摘要
蓄水湿化变形一直是制约高土石坝长期安全运行的技术难题,为此开展了筑坝堆石料的湿化变形试验,却极少针对砾石土心墙料进行湿化变形试验,这主要是受限于目前的砾石土料试验技术手段而难以开展试验研究。采用在大尺寸砾石土料试样中设置砂芯增加进水通道、缩短湿化路径的方法,可以解决砾石土心墙料的湿化变形试验所需时间较长、样品不能充分饱和等技术难点,实现砾石土心墙料的大三轴湿化变形试验。开展的砾石土心墙料的单线法湿化变形试验成果表明,砾石土心墙料存在明显的湿化变形现象,轴向湿化变形、体积湿化变形与围压、应力水平等密切相关,湿化变形与应力水平关系,在围压较小时随应力水平的增加而增加,在围压较大时随应力水平的增加而减小,关系曲线呈现明显的分叉现象,湿化变形与围压关系基本呈现先增加后减小的规律,与堆石料的湿化变形规律相比较,砾石土心墙料的湿化变形规律更加复杂。
Wetting deformation of water storage has always been a technical issue that restricts the long-term safety operation of high earth-rockfill dams.The wetting deformation tests have been commonly carried out for rockfill materials,but seldom for gravelly soil core wall materials,which is mainly because it is difficult to carry out experimental studies due to the current testing techniques of gravel soil materials.By setting sand cores in large-scale gravelly soil samples to increase the water inlet channel and shorten the wetting path,the technical difficulties such as the long time required for the wetting deformation tests on gravelly soil core materials and the insufficient saturation of samples can be solved.Then the large-scale triaxial wetting deformation tests on gravelly soil core materials can be conducted successfully.The wetting test results show that there is obvious wetting deformation phenomenon in gravelly soil core wall materials.The axial and volume wetting deformations are closely related to the confining pressure and stress level.The relationship between the wetting deformation and the stress level increases with the increasing stress level when the confining pressure is small,and decreases with the increasing stress level when the confining pressure is large.The relationship between the wetting deformation and the confining pressure basically shows the deformation tendency of increasing first and then decreasing.Compared with that of rockfill materials,the wetting deformation tendency of gravelly soil core materials is more complex.
作者
左永振
程展林
潘家军
周跃峰
赵娜
ZUO Yong-zhen;CHENG Zhan-lin;PAN Jia-jun;ZHOU Yue-feng;ZHAO Na(Key Laboratory of Geotechnical Mechanics and Engineering of Ministry of Water Resources,Changjiang River Scientific Research Institute,Wuhan 430010,China)
出处
《岩土工程学报》
EI
CAS
CSCD
北大核心
2020年第S02期37-42,共6页
Chinese Journal of Geotechnical Engineering
基金
国家重点研发计划项目(2017YFC0404804)
国家自然科学基金–雅砻江联合基金重点项目(U1765203)
水利部土石坝破坏机理与防控技术重点实验室开放基金项目(YK319013)
关键词
砾石土心墙料
湿化变形
单线法
大型三轴
gravelly soil core material
wetting deformation
single-line method
large-scale triaxial test
作者简介
左永振(1980—),男,高级工程师,硕士,主要从事粗粒土的力学特性试验研究和岩土力学CT可视化技术研究。E-mail:zuoyongzh@163.com。
