conducive to control floor surrounding rock. When the horizontal distance between roadway and overlying workface is near, the stability of surrounding rock will be impacted by the overlying mining face and the smaller vertical distance, the greater the impact. The arch lumbar side of the roadway near the workface is the most easily get into the damaged state and its extent of damage is the largest. It is the weak point for the roadway surrounding rock.(4) Using numerical simulation and similar simulation, this paper studies the control effects of different supporting strengthens of abutment pressure in cross-mining roadway with dynamic pressure. And this reveals roadway surrounding rock deformation characteristics of cross-mining roadway with dynamic pressure. Therefore, the idea of "stages" supporting is proposed. That is, the choice of different support programs is based on the different coal mining orders.(5) For the existing support problems of cross-mining roadway with dynamic pressure in Cross Haizi Coal Electricity Huaibei Coal Mining Co., Ltd., a stage supporting program with the core of grouting bolt is put forward. Through field observations, the results show that the support scheme can effectively control the severe deformation of surrounding rock and maintain the stability of roadway. And the roadway safety is greatly enhanced.更多还原