宽级配黏土与混凝土结合带渗透特性试验研究  

Experimental study on permeability characteristics of joint zone between widely graded clay and concrete

作　　者：张茵琪[1,2] 邓刚[1,2] 张延亿[1,2] 卢吉 曹学兴 ZHANG Yinqi;DENG Gang;ZHANG Yanyi;LU Ji;CAO Xuexing(State Key Laboratory of Simulation and Regulation of Water Cycle in River Basin,China Institute of Water Resources and Hydropower Research,Beijing 100038,China;Key Laboratory of Water Project Construction and Safety,Ministry of Water Resources,China Institute of Water Resources and Hydropower Research,Beijing 100038,China;Huaneng Lancangjiang Hydropower Co.,Ltd.,Kunming 650214,Yunnan,China)

机构地区：[1]中国水利水电科学研究院流域水循环模拟与调控国家重点实验室,北京100038 [2]中国水利水电科学研究院水利部水工程建设与安全重点实验室,北京100038 [3]华能澜沧江水电股份有限公司,云南昆明650214

出　　处：《水利水电技术（中英文）》2021年第10期182-190,共9页Water Resources and Hydropower Engineering

基　　金：国家重点研发计划课题(2017YFC0404803);中国水科院基本科研业务费专项(GE0145B032021);流域水循环模拟与调控国家重点实验室自主研究课题(SKL2020ZY09)。

摘　　要：针对宽级配黏土与混凝土结合带在大剪切变形条件下的渗透特性对高心墙堆石坝等构筑物安全影响较大的问题,采用自主研发的大剪切变形和应力联合作用下结合带渗透特性试验装置,模拟实际工程岸坡坝段心墙底部宽级配黏土层应力-变形-渗流条件,开展了宽级配黏土与混凝土结合带渗透特性试验,从而探讨试样渗透系数随剪切变形的变化规律。结果显示,剪切变形突然启动瞬间,试样渗透系数快速增大至瞬时峰值,然后逐步减小并趋于稳定,剪切变形停止后经历一定时间,渗透系数从终止值减小至延时稳定值后不再变化;经历过剪切渗流历史的土料在再次剪切时的渗透系数瞬时峰值低于上一次剪切过程。通过分析应力和水力比降等条件对上述规律的影响,并以结合带导水系数与其初始值的比值和试样渗透系数与其初始值比值间的对应关系为依据,给出了结合带可能的厚度。同时,通过结合带黏土颗粒团聚体的组构变化分析,较好地解释了结合带渗透性的变化机理。The permeability characteristics of the joint zone between widely graded clay and concrete has a larger impact on the safeties of the structures such as high rockfill dam with core-wall under the condition of large shearing deformation. Therefore, a self-developed testing apparatus for the permeability characteristics of the joint zone under the combined effect of large shearing deformation and stress is adopted to simulate the actual condition of stress-deformation and seepage of the widely graded clay layer for the core-wall bottom of the bank-slope dam section of a actual project and the experiment is carried out on the permeability charateristics of the joint zone between widely graded clay and concrete, and then the changing law of the permeability coefficient depending on shearing deformation is discussed. The result shows that at the moment when the shearing deformation suddenly starts, the permeability coefficient of the sample is to rapidly increase to its instantaneous peak value and then gradually decrease and tend to be stable. After the shearing deformation stops for a certain time, the permeability coefficient does not change after decreasing from its stop value to its delay stability value, while the instantaneous peak value of permeability coefficient of the soil material that ever experiences shearing seepage is lower than that during its last shearing process. Through analyzing the influences from the conditions of stress, hydraulic gradient, etc.on the laws mentioned above and in accordance with the corresponding relationship between the ratio of hydraulic conductivity of the joint zone to its initial value and the ratio of permeability coefficient of the sample to its initial value, the feasible thickness of the joint zone is given. Meanwhile, the changing mechanism of the permeability of the joint zone is better explained through the analysis made on the fabric change of the clay particle aggregate of the joint zone.

关 键 词：宽级配黏土 结合带 渗透特性 试验 组构 

分 类 号：TU443[建筑科学—岩土工程]