Near-field horizontal and vertical earthquake ground motions

Abstract

Strong-motion attenuation relationships are presented for peak ground acceleration, spectral acceleration, energy density, maximum absolute input energy for horizontal and vertical directions and for the ratio of vertical to horizontal of these ground motion parameters. These equations were derived using a worldwide dataset of 186 strong-motion records recorded with 15 km of the surface projection of earthquakes between M s = 5.8 and 7.8.The effect of local site conditions and focal mechanism is included in some of these equations.

The importance of crustal structure in explaining the observed uncertainties in ground motion estimation

“…The implicit assumption, therefore, made is that the scatter at moderate and large distances is similar to that at short distances where ground motions are damaging. Ambraseys and Douglas [2003] show using a set of data from distances of 15 km or less that this assumption is valid, since they found similar standard deviations for their near-field GMEEs to those of GMEEs derived using data from moderate and large distances. Hence it is important to understand the cause of the scatter at moderate and large distances even though such motions are unlikely to be damaging to engineering structures.…”

Sensitivity Analysis of the Seismic Response of Brittle Structural Elements Under Near-Field Seismic Input Effects

“…Due to the lack of adequate data from close earthquakes, equations to estimate the motion are usually derived from intermediate and far-fields records. Ambraseys and Douglas presented strong-motion attenuation relationships for peak ground acceleration, spectral acceleration, energy density, maximum absolute input energy for nearfield inputs [13]. That research highlights some of the singularities of those inputs (e.g.…”

“…the 1884 Earthquake) in the Granada basin and Málaga [15]. A seismic catalogue is constructed to define the historical seismicity of the area, considering a radius of 300 km, From a literature review, the Ground Motion Prediction Equation proposed by Ambraseys and Douglas for the near-field [13] is selected as the most adequate for the area. The period range of interest includes all frequencies that are expected to significantly contribute to the non-linear response.…”

Seismic Responses of Regular Highway Bridges Under Near-Fault Ground Motions

“…Fling-step is the permanent static displacement caused by tectonic offset characterized with a single-sided velocity pulse, so that integration results in a permanent offset in the displacement time history [2]. In comparison with the ordinary earthquake records, the NF pulse-like records concentrate most of energy in a narrow frequency band and can lead to larger elastic spectral demands especially for structures with periods close to the velocity pulse period [3] [4]. The pulse features also lead to more severe inelastic demands to the SDOF system [5] [6].…”