Abstract: In order to explore the effect of structure on one-dimensional compression deformation of soft clays, we described the characteristics of structural failure under one-dimensional compression firstly. On this basis, the relationship between compression index and void ratio was revealed and a new mode that describes the progressive destructuration during the 1D compression was proposed. Secondly, the formula of the virgin compression curve of structured soft clays is deduced based on the above proposed descriptive mode and the effects of structural parameters on the virgin compression curves are analyzed. Thirdly, the experimental data of 10 representative structured clays from literatures together with the results of conventional oedometer tests on Ningbo clay are used to verify the proposed descriptive mode’s validity. Furthermore, a comparative analysis on the simulated results of 1D compression curves for Mexico City clays is made between the proposed descriptive mode and other 6 common descriptive modes. Finally, the variation regularity of structural parameters with the difference between nature water content and plastic limit is discussed and then the empirical formulas of structural parameters are established by the linear regression method. The results show that the proposed descriptive mode characterizes the compression destructural behavior of structured soft clays under 1D loading condition accurately. This research provides theoretical basis for establishing constitutive models of natural structured soft clays, and also offers a new idea for further study on compression deformation behavior.

Key words: soft clay, structural property of soil, destructuration, compression behavior, mathematical description, virgin compression curves, structural parameter