Study On The Fundamental Properties Of Asphalt Concrete Cores For Embankment Dams--Research On Creep And Dynamic Character

Asphalt concrete core for embankment dams have got notable development in recent years, but the fundamental properties of asphalt concrete cores is not known clearly which has a hold on wide use of this kind of dams. Preliminary research on creep and dynamic characteristics, which are two important properties of asphalt concrete cores for embankment dams, through triaxial compression creep tests and dynamic triaxial test with the aid of the viscoelastic theory and the soil dynamics theory. Using the three梡arameter solid model and the Burgers four-parameter model to fit the creep curve separately, it was found that the Burgers model can describe the creep process more well, and then provide parameters for finite element analysis of asphalt concrete cores for embankment dams. The dynamic parameters of the asphalt concrete can be obtained through dynamic triaxial test, combined with the CunLi Chen's studying results, discovering that the dynamic stress-strain relationship obeys the hyperbolic model well, and the maximum dynamicmodulus Edmax and the maximum shear modulus Gdmax increasing along with the decreasing of the temperature and the increasing of consolidation ratio Kc. Confining stress and consolidation ratio have little effect on damping ratio of the asphalt concrete, and the damping ratio has decreasing tendency along with the increasing of the temperature. Vibration times hardly have effect on the changing of the elastic strain in the condition of the dynamic stress. Under the same consolidation ratio and the vibration times, effect of the dynamic stress on the dynamic residual strain shows linear relationship, and effect of the vibration times on the dynamic residual strain increasing. In the condition of the different confining stress and the temperature of 8. 8癈, dynamic strain of the asphalt concrete is very little within 100 vibration times under rather big dynamic stress, the total axial strain is only about 1%~2% within 3000~5000 vibration times. It seems that no dynamic strength destroy problem for the asphalt concrete.