Seismic Performance Evaluation and Retrofit of an R/C Frame with Brittle Beam-Column Joint Damaged by the 2013 Bohol, Philippines Earthquake

A magnitude 7.1 earthquake attacked Bohol Island, Philippines on October/15/2013 (local time) and damaged a number of reinforced concrete (R/C) buildings. This paper focuses on one of moderately damaged R/C buildings where severe damage was observed to exterior beam-column joints, because no lateral reinforcement was provided at the joints. There is no realistic method to evaluate and/or upgrade the seismic performance of such substandard R/C beam-column joints. Therefore, a series of laboratory tests was conducted to experimentally evaluate the seismic behavior and performance of a 1/2.5 scale partial frame representing the damaged structure. As a result, the specimen exhibited a lower seismic resistance compared to that from design calculations. Moreover, in this experimental study, R/C wing walls were applied to the other specimen to prevent join failure and to upgrade the seismic performance. Effectiveness of the seismic retrofit by wing walls was verified through comparing the experimental results between both specimens with/without retrofit.