冻融循环和干湿交替对黄土力学性质影响的试验研究

摘要

采用青海东部民和—小峡公路K70+050处非饱和黄土进行室内冻融循环、干湿交替以及两者共同作用下的直剪试验.结果表明:随着冻融循环和干湿交替次数的增加,土样的黏聚力开始时劣化效应强烈,是造成黄土破坏的主要因素,最终黏聚力趋于一个稳定值,内摩擦角随冻融循环和干湿交替次数的增加无明显变化;冻融循环和干湿交替共同作用对土样强度参数的影响大于单纯的冻融循环或干湿交替作用,冻融循环和干湿交替共同作用对土样的破坏更严重.%The engineering background is the unsaturated loess of Minhe-Xiaoxia road in eastern Qinghai.Direct shear tests of loess are conducted under the condition of freeze-thaw cycles,dry-wet alternation,and the combination of these two actions.The results show that the cohesion of the soil degradation effect is signif icant due to increasing freeze-thaw cycles and dry-wet alternation,and the ultimate cohesion tends to be a constant value.By comparison, freeze-thaw cycles and dry-wet alternation have little influence on internal friction angle.With the combination of freeze-thaw cycles and dry-wet alternation,its effects on soil sample strength parameters and soil destruction are more signif icant than the effects due to only one action.