摘要
为探究含瓦斯水合物煤体在剪切破坏过程剪切带演化特征及其受围压影响的规律,采用离散元方法,开展饱和度(25%),围压(5,6,7 MPa)下的双轴数值模型,并结合室内试验验证模型可靠性。研究结果表明:随着围压增大,试样破坏模式由单斜面剪切破坏向X型剪切破坏转变;剪切带宽度随着围压升高减小,6 MPa和7 MPa围压下较5 MPa时分别降低30%和36%;6 MPa围压下,孔隙率呈主带>副带>带外的分布特征,力学配位数演化表现为先降低后趋于稳定,其中主带与副带降幅显著,而带外保持相对稳定;水合物胶结破坏以剪切破坏为主,而试样发生的剪切破坏以压剪破坏为主导。研究结果可为深入认识含瓦斯水合物煤体力学性质提供参考。
In order to investigate the evolution characteristics of shear bands in gas hydrate-bearing coal during shear failure and their dependence on confining pressure,the discrete element method(DEM)was employed to construct biaxial numerical models with a saturation of 25%under confining pressures of 5,6,7 MPa.Laboratory tests were also conducted to validate the model reliability.The results indicate that as the confining pressure increases,the failure mode of the specimen transitions from a single inclined shear failure to an X-shaped shear failure.The shear band width decreases with increasing confining pressure,showing reductions of 30%and 36%at 6 MPa and 7 MPa,respectively,compared to that at 5 MPa.Under 6 MPa confining pressure,the porosity exhibits the distribution pattern:main shear band>secondary shear band>outside shear band.The mechanical coordination number initially decreases and then stabilizes,with a significant reduction observed in the main and secondary bands,while the coordination number outside the bands remains relatively stable.The hydrate cementation failure is predominantly due to shear failure,and the shear failure of the specimen is primarily compressive-shear failure.These findings provide references for a deeper understanding of the mechanical properties of gas hydrate-bearing coal.
作者
高霞
白海瑞
巩在阳
张保勇
吴强
崔祥龙
GAO Xia;BAI Hairui;GONG Zaiyang;ZHANG Baoyong;WU Qiang;CUI Xianglong(School of Architecture and Civil Engineering,Heilongjiang University of Science and Technology,Harbin Heilongjiang 150022,China;School of Safety Engineering,Heilongjiang University of Science and Technology,Harbin Heilongjiang 150022,China;HydroChina ITASCA R&D Center,Hangzhou Zhejiang 311122,China)
出处
《中国安全生产科学技术》
北大核心
2025年第10期73-80,共8页
Journal of Safety Science and Technology
基金
国家自然科学基金项目(U21A20111,51974112)。
关键词
剪切破坏
剪切带
离散元
水合物胶结破坏
shear failure
shear band
discrete element
hydrate cementation failure
