Deduction and application of strength parameters of soft clay by use of vane strength

In Tianjin Port,the foundation soils are soft clay with underconsolidated condition,low bearing capacity and high water content.The vane strength is more frequently used among the currently used strength parameters in assessing the stability analysis of the structure during the construction stage.Research results have shown that the vane strength is smaller than compared with the strength on other shear surfaces.Furthermore,a single value of the vane strength can not meet the requirements for calculating the earth pressure and bearing capacity.A new approach which can deduce the two conventional strength parameters based on the linear distribution of vane strength along the depth and the Mohr-Coulomb strength mechanism is presented by use of the statistical regression methods.The deduced parameters have been used to calculate the stability of slopes and the cylindrical caisson foundations in Tianjin Port.