Kinetic Evolution of Debris Flow Grain Composition
Debris flow fluids are characterized by a broad grain size distribution(GSD),which undergo constant variation in composition in movements.Previous studies used source or deposition samples as representatives of the fluid materials,but they failed to distinguish their gradations in phrases if only via classical granulometric parameters to be used by traditional grain size analysis.In this study,a universal scaling distribution function of GSD was applied to reveal significant differences in the scaling distribution parameters among the source,fluid,and deposition of debris flow based on sample data collected at the Jiangjiagou gully,a well-known debris flow observation site in Yunnan Province,China.On this basis,a series of dynamic mixing and slump tests were designed and conducted using soil samples from the debris flow source at Jiangjiagou as experimental materials,aiming to understand the changes in GSD during artificial movements and their impact on debris flow mobility.(1)The GSD exhibited significant changes under dynamic mixing,with the two GSD parameters of scaling distribution:µ and Dc transitioning from an initial discrete state to a negative power-law correlation;(2)Under sufficient dynamic mixing,the GSD gradually transformed into a stable state,quite possibly corresponding to the optimal mobility of debris flows,manifested by stable high values in indicators such as specific surface area,slump spread,and diffusion area.These experiments demonstrate how variations in debris flow composition affect its movement process,which is of great significance for constructing a more comprehensive theoretical model of debris flow dynamics.
万方数据
维普
