Effect of Boundary Conditions And Other Factors On URM Wall Out-Of-Plane Behaviour: Design Demands, Predicted Capacity, And In Situ Proof Test Results

REFERENCE

Experimental and analytical campaigns were undertaken to provide specific examples for structural engineering practitioners assessing the out-of-plane (OOP) seismic behaviour of URM walls.
19 tests on masonry walls were performed in 6 different buildings utilising airbags to simulate distributed OOP forces.
Test samples represented a variety of geometries, boundary conditions, pre-test damage states, and material properties.
The effects of simulated in-plane damage on the OOP capacity of a URM infill wall was also investigated.

The walls were capable of resisting seismic demands of regions with moderate to high seismicity despite simplified predictive methods suggesting much lower strengths.
In-plane damage was found to reduce the out-of-plane capacity of a URM infill wall by up to 40%.
On-site proof testing was shown to be a simple way to establish actual wall lateral capacities in cases where boundary conditions cannot be clearly established, and the models predict low lateral capacities.
Restraint at the walls’ vertical edges resulting in two-way OOP flexure as compared to one-way vertical OOP flexure, substantially improve the OOP load-carrying capacity.
Topside fixed restraint and presumed ‘arching’ action from the building frame can significantly increase the OOP capacity of URM walls.
The performance of different types of ties was investigated including: helifix ties, concrete ties, adhesive ties, retroties, dryfix, helities.