Measurement of vibrations of tall buildings with GPS: a case study

Experimental studies have been carried out to employ GPS to measure the vibrations of the 384 in tall Di Wang building in Shenzhen, China. Two GPS receivers were employed in the experiment with one set on the top of the building and the other on a reference station on the ground near-by. The GPS data were collected at a rate of 4 sets per second. The experiment was conducted under different weather conditions over two 24-hour periods. This paper describes the GPS equipment used, the field operations, the data processing and analysis strategies, and the results obtained from the study. It is shown from the study that GPS can be successfully applied for monitoring structural vibrations. However cautions have to be exercised in analyzing GPS data to remove biases such as the so-called GPS multi-path errors, Besides, some practical issues still need resolved before GPS can be applied routinely for this type of applications.