Online simultaneous reconstruction of wind load and structural responses for high-rise structures

The actual wind load information is critical for evaluating the health status of highrise structures after experiencing extreme events, e.g. typhoons. However, as a type of distributed load, the wind load is difficult to be measured directly. A possible solution is to reconstruct it from the structural response measurements. This process is often an ill-posed inverse problem. In this paper, a steady-state Kalman filter based unknown input estimator is adopted to solve the above mentioned ill-posed inverse problem by fulfilling some stability criteria. Being translated from mathematics, such stability criteria are actually some requirements on sensor type, sensor number and sensor position. This type of estimator is real-time executable and is capable of estimating the unknown input and the system states within in one sampling time, which indicates the online reconstruction of wind load and structural responses is possible. The 600 meter tall Canton Tower is situated in a typhoon active area, and a structural health monitoring (SHM) system has already been integrated onto this tower. This makes it an ideal testbed for validating the above illustrated wind load reconstruction stragtegy. Measurements obtained during the Typhoon "Nanmadol" and the Typhoon "Kai-tak" are analyzed and the reconstruction results are presented.