Soil-Structure Interaction and Earthquake Input Models Effect on the Structural Response of the Santa Maria Church and Guesthouse Building

Abstract

The fragility and capacity of historical structures can be evaluated under seismic loads with the help of a rigid-base assumption by neglecting soil-structure interaction effects. However, this approach may not be accurate because earthquake waves reach the structure by spreading through a soil medium. Wave propagation, soil amplification, and deformability of the subsoil may affect the seismic response of structures. Therefore, soil-structure interaction should be considered in the finite element model, especially in historical structures that require detailed analyses to determine the structural behavior. This paper focuses on the structural behavior of the Santa Maria Church and its Guesthouse Building, which are two of the historical landmarks in Trabzon, Turkey. The church, which has features that distinguish it from similar structures belonging to its period, is one of the important symbols for the city of Trabzon and continues its religious function. The seismic performance of the building was evaluated based on the soil - structure interactions for different soil conditions. The finite element models of the buildings were generated based on earthquake input models (rigid-base free earthquake input, massless-soil-free earthquake input, massed-soil-free earthquake input, and massed-soil deconvolved earthquake input models) and different soil conditions (hard, medium, and soft soil). Time-history analyses were conducted based on earthquake input models (rigid-base free earthquake input, massless-soil-free earthquake input, massed-soil-free earthquake input, and massed-soil deconvolved earthquake input models) and different soil conditions (hard, medium, and soft soil). Time-history analyses were conducted with respect to the horizontal components of the 1992 Erzincan Earthquake. Evaluating the effects of earthquake input models on the seismic responses was done with respect to the obtained maximum displacement and principal stress. The results show that the soil-structure interaction and the soil types have significantly altered the structural responses of both buildings.