摘要
大型水工混凝土结构易在结构突变部位出现应力集中现象,工程结构的整体失效破坏起源于局部区域的损伤积累和裂缝失稳扩展。为明确混凝土重力坝在地震荷载作用下的力学特性,采用子模型法构建了基于实际工程的重力坝坝踵高应力区的精细化模型。基于坝踵代表体的细观结构模型,研究了地震作用下重力坝局部受力变形特征以及损伤演变过程。研究结果表明:与宏观模型计算结果相比,细观子模型计算结果能够更真实地反映应力场,位移场,裂纹分布以及损伤演变过程。此外,研究发现细观结构内部的损伤发生时间早于宏观结构,表明宏观裂缝源于内部,混凝土结构破坏并非瞬间完成,而是由于其内部微细裂纹的演化形成更大的宏观裂缝导致。研究结果为重力坝宏观和细观尺度的损伤分布形式提供参考和借鉴。
Large hydraulic concrete structures are prone to stress concentration at points of structural discontinuity.The overall failure of engineering structures originates from damage accumulation and crack instability extension in local areas.To clarify the mechanical properties of concrete gravity dams under seismic loading,this study adopts the submodel method to construct a refined model of the high stress zone in the heel of gravity dams based on actual engineering projects.On the basis of the meso structural model of the representative element of the dam heel,the local force deformation characteristics and damage evolution process of the gravity dam under seismic action are studied.It shows that the results of the meso submodel can more realistically reflect the stress field,displacement field,crack distribution and damage evolution process than the macro model.In addition,it finds that the damage occurrence in the meso structure is earlier than in the macro structure.This indicates that the macro cracks originate from the inside,and the destruction of concrete structure is not instantaneous,but caused by the evolution of its internal microcracks to form larger macrocracks.These results provide a reference for the formation and distribution of the damage of gravity dams at macro and meso scales.
作者
殷亚娟
任青文
YIN Ya-juan;REN Qing-wen(College of Civil Engineering and Transportation,Hohai University,Nanjing,Jiangsu 210098,China;College of Mechanics and Materials,Hohai University,Nanjing,Jiangsu 210098,China)
出处
《工程力学》
EI
CSCD
北大核心
2024年第S01期15-22,82,共9页
Engineering Mechanics
基金
国家自然科学基金项目(51739006)。
关键词
混凝土重力坝
地震荷载
力学特性
子模型
损伤演变
concrete gravity dam
seismic load
mechanical properties
submodel method
damage evolution