高温间歇对碾压混凝土坝施工期温控防裂影响研究

Influence of high-temperature break on temperature control and crack prevention of roller compacted concrete dams during construction period

中国东部沿海地区夏季温度高,该类地区的碾压混凝土坝工程在施工期往往会设置高温间歇,但目前设置高温间歇主要依赖经验,缺少相关定量分析。依托福建省霍口水库工程,以有限元仿真分析为手段,对比分析了高温间歇对该碾压混凝土坝施工期温度、应力的影响。分析结果表明:夏季高温季节连续施工,会造成坝体基础温差与内外温差过大,存在开裂风险;与连续施工相比,设置高温间歇能显著降低碾压混凝土坝表面和内部的后期开裂风险,但复工后浇筑的混凝土仍然需要采取通水冷却措施进行降温,以避免开裂。研究成果可为碾压混凝土在施工期设置高温间歇提供科学依据和参考。

The temperature in the eastern coastal areas of China is high in summer,and roller compacted concrete dam projects in such areas often have high temperature intervals during the construction period.Aiming at the current cases of setting high-temperature breaks relying mainly on experiences and lacking relevant quantitative analysis,this article carried out FEM analysis on Huokou Reservoir project to analyze the impact of high-temperature breaks on temperature and stress during the construction period of the roller compacted concrete dam.The results indicate that continuous construction in high temperature period will cause large temperature difference at dam foundation as well as inside and outside of the dam body,and give rise to cracking risks.Compared to continuous construction,setting high-temperature breaks can significantly reduce cracking risks on the surface and interior of the roller compacted concrete dam.However,the concrete poured after resumption of work still needs to be cooled down by water cooling measures to avoid cracking.The results can provide reference for high-temperature breaks in construction period of roller compacted concrete dams.