Abstract:

Recently, high clay dredger fill has been used as the main soil of land reclamation. However, the vertical drain pipes used in vacuum preloading projects were always stagnated by high clays because of high clay content. In order to research the characteristics of this soil, vacuum preloading with 80 kPa vacuum degree was set up based on the physical model. And the physical and chemical indicators of dredger fill were tested by experiments. So the curves of moisture content, soluble salt content, sodium content, pH value, cation exchange value, and organic matter content were shown as figures. Tests show that in the consolidation process the moisture content was inversely proportional to the soluble salt content, pH and other chemical indicators; and the more soluble salt content was in dredger fill around vertical drainage pipes, the higher organic matter content was. At the same time, cation exchange capacity was directly related to pH value. Furthermore, drain pipes stagnation ralated on the vacuum preloading method with 80 kPa were indicated by the physical and chemical indicators. It is adviced to use new technology of step vacuum preloading for the high clay dredger fill reclamation approach to provide improved measures.

Key words: high clay dredger fill, vacuum preloading method, physical and chemical indicators, step vacuum preloading