GPS测量系统和全站仪对在建超高层建筑动力特性的识别

超高层建筑在施工过程中,随着施工高度的逐渐增加,在风荷载、温差和塔吊动荷载的作用下主体结构在施工期的水平位移和结构动力特性会不断发生变化。为了识别超高层建筑在施工过程中,其结构水平位移和结构的动力特性变化情况,应用GPS定位测量系统结合全自动测量机器人——全站仪,实测得到结构在施工期间在两主轴方向的位移时程。并且将GPS数据经过经验模态分解(empirical mode decomposition, EMD)和希尔伯特-黄变换(Hilbert-Huang transform, HHT)后,再把瞬时频率与施工期间塔楼自振频率接近的部分固有模态函数分量进行叠加,得到结构在施工期间的动位移时程,然后再将经验模态分解后的GPS和全站仪测试数据进行功率谱密度(power spectrum density, PSD)分析,从而得到结构的自振频率。从而识别超高层建筑在施工过程中的结构动力特性,分析结果对超高层建筑施工安全评估具有较大帮助。

Dynamic Characteristics Identification of Super High-rise Building Under Construction by GPS and Total Station Measuring SystemLiang Qiangwu1,Wu Jiurong1,Qu Kangneng2

With the gradual increase of construction height, the dynamic characteristics of tall buildings under construction vary continuously under the action of wind loading, temperature difference and dynamic load of tower crane. The continuous monitoring of its horizontal displacement and identification of its dynamic characteristics is important to ensure the safety of tall building during during construction. Both the GPS positioning measurement and the total station measuring robot system are utilized to monitor the horizontal displacement of tall building in Nanning. i The Empirical Mode Decomposition (EMD) and the (Hilbert-Huang Transform) HHT technology are adopted for both GPS and total station measured displacement to obtain the history of dynamic displacement of the monitored tall building under construction. Then the Power Spectrum Density (PSD) analysis of GPS and total station measured data are conducted to identify the first natural frequencies in the direction of two axis of the tall building under construction. It can be seen that the dynamic displacement time history obtained from both GPS positioning system and total station measuring robot can be processed to identify the structural dynamic characteristics of the monitoring tall building successfully, which is of great significance to the construction safety evaluation of such tall building during construction.