加载方式对冰单轴压缩强度影响的试验研究

Experimental study on the loading mode effects on the ice uniaxial compressive strength

针对冰的单轴压缩强度行为同加载方向、加载位移速度和试样相对尺寸有关，在-10℃冰样温度条件下，对不同尺寸的5种试样、平行冰面和垂直冰面的2种加载方向和位移速度在0．0072—387mm／min范围内，进行了25种组合的385次单轴压缩强度试验，获得375个试样的有效试验数据。结果发现，每组试样随加载位移速度的增加，其冰样的极限破坏应力（强度）也增加，达到一定值后，随加载位移速度的增加而减小；对应的冰样破坏形式也由韧性剪切破裂过渡到脆性破碎；垂直冰面方向柱状晶体的冰样强度约是平行冰面方向加载强度的1．87～2．40倍，表现出各向异性；试样相对尺寸小时其强度相对较大。

Considering the ice uniaxial compressive behaviors with loading directions, loading displacement speeds and specimen sizes, 385 tests in 25 groups were conducted with five different specimen sizes, two different loading directions parallel or perpendicular to the original ice surface, and the loading displace- ment speeds ranging between 0.0072N387 mm/min under the ice specimen temperature of-10℃. A total of 375 tests were successful in the 385 specimen tests. The experimental results show that （a） the ice ulti- mate stress （strength＇） increases firstly, reaches a top value, and then decreases with the loading displace- ment speed increasing; （b） the corresponding ice specimen failure modes change from ductile break to brit- tle break with the strain rate increasing; （c） the peak strength perpendicular to ice surface is 1.87~2.40 times of the strength parallel to ice surface in the columnar crystal ice, which it is a typical anisotropy ma- terial characteristics; and （d） the peak strength is higher in the cases of relative smaller specimens.