Abstract:

Based on a lot of laboratory testing records from geotechnical investigation of an expressway located in the central region of Jiangsu province and using random field theory to model soil profile as a random field rather than traditional random variable, a statistical method of variability of soil parameters based on random field theory has been recommended, which can take account of the deterministic spatial trend components at the same time. Based on this, the properties of soil variability of lacustrine soft soil in the central region of Jiangsu province were statistically analyzed and the variability characteristics between laboratory physical index, deformation and strength parameters ware compared. It is indicated that the variability of the laboratory physical index parameters in this region is relatively small; no obvious trends or deterministic components can be observed; and traditional statistical method is effective for them too. Correspondingly, the laboratory deformation and strength parameters have obvious deterministic trends. They have to be destrended by regression analysis before statistical estimation, and then estimated by the recommended method due to random field theory. The conclusions of this paper provide not only a new method for statistical estimation of the properties of soil variability, but also prescriptions for engineering or construction in the central region of Jiangsu province. The third but not the least value of this paper is that it can lay a solid foundation for establishing random field model of regional soft soil properties.

Key words: lacustrine soft soil, variability of parameters, statistical estimation, random field theory