Structural Health Monitoring of a Tall Building with Huge Floating Platform

Abstract

The New Headquarters of Shenzhen Stock Exchange (NHSSE), located in Shenzhen, China, is a high-rise building with a height of 228 m. One salient feature of NHSSE is its huge floating platform. It is a steel truss structure assembled with a total of 14 steel trusses in six types. It overhangs from the main tower 36 m along the long axis and 22 m along the short axis at a height of 36 m above the ground. As a result, the huge floating platform has an overall plan dimension of 98 m × 162 m and a total height of 24 m, making it one of the largest cantilever structures in the world. In view of the uniqueness of the floating platform, a long-term structural health monitoring (SHM) system has been designed and implemented on NHSSE by The Hong Kong Polytechnic University. In this monitoring system, the strain and deflection of the cantilever structure are of the utmost concern. A total of 224 vibrating-wire strain gauges have been installed to measure the strain and a novel vision-based displacement tracking system has been employed to monitor the deflection. In addition, accelerometers and a wireless sensing network (WSN) are implemented to monitor dynamic responses and modal properties of the structure. This paper reports the monitoring results of stress evolution of NHSSE during the construction process of dismantling the shoring and modal properties of NHSSE under ambient vibration environment, as well as their comparison with the prediction results through finite element analysis.