| Firstly,based on the theory of mesomechanics homogenization,the numerical model of asphalt concrete is established by using the multi-scale nonlinear composite material modeling method to simulate the macro-effective performance of asphalt concrete and to predict the parameters such as the elastic modulus of asphalt concrete under low temperature,and to study the influence of each component of the material on the macro-mechanical properties.The results show that the components of composite asphalt concrete have a certain degree of influence on the mechanical properties,and at the same time the validity of multi-scale nonlinear method to predict the physical and mechanical parameters such as the elastic modulus of asphalt concrete is verified.Secondly,based on the Duncan-Chang E-B nonlinear elastic constitutive model,the three-dimensional nonlinear finite element method is used to establish the actual geological topographic model of an asphalt concrete core rockfill dam located in the high-cold and high seismic intensity zone.The stress and strain distribution of rockfill and asphalt concrete core wall under the two conditions of completion and storage are studyed,and the influence of the temperature of the core wall on the performance of asphalt core wall in the dam is discussed.It is found that the distribution of displacement isoline of the rockfill body and the core wall meet the general rules and the stress is within the allowable range.Asphalt concrete core wall stress and strain changes with temperature,but the amplitude is not obvious,the change of core wall temperature has little effect on the performance of asphalt concrete core wall of this project,and the work performance of the core wall inside the dam body is basically stable.Finally,based on the three-dimensional nonlinear finite element model of the rockfill dam with asphalt concrete core wall,the time-history analysis method is used to analyze the dynamic response characteristics of the dam under the earthquake load in the direction of the river and in the direction of the vertical river.By the time-history analysis results of typical node A to determine the distribution of stress and deformation isoline of the maximum section of dam and asphalt concrete core wall at the maximum moment of earthquake response and to determine the weakest part of dam body under earthquake load,the seismic performance of asphalt concrete core wall and dam body is evaluated.The results show that the tensile and the compressive stress of rockfill body and asphalt concrete core wall under earthquake load are within the allowable range,and the possibility of deformation failure is small.The top of the dam body is the weak point of seismic resistance of the whole dam structure.It is suggested that a geogrid should be set at the top of the dam body to improve the seismic performance of the top of the dam body in the seismic zone with high intensity. |
