Experimental response of historic brick masonry under biaxial loading

- Response under earthquake actions of historic unreinforced masonry (HURM).
- HURM is greatly influenced by the proper values of strength under biaxial in-plane loading.
- Results of an experimental research campaign on wallets, triplets, and walls built with solid historic bricks in 1/3rd scale.
- Experimental tests provide data useful to calibrate failure criteria available for assessing HURM.

Unreinforced masonry (URM) structures in seismic areas are usually considered weak in terms of supporting dynamic action. Sufficient regularity of structural organisms plays an important part in fostering adequate behaviour of masonry building although the response of historic-URM (HURM) is greatly influenced by the strength of brick and mortar materials. The analysis of damaged masonry structures following an earthquake puts emphasis on knowing the proper values of strength under biaxial in-plane loading to estimate the response of HURM. On the other hand, damage to masonry buildings subjected to the last earthquakes in Italy (2016-17) which invested mainly its central regions, highlighted the need to further investigate HURM present in many small Italian towns to define the actual behaviour of masonry walls. This paper describes and discusses the results of an extensive experimental research campaign, developed over several years, on wallets, triplets, and walls built with solid historic bricks in 1/3rd scale. Additional experimental tests reported in this paper provide data useful to calibrate failure criteria available for assessing HURM buildings by numerical modelling using FE codes.