Seismic retrofitting of typical RC frame residential building by using textile reinforced mortar (TRM)

Abstract

Using of infill walls is a common practice as partitions in RC frame buildings in all around the world. Usually, in design period of buildings the infill walls is not considered and assumed them as bare frame. Infill walls change the predicted behavior of buildings during earthquake actions. Mostly the seismic loads have not been considered in the design of existing RC frame buildings. Damage of infill walls identified as the main cause of loos of life, serviceability, property and harming injuries. To enhance the seismic capacity and energy dissipation of vulnerable buildings an appropriate reinforcing system is necessity. Different infill walls strengthening systems in respect of materials, configuration, difficulties in their application and effectiveness have been proposed and studied in last decades. A four and half story typical residential building in Kabul city, Afghanistan was selected as case study in this study. Using of textile reinforced mortar (TRM) was adopted as rehabilitation method for improvement of masonry walls. Seismic performance of the building was evaluated using nonlinear three dimensional pushover static analysis on nonlinear model of the building in Perform 3D as a tool. Collapsing of first floor infill walls and plastic deformation of first floor columns leads to soft story mechanism and poor seismic performance of un-retrofitted building. Adopted strengthening systems provided additional lateral strength and sufficient stiffness and control soft story mechanism. Obtained result from TRM retrofitted model analysis showed significant reduce of inelastic deformation in the columns and shifted damage condition of infill walls from collapse state to extensive cracking. By used method the building can withstand with severe cracking of infill walls and minor damage of frame elements against strong ground motions.