Research On Deformation Characteristics Of Soft Soil Foundation In Reclamation Area And Negative Skin Friction

In the process of reclamation, dredger fill will have a complex transformation from liquid slurry to the plastic soil with a certain strength, accompanied by the structure of dredger fill, its engineering properties also gradually change. The pressure-bearing of dredger is very small, once under pressure will happen huge deformation and its permeability is poor, which has a big difference with lower natural soil. However, at present the study on engineering properties of layer with different depth caused by various factors has rarely been reported. The engineering practice has shown that the lower layer of dredger fill is not only the key to control the bearing capacity of the foundation also the major part occur consolidation settlement. So it is necessary to strengthen the research on the different soil layers of hydraulic fill, and basis on which to propose a deformation model to predict hydraulic fill's second-consolidation settlement, expect to provide theoretical support for the engineering practice.In this paper, conduct a serials secondary-consolidation experiment on the vacuum processed soils from the central fishing port of Tianjin Binhai New Area. The main conclusions are as follow:Proposing a new secondary-consolidation test method about dredger fill, fill the blank of the existing code for corresponding parts, maybe it will be used as a supplement content for related codes in the future.Conduct a serials indoor one-dimensional secondary-consolidation tests on soil layers with different depth form hydraulic fill, analyzed different soil lays'(dredger fill, natural soil layer containing plastic drainage plate, natural sedimentary soil layers below the plastic drainage plate) engineering properties caused by various causes. And obtain the result that the impact depth of vacuum preloading is about 20 m.Carrying on a serials of graded loading secondary-consolidation test, through the analysis of test results, and also basing on Godleweki and mesri's research on the relation between the secondary-consolidation coefficient and compression index, finally establishing the predictive model about the coefficient of secondary-consolidation. And further deduced the secondary-consolidation deformation predictive model, through the contrast between the test value and calculated value validated that the model is applied to Tianjin reclamation fill.Establishing contact interaction model of pile and soil by using ABAQUS software, analyzing the distribution of the pile side friction of Central Fishing Port under such influence as surcharge, the load on pile top, time effect and pile group's effect.