After Miami: are our Australian bridges safe?
Six people died when a brand new pedestrian bridge collapsed near Florida International University in March 2018. At least eight cars were crushed under the bridge and ten people were transported to hospitals for treatment. It is a natural question to ask: are our bridges here in Australia safe?
There are 50,000 bridges in Australia. Only 18% of them have been constructed after 1976. Often they have to be taken out of service for a lengthy period of time in order to conduct inspections using traditional techniques. Therefore, it is very important to find efficient, cost-effective and easy-to-implement ways to monitor the health of bridges so that maintenance of bridges, no matter old or new, can be carried out in a timely manner.
A recent joint experiment between CIES (Centre for Infrastructure Engineering and Safety) and SAGE (Surveying and Geospatial Engineering) researchers at the School of Civil and Environmental Engineering, UNSW Sydney, is an important step forward in this direction. The experiment was led by A/Professor Linlin Ge and Dr Mehrisadat Makki Alamdari, strongly supported by professional officers Dr Yincai Zhou and Dr Zhitao Xiong, as well as several student assistants, namely, Patrick Du, Rachel Zhang, Jerry Kuang, Ben Martyn, and John Touma. The team went to Penrith on 23 February 2018 to deploy a suit of high precision surveying techniques to monitor a bridge which connects the two campuses of the University of Western Sydney.
The techniques deployed include terrestrial laser scanning (TLS), robotic total station (RTS), close range photogrammetry (CRP), tilt meters and GPS, in addition to accelerometers and strain gauges already wired on the bridge.
One of the key objectives of the CEIS-SAGE joint experiment is to investigate the effectiveness of remote sensing techniques such as TLS, RTS and CRP in monitoring the health of bridges while minimising the impact on their operations because there is no need to close the bridges. The team aims to publish their results in high impact journals and explore external research collaboration with agencies such as the Road and Marine Service of New South Wales.