Proceedings of conference XLVII; a workshop on USGS's new generation of probabilistic ground motion maps and their applications to building codes

1989 ◽  
Keyword(s):  
Ground Motion ◽  
Building Codes ◽  
New Generation

Testing non-linear amplification factors used in ground motion models

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

<p>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 <span>whether or not</span> 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-record<span>ing</span> 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).</p>

Estimation of ground motion at deep-soil sites in eastern North America

1991 ◽  
Vol 81 (6) ◽  
pp. 2167-2185 ◽  
Author(s):  
David M. Boore ◽  
William B. Joyner
Keyword(s):  
North America ◽  
Ground Motion ◽  
Soil Column ◽  
Response Spectra ◽  
Building Codes ◽  
Eastern North America ◽  
Deep Soil ◽  
Period Range ◽  
First Time ◽  
Deep Soils

Abstract The stochastic model used previously to estimate motions at hard-rock sites in eastern North America has been modified to include the effect of deep soils. We simulated motions for a number of distances and magnitudes for a representative soil column and used these motions to derive equations giving ground motion as a simple function of magnitude and distance. These new equations are intended for use in building codes and those engineering applications that do not require detailed site evaluations. The ground motions for which we derived equations include 5%-damped response spectra at 13 periods ranging from 0.05 to 4 sec, peak acceleration and the maximum pseudovelocity and maximum pseudoacceleration responses. The latter two quantities are introduced here for the first time. They represent the maxima over the period range 0.1 to 4 sec for a given magnitude and distance, and they may be useful as a basis for determining the seismic coefficient in building codes.

scholarly journals Earthquake ground motion and human behavior: Using DYFI data to assess behavioral response to earthquakes

2020 ◽  
Vol 36 (3) ◽  
pp. 1231-1253 ◽  
Author(s):  
James D Goltz ◽  
Hyejeong Park ◽  
Genta Nakano ◽  
Katsuya Yamori
Keyword(s):  
Ground Motion ◽  
News Media ◽  
Behavioral Response ◽  
Developing Nations ◽  
Building Codes ◽  
Earthquake Ground Motion ◽  
Science Literature ◽  
Social Science Literature ◽  
The Subject ◽  
Developed Nations

Human behavioral response to ground motion produced by earthquakes has been the subject of response readiness campaigns like the Great ShakeOut, conventional wisdom regarding how people respond as portrayed in news media, a small but growing social science literature and, in earlier versions of the Modified Mercalli Intensity scale, one component of the assignment of intensities to earthquakes. This study drew on the extensive USGS “Did you feel it?” (DYFI) database to explore human behavioral response in 12 earthquakes that occurred between 2005 and 2018 in 8 countries. These earthquakes varied from moderate in magnitude to very large and destructive events. Some occurred in developed nations with extensive earthquake preparedness campaigns and advanced building codes and others in developing nations with almost no attention to the hazards posed by earthquakes and no seismic provisions in building codes. Our objective was to describe and analyze the behaviors reported by those who navigated to the DYFI site and reported how they responded.

Testing Nonlinear Amplification Factors of Ground-Motion Models

2021 ◽  
Author(s):  
Karina Loviknes ◽  
Sreeram Reddy Kotha ◽  
Fabrice Cotton ◽  
Danijel Schorlemmer
Keyword(s):  
Ground Motion ◽  
Nonlinear Models ◽  
Site Response ◽  
Strong Motion ◽  
Site Amplification ◽  
Building Codes ◽  
Linear Amplification ◽  
Ground Acceleration ◽  
Nonlinear Site Response ◽  
The Impact

ABSTRACT We explore nonlinear site effects in the new Japanese ground-motion dataset compiled by Bahrampouri et al. (2020). Following the approach of Seyhan and Stewart (2014), we evaluate the decrease of soil amplification according to the increasing and corresponding ground motion on surface rock (VS30=760  m/s). To better predict the rock ground motion associated with each record, we take into account the between-event variability of the ground motion, and to better evaluate the impact of nonlinearity, we correct observed ground motion on soil by the site-specific linear amplification. Instead of grouping the stations by site-response proxy, we focus on individual stations with several strong-motion records. We develop a framework to test recently published nonlinear site amplification models against a linear site amplification model and compare the results with recent building codes that include nonlinearity. The results show that the site response varies greatly from site to site, indicating that conventional site proxies, such as VS30, are not sufficient to characterize nonlinear site response. Out of all of the Kiban–Kyoshin network stations, 20 stations are selected as having recorded sufficient data to be used in the test. Out of these 20 stations, five stations show signs of nonlinearity, that is, the nonlinear models performed better than the linear-amplification model for all periods T. For most sites, however, the linear site amplification models get the best score. This suggest that, for the range of predicted rock motion considered in this study (peak ground acceleration <0.2g), nonlinearity may not have a sufficiently large impact on soil ground motion to justify the use of nonlinear site terms in ground-motion functional forms and seismic building codes for such moderate-level shaking.

