Abstract: The thixotropic property of the soft clay is more significant. The studying in the compressive characteristics of the soft clay under the influence of thixotropic behavior is of great significance for in-depth analysis of the stability of soft soil foundations. The one-dimensional compression tests were conducted on the undisturbed and remolded samples in the Pearl River Delta, then the Scanning Electronic Microscopic (SEM) tests were performed on the samples after the one-dimensional compression tests. The influence of the thixotropy on the compressibility of the soft clay under different standing time and moisture content was analyzed from the perspective of microstructure. The experimental results show that as the standing time increases, the compression curve of the remolded sample gradually approaches that of the undisturbed sample, and the stiffness of the sample gradually increases. The structural shape of remolded specimens gradually tends towards the undisturbed specimens; The microstructure porosity of the sample shows a linear increasing trend with the increase of standing days and water content. When the standing days reach 120 days, the microstructure porosity of the reshaped sample is equal to that of the original sample. Besides that, the particle orientation gradually becomes mainly arranged vertically as the standing days increase. And the distribution intensity gradually increases. The above research results can provide experimental basis for revealing the mechanism of the influence of thixotropy on compression characteristics in soft clay.

Key words: Soft Soil in Delta, Thixotropic, One-Dimensional Compression Test, Microstructure, Porosity