水对库区路基不同密实度碎石土的弱化试验分析

摘要

It is vital to get the accurate data of the shear strength parameters of gravel soil with different water content and compactedness before they conduct the stability analysis for gravel soil roadbed .Under several test conditions ,a series of direct shear tests were performed by using some gravel soil samples obtained from a selected roadbed which is under the influence of water level fluctuation .The corresponding results show that the gravel soil cohesion increased as the water content of fine soil increases till it meets its peak value ,then it will decrease as the water content keeps increase .However ,the internal friction angle will decrease slowly with the increase of water content of fine soil in the initial phase ,and then it will decrease rapidly as the water content keeps increase .And on the other hand ,the fitted shear strength parameters calculated from the test data has been influenced by the pre-load values that used to prepare soil samples ,especially for the condition that the pre-load value less than the normal stress value applied in the direct shear test .All in all ,the fitted shear parameters will be controlled by the relationship among water content ,pre-load value and normal stress .%准确测定不同含水率不同密实度下的碎石土抗剪强度参数是碎石土路基稳定分析的重要前提，选取受库水影响的公路路基碎石土土样，进行了不同试验条件下的碎石土室内直剪试验。结果表明：碎石土粘聚力随碎石土中细粒土含水量的增加呈先增加后减小的现象，而内摩擦角则随细粒土含水量的增大呈现初始缓慢降低，而后急剧减小的趋势。若制备土样时的预压力值不同，特别是该预压力值小于直剪试验时对土样施加的正应力值时，试验拟合所得的抗剪强度参数值会受到其影响，表现有所差异。