Finding the Right Problems: Some HREM Applications to Interfaces

1984 ◽  
Vol 42 ◽  
pp. 376-379
Author(s):  
D. Cherns
Keyword(s):  
Grain Boundaries ◽  
High Resolution Electron Microscopy ◽  
Boundary Structure ◽  
Atomic Structures ◽  
Grain Boundary Structure ◽  
Resolution Electron ◽  
Point To Point ◽  
The Right ◽  
New Generation ◽  
Better Than

The use of high resolution electron microscopy (HREM) to determine the atomic structure of grain boundaries and interfaces is a topic of great current interest. Grain boundary structure has been considered for many years as central to an understanding of the mechanical and transport properties of materials. Some more recent attention has focussed on the atomic structures of metalsemiconductor interfaces which are believed to control electrical properties of contacts. The atomic structures of interfaces in semiconductor or metal multilayers is an area of growing interest for understanding the unusual electrical or mechanical properties which these new materials possess. However, although the point-to-point resolutions of currently available HREMs, ∼2-3Å, appear sufficient to solve many of these problems, few atomic models of grain boundaries and interfaces have been derived. Moreover, with a new generation of 300-400kV instruments promising resolutions in the 1.6-2.0 Å range, and resolutions better than 1.5Å expected from specialist instruments, it is an appropriate time to consider the usefulness of HREM for interface studies.

Total etch dentin bonding systems: scanning electron microscopy of the resin-dentin hybrid layer

1992 ◽  
Vol 50 (2) ◽  
pp. 1092-1093
Author(s):  
Jorge Perdigao
Keyword(s):  
Composite Resin ◽  
Mechanical Interlocking ◽  
Hybrid Layer ◽  
Agent Based ◽  
Dentin Bonding ◽  
Acid Agent ◽  
Bond Strengths ◽  
Main Component ◽  
Bonding Systems ◽  
New Generation

In 1955, Buonocore introduced the etching of enamel with phosphoric acid. Bonding to enamel was created by mechanical interlocking of resin tags with enamel prisms. Enamel is an inert tissue whose main component is hydroxyapatite (98% by weight). Conversely, dentin is a wet living tissue crossed by tubules containing cellular extensions of the dental pulp. Dentin consists of 18% of organic material, primarily collagen. Several generations of dentin bonding systems (DBS) have been studied in the last 20 years. The dentin bond strengths associated with these DBS have been constantly lower than the enamel bond strengths. Recently, a new generation of DBS has been described. They are applied in three steps: an acid agent on enamel and dentin (total etch technique), two mixed primers and a bonding agent based on a methacrylate resin. They are supposed to bond composite resin to wet dentin through dentin organic component, forming a peculiar blended structure that is part tooth and part resin: the hybrid layer.

Low-voltage, high-resolution scanning electron microscopy of polymers

1987 ◽  
Vol 45 ◽  
pp. 466-467 ◽  
Author(s):  
S. J. Krause ◽  
W.W. Adams ◽  
S. Kumar ◽  
T. Reilly ◽  
T. Suziki
Keyword(s):  
Electron Microscopy ◽  
Scanning Electron Microscopy ◽  
Low Voltage ◽  
Chromatic Aberration ◽  
Image Resolution ◽  
Resolution Limit ◽  
Crossover Point ◽  
New Generation ◽  
Beam Damage ◽  
Scanning Electron

Scanning electron microscopy (SEM) of polymers at routine operating voltages of 15 to 25 keV can lead to beam damage and sample image distortion due to charging. Imaging polymer samples with low accelerating voltages (0.1 to 2.0 keV), at or near the “crossover point”, can reduce beam damage, eliminate charging, and improve contrast of surface detail. However, at low voltage, beam brightness is reduced and image resolution is degraded due to chromatic aberration. A new generation of instruments has improved brightness at low voltages, but a typical SEM with a tungsten hairpin filament will have a resolution limit of about 100nm at 1keV. Recently, a new field emission gun (FEG) SEM, the Hitachi S900, was introduced with a reported resolution of 0.8nm at 30keV and 5nm at 1keV. In this research we are reporting the results of imaging coated and uncoated polymer samples at accelerating voltages between 1keV and 30keV in a tungsten hairpin SEM and in the Hitachi S900 FEG SEM.

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