CNCRP manual based Seismic Evaluation and Retrofitting of Existing RC Buildings: A Case Study

Document Type : Technical Report

Authors

1 Ahsanullah University of Science and Technology

2 World University of Bangladesh

10.22075/jrce.2024.32938.1980

Abstract

Recent seismic incidents in Turkey have raised concerns among engineers about the potential performance of existing buildings in earthquakes. Due to its location in a somewhat active seismic region, Bangladesh is susceptible to experiencing catastrophic damage if a heavy to moderate earthquake hits. Therefore, the assessment of the seismic capacity of existing buildings is essential to investigate potential risks. Before this, Bangladesh did not have a seismic assessment or retrofitting guideline. However, the Public Works Department (PWD) of Bangladesh has now adopted the seismic assessment procedure from the Japan Building Disaster Prevention Association Manual (JBDPA, 2001) and published it as CNCRP (2015). On top of that, the building design code of Bangladesh (BNBC) has been updated, and the calculation of seismic demand has also changed. This study aims to assess an existing RC building located in Bangladesh for local seismic loads and retrofit it if found vulnerable. A six-storeyed RC building was assessed in detail. The building's seismic capacity was calculated using the suggestions of the CNCRP seismic assessment manual (2015), which depends on the strength and ductility capacity of structural members. The storey collapse mechanism was considered; therefore, the capacity of each storey was computed by considering the lateral capacities (both strength and ductility) of all columns in that storey. The columns were classified according to tributary area, and their failure mechanism was identified. The seismic index was computed utilizing the strength and ductility correlations. After evaluation, some floors were found vulnerable, and the necessary reinforcement specifications were computed following the CNCRP retrofit manual (2015). The retrofit design was established, and a comprehensive re-examination was conducted. Ultimately, the building was found safe according to the CNCRP seismic assessment manual (2015) after the retrofit.

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Articles in Press, Accepted Manuscript
Available Online from 04 August 2024
  • Receive Date: 10 January 2024
  • Revise Date: 04 May 2024
  • Accept Date: 01 August 2024