深部开采煤体力学性能亏损的区域效应及其对巷道安全的影响

In deep mining, loss of mechanical properties of coal mass caused to roadway disaster, such as rock burst, great deformation, frequently . Considering area effect of weakening of mechanical properties of coal mass and its influence on roadway safety have not been investigated clearly, in this project, the main research contents are planed to be carried out as follows:(1)The basic mechanical parameters of coal mass in different stress region would be tested through lab experiment, area effect of loss and weakening of engineering coal mass mechanical properties would be studied, the correlation between mining supporting pressure and the weakening and loss of coal mass mechanical properties would be revealed. (2) Burst Potentiality are planed to be acquired through rock mechanics tests, considering energy distribution and burst tendency, method to evaluate roadway burst danger will be established in order to reveal roadway burst area effect. (3)The rheology experiments of coal mass in different stress region will be carried out, which could reveal area effect of rheology rule of coal mass. Considering effects of coal mass instantaneous strain and rheology, method to evaluate risk of roadway deformation will be established, and roadway deformation area effect will be revealed.(4)Rock mechanical experiment with non-uniform mechanical properties and non-uniform loading would be studied. Meanwhile, area effect of mechanical properties and its influence on the safety of roadway would be analyzed.This project is helpful to reveal area effects of weakening and loss of engineering coal mass mechanics properties which will provide new method to prevention and controlling of roadway disasters.

深部开采煤体力学性能急剧亏损，频繁导致巷道冲击地压、大变形等灾害的发生。针对煤体力学性能亏损的区域效应及对巷道安全的影响机制不清晰的难题，本项目进行如下研究工作：（1）对不同应力区域的煤体基本力学参数进行室内实验，分析其区域效应，揭示采动支承压力与煤体基本力学参数亏损程度的相关性。（2）通过室内试验获取工程煤体冲击倾向性的区域特征，考虑煤体能量分布和冲击倾向性双重作用，建立巷道冲击灾害危险性定量表征方法，揭示巷道冲击灾害区域表征；（3）对不同应力区域煤体进行流变实验，获取工程煤体流变的区域特征，考虑煤体瞬时应变和流变双重作用，建立巷道变形危险性定量表征方法，揭示巷道大变形灾害区域特征。（4）开发“非均衡力学性能岩样非均布加载实验方法”，协同分析煤体力学性能亏损的区域效应及其对巷道安全的影响。本项目有助于揭示采动应力下工程煤体力学性能亏损的区域效应，而且为回采巷道灾害防治提供新的方法

据统计，我国煤矿安全事故80%发生在回采巷道，科学决策回采巷道开掘区域，优化应力环境对回采巷道的灾害控制有重要作用。长期以来，回采巷道的开掘区域优化问题只考虑了造成灾害的动力源即采动应力的大小，没有考虑采场周围工程煤体的抵抗能力即煤体的力学特性。针对煤体力学性能亏损的区域效应及对巷道安全的影响机制不清晰的难题，本项目进行了前瞻性的研究。监测了采场周边煤体采动支承压力与煤体力学性能，揭示了工程煤体力学性能呈现明显的区域效应，发现对冲击灾害与变形灾害有重要影响。探究采动应力分布与煤体力学性能亏损程度相关性， 建立采动影响下通过工程煤体力学参数反演支承压力分布的方法。提出了衡量冲击危险性的新指标—冲击潜力，更加科学的表达了工程煤体冲击危险性，进一步建立了冲击潜能表征方程，并讨论了其分布的区域特征。提出了衡量巷道变形危险性的新指标—变形潜力，更加科学的表达了回采巷道变形危险性，进一步建立了变形潜能表达方程，并讨论了其区域特征。综合冲击潜力和变形潜力的双重影响，提出了回采巷道最优区域决策方法。开发“D-N-U”实验方法， 从新的试验方法揭示力学性能区域差异类岩石试样在非均布载荷下力学行为， 及巷道变形特征， 并评价该试验方法可行性。通过“D-N-U” 试验模式， 实现从细观到宏观研究方法的构建。项目实施过程，发表论文SCI论文7篇，中文核心论文2篇，出版专著1部，授权发明专利3项，科研获奖2项，延展性成果获国家自然科学基金面上项目1项，形成政策建议1篇被全国政协采纳转送中央领导及相关部门。本项目的研究将为煤矿回采巷道开掘区域的优化决策及相关灾害的控制提供重要思路。