摘要
堆石混凝土技术在高坝和大型工程中的应用呈增长趋势,部分工程场址的地震设防烈度较高,对堆石混凝土大坝的结构设计提出了更高要求,亟需对其动力性能开展深入研究。本文采用缩尺试验方法,开展了考虑不同围压和应变率的堆石混凝土单轴和三轴压缩试验。试验结果表明,堆石混凝土的单轴极限抗压强度随应变率的增加而增大,但随粗骨料粒径和试件尺寸的增大有一定降低趋势;围压对堆石混凝土的动强度提升作用显著;在相同围压下,采用较大粒径粗骨料的试件表现出相对较低的单轴抗压强度,但会有更高的三轴抗压强度,表明粗骨料自承骨架细观特性对堆石混凝土强度也有重要影响。基于试验结果,用八面体应力建立了堆石混凝土的破坏准则,以服务于堆石混凝土结构的抗震设计。
The application of rock-filled concrete(RFC)technology in high dams and other large-scale projects is on the rise.Given the elevated seismic fortification intensity at certain project sites is relatively high,there emerges a pressing need for enhanced structural design consideration for RFC dams,necessitating comprehensive research on the dynamic performance of RFC.This study employs a scaled-down testing approach to conduct a series of uniaxial and triaxial compression tests on RFC specimens subjected to varying confining pressures and strain rates.The results indicate that the uniaxial strength of RFC is positively correlated with the strain rate,while it will decline to some extent as the size of coarse aggregates or the dimension of the specimen increases.Confining pressure significantly increases the dynamic strength of RFC.Under the same confining pressure,specimens containing larger aggregates demonstrate lower uniaxial strength but exhibit higher triaxial strength.This observation suggests the mesoscopic characteristics of the self-sustaining skeleton formed by coarse aggregates play a crucial role in the strength of RFC.Based on the test results,a failure criterion is established using the octahedral stress,thereby providing experimental evidence for the seismic design of RFC structures.
作者
任艺莎
周元德
金峰
张楚汉
REN Yisha;ZHOU Yuande;JIN Feng;ZHANG Chuhan(Department of Hydraulic Engineering,Tsinghua University,Beijing,100084,China;State Key Laboratory of Hydroscience and Engineering,Tsinghua University,Beijing 100084,China)
出处
《水力发电学报》
北大核心
2025年第9期89-97,共9页
Journal of Hydroelectric Engineering
基金
国家自然科学基金项目(52039005)
国家自然科学基金国际(地区)合作与交流项目(51861165102)。
关键词
堆石混凝土
动强度
应变率
围压
破坏准则
rock-filled concrete
dynamic strength
strain rate
confining pressure
failure criterion
