Determining the pressure coefficients on the surfaces of a structure using the wind loading code AS1170.2 is not an easy task, as the code has very little coverage of real world buildings, and thus is a relatively deficient code, and little wind loading research is being done to fill in the gaps. So the following […]

Wind Classification Maitland, Yorke Peninsula and Surrounds

Introduction to Wind Speed Classification In Australia we have two wind loading codes AS1170.2 and AS4055. The latter (AS4055) whilst it refers to housing, was created to provide a simplified classification system for use with manufactured structural products (MSP’s). It is neither practical nor economical to use AS1170.2 directly to design a structured product. The […]

Wind Speeds and Topography

The wind loading code is based on the flow of fluid parallel to a flat plate. The plate can have roughness, this roughness is measured by roughness length (z0), and converted to terrain category. Appendices to AS1170.2:1989 contained charts for surface roughness length and relationship to terrain category: this information for the newer codes, can […]

Relating the recent Adelaide storms to the Adelaide Metro Wind Speed Map, the simplified wind classification system (AS4055), and our wind loading code (AS1170.2) The map typically classifies sites as either: N1 Vzp = 28 m/s [100.8 km/h] N2 Vzp = 33 m/s [118.8 km/h] N3 Vzp = 41 m/s [147.6 km/h] These commonly used […]

Design Wind Speeds for South Australia

BASIC REGIONAL WIND SPEED Typical Building/Structure V[R] = 45 m/s [162 km/h] mean return period 500 years 5% risk of exceedance for 25 year design life Post Disaster Building/Structure V[R] = 48 m/s [173 km/h] mean return period 2000 years 1.25% risk of exceedance for 25 year design life These wind speeds are typically as […]

Doubly Pitched, Gable Roof Structures, enclosed buildings and canopies.

Introduction Simple doubly pitched roof. Two structural members and three joints, with two of the joints as supports. The basic connection options for joints is pinned that is having no moment restraint, or fully fixed in which case has moment restraint. If have moment restraint then joint can resist forces which tend to cause rotation […]

TechNote#006 Internal Pressure Coefficients Industrial/Commercial Buildings

{Strictly speaking this is the first technical note I wrote back in 1996, but didn’t start to present such writings as notes until much later.} AS1170.2 Loading code : “Wind loads” is primarily set up for structures that have a single state-of-nature : permanently open to the atmosphere, or permanently sealed from the atmosphere. Many […]