文章摘要
张梦溪,李明超,张津瑞,胡昱.碾压式导电混凝土电热试验与供电模式分析[J].水利学报,2021,52(1):103-110,119
碾压式导电混凝土电热试验与供电模式分析
Experimental study on the electro-thermal performance of ERCC and its power supply mode analysis
投稿时间:2020-04-27  修订日期:2020-12-23
DOI:10.13243/j.cnki.slxb.20200277
中文关键词: 碾压混凝土坝  碾压式导电混凝土  越冬层面  温控  UT模型  供电模式  电-热-结构耦合仿真
英文关键词: RCC dam  ERCC  overwintering layer  temperature control  UT model  power supply mode  structural-thermoelectric simulation
基金项目:国家自然科学基金项目(51879185);国家大坝安全工程技术研究中心开放基金项目(CX2019B02)
作者单位E-mail
张梦溪 天津大学 水利工程仿真与安全国家重点实验室, 天津 300350  
李明超 天津大学 水利工程仿真与安全国家重点实验室, 天津 300350 LMC@tju.edu.cn 
张津瑞 天津大学 水利工程仿真与安全国家重点实验室, 天津 300350  
胡昱 清华大学 水沙科学与水利水电工程国家重点实验室, 北京 100084  
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中文摘要:
      我国的建坝重心不断向高寒地区转移,工程经验表明,低温作用下碾压混凝土坝越冬层面所在高程附近易发生温度开裂,给该类坝型温控防裂提出了更高的要求。传统的外置保温措施在大仓面上的铺设和拆除必然会提高施工成本,同时降低施工效率。针对上述问题,制备了一种能够适用于碾压工艺的导电混凝土材料(ERCC),测试了大尺寸碾压试件ERCC层的电热温升性能,基于测试数据反演了ERCC的导热系数和比热容;根据热流量平衡关系推导了坝体内外温差与抵御寒潮所需通电电压的U-Δ;T定量模型,利用电-热-结构耦合的方法模拟了气温骤降作用下越冬层面温度场和应力场演变过程,以典型测点温度平稳度为目标优化每日供电方式,通过优化结果验证了所推导模型的可靠性;通过对比气温骤降条件下“薄层表面保温+ERCC通电加热”与“常规保温材料”两组共9个温控方案的温度、应力以及经济成本,发现所提出的供电模式在改善温度和应力分布方面具有优良的效果,可为解决坝体越冬层面温控问题提供新的思路。
英文摘要:
      Engineering experience indicates that temperature cracking is easy to occur near the height of overwintering layer of RCC dams under the low temperature. More dams are being constructed in China's frigid region, which puts forward higher requirements for temperature control of concrete dams. The laying and dismantling of the traditional external insulation measures on the large warehouse surface will inevitably increase the cost and reduce efficiency in construction. In view of the above problems,a new type of elec- trically conductive roller compacted concrete (ERCC)is introduced in this paper. The electric temperature in- crease of large-scale ERCC layer specimen was tested, and the thermal conductivity and specific heat ca- pacity of ERCC was inversed according to the test data. Then,the quantitative calculation model of voltage required to resist the cold wave (U)and the temperature difference inside and outside the dam (Δ T)are de- duced according to the heat flow balance. The evolution process of temperature field and stress field of over- wintering layer under the action of sudden temperature drop was simulated by the coupling method of elec- tricity-heat-structure. The power supply mode is optimized with the temperature stability of typical measur- ing points as the objective function. The reliability of the U- Δ T model has been verified by the optimiza- tion results. Comparing the temperature, stress and cost of 9 schemes for temperature control, including "thin layer surface protection+ERCC electrified heating" and"conventional insulation materials", the power supply mode has a favorable effect in improving the temperature and stress distribution, which can provide a new way to solve the problem of temperature control of overwintering layer.
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