颗粒破碎对砂砾石料强度与变形特性的影响  

Effect of Particle Breakage on the Strength and Deformation Characteristics of Gravel Material

作　　者：王新民 钱亚俊[2] 姚芳芳 武颖利[2] 皇甫泽华 WANG Xinmin;QIAN Yajun;YAO Fangfang;WU Yingli;HUANGFU Zehua(Construction Management Bureau of Qianping Reservoir,Zhengzhou 450003,China;Geotechnical Engineering Department,Nanjing Hydraulic Research Institute,Nanjing 210024,China;Henan Shuijian Group Co.,Ltd.,Zhengzhou 450008,China)

机构地区：[1]河南省前坪水库建设管理局,河南郑州450003 [2]南京水利科学研究院岩土工程研究所,江苏南京210024 [3]河南水建集团有限公司,河南郑州450008

出　　处：《人民黄河》2020年第10期148-151,156,共5页Yellow River

摘　　要：砂砾石料是土石坝等工程的主要建筑材料,高应力状态下砂砾石料的颗粒破碎效应加剧,会显著影响其强度及变形特性,甚至威胁工程安全。以前坪水库筑坝砂砾石料为例,开展了不同围压、不同相对密度下三轴固结排水试验,分析了砂砾石达到临界状态之后的颗粒破碎规律与强度变形特性。研究表明,砂砾石料的级配在三轴试验前后都能用分形维数较好地描述,且分形维数与围压之间存在显著的线性关系,而与相对密度基本无关。这说明,围压是影响砂砾石料颗粒破碎程度的主要因素,相对密度的影响则可忽略。砂砾石料临界状态偏应力与围压正相关,而与相对密度无关。体积变形则受围压和相对密度的共同影响,围压越小、相对密度越大则体变的剪胀性越显著,反之则剪胀性越弱甚至无剪胀。Gravel material is one of the main soil materials in earth and rockfill dam engineering,and its particle breakage effect will increase with increasing stress,which may have a significant influence to the strength and deformation behavior of the soil and even threaten the safety operation of the project.Taking the gravel material from Qianping Dam as an example,a series of triaxial consolidation drainage tests were conducted under various relative densities and confining pressures,and the particle breakage and strength and deformation behaviors of the gravel material reaching critical state were analyzed.The results show that the particle size distribution curves of the gravel material before and after CD test can be expressed by the fractal function and the fractal dimensions and shows a notable linear relationship with confining pres⁃sure but non relationship with density.It is noted that confining pressure is the main reason causing particle breakage,while the role of the density can be ignored.The strain stress of the gravel material reaching critical state is proportional to the confining pressure.The deformation behavior is affected by the density and confining pressure simultaneously.The lower confining pressure and higher relative density make a more significant dilatation,otherwise the opposite.

关 键 词：土石坝 砂砾石料 颗粒破碎 强度 变形特性 前坪水库 

分 类 号：TV42[水利工程—水工结构工程] TU43[建筑科学—岩土工程]