基于熵增定律下粗粒土剪切运动状态分析

Analysis on Shear Motion State of Coarse-grained Soil based on the Law of Entropy Increase

为探究粗粒土剪切过程运动状态变化,采用离散元数值模拟与直剪试验,对不同接触方式的粗粒土(棱角型、圆型)剪切过程位移方向趋势、转角进行分析,根据熵增定律定义宏观运动状态混乱度M、混乱系数kn,探讨了剪切过程中粗粒土运动状态变化与力学特性响应。研究结果表明:棱角型接触粗粒土较圆型运动状态混乱度大,剪切系统颗粒整体运动状态相似,按运动状态混乱度可将剪切运动分为涡流区、静止区、水平运动区;随磨圆度(圆型→棱角型)减小,抗剪强度增大,运动状态变化趋势增强,运动状态混乱度、混乱临界位移、混乱系数增加,熵值递增,粗颗粒系统达到平衡态速率增大,整体稳定性增强。

In order to explore the change of the motion state of the coarse-grained soil in the shearing process,discrete element numerical simulation and direct shear test are used to analyze the displacement direction and rotation angle of the coarse-grained soil(angular,round)in different contact modes during the shearing process.According to the law of entropy increase,the macroscopic motion state chaos Mand chaos coefficient knare defined,and the motion state change and mechanical response of the coarse-grained soil during the shearing process are discussed.The study results show that the angular contact coarsegrained soil is more chaotic than the circular motion state,and the overall motion state of the particles in the shear system is similar.According to the chaos of the motion state,the shear motion can be divided into vortex area,static area and horizontal motion area;as the roundness(round shape→angular shape)decreases,the shear strength increases,the changing trend of the motion state increases,the motion state chaos,the chaotic critical displacement,the chaos coefficient increases,and the entropy increases,the rate of coarse particle system reaching the equilibrium increase,and the overall stability is promoted.