Revolutionary changes which have taken place in the USA over the past 50 years in earthquake engineering as applied to transportation structures (highway bridges, and transit and high-speed rail aerial structures) are reviewed, giving emphasis to seismic design criteria, characterization of seismic ground motions, dual strategy of seismic design, modelling and dynamic analysis, assessment of se...

We determine upper mantle seismic velocity heterogeneities below Southern California from the inversion of teleseismic travel-time residuals. Teleseismic P-wave arrival times are obtained from three temporary passive experiments and Southern California Seismic Network (SCSN) stations, producing good raypath coverage. The inversion is performed using a damped least-squares conjugate gradient met...

additional dampers are employed in order to decrease the dynamic response of structure against the earthquake and wind loading recently. in this study, two types of systems related to waste of inactive energy, i.e. frictional damper which is categorized in dampers dependent on movement and viscoelastic damper which is categorized in dampers dependent on velocity, in making steel structures resi...

Introduction: Understanding the origin and evolution of planets remains a major challenge since direct interrogation of planetary interiors other than Earth is either limited or not (yet) available. Seismic analyses provide the most detailed picture of present-day internal elastic structure and sources of seismic energy, but collecting seismic data represents a unique logistical challenge which...

The application of control devices in coupled building system has been recently recognized as an effective alternative for seismic protection. In consideration of passive control approach, most of previous studies focused on application of fluid dampers, and the buildings in the coupled systems were in similar structural configuration. By recognizing the potential merits, such as simple in desi...

The geodynamic complexity in the western Mexican margin is controlled by multiple interactions between Rivera, Pacific, Cocos, and North American plates, as evidenced a high seismicity rate, most of whose hypocenters are poorly located. To mitigate this uncertainty with aim improving these hypocentral locations, we undertook TsuJal Project, passive seafloor seismic project conducted from April ...

Earthquakes are one of the natural hazards that occur due to sudden violent movement of earth’s surface which releases energy and has destructive power in many parts of the world. The development of recent technologies for the control of seismic hazards catches the attention of structural engineers to make the structures seismically resistant. The seismic base isolation technique is a passive p...

We study the interaction of a seismic wave-field with a spherical acoustic gas-or fluid-filled cavity. The intention of this study is to identify characteristic features in the interaction that may help detecting cavities in the subsurface. This is important for many applications, as in particular the detection of underground nuclear explosions which are to be prohibited by the Comprehensive-Te...