煤矿安全2024，Vol.55Issue(8)：43-50,8.DOI:10.13347/j.cnki.mkaq.20240442
不同温度-冲击载荷下煤的渗透率演化规律研究
Evolution law of permeability of coal in different temperature-impact loads
摘要
Abstract
To explore the changes law of coal holes permeability after fracturing under different temperature and impact loads,based on fractal theory and classical model,the static strain and dynamic strain of coal caused by limiting impact load and temperature are analyzed,and the permeability model of coal in composite field is derived,and the permeability changes with temperature and im-pact load during coal hole fracturing are understood by using impact-fracturing seepage experiments under different temperature-im-pact loads.The results show that when the pressure is less than 1.0 MPa,the permeability channel becomes narrow due to the influ-ence of temperature-impact load,the coal permeability decreases gradually with the increase of impact load,and decreases and tends to be gentle with the increase of temperature;when the pressure is more than or equal to 1.0 MPa and less than 10.0 MPa,the impact load causes the penetration channels to become wider and number to increase,and the permeability increases approximatedly expo-nentially with the increase of the impact load;when the pressure is greater than or equal to 10.0 MPa,the impact load reaches the ul-timate compressive load,the coal fracturing occurs,the impact energy is released,the fracture structure is stable,and the permeabil-ity tends to be stable;under the action of composite field,coal hole impact fracturing goes through two stages:sensitive temperature penetration and sensitive impact load penetration;the calculated values of the new model are basically the same as those of the test,and the change law of the fracture permeability of coal holes under different temperature-impact loads is better presented;under the action of small impact load,the permeability of coal fractured by coal hole decreases,producing a slippage effect;when the impact load reaches the ultimate tensile load of coal,radial and circumferential fractures occur inside the coal,the slippage effect is weakened,and the permeability increases.关键词
温度-冲击载荷/冲击-压裂/静态-动态渗透率/敏感临界值/滑脱效应Key words
temperature-impact load/impact-fracture/static-dynamic permeability/sensitivity threshold/slippage effect分类
矿业与冶金引用本文复制引用
程士宜..不同温度-冲击载荷下煤的渗透率演化规律研究[J].煤矿安全,2024,55(8):43-50,8.基金项目
国家自然科学基金资助项目(52174229) （52174229）
