摘要
研究混凝土水化热作用对主塔早期开裂的影响。首先,通过求解热传导方程推导出水化热作用下主塔的温度分布公式;其次,通过分析混凝土早期弹性模量、徐变影响,导出计入时变效应的塔壁表面温度应力计算公式。分析认为,水化热作用下塔壁可能发生开裂,常系数m、表面放热系数、塔壁厚度是影响温度应力的主要因素。对重庆忠县长江大桥主塔节段的水化热温升和应力变化进行跟踪监测,证明上述理论分析的正确性,并提出预防主塔早期开裂的措施。
This paper investigates the influences of concrete heat of hydration on early cracking of main tower. Fist of all, the temperature distribution formulae of the main tower under the effect of the heat of hydration are derived by solving the heat conduction equations; secondly, the calculating formulae for temperature and stress on tower walls by counting time-varying effect via the analysis for the early elastic modulus and creep influences are derived. According to the analysis, the tower walls may crack under effect of the hydration heat, and the constant coefficient m, surface heat emission coefficient and the thickness of tower walls are principal factors that may influence temperature and stress. The paper carries out the follow-up monitor for temperature rise and stress variation of the heat of hydration in king tower segment of the Yangtze River Bridge in Chongqing Zhong County to prove the correctness of above theoretical analysis, and proposes the measures to prevent the tower from early cracking.
出处
《公路交通技术》
2009年第5期83-89,共7页
Technology of Highway and Transport
关键词
斜拉桥
水化热影响
热传导方程
混凝土主塔
早期裂缝
cable stayed bridge
influences of heat of hydration
heat emission equation
concrete kingtower
early crack
