劈裂荷载下孔隙结构对砂岩宏观力学性质的影响  

Influence of dorous structures on macroscopic mechanical properties of sandstones under splitting load

作　　者：杨永明[1] 周勤[1] 王刚[1] 范朝阳[1] 鄢虹 王庆云[1] 

机构地区：[1]中国矿业大学(北京)力学与建筑工程学院,北京100083

出　　处：《中国科技论文》2016年第3期302-306,共5页China Sciencepaper

基　　金：高等学校博士学科点专项科研基金资助项目(20130023120020);北京市大学生科学研究与创业行动计划项目(C201506014);煤炭资源与安全开采国家重点实验室大学生科技创新计划项目(SKLCRSM14CXJH06)

摘　　要：为了解决砂岩内部孔隙结构对砂岩宏观力学性能的影响机理问题,以砂岩为研究对象,利用统计学原理和图像处理技术,建立了砂岩孔隙结构的三维重构模型。在此模型的基础上,利用数值模型方法开展了孔隙岩石劈裂数值模拟实验,分析了孔隙结构参数(孔隙大小、形态及孔隙率)对砂岩在劈裂荷载下的变形、应力分布和破坏连通区特征等宏观力学性质的影响,揭示了孔隙砂岩变形破坏的力学机理。研究结果表明:孔隙形态对砂岩应力分布和变形破坏有显著的影响;随着孔径的增大,砂岩从拉伸破坏和剪切破坏变成单一的拉伸破坏,破坏时的变形和最大拉应力均减小;孔隙率越大,砂岩更易破坏,且破坏时的变形和最大应力拉应力也越大,但影响程度随着孔径的增大而减弱。研究结果可为分析孔隙结构对岩石宏观物理力学性能的影响机理提供了一定的理论依据和参考。For exploring the effective mechanism of porous structures on the mechanical properties of sandstones,a three-dimensional porous model of sandstone is reconstructed by using statistics principle and image processing technique.Based on the reconstructed model,a series of split tests were carried out by use of numerical method.The influences of pore parameters on deformation,stress distribution and failed regions were analyzed,including pore size,form and quantity.The intrinsic mechanisms of deformation and failure of sandstones were disclosed.The geometrical form of pores has great influence on stress distribution and deformation failure of sandstones.With pore size increasing,tension-shear-induced failure converts to a single tension-induced failure,and the deformation and maximum tensile stress decrease gradually.A bigger porosity more easily brings on sandstone failure,and also leads to bigger deformation and tensile stress value.But the effect of porosity weakens when pore size is bigger.The research provides a certain reference which can help people to understand the influence mechanisms of porous structures on macroscopic physical and mechanical properties of rock.

关 键 词：砂岩 岩石力学 孔隙结构 劈裂荷载 数值模拟 力学性质 三维重构模型 

分 类 号：TD313[矿业工程—矿井建设]