Performance of posttensioned seismic retrofit of two stone masonry buildin…

Research papers, The University of Auckland Library

Seismic retrofitting of unreinforced masonry buildings using posttensioning has been the topic of many recent experimental research projects. However, the performance of such retrofit designs in actual design level earthquakes has previously been poorly documented. In 1984 two stone masonry buildings within The Arts Centre of Christchurch received posttensioned seismic retrofits, which were subsequently subjected to design level seismic loads during the 2010/2011 Canterbury earthquake sequence. These 26 year old retrofits were part of a global scheme to strengthen and secure the historic building complex and were subject to considerable budgetary constraints. Given the limited resources available at the time of construction and the current degraded state of the steel posttension tendons, the posttensioned retrofits performed well in preventing major damage to the overall structure of the two buildings in the Canterbury earthquakes. When compared to other similar unretrofitted structures within The Arts Centre, it is demonstrated that the posttensioning significantly improved the in-plane and out-of-plane wall strength and the ability to limit residual wall displacements. The history of The Arts Centre buildings and the details of the Canterbury earthquakes is discussed, followed by examination of the performance of the posttension retrofits and the suitability of this technique for future retrofitting of other historic unreinforced masonry buildings http://www.aees.org.au/downloads/conference-papers/

The Southland Times Image: Stacy Squires 2010:12:13 10:26:26

Images, UC QuakeStudies

Photograph captioned by Fairfax, "Christchurch CBD was 'yarn-bombed' during the weekend using yarn and fabric pieces to brighten public areas and earthquake-affected spaces. Visitor Ann Rees and her husband Bernard from South Wales said when looking at the yarn-bombed busts at the Arts Centre (from left: Diana Isaac, Elisie Locke, Charles Luney and Margaret Mahy) that it didn't appear like the work of vandals, but looked quite homely and warm".

Photographic Services Photograph 06

Images, UC QuakeStudies

A photograph of Graeme Kershaw, Technician at the University of Canterbury Department of Physics and Astronomy, sitting among the damaged parts of the Townsend Telescope. The telescope was damaged during the 22 February 2011 earthquake, when the Observatory tower at the Christchurch Arts Centre collapsed. Kershaw has been given the task of restoring the telescope. In this photograph he is holding the telescope's clock drive. In the foreground there is a plaque reading, "The equatorial telescope and accessories in this observatory were presented to Canterbury College by James Townsend Esq. 1891. A large contribution towards the erection of the tower was made by the Canterbury Astronomical Society".

Photographic Services Photograph 05

Images, UC QuakeStudies

A photograph of Graeme Kershaw, Technician at the University of Canterbury Department of Physics and Astronomy, sitting among the damaged parts of the Townsend Telescope. The telescope was damaged during the 22 February 2011 earthquake, when the Observatory tower at the Christchurch Arts Centre collapsed. Kershaw has been given the task of restoring the telescope. In this photograph he is holding the telescope's clock drive. In the foreground there is a plaque reading, "The equatorial telescope and accessories in this observatory were presented to Canterbury College by James Townsend Esq. 1891. A large contribution towards the erection of the tower was made by the Canterbury Astronomical Society".

Restoring the Townsend Telescope

Research papers, University of Canterbury Library

The Townsend Observatory is located in the Arts Centre of Christchurch, in what used to be Canterbury College (now University of Canterbury). The Townsend telescope itself is a historic 6-inch Cooke refractor built in 1864 for early Christchurch colonist, Mr James Townsend, and gifted by him to Christchurch College in 1891. At the same time, the Canterbury Astronomical Society handed over its funds to the College to help erect an observatory. The College used this, and money it had set aside for a medical school, to build a biological laboratory with an attached observatory tower, which was completed in 1896. The Biology Building and Observatory Tower was the last major design by architect Benjamin Mountfort. Mr Walter Kitson was appointed custodian of the telescope and regular public open nights commenced. and continued until 2010, with the telescope being operated by students of the Department of Physics and Astronomy, University of Canterbury. The Observatory Tower was badly damaged in the 4 September 2010 earthquake and collapsed in the 22 February 2011 earthquake. The telescope was badly damaged by the collapse, but, amazingly, the optics were found entirely intact. The Department of Physics and Astronomy plans to restore the Townsend Telescope so that it can be returned to a replica Observatory Tower in its central city home, enabling the people of Christchurch, and visitors, to enjoy views of the night sky through this beautiful and historic telescope once again.