
Light timber framed (LTF) structures provide a cost-effective and structurally efficient solution for low-rise residential buildings. This paper studies seismic performance of single-storey LTF buildings sheathed by gypsum-plasterboards (GPBs) that are a typical lining product in New Zealand houses. Compared with wood-based structural panels, GPBs tend to be more susceptible to damage when they are used in bracing walls to resist earthquake loads. This study aims to provide insights on how the bracing wall irregularity allowed by the current New Zealand standard NZS 3604 and the in-plane rigidity of ceiling diaphragms affect the overall seismic performance of these GPB-braced LTF buildings. Nonlinear time-history analyses were conducted on a series of single-storey baseline buildings with different levels of bracing wall irregularities and ceiling diaphragm rigidity. The results showed significant torsional effect caused by the eccentric bracing wall layout with semi-rigid/rigid ceiling diaphragms. On average, bracing wall drift demand caused by the extreme bracing wall irregularities was three times of that in the regular bracing wall layout under the rigid diaphragm assumption. This finding agreed well with the house survey after the 2011 Canterbury Earthquake in which significantly more damage was observed in the houses with irregular bracing wall layouts and relatively rigid diaphragms. Therefore, it is recommended to limit the level of bracing wall eccentricity and ensure the sufficiently rigid diaphragms to avoid excessive damage in these LTF buildings in future events.
Protected with bracing behind shipping containers
The Octagon Live Restaurant (formerly Trinity Church) on Worcester Street. Steel bracing has been placed on the tower to limit further damage from aftershocks. Sculptures of a cyclist, bungee jumper, rock climber and kayaker can be seen on the bracing posts.
Wood bracing on a building in the city centre.
Spotlights seen through the steel bracing of Christ Church Cathedral.
The damaged Oxford Terrace Baptist Church, supported by steel bracing.
The damaged Oxford Terrace Baptist Church, supported by steel bracing.
A photograph of details and bracing on 26 Canterbury Street in Lyttelton.
Damage to a residential house. A relatively intact wall is being supported with wooden bracing.
Steel bracing erected against the wall of a damaged building to prevent any further damage.
Our City O-Tautahi surrounded by bracing and scaffolding, seen from across the Avon river.
A photograph of St John the Baptist Church with steel bracing holding up one side.
A photograph of the front of 191 Armagh Street, with wooden bracing holding the wall together.
A photograph of the steal bracing holding up the walls of Deans farm buildings on Kahu Road.
A photograph of the steel bracing which is holding up one side of St John the Baptist Church.
A photograph of the steel bracing which is holding up one side of St John the Baptist Church.
Damaged building in Christchurch central, steel bracing and scaffolding are used to support the walls on the building.
A photograph of Deans farm buildings on Kahu Road. Steel bracing has been used to hold the walls together.
A photograph of Deans farm buildings on Kahu Road. Steel bracing has been used to hold the walls together.
A photograph of Deans farm buildings on Kahu Road. Steel bracing has been used to hold the walls together.
A photograph of Deans farm buildings on Kahu Road. Steel bracing has been used to hold the walls together.
A photograph of Deans farm buildings on Kahu Road. Steel bracing has been used to hold the walls together.
Damage to the front of the Cathedral. Steel bracing supports the front and the rose window has been removed.
Photograph captioned by Fairfax, "Tape bracing computer equipment in the server room at The Press, following the Canterbury earthquakes".
A photograph of Deans farm buildings on Kahu Road. Steel bracing has been used to hold the walls together.
Photograph captioned by Fairfax, "Tape bracing computer equipment in the server room at The Press, following the Canterbury earthquakes".
A house with wooden bracing supporting the front wall. On the fence are tape and spray painted USAR codes.
A photograph of St John the Baptist Church. The side of the building is being held up by steel bracing.
The west face of the damaged ChristChurch Cathedral. Steel bracing supports the wall where the Rose Window has collapsed.
Photograph captioned by Fairfax, "Bracing on a damaged section of the payroll office wall at The Press, following the Canterbury earthquakes".