Geology Reports⌕ Search
Home/Archive/USGS

USGS · 70016470

Optimum strong-motion array geometry for source inversion - II

M. Iida
View original source ↗Export metadata ↓

Abstract

Optimum strong-motion array geometry for source inversions is determined for each of three types of earthquake faults: strike-slip, dip-slip and offshore subduction thrust. It is found that the complete Green's function is capable of stabilizing the accuracy of an inversion solution obtained using theoretical seismograms, regardless of the differences in array configuration. The optimum strong-motion array for a strike-slip fault is characterized by stations well distributed in azimuth, while the optimum array for a dip-slip event has stations arranged in a grid-shaped form. -from Author

Explore related subjects

Earthquake Engineering and Structural DynamicsArticle

Keep this discovery

Explore connections, maps & timelines

BibTeXRIS

M. Iida. 2006-12-18. Optimum strong-motion array geometry for source inversion - II. https://doi.org/10.1002/eqe.4290190105

Cite the original work for its findings. Save a collection to share your selection of sources.

KEEP EXPLORING

Related USGS reports

USGS2023

Stochastic simulation of earthquake ground motions for the seismic assessment of monumental masonry structures: Source-based vs site-based approaches

Earthquakes are among the most destructive natural disasters and have resulted in a massive number of fatalities and economic losses all over the world. Simulated ground motion records are valuable, particularly for regions lacking seismic stations or with a limited history of large-magnitude earthquakes. Notably, a significant percentage of monumental masonry buildings are located in regions with limited access to real records; hence, simulated records play a paramount role in their seismic protection. However, few studies have investigated the structural response of heritage buildings via response history analyses to assess the performance of simulated earthquakes against real ones. To accomplish this, this study simulates the recorded time-series of the 9th of July 1998 Faial earthquake in the Azores (M w = 6.2) at four available stations, using two different simulation approaches, that is, a source-based stochastic finite-fault method and a site-based broadband stochastic method. First, two masonry facades with sidewalls characterized by different slenderness levels are adopted to conduct this research. Moreover, the proposed approach is also applied to an existing monumental structure, that is, São Francisco Church, located at Horta, which was affected by damage during the Faial earthquake. Results demonstrate that both simulation approaches provide similar results in terms of structural response prediction. The proposed framework also demonstrates that a small mismatch in terms of predicted damage patterns can result in a significant relative error in terms of displacement predictions.

Earthquake Engineering and Structural Dynamics↗
USGS2020

Tall building performance-based seismic design using SCEC broadband platform site-specific ground motion simulations

The scarcity of strong ground motion records presents a challenge for making reliable performance assessments of tall buildings whose seismic design is controlled by large-magnitude and close-distance earthquakes. This challenge can be addressed using broadband ground-motion simulation methods to generate records with site-specific characteristics of large-magnitude events. In this paper, simulated site-specific earthquake seismograms, developed through a related project that was organized through the Southern California Earthquake Center (SCEC) Ground Motion Simulation Validation (GMSV) Technical Activity Group, are used for nonlinear response history analyses of two archetype tall buildings for sites in San Francisco, Los Angeles, and San Bernardino. The SCEC GMSV team created the seismograms using the Broadband Platform (BBP) simulations for five site-specific earthquake scenarios. The two buildings are evaluated using nonlinear dynamic analyses under comparable record suites selected from the simulated BBP catalog and recorded motions from the NGA-West database. The collapse risks and structural response demands (maximum story drift ratio, peak floor acceleration, and maximum story shear) under the BBP and NGA suites are compared. In general, this study finds that use of the BBP simulations resolves concerns about estimation biases in structural response analysis which are caused by ground motion scaling, unrealistic spectral shapes, and overconservative spectral variations. While there are remaining concerns that strong coherence in some kinematic fault rupture models may lead to an overestimation of velocity pulse effects in the BBP simulations, the simulations are shown to generally yield realistic pulse-like features of near-fault ground motion records.

California↗
USGS2019

Seismic loss and damage in light-frame wood buildings from sequences of induced earthquakes

Activities related to oil and gas production, especially deep disposal of wastewater, have led to sequences of induced earthquakes in the central U.S. This study aims to quantify damage to and seismic losses for light-frame wood buildings when subjected to sequences of induced, small to moderate magnitude, events. To conduct this investigation, one and two-story multifamily wood frame buildings are designed, and their seismic response dynamically simulated using three-dimensional (3D) nonlinear models, subjected to ground motion sequences recorded in induced events. Damage is quantified through seismic losses, which are estimated using the FEMA P-58 methodology. Results show that at levels of shaking experienced in recent earthquakes, minor damage, consisting of cracking of interior finishes and nonstructural damage to plumbing and HVAC systems is expected, which is consistent with observed damage in these events. The study also examines how expected losses and building fragility will accumulate and/or change over a sequence of earthquakes. Results indicate that damage quantified in terms of absorbed hysteretic energy tended to accumulate over the sequences; this damage corresponds to elongation or widening of cracks. However, fragility is not significantly altered by damage in a preceding event, meaning structures are not becoming more vulnerable due to existing damage. In addition, sequences of events do not change losses if the building is only repaired once at the end of the sequence, as the worsening of damage does not alter repair actions. If repairs are conducted after each event, though, total seismic losses can increase greatly from the sequence.

Oklahoma↗