2006 NZSEE
Conference
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2006 NZSEE Conference |
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Contents |
Keynote Address Learning from Hawke's Bay 1931 Earthquake Performance Assessment and Retrofit Decision Making for Risk Mitigation Behaviour of Walls and Piers Understanding Reinforced Concrete Behaviour Modelling Earthquake Performance Earthquake Performance Poster Papers Design and Development Lessons from the Performance of Buildings in the Mw 7.8 Hawke's Bay Earthquake of 1931David Dowrick The powerful (Mw 7.8) shallow Hawke's Bay earthquake of 1931 was a direct hit on two provincial towns (Napier and Hastings) and was the most damaging in New Zealand's history, causing the most casualties, major fires, and much damage to the built and natural environments. A series of studies of the effects of the earthquake on buildings and the consequences of those effects for human casualties has resulted in important findings, including surprising insights into the good performance of brittle pre-code concrete buildings, ground-related effects in very strong shaking, and the spatial distribution of near source ground shaking. Paper P02: [Read] Post-earthquake Fire Spread between Buildings – Correlation with 1931 Napier EarthquakeGeoff Thomas, Robin Schmid, Jim Cousins, David Heron and Biljana Lukovic Two models, one static and one dynamic, were developed previously to estimate the spread of fire after an earthquake in an urban setting. These have now been compared with the behaviour of the fire that followed the 1931, Napier, New Zealand earthquake. The earthquake was of magnitude 7.8 and started 4 fires in the central business district of Napier. With a lack of water reticulation due to earthquake damage and limited fire fighting resources, the fire spread destroyed the majority of the central Business District. The static model correlates well with the actual extent of fire spread, given a critical separation between buildings that is consistent with the historical wind speed. The dynamic model gives a good correlation with both the extent of fire spread and the timing of the fire when the time steps in the model were increased to allow for slower fire spread in brick buildings compared with light timber frame houses and the longer duration of fires in commercial compared with residential occupancy initially assumed in the model. Wind speed is the major factor in the magnitude of post-earthquake fire losses. Paper P03: [Read] Lessons on Response and Recovery from the 1931 Hawke’s Bay EarthquakeNoel Evans Many books, papers and articles have been written about the disastrous 1931 Hawke’s Bay Earthquake. Many lives were lost and affected, buildings were destroyed or badly damaged and utilities and the total infrastructure were thrown into disarray. This paper reviews some of these publications and their descriptions of the engineering lifelines infrastructure performance in and around Napier and Hastings. It also looks at the response to the disaster and the restoration work that was undertaken. Some of the themes and observations made 75 years ago when the earthquake occurred appear to be just as relevant during recent disasters. As they are still relevant, we need to consider these insights in future disaster management planning, especially in regard to communication with the public and between utility organisations. Paper P04: [Read] Changes to the Seismic Design of Houses in New ZealandGraeme Beattie and Stuart Thurston Since the settlement of New Zealand there have been significant advances in the seismic design of houses. The influences of the country’s English heritage led to the construction of unreinforced masonry houses by the early settlers until it was discovered that earthquakes could demolish such structures with little effort. Subsequent to the 1848 Wellington earthquake, it was realised that timber framed construction had a better resilience than the traditional unreinforced masonry construction. Significant but incremental changes have subsequently been made to timber framed construction. The advent of NZS 3604 in 1978 introduced an engineering approach to ensure gravity, wind and earthquake loads could be appropriately resisted.This paper traces the development of the house construction standards for earthquake resistance over the years to the present day and also comments on the types of damage that have occurred in significant earthquakes over that time and how these deficiencies have been addressed in the standards. A prediction is made of the expected performance of the current building stock in the event of a major earthquake. Paper P05: [Read] Keynote Address Learning from Hawke's Bay 1931 Earthquake Performance Assessment and Retrofit Decision Making for Risk Mitigation Behaviour of Walls and Piers Understanding Reinforced Concrete Behaviour Modelling Earthquake Performance Earthquake Performance Poster Papers Design and Development |