摘要
针对碾压混凝土重力坝在施工期和运行期的温度控制问题,采用有限元法对工程溢流坝段进行了稳定温度场、非稳定温度场及温度应力的仿真分析。研究了自然入仓、通水冷却和控制浇筑温度3种温度控制方案,对比分析了不同方案下坝体温度场与温度应力的分布规律。结果表明:与自然入仓相比,采取控制浇筑温度(≤18℃)与通水冷却措施后,弱约束区碾压混凝土的最大温差由23.1℃降至16.5℃,温度应力由1.37 MPa降低至1.12 MPa,满足规范要求;综合采用控制浇筑温度和通水冷却措施后,施工期结束时坝体内部非稳定温度场的最高温度由30℃降至28℃,坝体内部温度场分布得到显著改善,高温区域显著减少,混凝土内部温差降低,温度应力降至允许范围内,坝体产生温度裂缝的风险减小。研究成果可为解决高寒与高温交替地区大体积混凝土温度裂缝难题提供科学依据。
To address the temperature control challenges of roller-compacted concrete(RCC)gravity dams during construction and operation,we employed a three-dimensional finite element method(FEM)to simulate the steady-state temperature field,transient temperature field,and thermal stress of the overflow dam section.Three temperature control schemes,namely,natural pouring,pipe cooling,and controlled pouring temperature were investigated,and the distribution patterns of the temperature field and thermal stress under different schemes were compared.The results indicate that by implementing controlled pouring temperature(≤18℃)and pipe cooling measures,the maximum temperature difference in the weakly constrained zone of the RCC decreased from 23.1 to 16.5℃,and the thermal stress reduced from 1.37 to 1.12 MPa,meeting the code requirements.The combined use of controlled pouring temperature and pipe cooling significantly improved the internal temperature field distribution of the dam body with less high-temperature zones and smaller internal temperature differences,reducing the maximum internal temperature of the transient temperature field from 30 to 28℃after construction.Consequently,thermal stress was reduced to within allowable limits,which can significantly decrease the risk of thermal cracking in the dam structure.The findings provide a scientific basis for solving thermal cracking challenges in mass concrete structures in regions with alternating low-and high-temperature climates.
作者
闫博
杨军严
李虎城
YAN Bo;YANG Junyan;LI Hucheng(Shaanxi Ecological Environment Monitoring Center for Soil and Water Conservation,Xi’an 710001,China;Department of Water Resources of Shaanxi Province,Xi’an 710001,China;College of Water Resources and Architectural Engineering,Northwest A&F University,Yangling 712100,China)
出处
《水资源与水工程学报》
北大核心
2025年第3期135-141,共7页
Journal of Water Resources and Water Engineering
关键词
碾压混凝土重力坝
温度控制
有限元仿真
温度场
温度应力
自然入仓
通水冷却
控制浇筑温度
roller-compacted concrete(RCC)gravity dam
temperature control
finite element method(FEM)
temperature field
temperature stress
natural pouring
pipe cooling
controlled pouring temperature
