为研究季节冻土地区冻融作用对道路边坡土体抗剪性能的影响规律，在不同冻结和融化温度、不同冻融循环次数、开放和封闭体系条件下对冻融饱和原状粉黏土试样进行了不固结、不排水剪切试验。试验结果表明：饱和原状粉质黏土冻融后，黏聚力降低，内摩擦角增大，冻结温度越低，冻融作用对黏聚力和内摩擦角的影响越小，随着冻融循环次数的增加，5～7次冻结循环后二者的变化逐渐趋于稳定。水分补给会强化冻融作用对试验土抗剪性能的影响；融化温度对试验土的抗剪性能影响很小。

In order to reveal the regular influence of freezing-thawing cycle on shearing strength properties of road slope soil in seasonally frozen area, unconsolidated-undrained test was carried out on saturated undisturbed silty clay under different experimental conditions such as freezing and thawing temperature, freezing-thawing cycle index and open or closed system. The test results indicate that after freezing-thawing, cohesion decreases, but internal frictional angle increases; the lower freezing temperature is, the less influence of freezing-thawing cycle on cohesion and internal frictional angle is. As freezing-thawing cycle number increases, after 5-7times, the changes of shearing strength properties gradually become stable. Water supply can reinforce the influence of freezing-thawing on C and ; thawing temperature has a slight effect on the shearing strength properties of saturated undisturbed silty clay.

铁道部科技开发计划项目（No. 2006G001-B-3）；国家自然科学基金资助项目（No. 40571032）。