Monitoring of wind properties and dynamic responses of a supertall structure during typhoon periods

A long-term structural health monitoring (SHM) system consisting of about 700 sensors has been designed and is being implemented by The Hong Kong Polytechnic University to the Guangzhou New TV Tower (GNTVT) of 618m high. This monitoring system is one of few SHM practices that integrate in-construction monitoring and in-service monitoring. As the city of Guangzhou is located at the edge of the most active typhoon generating area in the world, this SHM system has monitored the wind properties and structural responses of GNTVT during four typhoon events in 2008. This paper presents the measured wind properties (wind speed, wind direction, wind rose diagram, etc.) and the corresponding structural responses (including accelerations obtained by the accelerometers, displacements by the GPS, and strains by the strain gauges) during the four typhoons. The modal properties of GNTVT are identified using the measured acceleration responses acquired during the typhoon periods, and compared with those obtained under normal ambient vibration conditions. Some issues influencing the accuracy of operational modal analysis and environmental effects on the modal identification are also discussed.