堆石料在不同应力路径下的颗粒破碎特性  

Analysis on Particle Breakage Properties of Rockfill Materials Subjected to Different Stress Paths

作　　者：樊怀华 刘大才 刘恩龙[3] 马颜磊 

机构地区：[1]中国有色金属工业昆明勘察设计研究院,云南昆明650051 [2]中国市政工程西南设计研究总院有限公司,四川成都610081 [3]四川大学水利水电学院水力学与山区河流开发保护国家重点实验室,四川成都610065

出　　处：《人民黄河》2015年第1期137-139,145,共4页Yellow River

基　　金：国家自然科学基金资助项目(51009103)

摘　　要：采用大三轴试验设备,对直径为300 mm、高为600 mm的圆柱体堆石料试样进行了三种不同应力路径的固结排水试验,包括常规三轴压缩试验、等平均应力试验及等向压缩试验,探讨不同应力路径下堆石料的颗粒破碎特性,常规三轴压缩试验围压为200、400、800、1 200 k Pa,等平均应力试验平均应力为200、400、600、800 k Pa。试验结果表明,应力路径对堆石料的颗粒破碎特性有很大的影响。常规三轴压缩试验的应力—应变关系近于双曲线,低围压时试样先剪缩后剪胀、高围压时剪缩;等平均应力试验的应力—应变曲线呈应变软化型,体变表现为先体缩后剪胀。计算得到的颗粒破碎指数表明,等平均应力试验的颗粒破碎最为严重,等向压缩试验的颗粒破碎轻微。Using the large triaxial apparatus,consolidated drained tests with three different stress paths were conducted on rockfill samples with diameter of 300 mm and height of 600 mm to investigate the grain crushing properties of rockfill materials under different stress paths. The test types were the conventional triaxial compression test with confining pressures of 200,400,800 and 1 200 kPa,the constant mean stress test with constant mean stresses of 200,400,600 and 800 kPa,and isotropic compression test. The test results demonstrate that stress paths have great influence on the grain crushing features of rockfill materials. For the conventional triaxial compression tests,the stress-strain curves behave as hyperbolic curve,the volume contracts firstly and then dilate with low confining pressure,but it contracts with high confining pressure;for the mean stress tests,the stress-strain curves behave as strain softening,the volume contracts firstly and then di-late. The computed breakage index shows that the samples break seriously under constant mean stress path,while they break slightly under i-sotropic compression stress path.

关 键 词：堆石料 三轴试验 应力路径 颗粒破碎 

分 类 号：TV41[水利工程—水工结构工程]