Ambient vibration testings and field investigations of two historical buildings in Europe

In this study, the methodology and results of ambient vibration-based investigations of the historical Tash Mosque in Kosovo and a 3-story historical building in Bulgaria are presented. The investigations include full-scale in situ testing of both structures due to ambient vibrations induced by micro-seismic, wind, traffic, and other human activities. To this aim, Ranger seismometers and Kinemetric products were used. Measurements were performed in both horizontal directions in several points along the structures' height utilizing a high-speed data acquisition device. All recorded data have been analyzed and processed by the software developed at IZIIS, and then the processed data were used as input for modal analysis. The basic assumption is that the excitation can be considered as a stationary random process to have a relatively flat spectrum. The paper clearly describes the procedure used for investigations and presents the dynamic properties of the whole structures. The investigated structures are both historical buildings and defined as architectural heritage and the outcome of this study including the natural vibration frequencies and mode shapes) can be very beneficial for the verification stage of the analytical/numerical models for future retrofitting/rehabilitation schemes

DEFINING SEISMIC PARAMETERS FOR AN ESSENTIAL ELECTRIC POWER FACILITY

For the purpose of building a new electric power facility a project to determine seismic potential and seismic parameters for design is produced. Multiple in-situ geophysical investigations have been performed and soil samples have been taken to the laboratory where simple shear tests are done to determine the dynamic parameters of the soil layers. As a result, the dynamic shear modulus and damping ratio vs shear strain relationships of characteristic soil materials were defined. The response analysis was done using these curves, where the effects of the sub-surface local soil medium have a dominant influence upon the amplitude and frequency modification of the expected ground motion. Finally, the seismic design parameters, maximum accelerations at foundation level for design and maximum earthquake site-specific response spectrum have been obtained

Influence of Height in Simulation of Soil Structure Interaction Problems with Dampers

In numerical simulation of soil structure interaction problems the presence of dampers in the frame is an advantage yet a special topic to be considered. This paper presents valuable observation on the dynamic soil structure interaction analysis of multi storey frames and considers the effect of height in simulation of soil structure interaction problems. Comparison of these problems has been done by comparing the obtained results from different set up in the software ANSYS. The results of numerical analysis illustrate that it has to be paid more attention when considering the structures not alone but also considering the effect of soil medium

A new approach in simulation of soil-structure interaction problems including damper effects

In this paper, numerical simulation of the issues related to soil-structure interaction (SSI) in the structures equipped with prestressed damping device (PDD) is presented. More specifically, this research examines the impacts of dampers on the interaction between the soil and the structure, considering a variety of conditions, including the effects of the soil boundaries simulated by infinite elements. Comparative analysis of the results with different disposition of the dampers is made using ANSYS nonlinear platform. It could be observed from the results of the numerical analysis that regarding the impact of dampers in the structure on SSI, the selection of the damper type has a significant role