基于巴西劈裂试验的碎屑冰抗拉强度及影响因素研究

RESEARCH ON TENSILE STRENGTH AND INFLUENCING FACTORS OF DEBRIS ICE BASED ON BRAZIL SPLIT TEST

为了研究山岳冰川冰的抗拉强度特性,制备了150个不同碎屑含量(0、5%、10%、15%和20%)的重塑冰样,采用巴西劈裂试验研究了不同温度(-3℃、-5℃、-10℃、-15℃和-20℃)和不同加载速率(0.04 mm·s^(-1)和0.1 mm·s^(-1))条件下的冰的抗拉强度。结果表明:冰样沿着加载方向启裂、扩展而产生贯通破坏,破裂面的性状与碎屑含量和温度有关,碎屑含量越高、温度越低则冰的脆性越强。纯冰的抗拉强度随着温度的升高而线性减小;碎屑冰的抗拉强度则随温度的升高呈先上升后下降的规律,且在-10℃左右时达到最大值;冰的抗拉强度随着碎屑含量的增加而增大,碎屑含量20%的冰的抗拉强度可达纯冰的1.82倍;温度较低、碎屑含量较少时,加载速率越大则抗拉强度越高。该成果为揭示山岳冰川冰的拉裂破坏和成灾机理提供了理论基础。

To study the tensile strength characteristics of mountain glacier ice,150 remolded ice samples with different debris contents(0,5%,10%,15%,and 20%)were prepared.The Brazil split test was used to study the tensile strength of ice under different temperatures(-3℃,-5℃,-10℃,-15℃,and-20℃)and loading rates(0.04mm·s^(-1) and 0.1mm·s^(-1)).The results show that ice samples initiated cracks,expanded,and underwent through-thickness failure along the loading direction.The characteristics of the rupture surface are related to the debris content and temperature.The higher the debris content and the lower the temperature,the more brittle the ice is.The tensile strength of pure ice decreases linearly with temperature;the tensile strength of debris ice rises first and then decreases with temperature,reaching the maximum value at about-10℃.The tensile strength of ice increased with the increase of debris content,with 20%debris content reaching 1.82 times that of pure ice.When the temperature is low and the debris content is less,the greater the loading rate,the higher the tensile strength.The results provide a theoretical basis for revealing the mechanism of cracking and disaster of mountain glacier ice.