摘要
心墙砾石土的力学性质直接影响土石坝心墙沉降变形及结构安全。针对目前对其影响因素的研究多集中于砾石掺配比例和空间分布,且存在缺乏考虑砾石形状对砾石土力学性质影响的问题,提出基于不规则砾石形态的砾石土离散元数值分析方法,探究砾石形状对砾石土力学性质的影响。首先,基于三维激光扫描技术构建不规则三维形态砾石模型库,并提出三变量形状评定标准对砾石形状特征进行判定;然后,提出颗粒原位替换法构建砾石土颗粒流模型;最后,进行不同砾石形状的三轴压缩数值试验,分析砾石土的力学性质。结果表明,提出的三变量形状评定标准简单有效,能够精确识别不规则砾石的多重形状特性;砾石形状对砾石土的宏观力学性质影响显著,不同形状砾石数量的均匀性有助于提高试样强度。研究可为改善心墙砾石土力学性质提供参考。
Mechanical properties of the gravelly soil of an earth-rock dam core wall directly affect its settlement deformation and structure safety. Most previous studies focus on the proportion and spatial distribution of its gravel blending, and lack consideration of the influence of different gravel shapes on the soil mechanical properties. This paper presents a numerical discrete element method(DEM) for simulating the gravelly soil of irregular-shaped particles to explore this shape influence. First, we construct a model library of three-dimensional irregular gravels based on the test data collected using 3 D laser scanning technology, and suggest a three-variable shape evaluation standard to classify the particle shape characteristics. Then, we formulate a particle in-situ replacement method and use it to construct a particle flow model for gravelly soil.Finally, numerical tests of triaxial compression on different gravel shapes are carried out to investigate the mechanical properties of gravel soil. Results show that this standard is simple and effective and can identify accurately the multiple shape characteristics of irregular gravel. Gravel shape has a significant influence on the macroscopic mechanical properties of gravel soil;uniformity in blending various gravel shapes helps increase the strength of soil samples, thus suggesting a new direction for improving the gravel soil of earth-rock dam core walls.
作者
崔博
邓博麒
刘明辉
余佳
王晓玲
CUI Bo;DENG Boqi;LIU Minghui;YU Jia;WANG Xiaoling(State Key Laboratory of Hydraulic Engineering Simulation and Safety,Tianjin University,Tianjin 300350)
出处
《水力发电学报》
EI
CSCD
北大核心
2020年第4期73-87,共15页
Journal of Hydroelectric Engineering
基金
国家自然科学基金雅砻江联合基金(U1765205)
国家自然科学基金创新研究群体项目(51621092)
国家自然科学基金(51779169)
关键词
砾石土
砾石形状
三轴试验
数值模拟
三维激光扫描
gravelly soil
shape of gravel
triaxial test
numerical simulation
3D laser scanning
作者简介
崔博(1983—),男,副教授,E-mail:cuib@tju.edu.cn
