Proposed methodology on performance-based assessment and retrofit of reinforced concrete heritage buidlings with case studies on selected heritage buildings in the Philippines

• Main Author: Del Prado, Marabelle R.
• Format: text
• Language: English
• Published: Animo Repository 2015
• Online Access: https://animorepository.dlsu.edu.ph/etd_masteral/4960
• Institution: De La Salle University

Strengthening of Heritage Structures in order to withstand seismic ground motions is important in order to preserve the irreplaceable history that it holds about our past. Part of the irreplaceable history it holds is the artistic details attached into and supported by the primary components, which includes the beams and columns. Hence, the assessment and strengthening of the primary components of heritage buildings are vital parts of heritage conservation. Today, methods developed for structural assessment and strengthening focuses on the life safety and structural stability of existing ordinary buildings. These developed methods have minimal consideration to the historical value that made these heritage buildings unique and important. This study developed a methodology that would assess reinforced concrete heritage buildings with consideration to its artistic assets, which is part of its historical value. The artistic assets were included in the methodology by quantifying the artistic loss that the heritage building will incur after a predetermined seismic demand. The quantified losses was amplified, using importance factors, to consider the artistic value of the components, by classifying each based on how it supports or carries the artistic details of the heritage building. The total damage incurred by the heritage building, represented by a damage index, depends on the loss of strength incurred by each component after the predetermined seismic demand. The performance state of the heritage building was determined from a code-based performance criterion. The yielding of the hinges quantified the performance state reached by the heritage buildings from the fraction of hinges formed at the beams and columns. This methodology included numerical investigations using non-linear static analysis or pushover analysis to assess the performance of heritage buildings and evaluate the application of different retrofit systems. The developed methodology assessed and strengthened the analytical model of a heritage building from Quezon. The collected properties from destructive and non-destructive tests developed the analytical model. The numerical investigations were performed using SAP2000. The importance of the heritage building indicated performance objective designated. The heritage building satisfied the designated performance objective but applied with retrofit systems for further strengthening. Two retrofit strategies assessed are the Reinforced Concrete (RC) Jacketing of Columns and Extended Frame (EF). Both retrofit systems are capable of significantly increasing the seismic capacity of the heritage building according to analysis. However, the assessment of architectural effect favored the use of extended frame because of lesser structural intervention. The EF system strengthened the heritage building from Quezon. After strengthening, the weak axis of the building has significantly improved based from the results v of the computed damage index. This improvement has affected the strong axis such that the damage index computed increased. However, the performance state has still passed the designated performance objective for the heritage building. The second case study was the recommendation for possible retrofit strategies for three heritage buildings in Iloilo City to address the deficiencies observed from the rapid visual screening from previous studies. Heritage buildings represent the identity of the society. The preservation of these structures would require the cooperation of architects, engineers, heritage building owners and local government. Despite these tedious task of assessment and strengthening, the results would be for the benefit of the future generation by giving them a chance to have a glimpse of their past.