摘要
【目的】大坝各个坝段首仓浇筑混凝土常采用大量三级配混凝土浇筑,混凝土绝热温升较高,同时该区域受基础约束大,在温控措施失效的情况下温度峰值容易超过设计允许值,即温度超标而产生较大的应力。为保障大坝的安全,需要采用合理的二期冷却措施控制大坝的温度应力。【方法】在分析了高寒高海拔地区坝体首仓混凝土温度超标和应力形成的原因,以及温度超标后大坝最大应力及安全系数的基础上,对二期冷却进行优化分析。然后以叶巴滩工程为例,设置一、二灌区(拱坝浇筑过程中,在横缝位置,按一定高程埋设止浆片,形成各个灌浆区域,即为横缝灌浆中的灌区)同冷,将16-1仓的温度降低到12.50℃时进行暂时的控温处理,保持首仓的温度高于第一和第二灌区其余仓2.00℃,将首仓混凝土二期冷却目标温度设定为设计可行的上限11.00℃。【结果】计算结果显示,通过温控措施优化,可将坝体的安全系数从优化前可能出现的最不利情况的1.25提高至优化后的1.63。【结论】结果表明,温控优化措施可有效避免大坝首仓混凝土出现裂缝,同时可为同类工程类似情况提供温控措施建议。
[Objective]The pouring of concrete in the first layer of each dam section often uses a large amount of three graded concrete,which has a high insulation temperature rise.At the same time,this area is greatly constrained by the foundation,and in the event of temperature control measures failure,the temperature peak is prone to exceed the design allowable value,resultsing in significant stress.To ensure the safety of the dam,it is necessary to adopt reasonable secondary cooling measures to control the temperature stress of the dam.[Methods]This paper analyzes the reasons for the excessive temperature and stress formation of the concrete in the first layer of the dam in high cold and high altitude areas,and analyzes the maximum stress and safety factor of the dam after the temperature exceeds the standard.On this basis,optimization analysis is conducted on the second phase cooling.Taking the Yebatan Project as an example,the measures include setting up the first and second simultaneous-cooling areas for simultaneous cooling,temporarily controlling the temperature of the 16-1 warehouse to 12.50 ℃,keeping the temperature of the first layer 2.00 ℃ higher than the other layers in the first and second simultaneous-cooling areas,and setting the target temperature for the second phase cooling of the first layer concrete to 11.00 ℃(the upper limit value specified in the design).[Results]According to the calculation result,reasonable temperature control measures can increase the safety factor of the dam body from 1.25(in the most unfavorable situation) to 1.63.[Conclusion]This measure can effectively avoid cracks in the concrete of the first warehouse of the dam,and can also provide temperature control measures for similar situations in similar projects.
作者
夏勇
刘毅
齐问坛
张磊
李建武
盛志刚
刘露
刘伟
朱振泱
XIA Yong;LIU Yi;QI Wentan;ZHANG Lei;LI Jianwu;SHENG Zhigang;LIU Lu;LIU Wei;ZHU Zhenyang(Huadian Jinsha River Upstream Hydropower Development Co.Ltd.,Chengdu 610041,Sichuan,China;China Institute of Water Resources and Hydropower Research,Beijing 100038,China;Power China Sino-hydro Bureau 7 Co.Ltd.,Chengdu 611730,Sichuan,China;Institute of Disaster Prevention,Langfang 101601,Hebei,China)
出处
《水利水电技术（中英文）》
北大核心
2024年第4期71-80,共10页
Water Resources and Hydropower Engineering
基金
国家重点研发计划项目(2018YFC0406703)
中国地震局教师科研基金(20110104)。
关键词
混凝土坝
混凝土温度超标
温度控制
温控措施优化
变形
混凝土
concrete dam
concrete excessive temperature
temperature control
optimization of temperature control measures
deformation
concrete
作者简介
夏勇(1984-),高级工程师,研究方向为水工结构。E-mail:114771181@qq.com;通信作者:朱振泱(1985-),男,正高级工程师,博士,研究方向为大体积混凝土温度控制。E-mail:1219921552@qq.com。
