深部回采巷道主应力偏转及塑性区分布形态的煤柱尺寸效应研究

Coal pillar leaving, taken as a normal way to maintain roadway stability in roadway surrounding rock control, which has been used to now. While, with the increasing of mining depth, the principal stress direction caused by coal pillar size can change the plastic zone distribution of surrounding rock. and causing deep roadway surrounding rock principal stress deflection and the size of coal pillar of the plastic zone distribution has obvious effect, then influence the stability of the surrounding rock and coal pillar. Therefore, based on the theory of deep mining roadway surrounding rock plastic zone distribution patterns, the research methods of theoretical analysis,laboratory test, numerical simulation, site detection have intended to be used in this project, thus to analyses the law of the stress field’s direction around deep mining roadway surrounding rock under the influence of coal pillar systematically, and to study on the mechanical mechanism of the influence of the size of coal pillar on the evolution of the plastic zone of the surrounding rock; Meanwhile, to reveal the mechanical nature of the size effect of the coal pillar in the main stress deflection and plastic zone distribution of deep mining roadway. Based on this, and studying the influence mechanism of plastic zone distribution on the stability of mining roadway and coal pillar，and searching for the effective way to control the large plastic area and control the maximum plastic failure direction based on the size of the control pillar, thus to form the guidelines of coal pillar design in deep mining roadway by considering the distribution of the plastic zone of surrounding rock, thus to provide scientific theory foundation for coal pillar design and surrounding rock control in deep mining roadway in practice.

留设煤柱作为一种维护巷道稳定的常规方法在巷道围岩控制中一直沿用至今。然而，随着开采深度的不断增加，煤柱尺寸引起的主应力偏转会使围岩塑性区分布形态发生变化，导致深部回采巷道围岩主应力偏转及塑性区分布形态具有明显的煤柱尺寸效应，进而影响回采巷道围岩及煤柱自身的稳定性。因此，本项目以深部回采巷道围岩塑性区形态为主线，拟采用理论分析、实验室实验、数值模拟及现场探测等综合研究方法，系统分析煤柱尺寸对深部回采巷道围岩应力场方向的影响规律，研究煤柱尺寸影响围岩塑性区形态演化的力学机制，揭示深部回采巷道围岩主应力偏转及塑性区分布形态形成煤柱尺寸效应的力学本质；在此基础之上，研究塑性区分布形态对回采巷道及煤柱稳定性的影响机理，探寻以调控煤柱尺寸为核心的遏制大范围塑性区形成和控制最大塑性破坏方向的有效途径，形成以考虑围岩塑性区分布形态为核心的深部回采巷道煤柱留设准则，为深部巷道煤柱留设和围岩控制提供理论基础。

留设护巷煤柱是一种常见的煤炭地下开采回采巷道维护方式。随着开采深度和开采强度的日益增加，深部回采巷道及煤柱的稳定性控制问题日益突出。现有巷道矿压理论分析的基础是利用采场支承压力分布规律进行回采巷道及煤柱稳定性的研究，而忽视了围岩应力场主应力方向对回采巷道及煤柱稳定性的影响。因此，本项目突破传统支承压力理论忽视深部巷道应力场方向的局限，研究了深部煤柱尺寸对回采巷道围岩应力场主应力方向的影响机制，揭示了煤柱尺寸诱导深部回采巷道围岩主应力偏转的力学机理。在此基础之上，以深部回采巷道围岩塑性区形态为主线，探究了煤柱诱导主应力偏转对围岩塑性区形态演化的影响机制。. 本项目通过三年的系统研究工作，按照项目计划，完成了研究内容，达到了预期目标。通过本项目的研究首次发现了蝶形塑性区方向特性，揭示了围岩主应力偏转和塑性区形态的煤柱尺寸效应形成机制，建立了以围岩塑性区分布形态为核心的深部煤柱留设方法，为认识深部回采巷道围岩大变形灾害机理提供了一种新思路，并为深部回采巷道护巷煤柱留设工程实践提供了一种新方法，丰富了深部巷道围岩矿压理论和控制技术。依托本项目研究成果共发表学术论文6篇（SCI检索3篇，EI检索2篇），出版学术专著1部，授权国内发明专利1项、澳大利亚革新专利2项，软件著作权2项。