Seismic Assessment and Rehabilitation of Historical Unreinforced Masonry (URM) Buildings in Istanbul

Abstract

The aim of the study is to evaluate the earthquake performance of two historical buildings located in Istanbul exposed to a M+7 earthquake expected to hit the city and, to propose solutions for their structural rehabilitation and/or strengthening. Both of the buildings are unreinforced clay brick masonry (URM) structures built in 1869 and 1885, respectively. The first building is a rectangular-shaped structure rising on four normal floors and the second one has an L shape with one basement floor and three normal stories. They survived the 1894, Ms7.0 Istanbul earthquake, during which widespread damage to URM buildings took place in the city [3]. No information could be reached whether and in what way they were affected by this earthquake. Although, there can be seen some cracks on some perimeter as well as secondary walls of the buildings. Determination of the site-specific performance assessment and retrofit design basis earthquake ground motion is achieved through deterministic seismic hazard assessment. The buildings are modeled and analyzed as a three-dimensional assembly of finite elements using SAP2000 v11 (Static and Dynamic Finite Element Analysis of Structures) [8] software package. The linear dynamic analysis procedure of FEMA 356 and ASCE41-06 [1, 2] is followed for the seismic assessment of the buildings. In order to improve earthquake resistance of the buildings, reinforced cement jacketing of the main load-carrying walls and application of fiber reinforced polymer (FRP) bands to the secondary walls are proposed.