SHANSEP试验方法改进与验证

Improvement and verification of SHANSEP test method

为满足工程实际需要,对SHANSEP试验方法加以改进,将淤泥固结至远大于其前期固结压力后,再逐级卸载以模拟超固结黏土,在不同的超固结比下进行了三轴固结不排水试验。试验表明:等向固结的三轴试验,也能较好地拟合出超固结土不排水强度与正常固结土强度、超固结比之间的关系式;提出了工程地区超固结土不排水强度公式,可推算不同超固结比下的土体强度;通过本次试验中对加荷方式的改进与拓宽,取代了原有k0固结或单剪仪的要求,提高了试验效率、节约成本,且该方法可推广使用到更多土类上,对研究超固结土的性质有一定工程实用意义。

The SHANSEP test method is improved to satisfy the practical needs of engineering.Firstly,the very soft clay is consolidated to a load that much higher than its preconsolidation pressure,and then it is unloaded gradually to simulate the overconsolidated clay.Consolidated undrained triaxial tests were carried out under different over consolidation ratios.It is concluded that the triaxial tests of isotropically consolidated can also reveal the relationship between the undrained strength of overconsolidated soil,the strength and the over consolidation ratio of normally consolidated soil.A formula for the undrained strength of overconsolidated soil in the area has been proposed,which can be used to estimate the soil strength under different over consolidation ratios.By the improvement and broadening of the loading method during the test,the requirements of k0 consolidation or simple shear apparatus are replaced,improved the test efficiency and saved costs.Moreover,this method can be extended to more types of soils,which has certain engineering practical significance for studying the properties of overconsolidated soils.