【作者】 张寅；

【导师】 缪协兴；

【作者基本信息】 中国矿业大学 ， 工程力学， 2010， 博士

【摘要】 冲击地压是一种复杂的矿井动力现象,一直是岩体力学及矿山灾害防治研究的难点之一。近年来随着煤矿开采深度的不断增加,开采强度不断加大,出现冲击地压显现的矿井明显增多,分布范围越来越广,给矿井生产和安全带来了极大的威胁,因而开展对深部煤矿冲击地压等动力灾害的防治理论与技术研究工作是一项刻不容缓的任务。本文综合利用理论分析、数值模拟、现场实测等方法和手段,系统研究了深部特厚煤层巷道在静载和冲击载荷作用下的响应规律,得到了巷道在冲击作用下的应力、速度、加速度以及能量分布等规律,主要的创新工作与成果包括以下几个方面:(1)利用弹性力学理论推导了双层及四层复合厚壁圆筒在围压下的应力分布公式,基于有限元理论分析了三层厚壁圆筒在围压下的应力分布规律,针对深部特厚煤层全煤巷道进行了煤体及其支护结构分区性、结构性、功能性研究,提出了巷道围岩由U型钢可缩性金属支架组成的约束圈,锚网索等巷道支护及围岩组成的支护圈,经过注水软化或放炮松动后所形成的卸压缓冲圈,原岩组成的完整拱形圈的“弱-强-弱-强”力学模型,并分析了该模型的防冲击机理。(2)在冲击波传播特性理论分析的基础上,借助通用显式动力分析程序ANSYS/LS-DYNA对冲击作用下单层及多层复合巷道围岩进行了数值模拟,得到了整个冲击过程中巷道及其围岩的应力场、速度场及加速度场,通过两者的对比,发现具有弱夹层的复合结构巷道有较好的防冲击性能,并分析了其防冲机理。(3)采用数值模拟方法对不同截面形状巷道开挖后的应力状态及巷道围岩集聚的弹性应变能分布状态进行了研究,得出了有利于防止冲击地压等动力灾害的合适巷道截面形状以及巷道围岩弹性应变能的分布规律。利用FLAC3D对3种不同形状的巷道在冲击载荷作用下的力学和能量响应进行分析和比较,得到了冲击过程中围岩应力分布情况以及能量积聚的特征,为分析冲击地压提供了一种可行的分析手段。(4)首次提出沿综放工作面顺槽预掘卸压硐室来达到消除冲击地压现象的方法。通过数值模拟的方法确定了卸压硐室的合理间距和开挖深度,为了研究预掘卸压硐室防冲击地压方案的卸压效果,对卸压硐室和运输巷的表面位移和锚杆应力进行现场实测,得到了部分卸压硐室以及硐室邻近的巷道位置处顶板锚杆的应力变化规律,验证了预掘卸压硐室卸压的效果。本论文有图139幅,表20个,参考文献177篇。更多还原

【Abstract】 Rock burst is a complex dynamic phenomena and one of the difficulties of research on mine disasters controlling. The number of mines in which rock burst occurred is increasing and the rock burst distribution is extending as the mining depth and intensity increases, which threatenes the production and safety of mines, so the study on controlling theory and technology of deep coal mine rock burst is immediately needed. This dissertation systematically researched the response regularity of deep thick seam roadway suffering static load and dynamic load through theoretical analysis, numerical simulation and field measurement etc, and stress, velocity, acceleration and energy distribution of roadway under impulsive load were gained. The mainly original works and achievements are as follows:(1) Stress distribution equations of double-layer and four-layer thick walled cylinder under confining pressure were deducted with elasticity theory, and finite element theory was used to analyze the stress distribution of triple-layer cylinder, also suffering confining pressure. Zoning, structure and function of coal mass in deep super thick seam and its support structure were studied. Based on those studies, we can bring forth the standpoint that roadway surrounding rock can be simplified to a“strong-weak-strong-weak(S-W-S-W)”mechanical model including the following parts: constraint circle formed by U-shaped contractible metal stents; support circle made up of bolt-mesh-cable support and surrounding rock; pressure relief and buffering circle formed after water injection or loosening blasting; fully arch circle formed by initial rock. Rock burst controlling mechanism of the S-W-S-W model was analyzed.(2) Based on the analysis of shock wave spreading characteristic, single-layer and multi-layer composite roadway surrounding rock under impulsive load were analyzed in universal explicit dynamic analysis program ANSYS/LS-DYNA. Comparison between stress, velocity, acceleration field of roadway and surrounding rock shows that the composite structure roadway containing weak interlayer has a better effect of rock burst controlling, and its controlling mechanism was analyzed.(3) Stress condition and distribution of concentrated elastic strain energy in surrounding rock of roadways with different shaped sections were analyzed by using numerical simulation, proper shapes of roadway section better for preventing rock burst and other dynamic disaster was gained. Mechanics and energy response of roadways with three different shaped sections were analyzed and compared, stress distribution and energy concentration characteristics during impulse were acquired, a feasible method for rock burst analysis can be derived from those results.(4) The rock burst controlling method of pre-excavating pressure relief chambers orient fully mechanized top coal caving face has been advanced for the first time. Proper interval and depth of pressure relief chambers were decided in numerical simulation. Pressure relief chambers and transport gateways surface displacement and stress in the bolts were measured in the field to study the pressure relief chambers design’s effect of controlling rock burst. Stress in some of the pressure relief chambers and nearing roadways’roof bolts was acquired, and that confirmed the pre-excavated pressure relief chambers’effect of controlling rock burst.There are 139 figures, 20 tables and 177 references in this dissertation.更多还原