in this paper, seismic behavior of the existing buildings equipped by friction dampers is studied. seismic performance of6-story, 9-story and 12-story steel buildings with damper and without damper were studied. the finite element modeling technique (sap2000 software) is used for analysis. time history analyzing was done to achieve this purpose. for nonlinear dynamic analysis, the responses of ...

Response modification factors (R-factor) are used in current seismic building codes to reduce earthquake forces associated with seismic design level to determine force levels. In recent years, many authors have shown great interest in the development of seismic structural systems and several theoretical and experimental studies have been conducted to investigate performance of dampers but littl...

The knee bracing steel frame (KBF) is a new type of energy dissipating frame which enjoys exceptional ductility and lateral stiffness. Rather than the beam-column joint, one end of the diagonal brace in KBF is attached to the knee element. Indeed, the knee element as a hysteretic damper is designed and detailed to behave like a structural fuse by sustaining controlled inelastic deformations as ...

Many researches have been currently conducted on the effects of fault distance on structures revealing that their seismic response can differ according to their distance from the fault. Suspension bridges due to their long period and high flexibility can be more sensitive to this phenomenon, especially in vertical vibration. Since the engineers tend to use longer spans, the length factor should...

To date, seismic communication has been demonstrated in a single amphibian, the frog Leptodactylus albilabris. Calling males produce both acoustic and seismic signals simultaneously. The inflating vocal sac not only aids in radiating the call into the air, but also strikes the wet substrate generating vertically polarized Rayleigh waves. These animals are highly sensitive to seismic signals (-1...

The influence of frequency content of seismic excitation on the extent and pattern of pore-water pressure build-up in saturated soil deposits is addressed. Seismic acceleration time histories are generated as uniformly modulated nonstationary stochastic processes, in accordance with prescribed response spectra and prescribed modulating functions. Based on numerical examples, it is shown that th...

The seismic response of bridges seismically isolated by lead-rubber bearings (LRB) to earthquake excitations of different magnitudes is presented in this thesis. The force-deformation behavior of LRB is considered as bilinear. The specific purpose of the study is to assess the effect of seismic isolation on the peak response of bridges subjected to different base accelerations ranging from 0.05...

Formal extensions of the response spectrum method to include spatial seismic effects are reviewed. Two approaches are described in detail: the first based on random vibrations of a simple oscillator under two-component excitations, and the second analyzing multi-column building seismic response. The subjective choice of these two complementing approaches aims at analyzing the phenomenon of spat...

1 T a b l e o f C o n t e n t s Abstract i i Acknowledgments viii Problem and Thesis Objective I Review of Previous Work 2 Multi-Criteria Optimal Design 2 Reliability-Based Design Earthquake Identification 6 A Time Variant Approach to Performance-Based Engineering 9 Seismic Performance Evaluation For Steel Moment Frames 10 Optimal Probabilistic Seismic Demand Models For Typical Highway Overpass...

Fiber optic seismic sensors have been increasingly recognized as promising technologies for many applications, such as intruder detection and perimeter defense systems. Among these, a military seismic sensor is especially challenging because it requires a robust, compact, reliable, easily installable and operated product. This article reports on our recent experimental investigations of a milit...