These models use GIS and transportation network analysis tools to estimate the losses from damage to components of the system as well as those due to traffic time delays or inaccessibility of particular locations. Tools for emergency response and resource allocation following disasters are key features currently under development.
Prediction of strong ground motion continues to be a major research area in earthquake engineering, using simulation of ground motion models for seismic hazard analysis, stochastic-physical rupture process models for ground motion prediction, prediction of ground motion for engineering applications, and study of the nonstationary characteristics of simulated and recorded ground motions for nonlinear analysis of structures.
Various geophysical models are being considered for simulating strong ground motion, and recorded motions from recent earthquakes are being studied for their characteristics and damage potential. Recent seismological studies have focused on the understanding and characterization of strong ground motion in the near field. The effect of near-field motions on structures has been observed from past earthquakes to be particularly important; however, systematic studies of these effects had not been conducted so they now are a focus of current research.
Experience in past earthquakes has shown that the engineering profession has not yet succeeded in defining ground-motion parameters that correlate well with observed damage. Thus, both demand and capacity need to be evaluated, the latter with due regard to structural characteristics and cumulative damage effects that depend on strong motion duration.
If this can be achieved, seismic risk analysis can be based on reliability concepts, and design parameters can be derived that are consistent with the damage potential of the ground motions. Research studies on seismic hazard analysis, input and response characterization, structural reliability, and design are treated as interrelated subjects through a consistent and coordinated approach.
The major components of this research are development of damage models for structural response; characterization of ground motions based on damage potential; reliability evaluation; seismic risk analysis; and development of design parameters. Considerable effort is being devoted to design research that can be implemented directly in engineering practice. Select another language:. Please enter your email address: Subscribe. Notify me of new comments via email. Cancel Report.
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Two clicks install ». Quiz Are you a words master? Vibration control devices assist in the reduction of the damaging effects, and enhance the seismic performance characteristics of the building. When the seismic waves penetrate a superstructure, these are dissipated by the use of dampers, or dispersed in a wide range of frequencies.
Mass dampers are also employed to absorb the resonant wave frequencies of seismic waves, thus reducing the damaging effects. Seismic isolation techniques are sometimes used to partly suppress the flow of seismic energy into the superstructure by the insertion of pads into or beneath the load bearing elements in the base of the structure.
Thus, the structure is protected from the damaging consequences of an earthquake by decoupling the structure from the shaking ground. In order to properly understand how buildings and structures can stand up to earthquakes, extensive research has also been conducted on earthquakes. In order to obtain an in depth knowledge concerning the initiation and behavior of earthquakes, it is essential to ascertain the mechanical properties and frictional characteristics of the crust of the earth.
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