摘要
反复的冻融循环是在严寒地区影响高土石坝安全的重要问题。本文依托西藏澜沧江如美高心墙堆石坝工程,利用清华大学研制的堆石料风化试验仪,对如美筑坝堆石料进行了不同法向应力条件下的冻融循环试验和直剪试验,研究了冻融循环过程中堆石料的变形与强度特性。试验结果表明,在一个冻融循环周期内,堆石料试样会依次经历"融缩"—"冻缩"—"冻胀"3个典型状态。冻融循环后会使堆石料试样产生较大的回胀变形,可使试样的密实度和抗剪强度有所降低。20次冻融循环后可使试样的就机抗剪强度降低约11.5%到15.4%。
Freeze-thaw cycling is an important factor affecting the safety of high earth-rock dams in severe cold regions.This paper presents the results of freeze-thaw cycling tests on the rockfill materials of the Rumei project,a high core wall rockfill dam on the Lancang River,Tibet.We conducted the tests using rockfill weathering test apparatus developed by Tsinghua University,together with direct shear tests under the conditions of different normal stress.Deformation and strength characteristics of the rockfill materials under freeze-thaw cycling were then examined.Test results show that during a given freezethaw cycle,a rockfill sample undergoes three typical stages:thaw shrinking,frost shrinking,and frost heaving.On completion of the freeze-thaw cycles,the sample starts a large back expansion deformation,reducing its compactness and shear strength.The reduction in shear strength is about 11.5%to 15.4%in the case of 20 freeze-thaw cycles.
作者
陈涛
保其长
王伟
殷殷
张丙印
孙逊
CHEN Tao;BAO Qichang;WANG Wei;YIN Yin;ZHANG Bingyin;SUN Xun(State Key Laboratory of Hydroscience and Engineering,Tsinghua University,Beijing 100084;China Institute of Water Resources and Hydropower Research,Beijing 100038)
出处
《水力发电学报》
EI
CSCD
北大核心
2019年第3期135-141,共7页
Journal of Hydroelectric Engineering
基金
国家重点研发计划课题(2017YFC0404802)
国家自然科学基金(51479099)
关键词
风化
堆石料
冻融循环
变形特性
抗剪强度
weathering
rockfill material
freeze-thaw cycle
deformation properties
shear strength
