An Advanced Estimation Algorithm for Ground‐Motion Models with Spatial Correlation

ABSTRACT Models for estimating earthquake ground motions are a key component in seismic hazard analysis. In data-rich regions, these models are mostly empirical, relying on the ever-increasing ground-motion databases. However, in areas in which strong-motion data are scarce, other approaches for ground-motion estimates are sought, including, but not limited to, the use of simulations to replace empirical data. In Israel, despite a clear seismic hazard posed by the active plate boundary on its eastern border, the instrumental record is sparse and poor, leading to the use of global models for hazard estimation in the building code and all other engineering applications. In this study, we develop a suite of alternative ground-motion models for Israel, based on an empirical database from Israel as well as on four data-calibrated synthetic databases. Two host models are used to constrain model behavior, such that the epistemic uncertainty is captured and characterized. Despite the lack of empirical data at large magnitudes and short distances, constraints based on the host models or on the physical grounds provided by simulations ensure these models are appropriate for engineering applications. The models presented herein are cast in terms of the Fourier amplitude spectra, which is a linear, physical representation of ground motions. The models are suitable for shallow crustal earthquakes; they include an estimate of the median and the aleatory variability, and are applicable in the magnitude range of 3–8 and distance range of 1–300 km.

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Testing non-linear amplification factors used in ground motion models

10.5194/egusphere-egu21-4829 ◽

2021 ◽

Author(s):

Karina Loviknes ◽

Danijel Schorlemmer ◽

Fabrice Cotton ◽

Sreeram Reddy Kotha

Keyword(s):

Ground Motion ◽

Site Effects ◽

Ground Motions ◽

Site Amplification ◽

Building Codes ◽

Linear Amplification ◽

Motion Models ◽

Earthquake Predictability ◽

Non Linear ◽

Ground Motion Models

Non-linear site effects are mainly expected for strong ground motions and sites with soft soils and more recent ground-motion models (GMM) have started to include such effects. Observations in this range are, however, sparse, and most non-linear site amplification models are therefore partly or fully based on numerical simulations. We develop a framework for testing of non-linear site amplification models using data from the comprehensive Kiban-Kyoshin network in Japan. The test is reproducible, following the vision of the Collaboratory for the Study of Earthquake Predictability (CSEP), and takes advantage of new large datasets to evaluate whether or not non-linear site effects predicted by site-amplification models are supported by empirical data. The site amplification models are tested using residuals between the observations and predictions from a GMM based only on magnitude and distance. When the GMM is derived without any site term, the site-specific variability extracted from the residuals is expected to capture the site response of a site. The non-linear site amplification models are tested against a linear amplification model on individual well-recording stations. Finally, the result is compared to building codes where non-linearity is included. The test shows that for most of the sites selected as having sufficient records, the non-linear site-amplification models do not score better than the linear amplification model. This suggests that including non-linear site amplification in GMMs and building codes may not yet be justified, at least not in the range of ground motions considered in the test (peak ground acceleration < 0.2 g).

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Relational database used for ground-motion model development in the NGA-sub project

Earthquake Spectra ◽

10.1177/87552930211055204 ◽

2021 ◽

pp. 875529302110552

Author(s):

Silvia Mazzoni ◽

Tadahiro Kishida ◽

Jonathan P Stewart ◽

Victor Contreras ◽

Robert B Darragh ◽

...

Keyword(s):

Subduction Zone ◽

Ground Motion ◽

Data Storage ◽

Relational Database ◽

Model Development ◽

Intensity Measures ◽

Motion Models ◽

Ground Motion Model ◽

Ground Motion Models ◽

Pseudo Spectral

The Next-Generation Attenuation for subduction zone regions project (NGA-Sub) has developed data resources and ground motion models for global subduction zone regions. Here we describe the NGA-Sub database. To optimize the efficiency of data storage, access, and updating, data resources for the NGA-Sub project are organized into a relational database consisting of 20 tables containing data, metadata, and computed quantities (e.g. intensity measures, distances). A database schema relates fields in tables to each other through a series of primary and foreign keys. Model developers and other users mostly interact with the data through a flatfile generated as a time-stamped output of the database. We describe the structure of the relational database, the ground motions compiled for the project, and the means by which the data can be accessed. The database contains 71,340 three-component records from 1880 earthquakes from seven global subduction zone regions: Alaska, Central America and Mexico, Cascadia, Japan, New Zealand, South America, and Taiwan. These data were processed on a component-specific basis to minimize noise effects in the data and remove baseline drifts. Provided ground motion intensity measures include peak acceleration, peak velocity, and 5%-damped pseudo-spectral accelerations for a range of oscillator periods.

