Comparison of microtremor measurements and 3-D soil structure interaction analysis for a historical masonry arch bridge under near-fault and far-fault earthquakes

The aim of this study is to compare the microtremor measurements with 3D soil-structure interaction model of historical masonry arch bridge structure which has an important historical and cultural value in our country that regards to near and far fault ground motions. For this purpose, it is evaluated the comparisons between 3D numerical earthquake model and experimental measurements. The historical Yakacik bridge which is thought to belong to the Ottoman period and masonry stone arch form in the town of Oğuzeli in the province of Gaziantep, is studied. As a source of earthquakes in which SSI interaction is evaluated, near-fault and far-fault ground motions are used. Microtremor measurements are made on the several locations of bridge, in situ natural period and spectral amplifications are determined. Spectral responses (resonance status) obtained by microtremor measurements were found to be potentially promising to support the results obtained from SSI modeling. It is observed that the far-fault motion due to SSI influences results in larger responses than near-fault motion. It is found that the experimentally finding of the possibility of resonance case by microtremor is valuable for the bridge.