Large triaxial test study on dynamic characteristics of round gravel

A series of large-scale drained dynamic triaxial tests were conducted on Nanning saturated gravel soil to investigate dynamic characteristics. The effects of relative density, dynamic stress amplitude, and the number of load cycles on the pore pressure, accumulation strain, and stress–strain hysteresis loops of saturated round gravel soil were analyzed. Experimental results indicated that the curves of accumulated axial strain with the number of load cycles present stable type. When the dynamic stress amplitudes were small, the increasing rule conforms to hyperbolic function. A linear relation between the parameter α in the hyperbolic function with the dimensionless DCR had been found. A double-lined model was set up to simulate the stress–strain hysteresis of saturated round gravel under a large number of load cycles. Then, results of the double-line model were validated against triaxial test results. The model was verified to be capable of predicting with accuracy the relationship between the stress–strain and area change behavior of saturated gravel soils. A particular feature of the model was that it only has three parameters than other models and applicable.