Seismic Behaviour and Retrofitting of Timber Frame Walls

Half-timbered buildings are well known as one of the most efficient seismic resistant structure in the world, but their popularity is not only due to their seismic performance, but also to their low cost and the strength they offer. These structures generally consist of exterior masonry walls with timber elements embedded which tie the walls together and internal walls which have a timber frame with masonry infill and act as shear walls. Generally, different types of infill could be applied to half-timbered walls depending on the country, namely brick masonry, rubble masonry, hay, mud, etc. The focus of this paper is to study the seismic behaviour of the walls when no infill is present, i.e. considering only the timber frame, and then compare the results with those of the infill walls. Static cyclic tests have been performed on unreinforced timber frame walls and appropriate strengthening solutions have been applied in order to test the walls in a retrofitted condition, namely (1) steel plates with different configurations and (2) steel flat bars inserted with the NSM technique.