@article {bnh-5506, title = {Internal pressures in a full-scale test enclosure with windward wall openings}, journal = {Journal of Wind Engineering and Industrial Aerodynamics }, volume = {189}, year = {2019}, month = {04/2019}, abstract = {

A single opening on the windward wall which generates large\ internal pressures\ in a building often defines the critical\ wind loadingstructural design\ criterion. This paper presents internal pressure fluctuations in a sealed\ Full-Scale Test\ Enclosure (FSTE) for a range of single windward wall opening configurations induced by atmospheric wind flow, to assess the influence\ opening size\ (i.e. S*\ =\ (A3/2/V)(as/U{\textasciimacron}h)2) has on the internal pressure. Damped\ Helmholtz\ resonance was observed for S* \> 0.88, with peak and standard deviation internal pressures being about 5\% higher than the\ external pressures\ when S* \> 1.9. Internal pressure fluctuations are attenuated when S* \< 0.75. The inertial coefficient\ CI\ is between 1.3 and 1.5 and the\ loss coefficientCL\ increases with increasing\ opening area(0.88\ \<\ S*\ \<\ 5.8) between 10 and 20. These parameters have a significant influence on the internal pressure fluctuations, and this controlled\ full-scale\ study carried out for the first time provides data for validating analytical and\ model-scale\ studies on internal pressure fluctuations in buildings.

}, keywords = {Full-scale, Helmholtz resonance, Inertial coefficient, Internal pressure, Loss coefficient, Low-rise buildings, Single opening}, doi = {https://doi.org/10.1016/j.jweia.2019.03.024}, url = {https://www.sciencedirect.com/science/article/pii/S0167610518310304}, author = {Humphreys, M and John Ginger and David Henderson} } @article {bnh-4230, title = {Severe wind hazard preliminary assessment: Tropical Cyclone Debbie, Whitsunday Coast, Queensland, Australia}, year = {2017}, month = {03/2017}, institution = {James Cook University}, address = {Townsville}, abstract = {

Severe Tropical Cyclone Debbie was a category 4 system that made landfall near Airlie Beach (Figure 1) on the north Queensland coast at midday on the 28th of March, 2017. As part of a continuing effort to better characterize wind fields that impact communities during severe wind events, the Cyclone Testing Station (with collaborators from the Wind Research Laboratory at The University of Queensland) deployed SWIRLnet (Surface Weather Relay and Logging Network) weather stations to the region prior to Debbie{\textquoteright}s landfall. Six SWIRLnet towers (3.2 m high anemometers placed in the communities likely to be affected) collected data continuously prior to, during and after landfall. Three towers were deployed in the Ayr/Home Hill region, two in Bowen and one in Proserpine (Figure 2). This Preliminary Assessment Report details the initial observations from these towers, compares these with Bureau of Meteorology Automatic Weather Station observations, and makes some preliminary comment on the damage to structures in stormaffected communities.

}, url = {https://www.jcu.edu.au/__data/assets/pdf_file/0005/422951/TC-Debbie-Rapid-Assessment-Report_v8.pdf}, author = {Thomas Kloetzke and Korah Parackal and D. J. Smith and Richard Krupar III and Leblais, Alex and Humphreys, M and Spassiani, Alessio and M. S. Mason and David Roueche and David O Prevatt and David Henderson and Boughton, Geoffrey N.} } @article {bnh-4227, title = {Tropical Cyclone Debbie: damage to buildings in the Whitsunday Region}, number = {63}, year = {2017}, month = {06/2017}, institution = {James Cook University}, address = {Townsville}, abstract = {

Tropical Cyclone Debbie (TC Debbie) was classified by the Bureau of Meteorology (BoM) as a Category 4 cyclone and crossed the Queensland coast north east of Airlie Beach around midday on Tuesday 28 March 2017.

Before the event, the Cyclone Testing Station (CTS) deployed six mobile anemometers (SWIRLnet) in the area between Ayr and Proserpine. After the event, CTS teams investigated the performance of houses; larger residential structures such as apartments, strata properties and resort accommodation; commercial and public buildings; and sheds. The study area included the communities of Bowen, Proserpine, Airlie Beach, Hamilton Island, Dingo Beach, Wilson{\textquoteright}s Beach and Conway Beach. A wind field was developed using CTS and BoM anemometer data and showed that buildings within the study area experienced wind speeds lower than their relevant design wind speed.

CTS teams assessed the causes of damage to buildings from wind, wind-driven rainwater and storm surge. Inadequate tie-down details between battens and rafters or trusses, and between the roof structure and walls caused many of the structural failures in buildings constructed before the 1980s. Tie-down connections between roof structure and walls that had been inappropriately detailed also failed on some recently constructed buildings. Connections between verandah beams and posts on some buildings with larger verandahs also failed. \ 

This study confirmed the findings of previous damage investigations concerning the vulnerability of: windows with inadequate fixings, window and door furniture; poorly fixed flashings, gutters and soffit linings; large access doors that had not been strengthened so that they complied with AS/NZS4505; lightweight sheds; and fences.

Many occupants of newer buildings reported significant damage from wind-driven rain entering through windows and doors or under flashings even though there was no structural damage to the building. Many people reported that they mopped up water in front of windward wall windows during periods of maximum winds, which exposed them to risk of injury. Further research is required to improve performance of building elements that leak during high winds.

The storm tide generated during TC Debbie was lower than predicted because the cyclone crossed the coast after high tide. Lower-lying buildings in Wilson Beach were inundated to a height of up to 1.1 m causing damage to wall linings, built-in cupboards, floor coverings and contents. In some cases, wave action broke cladding elements and windows. Wave action and scour undercut footings in some buildings on Hamilton Island and Wilson Beach.\ 

The report provides recommendations to improve the performance of building structure and cladding systems including: adequate detailing for roof to wall connections; improved fixing of flashings, retrofitting options for older buildings; improvements in windows and door furniture under repeated wind loads; and revision of storm surge guidelines.

}, isbn = {978-0-9954470-4-2}, issn = {63}, url = {https://www.jcu.edu.au/__data/assets/pdf_file/0009/461178/TC-Debbie-report.pdf}, author = {Boughton, Geoffrey N. and Falck, D. J. and David Henderson and D. J. Smith and Korah Parackal and Thomas Kloetzke and M. S. Mason and Humphreys, M and Navaratnam, S and Bodhinayake, G and Simon Ingham and John Ginger} } @article {bnh-5099, title = {Wind loads on contemporary Australian housing}, journal = {Australian Journal of Structural Engineering}, volume = {17}, year = {2016}, month = {09/2016}, abstract = {

Design pressures given in wind loading standards are based on wind tunnel studies conducted during the 1970s to 90s on rectangular hip and gable roofs. However, most contemporary houses have complex hip-roof geometries with a range of plan footprints. Wind tunnel model studies were carried out on representative one- and two-storey houses to determine cladding design and truss hold-down loads. These loads were compared to design loads determined from wind loading standards AS/NZS 1170.2 and AS 4055. AS 4055 gave conservative design loads in most situations, and AS/NZS 1170.2 underestimated the loads near the windward edges and ridge on the roof. AS/NZS 1170.2 does give satisfactory design loads for wall cladding and truss hold down.

}, doi = {https://doi.org/10.1080/13287982.2016.1229375}, url = {https://www.tandfonline.com/doi/abs/10.1080/13287982.2016.1229375?journalCode=tsen20}, author = {Korah Parackal and Humphreys, M and John Ginger and David Henderson} }