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,
(Paulay and Priestley 1993)
2010 Chile earthquake
|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