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Are Near-Fault Fling Effects Captured in the New NGA West2 Ground Motion Models?

Earthquake Spectra ◽

10.1193/101713eqs270m ◽

2015 ◽

Vol 31 (3) ◽

pp. 1629-1645 ◽

Cited By ~ 6

Author(s):

Ronnie Kamai ◽

Norman Abrahamson

Keyword(s):

Ground Motion ◽

Vertical Component ◽

Strong Motion ◽

Motion Processing ◽

Large Set ◽

Pass Filter ◽

Motion Models ◽

Finite Fault ◽

Maximum Period ◽

Ground Motion Models

We evaluate how much of the fling effect is removed from the NGA database and accompanying GMPEs due to standard strong motion processing. The analysis uses a large set of finite-fault simulations, processed with four different high-pass filter corners, representing the distribution within the PEER ground motion database. The effects of processing on the average horizontal component, the vertical component, and peak ground motion values are evaluated by taking the ratio between unprocessed and processed values. The results show that PGA, PGV, and other spectral values are not significantly affected by processing, partly thanks to the maximum period constraint used when developing the NGA GMPEs, but that the bias in peak ground displacement should not be ignored.

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Identification of the importance of risk factors in seismic risk assessment based on stochastic ground motion models

Safety, Reliability, Risk and Life-Cycle Performance of Structures and Infrastructures ◽

10.1201/b16387-651 ◽

2014 ◽

pp. 4497-4504

Author(s):

C Vetter ◽

A Taflanidis

Keyword(s):

Risk Factors ◽

Risk Assessment ◽

Ground Motion ◽

Seismic Risk ◽

Seismic Risk Assessment ◽

Motion Models ◽

Ground Motion Models

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Ground Motion Models and Computer Techniques

10.21236/ada007451 ◽

1972 ◽

Cited By ~ 2

Author(s):

T. David Riney ◽

J. K. Dienes ◽

G. A. Frazier ◽

S. K. Garg ◽

J. W. Kirsch ◽

...

Keyword(s):

Ground Motion ◽

Motion Models ◽

Ground Motion Models

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Seismic hazard evaluation

Bulletin of the New Zealand Society for Earthquake Engineering ◽

10.5459/bnzsee.33.3.371-386 ◽

2000 ◽

Vol 33 (3) ◽

pp. 371-386 ◽

Cited By ~ 7

Author(s):

Paul Somerville

Keyword(s):

Seismic Hazard ◽

Ground Motion ◽

Ground Motions ◽

Strong Motion ◽

Earthquake Source ◽

Hazard Evaluation ◽

Data Set ◽

Motion Models ◽

The Past ◽

Ground Motion Models

This paper reviews concepts and trends in seismic hazard characterization that have emerged in the past decade, and identifies trends and concepts that are anticipated during the coming decade. New methods have been developed for characterizing potential earthquake sources that use geological and geodetic data in conjunction with historical seismicity data. Scaling relationships among earthquake source parameters have been developed to provide a more detailed representation of the earthquake source for ground motion prediction. Improved empirical ground motion models have been derived from a strong motion data set that has grown markedly over the past decade. However, these empirical models have a large degree of uncertainty because the magnitude - distance - soil category parameterization of these models often oversimplifies reality. This reflects the fact that other conditions that are known to have an important influence on strong ground motions, such as near- fault rupture directivity effects, crustal waveguide effects, and basin response effects, are not treated as parameters of these simple models. Numerical ground motion models based on seismological theory that include these additional effects have been developed and extensively validated against recorded ground motions, and used to estimate the ground motions of past earthquakes and predict the ground motions of future scenario earthquakes. The probabilistic approach to characterizing the ground motion that a given site will experience in the future is very compatible with current trends in earthquake engineering and the development of building codes. Performance based design requires a more comprehensive representation of ground motions than has conventionally been used. Ground motions estimates are needed at multiple annual probability levels, and may need to be specified not only by response spectra but also by suites of strong motion time histories for input into time-domain non-linear analyses of structures.

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