Abstract

Due to the characteristics of lower strength, anisotropy, heterogeneity and poor ductility, historical masonry structures usually show poor seismic performance. During earthquakes, the damage severity of masonry structural members varies with their real capacity mostly. To avoid waste and save resources, the following retrofitting strategies would be determined in comply with the cost-effective principles corresponding to the severity level of the damaged buildings. The mechanical properties as to the seismic performance of the critical load bearing walls in the damaged buildings could be improved by retrofitting and repairing. However, how to reasonably and effectively estimate the seismic performance of the retrofitted wall with some level of damage could be the most critical and challengeable point. Based on the finite element analyses, simulation method for the seismic performance of retrofitted masonry wall with damage in earthquake is developed in this paper. The stress and strain hysteretic model for the retrofitted wall element is proposed to consider the three stage effects: original damage, retrofitting or repair, and reloading. According to relevant codes and research results, the damage level of components is classified in terms of the loss level of the axial and shear capacity as well as the deformability. Damage patterns, hysteretic relationships among different retrofitting methods in terms of the external single side of reinforced mortar layer and external single side of fibre reinforced lime mortar layer are compared and analyzed. The seismic capacity and hysteretic skeleton curve of retrofitted masonry wall specimens with different damage levels are developed and discussed. The operational cost-effective retrofitting schemes for masonry walls with different damage levels are proposed.