摘要
研究掺砾心墙料的拉裂特性对深入研究高土石坝水力劈裂、坝顶裂缝以及坝肩横缝等问题至关重要,但目前已有的研究尚不够深入。基于自主研制的单向拉伸试验装置,对不同掺砾量下的心墙料进行了系列的单向拉伸试验,依据试验结果分析了掺砾心墙料拉裂破坏的机制。在此基础上得到以下结论:在试样各自最大干密度及最优含水率下,随着掺砾量的增加,心墙料的抗拉强度和拉应变呈线性递减关系;所有试样的拉应力-应变曲线呈分段指数关系,极限拉应力前后试验曲线可分别采用正负指数关系来描述;进行了系列三轴排水剪试验,分析各试样抗拉强度与强度指标的关系发现,对于所研究的掺砾心墙料,抗拉强度与其黏聚力呈较好的线性关系,在不具备试验条件的情况下,此关系可用来大致估算心墙料的抗拉强度。相关试验结果可为实际土心墙坝抗裂设计提供参照。
Tensile cracking characteristics of gravelly core material are crucial for in-depth knowledge of hydraulic fracturing, longitudinal cracks and abutment transverse cracks of high earth core dams. However, the existing research is still not deep enough. Using the self-developed uniaxial tensile test device, a series of uniaxial tensile tests was carried out on the core materials with different gravel contents. Based on the test results, the mechanism of the cracking failure of the gravelly core material was analyzed. The following conclusions are obtained: for the samples under the maximum dry density and the optimum water content, the tensile strength and tensile strain of the gravelly core material decrease linearly with the increase of gravel content;the tensile stress-strain curves of all samples can be described in a piecewise exponential relationship, i.e. positive and negative exponential function for the test curves before and after the ultimate tensile stress, respectively. A series of consolidated-drained triaxial tests was also conducted, the relationship between the tensile strength and the strength index of each sample was analyzed. The tensile strength has a good linear relationship with its cohesion. This relationship can be used to estimate the tensile strength of the gravelly core material without test conditions. The relevant test results can provide reference for the anti-crack design of the actual earth core rockfill dam.
作者
吉恩跃
陈生水
傅中志
JI En-yue;CHEN Sheng-shui;FU Zhong-zhi(Geotechnical Engineering Department,Nanjing Hydraulic Research Institute,Nanjing,Jiangsu 210024,China;Key Laboratory of Failure Mechanism and Safety Control Techniques of Earth-Rock Dam of the Ministry of Water Resources,Nanjing Hydraulic Research Institute,Nanjing,Jiangsu 210029,China)
出处
《岩土力学》
EI
CAS
CSCD
北大核心
2019年第12期4777-4782,4792,共7页
Rock and Soil Mechanics
基金
国家重点研发计划（No.2017YFC0404806）
国家自然科学基金青年基金项目（No.51809182）
中国博士后科学基金项目（No.2018M630578,2019T120444）~~
关键词
掺砾心墙料
掺砾量
应力-应变关系
抗拉强度
黏聚力
gravelly core material
gravel content
stress-strain relationship
tensile strength
cohesion
