For the purpose of grasping the stress state, vibration characteristics and safety of the steel arch in Nanjing Olympic Sports Center, which is the main support among the stadium roof system as well as the world's largest oblique arch structure, a real-time health monitoring system was established and the main achievements including the system constitution, monitoring items and layouts of measuring points were described. The monitoring data measured during the 2 years period from 2014 to 2016 as well as the SAP2000 finite element software were combined to conduct the status identification and safety evaluation. The results show that the simulation results are consistent with the measured date; The measured alignment of the large arch is relatively stable, although the structural stiffness of arch has weakened compared with the designed state, the low order vibration frequencies are stable during the 2 years period; The stress state of each monitoring component is at safe levels, and fluctuates within a small range affected by the extreme seasonal temperature changes.

Aimed at the human comfort problem with cantilevered floors arising from normal human activities, the Tuned Mass Dampers are used to control the vibration of the steel cantilevered floors which span 16.3m. Based on studies on the dynamic characteristics of the overall structure, with the position of TMDs optimized and the parameters set reasonably, the vertical vibration response of the cantilevered floors under different cases of pedestrian walking loads is calculated. The results show that the TMD system can effectively reduce the dynamic response of the cantilevered floors, in order to meet the requirements of human comfort.

This paper addresses the quantification of environmental variability of wavelet packet energy spectrum (WPES) extracted from the ambient dynamic responses of a suspension bridge using wavelet packet transform (WPT). The daily averaged WPES using multi-sample averaging technique are first obtained to eliminate the inherent randomness arising from the identification algorithm. Then the effect of temperature on the measured WPES is quantified using the seasonal correlation models. The traffic-induced and wind-induced variability are further quantitatively evaluated by establishing the traffic-WPES and wind-WPES correlation models. The analysis results reveal that temperature and inherent randomness are the critical sources causing WPES variability, and the WPES variability caused by wind speed and traffic loadings is negligible compared with temperature and inherent randomness. Considering seasonal correlation models of temperature-WPES can effectively eliminate the temperature effect and inherent randomness, it is suitable for structural damage warning of long-span bridges if future seasonal correlation models deviate from these normal models.

In this study, the seismic behavior of the main tower building of Beijing Yintai Center is presented with regard to the dynamic characteristics analysis and seismic response analysis. Firstly, by means of three-dimensional finite element analysis software, the dynamic properties and seismic responses under frequent earthquake action of the structure are obtained, respectively. It can be seen that the structure has a rational arrangement for structural elements and has a good seismic behavior. Then, the seismic behavior of the structure is studied through the dynamic elasto-plastic analysis method and static elasto-plastic analysis method under rare earthquake. Analysis results of both analysis methods show that the behavior of the structure accords with the earthquake performance objectives and the structure would not collapse under the rare earthquake action.