水利学报2023，Vol.54Issue(12)：1404-1414,11.DOI:10.13243/j.cnki.slxb.20230594
整体浇筑堆石混凝土拱坝施工期温度监测与等效均质仿真研究
Temperature monitoring and equivalent homogeneity simulation of integrally-poured rock-filled concrete arch dam during construction period
摘要
Abstract
The integrally-poured arch dam without transverse joints is an innovative construction technique that has promoted the rapid development of rock-filled concrete(RFC)arch dams in recent years.The determination of the equivalent parameters for heterogeneous RFC is an urgent issue to be solved before conducting temperature simula-tions of full-scale arch dams.In this study,based on the Fengguang arch dam project,on-site temperature moni-toring experiments were conducted during the construction period,to analyze the temperature evolutions of the rock-fill and self-compacting concrete(SCC).Additionally,a homogeneous RFC numerical model was proposed and simulated using the finite element method(FEM)to further investigate the temperature behaviors.The experimental results showed that the pre-laid rocks have a"thermal insulation effect"on the poured RFC beneath.After pouring of the fresh SCC,a secondary temperature rise occurs in the lower-layer poured RFC,but the influence depth does not exceed the thickness of each lift.In mild climate regions during winter,the estimated placement tempera-ture of the rockfill body is about 2.0 to 4.0 ℃ higher than the daily average air temperature.Combining the on-site findings with the FEM simulation results,it was observed that the early-age temperature of the RFC evolves from a non-uniform field to a uniform field.Once the SCC is poured,it quickly exchanges heat with the surrounding rocks.After the hydration reaction begins,the rockfill continuously absorbs heat from the SCC.Approximately 48 hours later,it reaches a temperature peak,and the temperature fields of the two materials approach a homogeneous distribution.The homogeneous RFC model was generated considering the structures of the precast concrete block formworks on the upstream and downstream surfaces,as well as the upstream SCC impermeable layer.The FEM numerical simulations were then conducted by considering equivalent parameters,including the equivalent place-ment temperature,weighted thermal conductivity,and equivalent adiabatic temperature rise.This model accurately simulated the equivalent homogeneous thermal field during the hydration and temperature decline process.Overall,the arch dam,with its relatively thin profile and rapid heat dissipation,exhibits a low measured hydration rise(only approximately 6 ℃ in winter)owing to the RFC damming material.This strongly supports the feasibility of the construction technology for integrally-poured RFC arch dams.关键词
堆石混凝土/整体浇筑拱坝/非均质材料/热传导/温度仿真计算Key words
rock-filled concrete/integrally-poured arch dam/heterogeneous material/thermal conduction/tem-perature field simulation分类
建筑与水利引用本文复制引用
徐小蓉,余舜尧,金峰,梁婷,罗键..整体浇筑堆石混凝土拱坝施工期温度监测与等效均质仿真研究[J].水利学报,2023,54(12):1404-1414,11.基金项目
国家自然科学基金重点项目(52039005) （52039005）
清华大学水沙科学与水利水电工程国家重点实验室开放基金项目(sklhse-2022-C-03) （sklhse-2022-C-03）
中央高校基本科研业务专项(2023MS071) （2023MS071）
