墩墙混凝土结构温控防裂研究

Study on Temperature Control and Cracking Prevention for Pier-Wall Concrete Structures

针对倒虹吸墩墙、水闸闸墩、导流墙、地涵边墙等墩墙型混凝土结构在施工期容易开裂的问题,分析了墩墙混凝土的温度与应力变化规律及开裂机理,并阐述了表面保温和底板约束对混凝土温度与应力的影响特性.提出合理的表面保温与减小后期底板约束相结合的防裂措施,且已成功在坟庄河倒虹吸工程上得到应用.迄今为止,在已完工的部分尚未发现一条裂缝,收到了很好的防裂效果.

The questions of cracking in concrete during the construction of pier-wall concrete structures,such as inverted-siphons,overhead crossing underground culvert,navigation lock,tunnel,cross channel,inlet and outlet passage of pumping station,etc.,an analysis was made of cracking and regularity of temperature and stress variation in pier concrete;and the effects of external heat preservation and the restriction from soleplate was expounded.The measures to preventing cracking are suggested that decreasing the anaphase restriction from soleplate combines with reasonable external heat preservation;this concept is accepted and applied to the construction of the Fenzhuanghe inverted-siphon project.Up to now,there is no cracking in all piers have constructed.