Study On Low Temperature Asphalt Concrete Static Three Axial Test And Finite Element Analysis Of Asphalt Concrete Core Rockfill Dam

With the difficulty of project development and construction of our country's water conservancy construction in the environment continues to increase,low temperature,high altitude,seismogenic zone,asphalt concrete core wall rockfill dam as a dam type to adapt to the complex geological conditions have been widely applied in areas in northwest,southwest and Northeast China's natural conditions of water engineering construction.In order to meet the new needs of the construction,the asphalt core wall is very urgent to study the mechanical properties and strain of asphalt concrete in low temperature environment.In this paper,firstly,the structure of hydraulic asphalt concrete is introduced,and the function of each component material is introduced.According to the running environment of the project,the materials which meet the engineering needs are selected through the test.The use of single factor treatment splitting test results analysis,a comprehensive analysis of relationship between porosity,cleavage strength and displacement and the asphalt aggregate ratio,filler concentration,grading index,select a group of optimal ratio as three axis test research on mixture ratio.Secondly,under the condition of temperature control,the static three axis test was designed under the condition of low temperature and normal temperature.In the experiment,two groups of normal temperature tests were used as reference for the low temperature test,and the mechanical properties and stress strain of asphalt concrete under low temperature were analyzed.The Duncan E-B model is used as the mechanical model of the three axial test,and the Mohr Coulomb theory is the strength criterion.In solving the model parameters of K,n and Rf,according to the curves of stress-strain characteristics,reference confidence and inverse fitting the stress-strain curve of the two method,all method and applicability of the segmentation method are compared,the calculation method of K,n and Rf were optimized to reduce the impact of human factors on calculation parameters.Finally,the conclusion is drawn that the method of selecting the 60%~95% stress level test point is the most suitable method to calculate the static three axial test model parameters.Finally,in the alpine region of a pumped storage power station,asphalt concrete core rockfill dam as the research object,the asphalt concrete Duncan by different test temperature E-B parameters are calculated from the finite element model,analysis the influence of stress and strain calculation parameters of different test temperature of the dam and core wall.The results show that the analysis of the low temperature group results tend to risk.This study laid a theoretical foundation for the asphalt concrete three triaxial test data processing,the reference value for analyzing the effect of temperature on performance of asphalt concrete,the calculation results obtained have important reference significance for similar engineering.