超高层建筑施工期结构静动态变形监测

Static and Dynamic Deformation Monitoring of Super High-Rise Buildings During the Construction Stage

针对超高层建筑施工期静动态变形实测研究不足的问题,在一座335 m的超高层建筑主体结构上搭建了施工期结构健康监测系统,进行主体结构施工期竖向变形、温度变形和动态位移的实测分析。探明了施工期主体结构的温度不均匀分布规律,分析了温度影响下的结构应变特点,结果表明:季节性温差引起的应变大于同时段内上部结构自重和混凝土收缩徐变引起的应变。阐释了主体结构施工期竖向变形与层间竖向变形差发展规律,层间不均匀竖向变形程度随高度和时间逐渐增大,同一层不同测点间的竖向变形差最大为5.3mm。主梁轴向应力与其两端竖向构件的竖向应变差成正相关,外框–核心筒竖向变形差可能使主梁存在受拉开裂风险。提出一种基于卡尔曼滤波的结构动态位移估计方法,通过融合加速度数据与应变数据提高动态位移估计精度,能够准确估计超高层建筑在施工动荷载下的动态位移。

To address the insufficient research on the measurement of static and dynamic deformations of super high-rise buildings during the construction stage,a structural health monitoring(SHM)system was installed on the main structure of a practical super high-rise building with a height of 335 m.Thus the temperature deformation,vertical deformation,and dynamic displacement of the main structure during the construction stage were measured and analyzed.The uneven distribution of temperature in the main structure during the construction stage was identified,and the strain characteristics of the structure under the influence of temperature were analyzed.The results showed that the strain caused by seasonal temperature difference was greater than the strain caused by the self-weight of the upper structure and the concrete shrinkage and creep over the same period.The developments of the vertical deformation and the inter-story uneven deformation during the construction stage were explained.The degree of uneven deformation increased with structural height and time.The maximum deformation difference among the points of the same floor was 5.3 mm.The axial stress of the girder was positive correlated with the difference in vertical strain between the two ends of the girder.The difference in vertical deformation between the outer frame and the core tube could lead to tensile cracking in the girder.A structural dynamic displacement estimation method based on Kalman filtering was proposed,which could improve could the accuracy of dynamic displacement estimation by fusing acceleration data and strain data,and could accurately estimate the dynamic displacement of super high-rise building under dynamic construction loads.