Experimental study on scale effect of dynamic characteristics on rockfill materials using super large-scale triaxial apparatus
The scale effect of rockfill materials is one of the significant factors leading to inaccuracies in the deforma-tion prediction of high rockfill dams.Currently,there have been partial studies on the static scale effect of rockfill materials,but research on the scale effect of dynamic deformation characteristics of such materials remains relatively scarce.This paper conducts dynamic experiments on Lianghekou shale and Gushui basalt with sample diameters of 800 mm(maximum particle size of 160 mm)for super large-scale test and sample diameters of 300 mm(maximum par-ticle size of 60 mm)for conventional large-scale test.The study investigates the influence of maximum particle size on the maximum dynamic shear modulus,dynamic shear modulus ratio,damping ratio,and the Shenzhujiang equivalent linear model parameters under parallel grading conditions.The experimental results show that the maximum dynamic shear modulus in super large-scale tests is greater than that in the conventional large-scale tests.As the dynamic shear strain increases,the difference in dynamic shear modulus between super large-scale and the conventional large-scale triaxial tests gradually diminishes.The dynamic shear modulus ratio Gd/Gdmax in super large-scale triaxial tests is smaller than that in conventional large-scale triaxial tests,indicating that the dynamic shear modulus in super large-scale triaxial tests decays more rapidly.The damping ratio in super large-scale triaxial tests is greater than that in conventional large-scale triaxial tests.As the dynamic shear strain increases,the difference between the two gradually enlarges.The Shenzhujiang equivalent linear model parameters k2,k1,and λmax in super large-scale triaxial tests are 1.14-1.32 times,1.26-1.31 times,and 1.31-1.44 times those in the conventional large-scale triaxial tests,respectively,while the modulus exponent n in super-large scale and the conventional large-scale triaxial tests remains nearly consistent.The research findings presented in this paper provide essential and more reasonable experi-mental and numerical basis for dynamic response analysis in similar engineering applications.
rockfillsuper large-scale triaxialscale effectdynamic shear modulusdamping ratio
万方数据
维普
