Experiment Study On The Residual Deformation Of Hydraulic Asphalt Concrete And Asphalt Concrete Core Rockfill Dam Three Dimensional Numerical Analysis

Hydraulic asphalt concrete is a kind of complex material composed of components, including asphalt, coarse aggregate, fine aggregate and mineral powder. Hydraulic asphalt concrete has many advantages, such as good seepage control performance, nice flexibility, adapting to the dam deformation easily and so on, it was used widely as impervious body of hydraulic structures.The water resources in China are mainly distributed in the south-west and north-west regions where have complex geological conditions and frequent earthquake, so the seismic safety of the asphalt concrete core wall dam built in these regions is a major problem considered by engineers. Asphalt concrete core wall as an important part of asphalt concrete core wall dam, the core wall action under seismic effect has important influence on seismic stability of dam. From the earthquake damage investigation, we can see that cracks, earthquake subsidence and landslides are all related to earthquake residual deformation, it is necessary to study the asphalt concrete residual deformation properties deep. However, there are few researchs on the dynamic characteristics of asphalt concrete, especialy the residual deformation research is in an almost bank. In this paper, a large number of residual deformation triaxial tests were experimented on the asphalt concrete samples which were drilled from the Pangduo asphalt concrete core wall dam, many factors were considered, such as stress ratio, loading frequence, cyclic number, confining pressure and temperature, and a residual deformation model was proposed. These researchs could provide theory support for seismic research and design of high asphalt concrete core dam.From the results of residual deformation triaxial tests, residual strain increases with the increase of cyclic number, and there is a linear relationship between residual strain and cyclic number; the residual strain increases with the increase of dynamic stress; with the increase of loading frequence, the residual strain becomes smaller; the residual strain is slight, its value appears10magnitude under most work conditions, its maximum axial residual strain is0.12377%, far less than failurestrain.Dynamic modulus of elasticity and damping ratio were calculated by equivalent linear model, under the same confining pressure, the dynamic modulus of elasticity remains unchanged with the increase of dynamic strain; the dynamic modulus of elasticity increases with the increase of confining pressure, but the increase range is small; the dynamic modulus of elasticity increases with the increase of loading frequence; the dynamic modulus of elasticity Ed mostly lay in the range of0.8GPa to1.2GPa; and damping ratio lay from15%to25%.Sensitivity analysis was performanced on the asphalt concrete Poisson’s ratio pi and unloading modulus coefficient kur, both μ and kur have effect on the deformation and pressure stress of core wall; static and dynamic superposition stress was slight bigger than full storage period pressure stress.