摘要
针对既有边坡冲蚀模型无法有效考虑散体颗粒实际形状对其运动状态影响的问题,分别采用格子Boltzmann方法(LBM)和离散元法(DEM)模拟水流及边坡散体颗粒,基于动量定理计算颗粒承受的水流冲击力,考虑库仑摩擦、土体颗粒黏聚力等因素建立颗粒起动准则,采用牛顿第二定律、动量及能量守恒等计算颗粒运动及碰撞,结合随机生长算法建立边坡计算域,从而构建基于LBM-DEM的边坡冲蚀演化模型,在验证模型可靠性基础上,分析颗粒形状、级配、密实度等因素对边坡冲蚀影响。研究结果表明,该模型能够有效表征大颗粒裸露、冲蚀坑洞形成、小颗粒沿大颗粒间缝隙迁移等现象;水流入口区域颗粒率先出现迁移,底部区域附近颗粒因水流速率较小难以发生迁移;填料扁平度增加会使得边坡冲蚀难度增加;随着中颗粒数量增加,小颗粒因被包围使得其受水流冲击影响降低,且中颗粒及大颗粒因互相嵌锁难以在水流冲刷作用下产生移动,使得边坡冲蚀难度增加;小颗粒易因水流冲刷发生流失,其数量增加引起的密实度增加会使得边坡冲蚀程度加剧,其数量减少引起的密实度降低会使得边坡内部因冲刷出现空洞。
To address the problem that existing slope scouring models fail to effectively capture the influence of particle shape on their motion states,the Lattice Boltzmann Method(LBM)and Discrete Element Method(DEM)are employed to simulate water flow and granular materials on a slope,respectively.The water impact force on particles is calculated based on momentum theorem.Factors such as Coulomb friction and cohesion of soil particle are considered in establishing the motion initiation criteria for particles.Particle motion and collisions are computed using Newton's second law,momentum conservation,and energy conservation principles.A random growth algorithm is introduced to generate the slope computational domain,and a slope scouring evolution model is finally established based on the coupled LBM and DEM.After verifying the reliability of this model,the effects of particle shape,gradation,and compactness on slope erosion are analyzed.Research results indicate that this model can effectively characterize phenomena such as large particle exposure,the formation of erosion pits,and the migration of small particles through the voids between large particles.Particles in the water inflow zone are mobilized first,while those near the bottom region remain stationary due to the low water flow velocity.Increased particle flatness can enhance slope erosion resistance.As the medium particles increase,small particles experience reduced hydrodynamic impact as they are shielded,and the interlocking between medium and large particles resists displacement under water scouring,thus enhancing the erosion resistance of slope.Small particles are prone to scouring-induced loss.An increase in their content raises compactness,thereby intensifying slope erosion.Conversely,a decrease in compactness from reduced small particles content results in the scouring-induced formation of internal voids.
作者
赵晨阳
雷明锋
贾朝军
鲁光银
崔振东
ZHAO Chenyang;LEI Mingfeng;JIA Chaojun;LU Guangyin;CUI Zhendong(School of Mechanics and Civil Engineering,China University of Mining and Technology,Xuzhou 221116,China;School of Civil Engineering,Central South University,Changsha 410075,China;National Engineering Research Center for High-Speed Railway Construction Technology,Changsha 410075,China;School of Geosciences and Info-physics,Central South University,Changsha 410083,China)
出处
《岩土工程学报》
北大核心
2026年第4期771-780,共10页
Chinese Journal of Geotechnical Engineering
基金
中国博士后面上基金项目(2025M773299)
国家自然科学基金项目(52378420)
湖南省自然科学基金项目(2024JJ9080)。
