1.10.

........................................................................................................................... iii ACKNOWLEDGMENTS........................................................................................................iv TABLE OF cONTENTS ...........................................................................................................v LIST OF FIGURES........

[1] A hybrid method is developed for calculating synthetic seismograms for seismic waves propagating in two-dimensional localized heterogeneous anisotropic media. The hybrid method is a combination of analytic and numerical methods, with the numerical method (finite difference, or FD) applied in the heterogeneous anisotropic region only and the analytic method (generalized ray theory, or GRT) o...

This study presents experimental investigations on dynamic characteristics of bridges coupled with vehicles in order to clarify the vehicle-bridge interaction under earthquakes. Oscillator experiment is carried out at a one-box girder bridge coupled with a vehicle. Both acceleration responses of the bridge and those of the vehicle are measured in horizontal and vertical directions. The dynamic ...

In this paper we present a novel technique for micro-seismic localization using a group sparse penalization that is robust to the focal mechanism of the source and requires only a velocity model of the stratigraphy rather than a full Green's function model of the earth's response. In this technique we construct a set of perfect delta detector responses, one for each detector in the array, to a ...

We present a method for estimating seismic attenuation based on frequency shift data. In most natural materials, seismic attenuation increases with frequency. The high-frequency components of the seismic signal are attenuated more rapidly than the low-frequency components as waves propagate. As a result, the centroid of the signal’s spectrum experiences a downshift during propagation. Under the...

This paper presents an efficient control strategy for magnetorheological (MR) dampers embedded in building structures to mitigate quake-induced vibrations. In this work, MR dampers are used as semi-active devices, taking the advantages of the fail-safe operation and low power requirement. By using a static hysteresis model for the MR damper, a suitable controller is proposed here for direct con...