Abstract: A series of one-dimensional consolidation tests is conducted on soft clay from dredger fill site of central fishing port area in Tianjin. The relationship among stress, strain and time is obtained; the characteristics of the consolidation and secondary consolidation of dredger fill and natural sedimentary soil are compared, providing theory evidence for the deformation model of soft clay foundation of dredger fill site and the prediction of long-term settlement after construction. It is shown that strain rate has a good linear correlation with double logarithm curve of time for both dredger fill and natural sedimentary soil. After processing, the water content and compressibility of dredger fill is low, while that of natural sedimentary soil remains high. With the increase of consolidation pressure, the coefficient of secondary consolidation of dredger fills changes a little. For natural sedimentary soil, the coefficient of secondary consolidation increases first and then decreases, levels out eventually. The coefficient of secondary consolidation still has a good linear correlation with compression index. It keeps a logarithmic downtrend with the increasing of time.

Key words: dredger fill, natural sedimentary soil, secondary consolidation characteristic, secondary consolidation coefficient