1- Observations of out-of-plane instability

• Out-of-plane instability refers to buckling of a portion of a wall section out-of-plane, as a result of in-plane actions
• This mode of failure has been observed in several modern buildings in the 2010 Chile and 2011 Christchurch earthquakes causing concerns over the existing design provisions of walls
• The parameters controlling this mode of failure need to be identified and scrutinized, resulting in design provisions that can prevent out-of-plane deformations of rectangular walls

2- Prediction of wall failure patterns using a FEM model 

Capability of a finite element model in simulation of different failure patterns of rectangular walls is scrutinized using results of the wall experiments carried out by other researchers,

Out-of-plane instability (Paulay and Priestley 1993)	2010 Chile earthquake (Wallace 2012)	2011 Christchurch earthquake (Elwood 2013)

3- Further verifications 

The model has been verified extensively using test results of the wall specimens that had out-of-plane deformations. A blind prediction has also been done for further verifications. 

4- Which parameters control out-of-plane instability of walls?

The parameters identified as controlling out-of-plane deformations of walls are as the following:

• Wall thickness
• Axial load
• Wall length

Based on a comprehensive parametric study, design provisions preventing this mode of failure will be proposed.

5- Experimental investigation of the parameters

The identified parameters will be investigated based on the following test matrix

The specimens are half-scale, representing first story of four story prototype walls designed according to NZS3101:2006

6- Project timeline

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