A Dunedin structural engineer and church leader has
questioned why international seismologists and engineers are
analysing up to 29 Dunedin churches to gauge their seismic
fitness in the event of an earthquake.
The two-year project, funded by the Earthquake Commission,
will involve scientists from New Zealand, Italy and Portugal
developing a seismic vulnerability index for unreinforced
masonry churches and historic buildings to help with
decisions on retro-fitting to prevent damage in future
However, St Paul's Anglican Cathedral vestry and works
committee, and Opus Dunedin earthquake risk management and
strengthening consultant Thomas Moore had several concerns
about the research.
While he welcomed the funding of the international study to
explore rationally the seismic vulnerabilities of Dunedin's
heritage churches, he asked the research group to focus
closely on the practical issues of seismic upgrading by
presenting a library of construction details acceptable to
the New Zealand Historic Places Trust, rather than merely
running a scoring system.
Dr Moore said the New Zealand Society of Earthquake Engineers
(NZSEE) recently upgraded the initial evaluation procedure
(IEP) to give substantial credit for previous strengthening
work, such as that performed at St Paul's in 1968 when a new
apse was constructed, enlarging the cathedral substantially,
with new reinforced structural elements.
Under the IEP scoring system adopted in 2014, the work
improved the seismic capacity of the cathedral significantly,
''We would like to know if the new study will replace the
2014 scoring system.
''St Paul's is required to present an engineering evaluation
of the cathedral by July 31, 2014.
''It is unlikely that the new scoring system will be in place
by this date.
''Perhaps the real challenge is to design affordable
strengthening measures or stiffening measures that limit
building displacements, instead of focusing on another
scoring system,'' he said.
A spokesperson for the research group could not be contacted
yesterday for comment.
St Paul's Cathedral is one of 29 unreinforced churches that
are being analysed in Dunedin, under the project
''Vulnerability Analysis of Unreinforced Churches in New
Project leaders have emphasised the churches in their study
were being analysed because they were unreinforced masonry
churches, which are usually the most seismically vulnerable
buildings, but it did not mean they were unsafe.
It only meant scientists were trying to assess their
vulnerability to find out the type of damage that could be
expected in an earthquake.
Timber churches are usually less vulnerable to earthquakes,
and the main focus of this project was to scrutinise
unreinforced brick and stone churches throughout New Zealand.
The Dunedin churches involved in the study are.-
Knox Church, St Paul's Cathedral, Sacred Heart Church,
Glenhaven Church, First Church of Otago, St Michael's
Anglican Church, Gospel Chapel Mosgiel, Caversham
Presbyterian Church, St Mary's Catholic Parish, The Salvation
Army NZ Trust, Mosgiel Presbyterian Church, North Taieri
Presbyterian Church, Kaikorai Presbyterian Church, Halfway
Bush Union Church, Andersons Bay Presbyterian Church, St
Mary's Anglican Church, Baptist Union of New Zealand,
Northeast Valley Presbyterian Church, All Saints' Anglican
Church, St Clair Presbyterian Church, St Patrick's Basilica,
St Bernadette's, St Peter's Church, St Joseph's Cathedral,
New Zealand Methodist Church, Holy Cross Church, St Mary Star
of the Seas, Holy Trinity Church, and South Dunedin