孔隙岩石的物理模型与破坏力学行为分析  

Physical model and failure analysis of porous rock

作　　者：杨永明[1,2] 鞠杨[1,2] 王会杰[1,2] 

机构地区：[1]中国矿业大学煤炭资源与安全开采国家重点实验室,北京100083 [2]中国矿业大学力学与建筑工程学院,北京100083

出　　处：《岩土工程学报》2010年第5期736-744,共9页Chinese Journal of Geotechnical Engineering

基　　金：国家973计划课题(2002CB412705);国家973计划课题(2010CB226804);北京市教委;科委重点实验室项目;国家自然科学基金项目(50974125);国家自然科学基金青年科学基金项目(10802092)

摘　　要：根据真实岩石的孔隙结构分布统计特征,采用水泥砂浆和聚苯乙烯颗粒等相似材料模拟孔隙岩石,制作了岩石孔隙物理模型;利用CT扫描实验验证了物理模型与天然岩石孔隙结构在统计特征上的一致性;利用单轴受压试验获取了孔隙物理模型的力学性能;最后进行了巴西圆盘劈裂CT扫描实验,分析了孔隙岩石破坏机理及其孔隙结构的变化。研究结果表明:岩石孔隙物理模型与天然岩石具有一致的孔隙结构分布特征;孔隙不影响岩石的宏观弹脆性特征;但由于孔隙的存在,岩石内部的应力分布出现非对称性,导致劈裂裂纹偏离纵向对称轴;最终形成劈裂裂纹穿越孔隙,出现较宽的破坏裂纹。Physical models for porous rock are made by use of cement mortar and polystyrene according to the statistic distribution features of pore about rock.The CT scanning technology is used to investigate the consistence between porous physical model and natural rock on the statistical distribution characters.The mechanical properties of porous physical model are gained by means of uniaxial compression tests.A number of Brazil disc split-CT scanning tests are carried out to analyze the failure mechanism of porous rock and the changeable porous structure.The results show that the porous physical models of rock have a consistency with the natural rock on pore statistical distribution characters.Pores don’t affect the macro elastic-brittle properties of rock.The stress distribution of rock is asymmetric due to the presence of pores existing.The failure cracks deviate from vertical axis of symmetry.The split cracks penetrate pores,and finally wider failure cracks appear.

关 键 词：孔隙岩石 物理模型 CT实验 变形破坏 

分 类 号：TU452[建筑科学—岩土工程]