摘要
水库大坝工程中常见的颗粒材料有堆石体、土体、泥沙等。采用离散单元法(DEM)模拟了颗粒材料堆积过程,利用分形理论研究了颗粒粒径和颗粒摩擦系数对颗粒材料的侧向压力分布特性的影响规律,分析了DEM侧向压力分布与朗肯土压力理论解的差异性。研究结果表明:DEM侧向压力合力与理论解存在差异,颗粒粒径和颗粒摩擦系数越小,则两者差异越大,但合力作用点位置差异不大;由于颗粒材料堆积后内部呈现的拱结构效应,DEM侧向压力分布呈锯齿状且具有不连续性,部分侧向压力值较周围值骤增,工程设计时应考虑这些危险点的存在;侧向压力强度和作用位置分布具有分形特性;侧向压力强度分布分形维数受颗粒粒径和颗粒摩擦系数影响不大,分布范围在1.17~1.29;随着颗粒粒径和颗粒摩擦系数的增大,侧向压力作用位置分形维数减小,作用力分布位置趋向密集,表明刚性墙的某些部位将集中承载更多的侧向压力。
Rockfill,soil and sediment are common granular materials in reservoir and dam engineering.Discrete element method(DEM)is used to simulate accumulation process of granular materials.Fractal theory is employed to analyze how particle size and friction coefficient of particles affect lateral force distribution.The lateral force distributions obtained from DEM and Rankine's earth pressure theory are compared.The results show that differences exist between lateral force distributions obtained from DEM and theory.As particle size and friction coefficient of particles increase,the differences become more obvious.However,the locations of resultant lateral forces obtained from DEM and theory are almost the same.Due to the inner arch structure effect in the accumulation of particles,the lateral force distributions obtained from DEM are zigzag and discontinuous.Some lateral forces increase rapidly compared with their neighbor forces,which should be considered for the engineering design.The distributions of lateral forces and force locations obtained from DEM are fractal.The fractal dimension of lateral forces is not affected significantly by the particle size and friction coefficient of particles,the values of which are 1.17~1.29.With the increase in particle size and friction coefficient of particles,the fractal dimension of force locations decreases,which means that the force locations tend to be more intensive and more forces will intensively act on some parts of the lateral wall.
作者
来志强
赵连军
武彩萍
吴国英
张磊
LAI Zhi-qiang;ZHAO Lian-jun;WU Cai-ping;WU Guo-ying;ZHANG Lei(Key Laboratory of Yellow River Sediment Research, Yellow River Institute of Hydraulic Research, Zhengzhou 450003, China;Institute of Geographic Sciences and Natural Resources Research, CAS, Beijing 10010, China;School of Water Conservancy, North China University of Water Resources and Electric Power, Zhengzhou 450045, China)
出处
《中国农村水利水电》
北大核心
2020年第6期199-204,共6页
China Rural Water and Hydropower
基金
黄河水利科学研究院科技发展基金(黄科发201907)
中央级公益性科研院所基本科研业务费专项项目(HKY-JBYW-2019-02)
第四届中国科协青年人才托举工程全额资助项目(水学合同201938)
国家自然科学基金青年科学基金项目(51909102
51909092)。
关键词
离散单元法
侧向压力分布
颗粒材料
分形维数
颗粒摩擦系数
discrete element method
lateral force distribution
granular materials
fractal dimension
friction coefficient of particles
