A Quantitative Basis for Building Instrumentation Specifications

2011 ◽  
Vol 27 (1) ◽  
pp. 133-152 ◽  
Author(s):  
Derek A. Skolnik ◽  
Robert L. Nigbor ◽  
John W. Wallace
Keyword(s):  
Time Synchronization ◽  
Strong Motion ◽  
Sensitivity Analyses ◽  
Peak Ground Velocity ◽  
Ground Acceleration ◽  
Rate System ◽  
Intensity Measures ◽  
Quantitative Basis ◽  
Structural Responses ◽  
High Pass

A quantitative basis for key building instrumentation specifications—namely, sample rate, system resolution, and time synchronization—is established by quantifying the sensitivities of engineering demand parameters of peak floor acceleration and peak interstory drift to the errors associated with data acquisition. Details of the realistic simulation and digitization of structural responses are provided and automation of the seemingly signal-dependent procedure of high-pass digital filtering of relative displacements obtained by double numerical integration of accelerations is presented. Results from these studies, along with prior results from similar sensitivity analyses with respect to intensity measures of peak ground acceleration, peak ground velocity, and peak spectral acceleration, are used to recommend potential updates to structural instrumentation specifications of major strong-motion instrumentation programs.

scholarly journals Case Study of a Heavily Damaged Building during the 2016 MW 7.8 Ecuador Earthquake: Directionality Effects in Seismic Actions and Damage Assessment

Geosciences ◽  
2021 ◽  
Vol 11 (2) ◽  
pp. 74
Author(s):  
Luis A. Pinzón ◽  
Luis G. Pujades ◽  
Irving Medranda ◽  
Rodrigo E. Alva
Keyword(s):  
Damage Assessment ◽  
Strong Motion ◽  
Response Spectra ◽  
Seismic Action ◽  
Damage State ◽  
Ground Acceleration ◽  
Intensity Measures ◽  
Capacity Curves ◽  
Building Orientation

In this work, the directionality effects during the MW 7.8 earthquake, which occurred in Muisne (Ecuador) on 16 April 2016, were analyzed under two perspectives. The first one deals with the influence of these effects on seismic intensity measures (IMs), while the second refers to the assessment of the expected damage of a specific building located in Manta city, Ecuador, as a function of its azimuthal orientation. The records of strong motion in 21 accelerometric stations were used to analyze directionality in seismic actions. At the closest station to the epicenter (RRup = 20 km), the peak ground acceleration was 1380 cm/s2 (EW component of the APED station). A detailed study of the response spectra ratifies the importance of directionality and confirms the need to consider these effects in seismic hazard studies. Differences between IMs values that consider the directionality and those obtained from the as-recorded accelerograms are significant and they agree with studies carried out in other regions. Concerning the variation of the expected damage with respect to the building orientation, a reinforced concrete building, which was seriously affected by the earthquake, was taken as a case study. For this analysis, the accelerograms recorded at a nearby station and detailed structural documentation were used. The ETABS software was used for the structural analysis. Modal and pushover analyses were performed, obtaining capacity curves and capacity spectra in the two main axes of the building. Two advanced methods for damage assessment were used to obtain fragility and mean damage state curves. The performance points were obtained through the linear equivalent approximation. This allows estimation and analysis of the expected mean damage state and the probability of complete damage as functions of the building orientation. Results show that the actual probability of complete damage is close to 60%. This fact is mainly due to the greater severity of the seismic action in one of the two main axes of the building. The results are in accordance with the damage produced by the earthquake in the building and confirm the need to consider the directionality effects in damage and seismic risk assessments.

Nonlinear Site Effects from the 30 November 2018 Anchorage, Alaska, Earthquake

2021 ◽  
Author(s):  
John D. Thornley ◽  
Utpal Dutta ◽  
John Douglas ◽  
Zhaohui (Joey) Yang
Keyword(s):  
Site Response ◽  
Strong Motion ◽  
North American Plate ◽  
Peak Ground Velocity ◽  
Reference Station ◽  
Earthquake Hazards ◽  
Ground Acceleration ◽  
Nonlinear Site Response ◽  
Generalized Inversion Technique ◽  
Versus Peak

ABSTRACT Anchorage, Alaska, is a natural laboratory for recording strong ground motions from a variety of earthquake sources. The city is situated in a tectonic region that includes the interface and intraslab earthquakes related to the subducting Pacific plate and crustal earthquakes from the upper North American plate. The generalized inversion technique was used with a local rock reference station to develop site response at >20 strong-motion stations in Anchorage. A database of 94 events recorded at these sites from 2005 to 2019 was also compiled and processed to compare their site response with those in the 2018 Mw 7.1 event (main event). The database is divided into three datasets, including 75 events prior to the main event, the main event, and 19 aftershocks. The stations were subdivided into the site classes defined in the National Earthquake Hazards Reduction Program based on estimated average shear-wave velocity in of the upper 30 m (VS30), and site-response results from the datasets were compared. Nonlinear site response was observed at class D and DE sites (VS30 of 215–300 and 150–215  m/s, respectively) but not at class CD and C sites (VS30 of 300–440 and 440–640  m/s, respectively). The relationship of peak ground acceleration versus peak ground velocity divided by VS30 (shear-strain proxy) was shown to further support the observation that sites with lower VS30 experienced nonlinear site response.

