Movement Parameters And Impact Force Chain Characteristics Of Landslide Debris Flow In Different Particle Size Distribution

Affected by factors such as the lithological characteristics and structure of the site,different landslide rock and soil bodies collide and scrape with the slopes and valleys during the movement process,and then break and disintegrate,forming loose dry fragments with a certain particle size distribution.The debris flow will eventually continuously impact the building structure in the mountainous area,resulting in disastrous consequences such as displacement,deformation,and even overturning damage of the disaster-bearing body.Carrying out research on the motion parameters and impact force chain characteristics of rock and soil with different particle size distributions will not only help to improve the relevant understanding of the kinematics and dynamics of landslide hazards,but also the planning and prevention of mountain building structure design and landslide debris flow The work provides an important theoretical basis.Combining the lithological stratification phenomenon in the landslide source area at the disaster site,this paper takes the particle size distribution of the landslide rock and soil as the research factor,and uses a combination of model tests and numerical simulations to analyze the conditions of different particle size distributions(including particle order distribution conditions and Gradation conditions)Evolution characteristics of landslide rock-soil movement parameters and impact force chain characteristics.1)From a macro perspective,the average velocity of particles of each particle size in the landslide rock and soil mass is jointly affected by the particle size and the initial particle sequence of the slide source area,and the initial particle sequence has a greater impact on the average velocity of each particle;On the one hand,the size of the particle size has a greater impact on the arrangement of the particle sequence in the thickness direction,while the distribution of the particle sequence in the Huayuan area has a greater impact on the stacking morphology of a single particle;under the action of particle sorting,the particle size becomes the peak impact control The main factor of force,and the distribution of particle sequence in the sliding source area controls the impact force of the debris flow in the quasi-static accumulation stage by determining the accumulation form of the sliding body.2)From a meso-level perspective,during the movement of the debris flow,the total number of force chains will experience a process where the fluctuations decrease,then increase,and finally remain stable,and the total number of force chains is negatively correlated with the average velocity of the particles;In the process of impacting the retaining wall,both large particles and medium-sized particles may produce strong and super-strength chains.The closer the particles of the two are to the surface of the initial accumulation,the greater the probability that they will produce strong and super-strength chains;debris flow During the movement process,the particle sorting effects in different directions have a sequential relationship.The particle sorting along the thickness direction takes the lead and promotes the particle sorting in the moving direction.3)Finally,under different particle gradation conditions,during the movement of the debris flow,the coordination number of the force chain,the proportion of strong and super strong chains will experience a process of first fluctuation and decrease,then increase,and finally remain stable.The chain coordination number is negatively related to the average velocity of the particles;the uneven coefficient Cu in the particle gradation of rock and soil is the main factor affecting the proportion of the coordination number of the power chain,the super strong chain,the strong chain,and the weak chain;In the process of debris flow impacting the retaining wall,the strong and super strong chains are mainly concentrated in the bottom area,and with the increase of the content of coarse particles,the position of the peak coordination number of the super strong chains gradually increases.