Engineers carrying out biggest tests in southern hemisphere

Canterbury engineers carrying out biggest tests in the southern hemisphere

May 8, 2015

University of Canterbury civil engineers are carrying out the biggest bridge building tests in the southern hemisphere.

Tests are being undertaken in the College of Engineering’s structures extension laboratory on campus. The test bridge is a 1:3 scale model of a short-span precast concrete bridge and is more than 10 metres long, 2.5 metres wide and 3.5 metres high.

Associate Professor Alessandro Palermo is in charge of the bridge testing project with research work being explored by PhD student Zeinab Chegini.

``We are pushing the scale model bridge to a failure point in order to assess its seismic performance for extreme earthquake events. The tests are a world-first at an international level.

The Canterbury earthquakes damaged many of the city’s bridges, some of which still need to be repaired or replaced. Associate Professor Palermo says life safety is the primary objective of the engineering community but it is also aiming to limit disruption to transport systems through robust and resilient infrastructure.

“The Christchurch rebuild is a real driver for using new seismic design technologies available from the university’s bridge programme. Our designers are already moving towards low-damage system technology for both structural and non-structural components. Bridge engineers have to inherit those enhanced concepts and technologies.

“We are investigating technical solutions for bridges which are quick to construct and erect on the site that are resistant to earthquakes and with higher material quality control and more importantly that are cost-competitive,” Associate Professor Palermo says.

Chegini says the test bridge is being put under a load equivalent to 30 tonnes. The research is being funded by the Natural Hazards Research Platform under the Accelerated Bridge Construction and Design project.

“Design and testing of the current large scale model is part of a series of tests carried out at the University of Canterbury that aim to develop earthquake resistant design of precast concrete bridges.

“According to SCIRT, about 140 of 225 road and foot bridges and larger culverts in the city were damaged by the 2010 and 2011 earthquakes.

“My research will promote precast concrete construction in New Zealand. Many bridges in the country are reaching the end of their service life. Others have been damaged due to earthquakes and need to be repaired or replaced.

“One of the major issues associated with replacing damaged or vulnerable bridge structures is the resulting traffic interruption and related economic losses. Currently, most bridges are constructed using cast-in-place technology which is time-consuming, impedes traffic and is demanding in terms of quality control.
“Precast technology offers a potential solution to those issues outlined above. Manufacturing concrete elements in a well-controlled environment and assembling them on-site can reduce construction time and improve work-zone safety and construction quality. “

ENDS

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