Abstract: Soil physical and mechanical parameters are the basis for the design of soil treatment, slope stability analysis and supporting structures, etc. Based on a large amount of drilling and laboratory test data in Chengcheng County of Weibei Loess Plateau, the relationships among the soil compression coefficient, collapsibility coefficient, Atterberg Limits and other physical and mechanical parameters and the depth of the loess are analyzed. Thus, the space variations of the engineering geology characteristics of the loess and correlation among some indicators in the area are studied. The main conclusions can be obtained as follow: the physical and mechanical parameters show different characteristics with the sample depth; the dry density increase significantly with the increase of the sample depth. The collapsibility and the compression coefficient show the opposite trend. The variation of the water content, Atterberg Limits, internal friction angle, and cohesion with the sample depth is not obvious; The void ratio is positively correlated with the compression and collapsibility coefficients. The correlation between the collapsibility coefficient and the void ratio is higher. The correlation between the compression and collapsibility coefficients is more obvious when the compression coefficient of the loess is small. There is no obvious correlation between the collapsibility coefficient and the compression coefficient when the compressibility is large.

Key words: Loess, Statistical Analysis, Physical and Mechanical Parameters, Spatial Variation Relations, Correlation