Abstract：When the vacuum preloading method is applied to improve dredge fill，adequate bearing capacity needs to be provided for the large-scale spile machine installation equipment. A new technique is developed，in which the dredge surface is filled with a certain thickness of silt sand to provide enough bearing capacity to support the spile machine installation performance. A small-scale model test is carried out to intuitively identify the availability of crust improving the bearing capacity of foundation；and bearing characteristics and mechanism of foundation with crust are discussed. Finite element analysis is performed by PLAXIS software，in which the development of the plastic zones and displacement fields can be obtained. The calculated bearing capacity is compared with the analytical solutions achieved by Vesic formula. The contribution of a crust layer with silt sand to the bearing characteristics of foundation in rigid upper layer and soft lower layer is discussed，which can provide the technique with solid theoretical basis.
2013, Vol. 32 
