Experimental study on the cyclic dynamic characteristics of red clay in Nanning area
XIAO Guiyuan
LIU Xiaonan
Abstract：To study the cyclic dynamic characteristics of red clay in Nanning area,dynamic triaxial cylindrical specimens(hereinafter referred to as specimens)are prepared for a series of dynamic triaxial tests.The effects of different consolidation confining pressures,cyclic stress ratios,and loading frequencies on the dynamic strength degradation and dynamic deformation evolution characteristics of Nanning red clay are investigated,along with an analysis of the variation patterns of dynamic elastic modulus and damping ratio.The test results indicate that:1)Under different loading conditions(consolidation confining pressure,loading frequency,cyclic stress ratio),the dynamic stress of the specimens decreases rapidly and then tends to stabilize with the increase of the number of cycles.For the same number of cycles,dynamic stress increases with the increase of consolidation confining pressure,while it decreases with the increase of loading frequency and cyclic stress ratio,indicating that consolidation confining pressure,loading frequency,and cyclic stress ratio have a significant impact on the dynamic stress of the specimens.2)Under a consolidation confining pressure of 300 kPa and a loading frequency of 1.0 Hz,the compressive strength of the specimens reaches its maximum;furthermore,after a certain number of loading cycles,the sensitivity of compressive strength to loading conditions decreases.3)Consolidation confining pressure,cyclic stress ratio,and loading frequency all influence the dynamic elastic modulus of the specimens,which is characterized by a decrease in dynamic elastic modulus and a slowing rate of decrease with the accumulation of dynamic strain;for the same dynamic strain,the dynamic elastic modulus increases with the increase of consolidation confining pressure and loading frequency,while it decreases with the increase of cyclic stress ratio;under different conditions of consolidation confining pressure,loading frequency,and cyclic stress ratio,the inverse of the dynamic elastic modulus is approximately linearly correlated with dynamic strain.4)When the increment of dynamic strain is the same,the change in damping ratio decreases with the increase of consolidation confining pressure;it remains relatively constant and then decreases with the increase of cyclic stress ratio;and it decreases with the increase of loading frequency;the damping ratio fluctuates within a certain range and increases with the increase of dynamic strain.
Keywords：red claydynamic triaxial testdynamic modulus of elasticitydamping ratiodynamic strain
Publication Date：2025-09-30
Online Publishing Date：2026-05-22(First online date of this platform, not the publication date of the document)
Pages：10( 44-53 )