严寒地区某碾压混凝土重力坝施工期表面保温措施研究

Study on Superficial Heat Preservation Measures of RCC Gravity Dam in Cold Region

为研究严寒地区混凝土重力坝的保温措施,以东北严寒地区某碾压混凝土重力坝为例,采用FZFX3D软件计算分析了施工期不同厚度的上下游面保温板、越冬面保温被对第1年浇筑混凝土温度场、应力场的影响。结果表明,混凝土表面保温措施能有效降低混凝土表面的温度梯度、应力梯度及坝体混凝土内外温差,控制混凝土表面拉应力的增长;保温措施控制混凝土内外温差的作用不仅体现在寒冷季节,还体现在高温季节;该工程最佳保温措施为上下游面永久保温采用7cmXPS板,越冬保温采用7cm聚乙烯保温被。研究结果为类似工程的保温提供借鉴。

For study of heat preservation measures of concrete gravity dam in cold region,taking a RCC gravity dam in northeast cold region as an example,the whole period of concrete construction and operation of dam was studied based on three-dimensional finite element analysis of temperature field and stress field.The influence of thermal insulation board and the winter surface insulation on the temperature stress field in the first year were analyzed.The results show that insulation protection reduces the temperature and stress gradient of concrete surface and controls the growth of tensile stress on concrete surface effectively.The role of thermal insulation measures to control the difference temperature between the inside and outside of the concrete is not only reflected in the cold season,but also reflected in the high temperature season.7cm XPS board insulation used on the upstream and downstream surface and 7cm polyethylene insulation used as winter protection are the best heat preservation measures for this project.The results serve as a reference for the similar projects of heat preservation.