摘要
为积累有关纯热力生长淡水柱状冰单轴压缩强度的实际资料,选择黄河河迹湖-乌梁素海的柱状冰制备试样。利用具有严格恒温控温和位移速度控制的电子万能试验机,对垂直冰面加载和平行冰面加载的二类试样进行-2℃、-5℃、-7℃、-10℃和-15℃下不同恒位移速度的试验,研究了应变速率、加载方向及温度对单轴压缩强度的影响。试验结果得到:相应温度下试样的单轴压缩强度随着应变速率的增加,存在先增高到峰值,之后再降低,最后趋于平稳的特征;冰样存在3种破坏形式:鼓胀破坏、剪切破坏和劈裂破坏;在试验温度范围内,冰强度随温度降低有着明显提高;试样单轴压缩强度随温度和应变速率的影响由一个二元统计关系表达;垂直冰面方向加载的试样强度比平行冰面方向加载试样强度大。对于乌梁素海的柱状冰,垂直冰面方向加载的试样峰值单轴压缩强度是平行冰面加载试样的2.1倍;出现峰值强度的应变速率随温度升高而增加;峰值强度随温度的变化能够采用对数函数表达。
In order to accumulate the actual data concerning uniaxial compressive strength of thermalgrowth fresh water columnar ice,we chose the columnar ice in Wuliangsuhai Lake where is a kind of furio-tile lake beside the Yellow River as samples in the experiment. We loaded the samples in the directionsvertical to the ice surface and parallel to the ice surface under different displacement speedsat -2℃,-5℃,-7℃,-10℃ and-15℃ by electronic universal experiment machine with strict temperaturecontrol and displacement speed control. The influence of strain rate, loading direction and temperature onthe uniaxial compressive strength were studied. It was found that the uniaxial compressive strengths varywith the strain rates and temperatures. At a certain temperature, the strength feature increased to a peakvalue firstly, and then reduced, and finally was tending toward smooth with the increase of strain rate,The ice samples include three destruction forms： bulging failure, shear failure and splitting failure. In therange of the test temperature, the ice strength decreases with the increase of experiment temperature. Theuniaxial compressive strength can be fitted into a surface with the influence of temperature and strain rate.The strength loaded in the direction vertical to the ice surface is larger than that parallel to the ice sur-face. For the columnar ice in Wuliangsuhai Lake,the peak uniaxial compressive strength loaded in the di-rection vertical to the ice surface is 2.1 times as large as the strength loaded in the direction parallel tothe ice surface firstly,the strain rate at the peak strength increases with ice temperature increasing second-ly and logarithmic function can be used to express the variation of peak strength with ice temperature atlast.
作者
李志军
徐梓竣
王庆凯
李国玉
LI Zhijun;XU Zijun;WANG Qingkai;LI Guoyu(State Key Laboratory of Coastal and Offshore Engineering,Dalian University of Technology,Dalian 116024,China;State Key Laboratory of Frozen Soil Engineering,Northwest lnstitute of Ecology and Environmental Resources,Chinese Academy of Sciences,Lanzhou 730000,China)
出处
《水利学报》
EI
CSCD
北大核心
2018年第6期662-669,共8页
Journal of Hydraulic Engineering
基金
国家自然科学基金项目(51579028
51639003)
冻土工程国家重点实验室开放基金项目(SKLFSE201604)
关键词
淡水冰
压缩强度
温度
应变速率
试验
fresh water ice
compressive strength
temperature
strain rate
experiment
