The Study Of Dynamic Characteristics Of Lvliang Compacted Loess

Loess is a deposit formed during the Quaternary history, which mainly distributes in high seismic intensity areas in the Midwest of China. In recent years, with the shortage of building land in loess areas of the city has become increasingly prominent, large number of buildings built in a large area of the filling area. Since the porosity and structure of loess has undergone significant changes during compaction, which lead to a lots of differences in engineering properties compared to undisturbed loess. Therefore, to study on the dynamics properties of compacted loess becomes necessary.Based on summarizing the loess dynamic shear modulus, damping ratio and dynamic strength characteristics of the domestic and foreign status quo, and National Natural Science Foundation "Loess landslide mechanism caused by dynamic compaction", we use GDS dynamic triaxial apparatusto conduct conducted a comprehensive on dynamical properties of Lvliang compacted loess. The results show that the dynamic shear modulus of compacted loess decreases with the increasing of dynamic shear strain, which can be fitted with logarithmic equation better. The dynamic shear modulus is in the range between 20 MPa and 160 MPa. The dynamic shear modulus and initial dynamic shear modulus decrease with the increasing of moisture content and increase with the increasing of dry density, confining pressure, consolidation stress ratio and loading frequency. The data points of damping ratio are distributed in a narrow range, which are between 0 and 0.27.Damping ratio generally show a slowly increasing trend with the increasing of moisture content, and show a slowly decreasing trend with the increasing of confining pressure, consolidation stress ratio and loading frequency. Dry density has no obvious effect on the damping ratio. The dynamic strength of compacted loess decreases with the increasing of vibration times, which can be fitted with logarithmic equation. The dynamic strength and its parameters of compacted loess decrease with the increasing of moisture content and increase with the increasing of dry density and loading frequency. Dynamic cohesive force and dynamic internal friction angle decrease with the increasing of vibration times and finally tends to be stable.