循环交通动载下粗粒土动弹性模量及阻尼比试验研究OA

Coarse-grained soil is a widely used roadbed filler.In order to study the dynamic characteris-tics of coarse-grained soil under cyclic traffic dynamic load,dynamic triaxial tests of coarse-grained soil under multiple confining pressures(50,100,150 kPa)and consolidation ratios(1.0,1.5)were carried out.The variations of backbone curve,dynamic elastic modulus and damping ratio were analyzed,and the Hardin-Drnevich model was used to fit the backbone curve.The results show that:(1)As the dy-namic stress amplitude increases,the slope of the backbone curve gradually becomes steeper.With the increase of confining pressure,the dynamic stress required to achieve the same strain rises.Under the same dynamic stress level,the negative strain of isobaric consolidation is greater than that of eccentric consolidation,implying that the dynamic strain decreases with the increase of consolidation ratio.(2)With the increase of dynamic strain,the dynamic elastic modulus decreases gradually while the damping ratio increases.With the increase of confining pressure,the dynamic elastic modulus increases gradually,while the damping ratio decreases.Increasing the consolidation ratio will reduce the dynamic elastic mod-ulus.(3)The applicability of Hardin-Drnevich model effectively describes the hyperbolic characteristics of the backbone curve of coarse-grained soil.The research results can provide reference for the analysis of dynamic characteristics of coarse-grained soil used as subgrade filling.