Abstract: The natural sedimentary soft clay behaves the structural characteristic, the influence of which can not be reflected in the process of computing secondary consolidation of soft clay by conventional method. Secondary consolidation test on undisturbed and remolded soil samples from Zhangzhou and Qingdao are performed for researching the influence of soft soil structural characteristic on the secondary consolidation coefficient . It is shown that soft soils' increases with the increasing pressure P, and it gets to maximum while P gets close to yield pressure , and then it decreases and influenced little by P. Finally, it tends to be consistent with remolded soil clays' . The remoulded soft clays' which is influenced little by P is regarded as a constant. Determing according to may have some error. The normally consolidated soft clay may show false over-consolidation because of soil's structural characteristic, therefore, it is improper to illustrate structural soft clays' by using normally consolidated soft clay; it can be well illustrated according to the damage of soft clay structure under different pressures.

Key words: soft clay structure, secondary consolidation coefficient, structural yield pressure