The Dynamic Characteristics Study On The Laterite Of The Core Wall In The Dam Of The Yuanjiang Xiaobanbi Reservoir

With the rapid development of social economy,hydraulic engineering construction is also constantly improving.In the construction of hydraulic engineering,earth-rock dams have became the type of dams that are often used in dam construction.The core dam,one of the earth-rock dams,has also been rapidly developed and widely used in various construction projects.In the choice of core material,although the engineering geological property of the Laterite is special,it has a good anti-seepage effect as a core wall,and it is widely distributed and can be used locally to save costs.Therefore,the Laterite is widely used in core walls.However,due to the defects of the Laterite research,people lack systematic research on the engineering geological property of the Laterite,especially the research results on the dynamic characteristics of the Laterite.Therefore,it is necessary to explore the dynamic characteristics through experiments to provide reliable dynamic characteristics parameters for the seismic stability of the core wall and the dam.Based on the study of the engineering geological properties of the Laterite of the core wall in the dam of the Yuanjiang Xiaobanbi reservoir,this article focuses on the dynamic characteristics of the Laterite in the core wall.The main research contents are as follows:Research on engineering geological properties: Including the characteristic values of the particle size components,static triaxial shear and physical and mechanical properties.Finally,the best dispersant for the Laterite dispersion,dispersant concentrationin,the characteristic values of the particle size components,the static shear strength index,proportion,liquid limit,plastic limit,optimum water content,and maximum dry density in the study area was obtained.Dynamic deformation research: Through the dynamic triaxial test,the dynamic deformation characteristics of the Laterite of the core wall in the dam of the Yuanjiang Xiaobanbi reservoir are obtained,including dynamic stress-dynamic strain relationships,dynamic modulus-dynamic strain relationships and damping ratio-dynamic strain relationships under different confining pressures,different consolidation ratios,and different water contents.The results showed that: the dynamic stress-dynamic strain curve is nonlinear,and the dynamic stress increases as the dynamic strain increases.With the increase of consolidation confining pressure and consolidation ratio,the dynamic elastic modulus and dynamic shear modulus of the specimen increase.The reciprocal of the dynamic elastic modulus and the dynamic strain can be approximated by a straight line.The intercept a and the slope b are related to the confiningpressure and the consolidation ratio of the soil.As the confining confining pressure and the consolidation ratio increase,the values a and b are gradually decreasing.As the confining pressure increases,the damping ratio decreases,and as the consolidation ratio increases,the damping ratio increases.As the water content increases,the damping ratio gradually increases,but it does not increase indefinitely.Dynamic strength study: The dynamic strength tests of the Laterite of the core wall dam of the Yuanjiang Xiaobanbi reservoir was prepared in 12 groups of 36 samples,it consists of different confining pressures,different consolidation ratios and different water contents,and discussed the influence of various conditions on the dynamic shear strength index.The results showed that: When the number of destruction cycles is the same,the dynamic stress decreases with the increase of the consolidation ratio.If the consolidation is the same,the greater the dynamic stress,the less the number of vibrations that reach the failure.The destructive dynamic strength decreases as the consolidation ratio increases,and it increases as the confining pressure increases.as the consolidation ratio increases,the dynamic internal cohesive decreases and the dynamic angle of internal friction increases.Comparing the results of static and dynamic triaxial experiments,it is found that the static internal cohesion of the Laterite of the core wall in the dam of Yuanjiang Xiaobanbi Reservoir is greater than the dynamic internal cohesion,and the angle of internal friction measured by the static triavial is smaller than that of the dynamictriavial.When the water content is appropriately increased to the optimum water content,the dynamic internal cohesion is correspondingly increased,and the dynamic angle of internal friction is correspondingly decreased.