Abstract:
In this research, the effects of masonry infills on nonlinear behavior of R/C buildings under severe earthquakes are investigated. The scaled model experiments on Thai masonry infill indicate that the failure of masonry infill is initiated by corner crushing mode before shear failure in upper part of column. So, the two-strut model is proposed to capture Thai masonry infill behavior. It is showed that peak lateral load and failure sequence of masonry infill predicted from model are similar to the experimental results.The effects of masonry infill on nonlinear behavior of 4 and 10 story R/C buildings under earthquakes are investigated by nonlinear statics analysis and nonlinear time history analysis. From nonlinear statics analysis, the results show that including masonry infill in structured model significantly shortern the period of building due to its additional lateral stiffness. For nonlinear time history analysis, about 7 earthquake records are selected and employed as the input. It is found that the 4 story building without masonry-infilled will collapse under 2%/50 earthquake while the building with masonry-infilled can stand with minor damages. The 10 story building without masonry-infilled will get severe damages under 2%/50 earthquakes but the same buildings with masonry-infilled will have only minor damages. So it is concluded that the masonry-infilled walls need to be included in structure modeling in order to accurately predict the building responses.