Earthquake response of historical church within the perspective of structural dynamics: Oltu Russian Church

Abstract

Structural dynamic feature studies are increasingly applied as an important activity in assessing the vulnerability of cultural structures and identifying the possible damage mechanisms. The modal parameters of the building and soil dynamic properties have been obtained by several methods to assess the structural behavior of the Oltu Russian Church in this study. The H/V curves obtained from the microtremor results applied in the churchyard and inside the church show that the average soil dominant frequency is ∼3 Hz. The soil amplification factor values are calculated as ∼3 and ∼2.5 for the inside and outside of the church, respectively. The slip-strain value calculated in the light of microtremor results shows that the soil dynamic behavior can be elastoplastic in the design earthquake. A finite element model of the Oltu Russian Church is established with soil, modal parameters, and material information obtained from the field under the influence of a series of earthquake data. The response spectra of the domed and non-domed structures have been scaled and matched against these designed earthquakes with the horizontal elastic acceleration spectrum for the structure. It is concluded that the restoration of the domes increased the acceleration values in the towers. The application of restoration processes on the domes caused approximately 10 times more displacement. It has been observed that the average impacting earthquake structure has a 1st mode frequency of 0.7 Hz, a 2nd mode frequency of 1.8 Hz, and a 3rd mode frequency of 2.5 Hz.