基于固结试验的膨胀土地基变形预测方法

由广西膨胀土的固结试验,确定了广西膨胀土的体积变形指标。对依托工程膨胀土进行了现场静力触探试验,根据比贯入阻力随深度的变化曲线特征,确定了膨胀土活动区深度。给出了膨胀土裂隙开展深度的理论解,膨胀土裂隙开展深度的计算值与静力触探试验确定的膨胀土活动区深度和现场观测的裂隙开展深度基本一致。最后介绍了基于固结试验基础上的膨胀土地基变形计算方法,并在试验基础上给出了膨胀土地基变形的计算结果。以膨胀土地基变形量作为膨胀土地基的分类指标,对膨胀土地基进行了分类。分类结果对膨胀土基础选型具有重要意义。

PREDICTION OF GROUND HEAVES IN EXPANSIVE SOILS BASED ON CONSOLIDATION TESTS

Consolidation tests are applied to determine the indexes of volumetric deformation with respect to normal stress for expansive soils in Guangxi of China,and to predict ground heaves in expansive soils.Static cone penetration tests are conducted for expansive soil investigations,and test results are used to determine the active expansive zone.A theoretical solution is developed to determine cracking depth of expansive soils.The depths of the active zone from static cone penetration tests and theoretical solution are respectively identical to the results from observation in-situ.A simplified method for prediction of ground heaves in expansive soils based on consolidation tests is given.The index of ground heave in expansive soils is used as the basis for the classification of expansive soil foundations.The results of expansive ground heave have significant meaning to the choice of building foundations in expansive soil.