Experimental Study On Sedimentation-consolidation Behavior Of Dredged Clays At High Water Contents

A great deal of dredged mud are produced inevitably in the large scale dredging projects. Land reclamation yard disposal now has been the most common disposal method of the dredged mud produced in the inland dredging. During the design of reclamation yard disposal and foundation treatment of dredged clays in dredging projects, it is a crucial problem to determine the sedimentation behavior and consolidation properties. Based on the current situation and problems, a serial of sedimentation-consolidation tests were carried out to study the sedimentation behavior and consolidation properties. This test consider the effect of initial water content, initial height and model diameter on the self-weight sedimentation, and explores the effects of settling process and settling time on the consolidation properties.This paper mainly includes the following work:1) Considering the high water content, low strength and high compressibility of dredged clays, modified the settling column and developed the sedimentation-consolidation instrument. Realize the experiment that combined sedimentation and consolidation together. The instruments mainly consist of three parts, which are soil sample room, loading system and measuring system.2) A series of self-weight sedimentation tests were carried out. Study the effect of initial water content, initial height on the self-weight sedimentation behavior under the condition of static water.3) Consolidation tests of deposited soil were carried out. The compression behavior of the deposited soil are studied, change laws of the consolidation coefficient and the compression index are defined. Under the low stress level, with the increase of the consolidation pressure, the consolidation coefficient decreases firstly, then increases, compression index showed a reverse trend and tended to stable.4) The sedimentation-consolidation deformation of the high water content dredged clays was studied.The influence of the deposition process and deposition time on the consolidation deformation was analyzed. The sedimentation-consolidation deformation curve normalized properties are studied.