颗粒形状对粗粒土K_(0)压缩特性影响的离散元分析  

Influence of particle shape on K_(0) consolidation characteristics of coarse-grained soils via DEM

作　　者：李华章 覃泽华 Li Huazhang;Qin Zehua(College of Engineering and Technology,Zunyi Normal University,Zunyi 563006,Guizhou,China;Shaanxi Geology and Mineral Innovation Research Institute Co.,LTD.,Xi'an 710054,Shaanxi,China)

机构地区：[1]遵义师范学院工学院,贵州遵义563006 [2]陕西地矿创新研究院有限公司,陕西西安710054

出　　处：《陕西地质》2024年第2期107-113,共7页Geology of Shaanxi

基　　金：遵义市科技合作计划项目(资助号:遵市科合HZ字(2024)153号)。

摘　　要：K_(0)值是计算地基承载力、土坡稳定性和挡土墙土压力的关键参数。粗粒土往往具有形状不规则的特征,为研究其颗粒形状对粗粒土K_(0)压缩特性的影响,首先采用离散元法生成5种不同形状的颗粒簇并获取其形状参数,之后取相同的颗粒粒径,以同样的方法分别生成相同初始状态的试样,最后进行K_(0)压缩试验,就颗粒形状对粗粒土K_(0)压缩特性的影响及其细观机理做了详细的探讨。研究结果表明:(1)不同形状试样的K_(0)值均随法向应力的增长而降低,K_(0)值与颗粒形状参数(纵横比、圆形度、完整度以及球形度)呈正相关,即颗粒越规则(形状参数趋于1),K_(0)值越大。因此工程设计中应适当考虑颗粒形状的影响;(2)K_(0)值与颗粒的配位数CN值有关,颗粒形状越不规则,CN值越大,K_(0)越小;(3)K_(0)值与试样平均接触力MF和强力链占比SP相关,颗粒形状的不规则将导致强力链占比和平均力减少,二者共同影响K_(0)值的大小。研究成果可为现场K_(0)值的评估提供理论参考,避免过度设计或设计不足,确保工程安全和经济性。The K_(0) value is crucial for calculating the bearing capacity of foundations,the stability of slopes,and the earth pressure exerted by retaining walls.The particles in coarse-grained soil often have irregular shapes.To study the influence of particle shape on the K_(0) consolidation characteristics of coarse-grained soil,we used a discrete element method to generate five different particle cluster shapes and determine their shape parameters.Using the same particle size,we produced an initial state with the same method.Finally,we performed the K_(0) consolidation test to explore the impact of particle shape on the K_(0) consolidation characteristics and underlying mechanisms of coarse-grained soil.A comprehensive analysis was conducted on the impact of particle shape and the mechanisms involved.The results show that:(1)The K_(0) values of specimens with different shapes decrease as normal stress increases.The K_(0) value is positively correlated with the shape parameter of the particles;more regular particles(with a shape parameter closer to 1)have higher K_(0) values.Therefore,considering particle shape in engineering design is important;(2)The K_(0) value is related to the coordination number(CN)of the particles.More irregular particle shapes lead to higher CN values and lower K_(0) values.(3)The K_(0) value is connected to the average contact force(MF)and the ratio of strong chains to specimen SP.Irregular particle shapes reduce the ratio of strong chains and the average force,both influencing the K_(0) consolidation characteristics of coarsegrained soils.Such irregularities decrease the average force,affecting the K_(0) value.These findings can provide a theoretical basis for evaluating the K_(0) value in the field,helping to avoid over-or under-design and ensuring project safety and economy.

关 键 词：地质工程 静止土压力K_(0) 离散元压缩模拟 颗粒形状 

分 类 号：P694[天文地球—地质学]