DETERMINATION OF BUILDINGS PERIOD USING NON-INVASIVE GEOPHYSICAL METHODS


Timur E.

12th International İstanbul Scientific Research Congress on Life, Engineering, an Applied Sciences, İstanbul, Turkey, 21 - 23 January 2023, pp.111-116

  • Publication Type: Conference Paper / Full Text
  • City: İstanbul
  • Country: Turkey
  • Page Numbers: pp.111-116
  • Dokuz Eylül University Affiliated: Yes

Abstract

İzmir is located in a seismically active tectonic zone. After the major M6,6 earthquake occured in October 30, 2020, it is clearly realized that buildings should be investigated very carefully. In this study, microtremor measurements have been used to determine various building’s period and strength characteristics, as a non-destructive way of exploring bearing frame structure of the buildings. It is possible to measure dominant periods and amplifications at each floor, and also to calculate floor spectral ratios (FSR). Microtremor data were collected at each floor of 5 buildings in Karşıyaka, in the North of İzmir Bay. The buildings were selected along the shoreline and the construction ages as well as the heights were chosen to be similar, in order to make a consistent comparison between the results. The data were recorded at each floor of the buildings and outside the buildings simultaneously for 60 minutes and HVSR curves were obtained by using GEOPSY software. The validation of periods were determined using FSR in order to calculate damping ratios accurately. The variation range and tendency between damping ratio and period of each floor with damping ratios and vulnerability indices, along with the preliminary influence factor, were presented and discussed. In addition, a fitting curve was plotted indicating the relation between the damping ratio and dominant natural frequencies of the floors of each building. Furthermore, evaluation of strength, natural dominant vibration period and vulnerability index of the buildings were estimated by interpreting microtremor data. As a result, it was determined that 3 of the 5 buildings were seismically risky.