大体积混凝土筏板基础温度及温度应力研究

Study on temperature and temperature stress of mass concrete raft foundation

为研究武汉金控大厦筏板基础浇筑后的温度变化规律以及防止筏板基础开裂,利用Midas FEA有限元软件模拟筏板基础温度场,结合现场实测温度变化,对此工程进行温度分析,同时研究其温度应力及裂缝特征。研究结果表明:筏板基础混凝土实测与计算温度变化曲线局部位置存在误差,但总体变化基本一致,软件计算结果较为可靠;混凝土内部比表面散热慢,且混凝土越厚,温度峰值越大,内外温差越大;混凝土底部和表面位置温度应力大,易出现裂缝;内部温度下降慢,应力较小。

In order to study the temperature variation of the raft foundation after pouring and to prevent the cracking of the raft foundation in Wuhan Jinkong Building,Midas FEA software is used to simulate the temperature field of the raft foundation.Combined with the measured temperature changes on the spot,the temperatures during this project are analyzed,and the temperature stress and crack characteristics are studied.The results show:there are some errors in the local position of the curve between the measured temperature and calculated temperature of the raft foundation concrete,but the overall changes are basically the same;therefore,the software calculation results are reliable.The internal heat dissipation of concrete is slower than that of the surface,and the thicker the concrete,the greater the temperature peak and the greater the temperature difference between the inside and outside.The temperature stress at the bottom and the surface of concrete is large,which is prone to cracks.The internal temperature drops slowly and the stress is small.