Dynamic and Static Mechanical Properties of Loess Subgrade in Shanxi

The loess is very sensitive to moisture content. The dynamic and static mechanical properties of loess subgrade under moisture content are important parameters in the design of subgrade. A series of tests - static triaxial, dynamic triaxial, seismic subsidence, and collapse - were carried out under different moisture contents from Shanxi loess. We analyzed the relationships between: (1)the moisture content and the dynamic and static strength, (2) the collapse settlement, and (3) the rebound modulus. The results indicated that the dynamic and static strength decreased with increase of the moisture content. The dynamic strength of the loess is lower than the static strength when the moisture content is less than 15 percent, but the dynamic strength approached or exceeded the static strength when the moisture content was more than 15 percent. The collapse settlement of the loess decreased with the increase of the moisture content, and the seismic subsidence increased with increase of the moisture content. The rebound modulus of the loess decreased with increase of the moisture content. It decreased more with increase of the moisture content when less content of clay and decreased less with increase of the moisture content when higher content of clay. Through test dates analysis, it set up the relationship between dynamic strength and static strength of Shanxi loess.