Reserach On Measures To Improve The Stress Characteristics Of Super High Asphalt Concrete Core Wall Dam

Based on the three-dimensional finite element numerical simimulation technology,the stress and deformation analysis of an asphalt concrete core wall dam was carried out.The Duncan-Chang E-B model is used as the constitutive model of the dam body and the core wall material.Considering the humidification effect of the rockfill material after the water storage,the dam filling and reservoir water storage process are simulated and completed.Displacement and stress distribution of asphalt concrete core wall and dam under two working conditions and water storage period.The calculation results show that the stress and deformation values of the dam body and the core wall are within a reasonable range.The dam body packing and core wall materials meet the strength requirements,which provides a reference for structural design and construction.(1)The bending curvature at both ends of the core wall is k=8.27×10-4.and the lengths of the curved ends of the core wall are respectively taken as 10%,15%,20%of the length of the core wall along the axis of the dam.The length of the bending section,the displacement and stress characteristics and distribution law of the core wall under the action of the upstream water pressure,and determining which bending section length has the most significant effect on improving the stress characteristics of the core wall.The results show that the tensile stress and the tensile stress region of the core wall are smaller as the length of the curved section at both ends of the core wall increases.(2)Select the length of the curved section at both ends of the core wall as 15%of the length of the core wall along the axis of the dam,and take the curvature of the curved section at both ends of the core wall as k=5.0×10-4,k=8.27×10-4,k=3.0×10-3.Studying the curvature of different bending sections,the displacement and stress characteristics of the core wall and the distribution law under the action of the upstream horizontal thrust,and determining which bending section curvature has the most significant effect on improving the stress characteristics of the core wall.The results show that with the increase of the curvature of the curved section at both ends of the core wall,the tensile stress value and the tensile stress region of the core wall are smaller,and the stress concentration and arching effect at the bottom of the core wall can be reduced.(3)Select the length of the curved section at both ends of the core wall to be 15%of the length of the core wall along the axis of the dam.The bending curvature at both ends of the core wall is k=8.27×10-4,and the modulus K of the core wall is taken as K=304,K=608,K=1216,study the different elastic modulus of the core wall,the displacement and stress characteristics and distribution law of the core wall under the action of upstream water pressure,and determine the elastic modulus of the core wall.The results show that with the increase of the elastic modulus of the core wall,the tensile stress value and the tensile stress region at the abutment of the core wall are larger.