煤矿深部超大断面硐室群围岩连锁失稳控制研究进展

Research progress on chain instability control of surrounding rock forsuper-large section chamber group in deep coal mines

煤矿深部超大断面硐室群因其围岩应力集中程度高、破坏影响范围大,特别是在复杂动载扰动下易发生连锁破坏失稳现象,其安全和稳定已成为制约深部煤炭资源开采的主要瓶颈之一。围绕煤矿深部超大断面硐室群围岩连锁失稳控制开展研究,针对现有煤矿硐室仅以断面尺寸划分的不足,综合硐室失稳临界埋深、断面面积、围岩综合抗压强度和围岩综合完整性系数等影响因素,提出了基于模糊综合聚类分析的煤矿硐室地质力学等效分类方法,实现了对煤矿深部超大断面硐室的有效判识;通过室内试验、理论分析和数值模拟相结合的方法,考虑密实性系数构建了适于动静组合加载条件的岩石蠕变损伤本构关系,建立了深部复杂应力环境下硐室群围岩连锁失稳机理与能量判据,揭示了深部动静组合载荷下超大断面硐室群围岩变形破坏演化规律;提出了深部硐室群围岩协同支护机理,研发了新型高强超塑吸能支护材料及新型高强拉压耦合锚索,基于长期安全稳定性,构建了深部硐室群围岩递进式加固技术及分步设计方法;研发了超大断面硐室群围岩长时变形失稳监测预警平台,给出了围岩综合预警方法及阈值。在新巨龙煤矿煤矸分选硐室群,硐室断面最大收缩率约6.2%,松动圈发育范围1.0~1.5 m,保证了井下煤矸分选系统的空间安全利用。

The super-large section chamber group is prone to chain instability due to its high stress concentration and large failure range,especially under complex dynamic disturbance in deep coal mines.Its safety and stability have become one of the main bottlenecks restricting the exploitation of deep coal resources.In this paper,the chain instability control of surrounding rock for super-large section chamber group in deep coal mines is studied.The main results as follows:firstly,a geomechanical equivalent classification method based on the fuzzy comprehensive clustering method is established.The main influencing factors,such as critical buried depth,cross-section,comprehensive compressive strength and integrity coefficient of surrounding rock,are considered.It overcomes the deficiency of traditional division method based on cross-section only,and the effective classification of super-large section chamber is realized in deep coal mines.Secondly,through comprehensive research methods,such as laboratory tests,theoretical analysis and numerical simulation,the creep constitutive relationship considering compactness coefficient is derived,which is suitable for dynamic and static combined loading conditions.The chain instability mechanism and energy criterion of chamber group are established.On this basis,the deformation and failure evolution of surrounding rock under complex stress environment is revealed.Thirdly,a collaborative control mechanism is proposed.High-strength super-plastic energy-absorbing support materials and new supporting equipment such as high strength tension-compression coupling cable have been developed.For long-term stability,the progressive reinforcement technology and its design method are established.Fourthly,a monitoring and early warning platform for long-term deformation and instability has been built based on comprehensive warning threshold.Finally,in the case study at the Xinjulong Coal Mine,China,the maximum convergence rate of chamber section is about 6.2%,and the range of loosing circle is about 1.0-1.5 m of coal gangue separation chamber group.This research effectively ensures the space safety of coal gangue separation system.