| 正断层上盘煤与瓦斯突出特征与地应力场控制机理 |
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| 引用本文： | 曹运兴,张海洋,张震,刘高峰.正断层上盘煤与瓦斯突出特征与地应力场控制机理[J].煤田地质与勘探,2022,50(4):61-69. |
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| 作者姓名： | 曹运兴 张海洋 张震 刘高峰 |
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| 作者单位： | 1. 河南理工大学煤层气/瓦斯地质工程研究中心;2. 河南省非常规能源与开发国际联合实验室;3. 中原经济区煤层(页岩)气河南省协同创新中心 |
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| 基金项目： | 国家科技重大专项课题(2016ZX05067006-002)；;国家自然科学基金项目(41302126)； |
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| 摘 要： | 断层带是煤与瓦斯突出发生的主要地质单元。大量煤与瓦斯突出案例统计显示，对于正断层，发生在上盘的突出次数和强度明显大于下盘，但造成这一现象的地质机理研究不多，特别是正断层上盘的地应力场在采动前后的变化规律及其对突出发生的控制机理尚未完全揭示。基于此，以河南焦作矿区中马村煤矿DF4正断层为地质模型，应用FLAC3D软件，模拟研究煤层埋深分别为660、800、1 000 m，对应3种地应力场(σ1最大主应力、σH最大水平主应力、σh最小水平主应力、σv垂向主应力)状态σ1=σH，σ1=σv，σv=σH=σh 条件下，采动前和掘进工作面逼近断层面过程中正断层两盘的地应力场变化规律，探索地应力分布对煤与瓦斯突出的作用。结果表明，未采动原始状态下正断层上盘的地应力值高于下盘；无论上盘巷道还是下盘巷道，在掘进工作面逼近断层过程中，断层上盘的地应力值总是高于下盘；特别是，在巷道掘进至断层面附近10 m时，原始地应力与采动应力在断层带发生积聚叠加，地应力值在断层上盘大幅度增高。采动前后地应力在正断层上盘集中升高，可能是导致正断层上盘更容易发生煤与瓦斯突出的决定性因素。此项研究可为预测和防治煤与瓦斯突出灾害提供理论依据。
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| 关 键 词： | 煤与瓦斯突出 正断层 地应力 数值模拟 |
| 收稿时间： | 2021-08-10 |
Characteristics of coal and gas outburst and controlling mechanism of stress field in the hanging wall of normal faults |
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| Abstract: | The fault zone is the main geological unit where coal and gas outbursts occur. Statistics of many coal and gas outbursts show that the number and intensity of the outbursts in the hanging wall are significantly greater than those in the foot wall for normal faults. However, there are few studies on the geological mechanism of this phenomenon, especially the variation of the in-situ stress field in the hanging wall of normal faults before and after mining, and its controlling mechanism of coal and gas outbursts that has not been completely demonstrated. In view of this, the normal fault DF4 in Zhongmacun Coal Mine in Jiaozuo Mining Area was taken as a geological model, and the FLAC3D software was applied to simulate and study the variation law of the in-situ stress field on hanging and foot walls of the normal fault before mining and during the process of tunneling to approach the fault plane of the heading face under the conditions of the burial depths of the coal seams of 660 m, 800 m and 1 000 m, respectively, corresponding to the three kinds of stress fields with σ1=σH, σ1=σv and σv=σH =σh(σ1, σH, σh and σv are the maximum principal stress, maximum horizontal principal stress, minimum horizontal principal stress and vertical principal stress, respectively). The effect of in-situ stress distribution on coal and gas outbursts was investigated. The results show that the original in-situ stress of the hanging wall of normal faults is greater than that of the foot wall before mining. The in-situ stress of the hanging wall is always greater than that of the foot wall in the process of driving face approaching the fault plane. In particular, the original in-situ stress and the mining stress accumulate in the fault zone and then the in-situ stress of the hanging wall increases significantly when the roadway is 10 m near the fault plane. In summary, the in-situ stress concentrates and increases in the hanging wall before and after mining, which is deduced as the decisive factor for the occurrence of coal and gas outbursts in the hanging wall of normal faults. This research can provide a theoretical basis for preventing the coal and gas outburst disaster. |
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