【作者】 李海涛；

【导师】 谭云亮； 宁建国；

【作者基本信息】 山东科技大学 ， 工程力学， 2011， 硕士

【摘要】 随着开采深度的增加,巷道围岩的变形破坏日趋严重,支护更为困难,对深部资源的安全开采带来了巨大威胁。研究表明：在深部高应力开采条件下,巷道围岩内将会出现完整区和破坏区相间隔的现象,称之为“非连续破裂”现象。采用传统的连续介质弹塑性力学已不能完全解释清楚,科学揭示深部巷道围岩非连续破裂机理已成为一个热点,本文通过现场探测、理论分析、数值模拟等研究方法,对这一现象进行系统分析。(1)以新汶矿业集团有限责任公司孙村煤矿、良庄煤矿、鄂庄煤矿深部巷道为探测地点,使用岩层钻孔探测记录仪对不同岩层结构顶板进行探测,探测结果表明：弱结构附近总是伴随着破裂区的出现,由此可知,在高应力作用下,深部巷道围岩内弱结构是产生非连续破裂的关键。(2)利用流变力学知识建立了具有强流变特性的本构模型,即“强流变模型”。该模型除包含传统流变力学元件外,还增加了非线性流变元件,用以描述岩石的加速蠕变阶段,并将其加入Flac3D模型库中,供数值模拟使用；基于理想介质圆形巷道的分析模型,探讨在考虑巷道轴向应力的影响下围岩中应力分布规律,确定了以最大拉应力准则为主、最大剪应力准则及能量准则为辅的破坏准则。(3)在提出合理数值模拟方法后,利用Flac3D考察采深、弱结构、围岩整体强度、巷道断面形状、采动及蠕变对于非连续破裂现象的影响程度,结果表明：足够的采深是产生非连续破裂现象前提条件,而弱结构是围岩内形成非连续破裂现象的关键,围岩强度的大小及采动将会影响到非连续破裂现象的破坏程度以及破坏范围,巷道断面形状对非连续破裂现象影响不大。(4)结合力学分析模型,以径向应变为依据,通过求解最大径向应变出现位置对非连续破裂现象进行力学分析,并基于各因素对非连续破裂现象的影响程度,对非连续破裂现象机理进行解释,进一步明确了“弱结构”在形成非连续破裂现象中的关键作用。更多还原

【Abstract】 Along with mining depth’s increasing, deformation of the rock around tunnels destroys seriously day by day and the supports become more difficult. Depth portion resources’ safe mining is threaten greatly by it. The research indicated:On mining condition of high stress in depth, the phenomenon which the complete area and the destruction area will be separated is presented in surrounding rock and called "Non-continuous disintegrate". It is not able to be explained complete clearly by traditional continuous medium elasto-plasticity mechanics and scientific research about mechanism of Non-continuous disintegrate becomes a hot spot in surrounding rock. The system analysis research to this phenomenon through methods of scene survey, theoretical analysis, numerical simulation and so on is conducted in this dissertation.(1) The survey to the different roof structure tunnel is carrried on by using rock layer drill hole survey recording instrument in Xinwen coal mine, Liangzhuang coal mine, Ezhuang coal mine, Xinwen Mining Group Co., Ltd. The survey result indicated:, the weak structure is the reason which leads to Non-continuous disintegrate on condition of the high stress function in deep roadway. At the same time, factor of creepage and so on also have a great influence.(2) Constitutive model with strong rheological properties is Established by Rheology knowledge and named "strongly rheological model". Nonlinear rheological components is increased in this model besides of traditional rheological mechanical components to describe accelerated creep stage of the rock which is provided to research creep buckling in high stress condition.This model is added in the Flac3D model base for numerical simulation use; Based on media ideal analysis model of circular tunnel, Stress distribution in the surrounding rock is discussed about Tunnel excavating in the initial period under the conditions of axial stress, and the failure criteria which determined mainly by the maximum tensile stress criterion and supplemented by maximum shear stress criterion and energy criterion by numerical simulation of the mechanical angle.(3) After reasonable numerical simulation method determined, the impact of non-continuous fracture phenomenon which is caused by mining depth, weak structure, the overall strength of rock, roadway shape, mining and creep is simulated in Flac3D. The results show that:Enough mining depth is precondition of Non-continuous disintegrate phenomenon. However, weak structure plays a key role. The overall strength of rock and mining affect the scope of the damage and destruction of the non-continuous fracture phenomenon, but roadway shape has small effects.(4) Take the radial strain as the clue, combining with mechanical model, to explain the theoretical mechanism about Non-continuous disintegrate. Based on affect of various factors on the phenomenon of Non-continuous disintegrate explain the phenomenon, Site mechanism is interpreted and critical role which "weak structure" plays is further defined.更多还原