Indian Journal of Science and Technology

Abstract

Objectives: An existing multistory framed building structure analyzed for its performance under seismic environment and seismic upgradation of buildings is suggested based on the findings of methodological field investigation and structural analysis techniques. Methods/Statistical Analysis: The office building in question was studied and analyzed in three stages. In the first stage, reconnaissance (post-earthquake study) of the building that faced recent high magnitude Nepal earthquake (25th April, 2015 with a magnitude of 7.8), collection of as-built layout plan and section of reinforcement detailing of beams, slab and columns as well as additional available technical parameters were gathered like the subsoil type, concrete mix used, etc., was done. In the second stage, with the help of as-built drawings, detailed structural analysis of the building was carried out using Response Reduction Method (IS 1883-Part 1) with the help of commercially available software ETAB.In the third and last stage, based on the outcome of structural analysis, the upgradation methods were suggested to mitigate structural inadequacy of the building. Findings: The analysis recommends installation of fluid viscous dampers in the frame of building, for example, inclined bracings with ends connected to columns at base and top with the beams. I addition to that few columns are also required to be retrofitted by increasing their size, the jacketing of columns. Application/Improvements: The study provides an insight to how to judge structural deficiency of buildings and provide knowledge of use of dampers to arrest seismic forces thereby enhancing the structure performance during a seismic activity.
Keywords: Damper, Frame Structure, Numerical Analysis, Seismic Retrofitting