黄河冰单轴压缩强度的试验与影响因素探究

Study on test of uniaxial compressive strength of ice in Yellow River and its influencing factors

为进行黄河冰单轴压缩强度的试验,在黄河头道拐水文站附近取冰坯,加工成单轴压缩试验冰样,在实验室测试了其单轴压缩强度。试验温度分别为-3℃、-5℃、-7℃、-10℃、-15℃,应变速率范围10-7s^(-1)~10-2s^(-1)。试样按加载方向分为垂直冰面方向和平行冰面方向,分别测试75个和212个。试验得到250组有效数据,分析结果验证了单轴压缩强度的应变速率效应,建立了单轴压缩强度随应变速率变化的拟合公式;给出不同力学行为下的单轴压缩强度与温度和应变速率的统计关系,进而得到了宽应变速率范围下单轴压缩强度随温度变化的统计关系曲面。此外,试验还推断出河流流向与黄河冰单轴压缩强度之间不存在相关关系,垂直冰面方向加载试样的峰值强度比平行冰面方向加载试样的峰值强度高。

In order to make a uniaxial compressive strength test on the ice in the Yellow River, the ice block for the test is taken near Toudaoguai Hydrological Station of the river, and then the ice is processed into the ice-samples for the uniaxial compressive test, of which the uniaxial compressive strengths are tested in lab. For the test, the testing temperatures are -3℃ -5 ℃, - 7 ℃ , - 10 ℃, - 15 ℃ respectively and the strain rate range is 10 ^-7s ^-1 - 10^-2s^-1. For the loading direction, the ice-samples are divided into the samples with the loading direction vertical to the ice surface and the samples with the loading direction horizontal to the ice surface, from which 75 samples and 212 samples are respectively tested. From the test, 250 groups of effective data are obtained, furthermore, the analysis result verifies the strain rate effect of the uniaxial compressive strength, and then the fitting formula for the variation of the uniaxial compressive strength along with the strain rate is established ; from which the statistical relationship between the uniaxial compressive strength and temperature and the strain rate under various mechanical behaviors is given out, thus the curved plane for the statistical relationship of the variation of the uniaxial compressive strength along with temperature in a wide range of strain rate is obtained as well. Moreover, it is deduced out from the test that no any corelationships are there between the river flow direction and the uniaxial compressive strength of the ice in the Yellow River, while the peak strength of the samples with the loading direction vertical to the ice surface are higher than those of the samples with the loading direction horizontal to the ice surface.