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New Zealand Engineering 1998 MarchAre You Being Prepared?Richard Sharpe, FIPENZ, is a principal and director of earthquake engineering, Beca Carter Hollings & Ferner Ltd, and is currently a member of the Management Committee of the New Zealand National Society for Earthquake Engineering
By coincidence, of course, our first lecture in the 3rd pro elective on earthquake engineering had been scheduled for 8.00 am on the 25 May 1968, two and a half hours after the Inangahua earthquake had awoken us in Christchurch. A university vacation was spent with a university team surveying the effects, measuring the scratches left by sliding tanks, marvelling at the power of the shaking which had made hills slide, churches jump on their foundations and brick veneers collapse alongside the chimneys. The National Roads Board provided funds for shaking machines (with which we made university staff nervous in their new tower blocks at Ilam), and had our knees vibrating as we helped find the resonance frequencies of motorway and railway bridges. Thirty years later, our knowledge of the effects of earthquakes on structures and our skills in seismic design have increased dramatically. Whether we have implemented that knowledge sufficiently is less certain. Perhaps we have now reached the level of investment in preparedness via design, above which our clients do not want to go. It is much less clear as to whether we are sufficiently prepared as the public will expect for the aftermath of a severe earthquake affecting a major city. Undoubtedly, the current leadership in preparedness is coming from the Earthquake Commission and the NZ National Society for Earthquake Engineering (NZNSEE). The latter is a technical group of IPENZ. Practice The Earthquake Commission (formerly known as the Earthquake and War Damages Commission) has been steadily commissioning studies tightly focused on improving its delivery of services when the big(ger) one comes. Luckily, perhaps, it gets plenty of small-scale practice with the more regular small earthquake, flooding and landslip disasters. Its moves to develop cooperative approaches amongst the loss adjusters and to record information in geographical information systems are born of its real knowledge of what will be involved. Its studies into the risks it is covering and the casualties to be expected must surely be as good as any in the world. Its funding of research into earthquake engineering must be one of the few encouragements left for the university-based researchers in New Zealand today. Advising its research funding programme is one of those New Zealanders perhaps more well-known in this context in countries other than his own, Dr Ivan Skinner. The NZNSEE recently set up and ran a study group set up specifically to decide how New Zealand engineers with the appropriate expertise could assist local authorities after a disastrous earthquake. Led by Andrew Charleson, the group brought together representatives of the insurance industry, local authorities, central government's civil defence and practising engineers to produce a suggested model of an organisation that would go into action after the event. It was quite clear that reorganisation in many local authorities had left them without the traditional knowledge in this area. It was also clear that there was little thought of the economies of resources that could be gained out of combining inspection resources and databases. The NZNSEE's draft recommendations appear to have been gratefully received by the local authorities which have received them. The initiative did not come from the local or central government as would have once been expected, but from an independent professional group with nothing to gain financially and prepared to contribute their time to such endeavours.Unfortunately, this progress in knowledge and design capability has not been matched by progress in the practical implementation of standards in buildings. The codes of practice have become thicker. Responsibilities are being documented in producer statements and the like. But one has to question whether the built product is getting any better. A year or so ago I was participating in a Commonwealth Science Council workshop in India that was introducing the essentials of seismic design to representatives of African, Caribbean and Southeast Asian countries. However, what hit me the hardest was the presentation by my colleague from New Zealand on the lack of compliance with simple seismic detailing in new residential structures in New Zealand. So much for us trying to persuade our Commonwealth friends to move against masonry infill structures with torsionally unbalanced walls, soft lower storeys and potential for disastrous failure through short-column effects. Let us hope that all the developers currently adding lightweight apartment blocks on top of existing buildings downtown are not going to let their clients down at some stage in the future. Presumably we have learnt our lessons from the examples of earthquake damage we saw at Kawerau after the 1987 Edgecumbe earthquake when it paid special attention to structures with changes in stiffness up their height. Hope With our current state of preparedness, we would also have to hope that there are a whole lot of hidden, yet-to-be-sung heroes out there with the calibre of Bill Hodges, in 1987 the chief engineer at Tasman Pulp and Paper's Kawerau mill, who obtained and marshalled his resources like an army general to get that plant back into operation in an unbelievably short time. Will we as earthquake engineers be found wanting by the public when the day of judgement of our structures comes? Will the technical press be filled with stories of the failure of common elements like it was with the steel beam-column joints at Northridge, California in 1994? Will they be asking us about how much we understood the precast connection details we used in the mid 1980s, or why we did not push harder for the residual unreinforced masonry buildings to be secured? These things will happen if we do not focus strongly on practical preparedness, having clearly reached the level of seismic design for which the market is prepared to pay. Are our businesses also prepared for the immediate aftermath? ACENZ has recently sent to its members an excellent one-page checklist for their business recovery plans.One would have to conclude that what we need is a good shake-up. I am
off home to secure the hot water tank in my tile roof house on the side
of a steep Wellington hill.
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As
graduate civil engineers undertaking research in earthquake engineering
at the University of Canterbury some thirty years ago, a number of us were
part of an exciting wave of new discovery in a new field. Dr Robin Shepherd
had brought enthusiasm and experience from his involvement in the analyses
of failure by fatigue of the Comet jet-liner in the UK and had connected
them with the pioneering efforts in seismic design of practising engineers
such as Lyall Holmes, Latham Andrews, Pat Garden and John Hollings.