高围压条件下含瓦斯水合物煤体强度准则研究  

Strength criteria of gas hydrate-containing coal under high confining pressure

作　　者：高霞 沈爽 张保勇 GAO Xia;SHEN Shuang;ZHANG Baoyong(School of Architecture&Civil Engineering,Heilongjiang University of Science&Technology,Harbin 150022,China;School of Safety Engineering,Heilongjiang University of Science&Technology,Harbin 150022,China)

机构地区：[1]黑龙江科技大学建筑工程学院,黑龙江哈尔滨150022 [2]黑龙江科技大学安全工程学院,黑龙江哈尔滨150022

出　　处：《煤矿安全》2023年第2期8-14,共7页Safety in Coal Mines

基　　金：国家自然科学基金资助项目(51974112,51674108)。

摘　　要：为了探讨Mohr-Coulomb(M-C)准则、Hoek-Brown(H-B)准则以及广义Hoek-Brown(GH-B)准则3种强度准则对高围压条件下含瓦斯水合物煤体的适用性;基于不同饱和度(50%、80%)和不同围压(12、16、20 MPa)条件下,进行常规三轴加载试验,对试验获得的应力-应变曲线进行分析,并利用3种强度准则对最大主应力和围压进行拟合;同时引用均方根偏差RMSE、相关系数等评价指标,探讨不同的强度准则对于含瓦斯水合物煤体的适用性。研究表明:在高围压条件下,应力-应变曲线呈应变硬化型,围压和饱和度越高,峰值强度越高,围压对峰值强度的影响较为显著;M-C准则和GH-B准则对于试验数据拟合的相关系数较高,拟合效果较好,RMSE值较低,预测值与试验值的线性拟合直线与1∶1梯度线非常接近,说明2种准则对含瓦斯水合物煤体的适用性较好;H-B准则的相关系数低于M-C准则和GH-B准则,RMSE值较大,对含瓦斯水合物煤体的适用性略低于M-C准则和GH-B准则。The conventional triaxial loading tests were conducted under different saturation(50%, 80%) and confining pressures(12 MPa, 16 MPa, 20 MPa)to explore the applicability of Mohr-Coulomb(M-C)criterion, Hoek-Brown(H-B)criterion as well as Generalized Hoek-Brown(GH-B) criterion to gas hydrate-containing coal under high confining pressure condition. The stressstrain curves were analyzed, and the variation of the main principal stress with the confining pressure was fitted by using the formulas of three strength criteria. Meanwhile, the root mean square deviation RMSE and correlation coefficient were introduced to evaluate the applicability of different strength criteria for gas hydrate-containing coal. The results show that the stress-strain curves exhibit strain hardening characteristics under the condition of high confining pressure. The higher the confining pressure and saturation, the higher the peak strength. The confining pressure has a significant effect on the peak strength. M-C and GH-B criteria are proved to have good fitting effect on the test data, with higher correlation coefficient and lower RMSE value than H-B criterion. The linear fitting line between the predicted value and the test value is very close to the 1 ∶1 gradient line, indicating that the two criteria have good applicability to gas hydrate-containing coal. The correlation coefficient of H-B criterion is lower than M-C and GH-B criterion. The RMSE value is larger, and the applicability of H-B criterion to gas hydrate-containing coal is slightly lower than M-C criterion and GH-B criterion.

关 键 词：高围压 含瓦斯水合物煤体 应力应变曲线 强度准则 饱和度 

分 类 号：TD712[矿业工程—矿井通风与安全]