State Key Laboratory of Mining Response and Disaster Prevention and Control in Deep Coal Mines, Anhui University of Science and Technology
Engineering Technology Research Center for Safe and Efficient Mining, Anhui University of Science and Technology
State and Local Joint Engineering Laboratory for Gas Drainage & Ground Control of Deep Mines, Henan Polytechnic University
Beijing Kunming High-speed Railway Xikun Co., Ltd.

目前缺乏对空气致裂全过程进行精准监测和评价的手段，而应变监测能够实时记录裂纹萌生和扩展的过程。通过研究高压气体冲击全过程中孔壁的应变响应，可明确致裂过程裂纹与应变响应之间的关系，获得最优致裂角度。为了探寻高压气体致裂煤岩体过程中裂纹和与应变之间的关系，利用高压气体冲击致裂煤岩体真三轴实验系统，开展了5种冲击角度（0，30，45，60，90°）下的高压气体致裂实验，研究了气体致裂过程中煤岩体裂缝形态、气压曲线与孔壁应变响应特征。实验结果表明：① 随着冲击角度增加，煤岩体裂缝形态呈现先复杂后单一的分布特征。② 致裂过程中气压呈现上升、陡降、聚集、稳定释放4个阶段。③ 孔壁应变数据主要由拉应变组成，应变曲线出现2个明显峰值，第1个峰值在气压曲线达到峰值0.1 s后出现并伴随主裂纹产生，第2个峰值常伴随着主裂纹的衍生与扩展。④ 当冲击角度为45°时，试件内部容易萌生复杂裂纹网络，致裂效果最佳。

There has been a lack of precise methods for monitoring and evaluating the entire process of gas fracturing. However, strain monitoring can effectively record the real-time initiation and propagation of cracks. By studying the strain response of borehole walls during high-pressure gas impact, the relationship between crack formation and strain response during the fracturing process can be clarified, enabling the identification of the optimal fracturing angle. A true triaxial experimental system for high-pressure gas fracturing of coal and rock was used, and experiments were conducted at five different impact angles (0, 30, 45, 60, 90°) to investigate crack morphology, pressure curves, and strain response characteristics of the borehole walls. The experimental results revealed that: ① As the impact angle increased, the crack morphology of coal and rock exhibited a pattern that was initially complex but later became simpler. ② The gas pressure during the fracturing process passed through four stages: an increase, a sharp drop, accumulation, and steady release. ③ The strain data for the borehole walls were predominantly tensile, and the strain curve displayed two distinct peaks: the first peak occurred 0.1 seconds after the pressure curve reached its peak, coinciding with the formation of the main crack; the second peak was generally associated with the propagation and expansion of the main crack. ④ When the impact angle was 45°, a more complex crack network tended to form within the specimen, resulting in the most effective fracturing.

云南省重点研发项目（202303AA080014）；深井瓦斯抽采与围岩控制技术国家地方联合工程实验室开放基金资助项目（SJF2203）；安徽省高校杰出青年科研项目（2024AH020001）。

孔子幸，马衍坤，杨发德，等. 高压气体致裂煤岩孔壁应变响应特征研究[J]. 工矿自动化，2024，50（10）：105-111.

KONG Zixing, MA Yankun, YANG Fade, et al. Study on the strain response characteristics of coal and rock borehole walls under high-pressure gas fracturing[J]. Journal of Mine Automation，2024，50（10）：105-111.