干湿循环下高液限土力学特性研究

路基填料的承载比大小反映土体局部抵抗剪切破坏的能力，是评价路基填筑质量的重要检测标准之一。本文以实际工程高液限土改良方案确定为背景，通过一系列的室内试验研究了具体明显地区特征的掺砂高液限粉土和高液限黏土的承载比影响因素，获得了高液限土在不同掺砂量下，不同干湿循环次数后的吸水量、膨胀率、脱水量对土体的CBR值的影响规律，得出有益结论：水是引起土体膨胀、收缩及CBR值差异的主要原因；在干湿循环初期以“砂化作用”为主，后期以“裂缝作用”为主；高液限土应填筑在较深的93区；掺砂改良后，其可以填筑在相对较浅的94区。

Mechanical Properties of High Liquid Limit Soil Under Different Drying and Wetting Cycles

CBR value which reflects the capacity of partial soil resisting shear failure is an important testing standard of embankment filling quality. Based on the background of improving project scheme of high limit liquid soil,a series of indoor tests was carried out to study bearing ratio influencing factors of the obvious regional characteristics of high liquid limit soil mixed with soil,and the influence rule of water content, swelling rate,dehydration rate of the high liquid limit soil in different sand content and different wet and dry cycles on CBR value was obtained.The results showed that water is the main reason of expansion shrinkage and differences of CBR value.The action of sand and fracture dominates at the earlier stage and the later stage of dry-wet circulation, respectively.The high liquid limit soil should be filling in the deep 93 area,but after improved by sand,it can fill in the relatively lower 94 area.