堆石料本构模型对混凝土面板坝应力变形计算结果的影响研究  

Influences of constitutive model for rockfill materials on calculated stress and deformation of concrete-faced dams

作　　者：傅中志[1,2] 张意江 陈锦祎 王永生 FU Zhongzhi;ZHANG Yijiang;CHEN Jinyi;WANG Yongsheng(Nanjing Hydraulic Research Institute,Nanjing 210029,China;Key Laboratory of Reservoir and Dam Safety,Ministry of Water Resources,Nanjing 210024,China;China Water Resources Beifang Investigation,Design and Research Co.,Ltd.,Tianjin 300222,China)

机构地区：[1]南京水利科学研究院,江苏南京210029 [2]水利部水库大坝安全重点实验室,江苏南京210024 [3]中水北方勘测设计研究有限责任公司,天津300222

出　　处：《岩土工程学报》2024年第10期2089-2100,共12页Chinese Journal of Geotechnical Engineering

基　　金：国家自然科学基金项目(52222906,U21A20158);国家重点研发计划项目(2021YFC3090101)。

摘　　要：堆石料本构模型选择是影响混凝土面板坝应力变形计算结果的主要因素。以某典型面板坝为例,采用邓肯E-B非线性弹性模型和“南水”双屈服面弹塑性模型,对坝体填筑过程和蓄水过程进行了三维有限元模拟;研究了两种模型计算的坝体和面板的位移和应力分布差异;分析了两种模型计算结果呈现差异的原因。两种模型计算结果最显著的差异体现在两个方面:(1)“南水”模型计算的坝体沉降、面板挠度等位移指标小于E-B模型,其原因是“南水”模型计算的坝体小主应力和变形模量更高。(2)E-B模型计算结果显示蓄水后面板底部顺坡向受拉;而“南水”模型计算的面板顺坡向应力为全断面受压。前者是由E-B模型的各向同性弹性本质决定的,垫层料因水压力作用顺坡向膨胀,产生沿坡面向上的位移;后者是其F1屈服面持续扩张产生塑性体积收缩导致的,塑性体缩抵消了顺坡向弹性膨胀,使垫层料产生沿坡面向下的位移。Choice of constitutive model for rockfill materials is the most influencing factor that affects the computed stress and deformation results of concrete-faced dams(CFD).In this study,the Duncan’s E-B(EB)nonlinear elastic model and the Nanshui(NS)double-yield surface elastoplastic model are used for rockfill materials to simulate the construction and impounding processes of a typical CFD by using three-dimensional finite element method.The differences in the displacement and stress of rockfill zones and concrete slabs are compared,and the reasons were analyzed.Two most important differences are found.First,the displacement quantities such as the dam settlement and slab deflection predicted by the NS model are smaller than those obtained by the EB model,and this difference can be attributed to the higher minor principal stresses and therefore higher deformation moduli within rockfill zones by the former.Second,the EB model predicts a tensile zone along the upstream slope near the bottom of face slabs,while the results by the NS model shows that the slope stresses of face slabs are completely compressive.The tensile stress predicted by the EB model is due to its isotropic elasticity nature,i.e.,the cushion materials expand along the slope under the huge hydrostatic pressure,leading to a displacement upward towards the dam crest.The NS model,on the other hand,predicts an additional plastic volume contraction within the upstream rockfill zones due to the expansion of F1 yield surface,which completely counteracts the elastic expansion along the slope and results in a downward displacement of the cushion layer.

关 键 词：混凝土面板坝 堆石料 本构模型 应力变形 

分 类 号：TU43[建筑科学—岩土工程]