摘要
针对筑坝料变形特性的尺度效应,以接触变形理论为基础,从粒径尺度、试件尺度及外部影响因素角度,结合试验的方法开展了研究。建立了粒径尺度与归一化压缩模量的指数相关模型,论证了试件尺度径径比大于5时压缩试验的变形可靠性,揭示了侧限条件、干密度、边缘破碎及荷载等级5个外部因素对尺度效应的影响规律和内在机理,并分别建立了各因素与变形的相关模型。基于试验回溯现场过程,建立了综合考虑可破碎材料(堆石料)与不破碎材料(砂砾石)的多尺度统一修正模型。通过对大坝堆石料EB模型计算参数的修正及变形计算,验证了多尺度统一修正模型对变形计算的适用性与可靠性,较直接采用缩尺试验结果准确度提升了约20%,为解决坝体变形预测不准确提供了新的思考方法与解决路径。
In view of the scale effects of deformation characteristics of rockfill,based on the contact deformation theory,the research is carried out from the perspective of particle sizes,specimen sizes and external factors,combined with the test method.The exponential correlation model between the particle sizes and the normalized compression modulus is established.The deformation reliability of compression tests is demonstrated when the particle size ratio is greater than 5.The influence rules and internal mechanism of five external factors on the scale effects,namely,the lateral limit condition,the dry density,the edge breakage and the load level,are revealed,and the relevant models for each factor and deformation are established respectively.Based on the field experiments,a multi-scale unified correction model is established,which takes into account the crushed material(rockfill)and the non-crushed materials(gravel).The applicability and reliability of the multi-scale unified correction model for deformation calculation are verified by modifying the parameters and deformation calculation of the EB model for dam rockfill.The accuracy of the model is about 20%higher than that of the direct scale tests.This provides a new thinking method and solution path to solve the inaccuracy of dam deformation prediction.
作者
魏然
吴帅峰
汪小刚
蔡红
WEI Ran;WU Shuai-feng;WANG Xiao-gang;CAI Hong(State Key Laboratory of Simulation and Regulation of Water Cycle in River Basin,China Institute of Water Resources and Hydropower Research,Beijing 100048,China)
出处
《岩土工程学报》
EI
CAS
CSCD
北大核心
2020年第S01期161-166,213,共7页
Chinese Journal of Geotechnical Engineering
基金
中国水科院基本科研业务费项目(GE0145B412019)
国家自然科学基金项目(U19A2049)
关键词
尺度效应
压缩模量
影响因素
修正模型
坝体变形
scale effect
compression modulus
influencing factor
correction model
dam deformation