Analysis of Damage to Steel Gas Pipelines Caused by Ground Shaking Effects during the Chi-Chi, Taiwan, Earthquake

2004 ◽  
Vol 20 (4) ◽  
pp. 1095-1110 ◽  
Author(s):  
Howard Hwang ◽  
Yi-Huei Chiu ◽  
Wei-Yao Chen ◽  
Ban-Jwu Shih
Keyword(s):  
Seismic Vulnerability ◽  
Strong Motion ◽  
Peak Ground Velocity ◽  
Gas Pipelines ◽  
Arias Intensity ◽  
Ground Acceleration ◽  
Ground Shaking ◽  
Natural Gas Pipelines ◽  
Taiwan Earthquake ◽  
Vulnerability Functions

This paper presents an investigation on damage to natural gas pipelines in Taichung City from the Chi-Chi Taiwan earthquake. This paper addresses damage due to ground shaking effects and does not address damage due to large ground deformations. Four parameters, that is, peak ground acceleration, peak ground velocity, Arias intensity, and spectral intensity, are used to represent ground shaking. Based on pipe repair data and recorded strong motion data, regression analyses of pipe repair rates were carried out to develop seismic vulnerability functions. From the regression analysis results, Arias intensity is considered as the best parameter for the derivation of seismic vulnerability function. The seismic vulnerability functions derived in this study are for steel gas pipelines with mechanical joints and the pipelines are located in firm soils and in the footwall area subject to ground shaking from an earthquake caused by a thrust fault.

Empirical Correlations between Generalized Ground-Motion Intensity Measures for Earthquakes in China

2020 ◽  
Author(s):  
Kun Ji ◽  
Yefei Ren ◽  
Ruizhi Wen
Keyword(s):  
Ground Motion ◽  
Correlation Coefficients ◽  
Parametric Models ◽  
Peak Ground Velocity ◽  
Ground Acceleration ◽  
Intensity Measures ◽  
Vibration Period ◽  
Significant Duration ◽  
Cumulative Absolute Velocity ◽  
Spectrum Intensity

ABSTRACT This study used earthquake records from China to investigate comprehensively the correlation coefficients between various intensity measures (IMs), including peak ground acceleration, peak ground velocity, spectral acceleration, spectrum intensity, acceleration spectrum intensity, Arias intensity, cumulative absolute velocity, and significant duration. After collection of metadata information, 681 three-component ground-motion recordings with magnitudes of Mw 4.9–6.9 were carefully processed and extracted from the China National Strong-Motion Observation Network System dataset (2007–2015). The applicability of both the Next Generation Attenuation (NGA)-West2 ground-motion model (GMM) and of other GMMs was verified for different IMs, regarding the China dataset. Then, empirical correlation coefficients between different IMs were computed, considering the uncertainty due to the different sample sizes of the observational data using the bootstrap sampling method and Fisher z transformation. Finally, the median values of the correlation coefficients were fitted as a continuous function of the vibration period in the range of 0.01–10.0 s and compared with the results of similar studies developed for shallow crustal regions worldwide. The developed region-specific correlation coefficient prediction model yielded tendencies approximately like those reported in other studies. However, obvious differences were found in long-period ranges of amplitude-based IMs, cumulative effect IMs, and significant duration. These results suggest the necessity of using region-specific correlation coefficients for generalized IMs in China. The presented results and parametric models could be easily implemented in a generalized IM ground-motion selection method or a vector-based probability seismic hazard analysis procedure for China.

Chile Strong Ground Motion Flatfile

2016 ◽  
Vol 32 (4) ◽  
pp. 2549-2566 ◽  
Author(s):  
Nicolas Bastías ◽  
Gonzalo A. Montalva
Keyword(s):  
Ground Motion ◽  
Plate Boundary ◽  
Peak Ground Velocity ◽  
South American ◽  
Ground Acceleration ◽  
Data Set ◽  
Intensity Measures ◽  
South American Plate ◽  
Rupture Plane ◽  
Illapel Earthquake

The Nazca-South American plate boundary produces large-magnitude events (Mw > 8) every 20 years on the coast of Chile. This work describes a public ground motion database that contains 3,572 records from 477 earthquakes and 181 seismic stations, which includes the recent 2015 Mw 8.3 Illapel earthquake. The data set is controlled by subduction interface and inslab events. The oldest event included is Valparaiso (1985), and the magnitude span is 4.6–8.8 Mw. The source-to-site distance metrics reported are the closest distance to the rupture plane ( R rup), epicentral ( R epi) and hypocentral ( R hyp) distances, with a range for R rup from 20 to 650 km. Site characterization is based on V S30, ranging from 110 to 1,951 m/s. Intensity measures included are peak ground acceleration, spectral acceleration values from 0.01 to 10 s, Arias intensity, and peak ground velocity. Each record was uniformly processed component by component. A flatfile with the related metadata and the spectral accelerations from processed ground motions is available at NEEShub ( http://doi.org/10.17603/DS2N30J ; Bastías and Montalva 2015 ).

scholarly journals Empirical Correlations between Peak Ground Velocity and Spectrum-Based Intensity Measures

2012 ◽  
Vol 28 (1) ◽  
pp. 17-35 ◽  
Author(s):  
Brendon A. Bradley
Keyword(s):  
Ground Motion ◽  
Peak Ground Velocity ◽  
Strongly Correlated ◽  
Correlation Equations ◽  
Ground Acceleration ◽  
Intensity Measures ◽  
Ground Motion Selection ◽  
Crustal Earthquakes ◽  
Short Period ◽  
Spectrum Intensity

Empirical correlation equations between peak ground velocity ( PGV) and several spectrum-based ground motion intensity measures are developed. The intensity measures examined in particular were: peak ground acceleration ( PGA), 5% damped pseudo-spectral acceleration ( SA), acceleration spectrum intensity ( ASI), and spectrum intensity ( SI). The computed correlations were obtained using ground motions from active shallow crustal earthquakes and four ground motion prediction equations. Results indicate that PGV is strongly correlated (i.e., a correlation coefficient of [Formula: see text]) with SI, moderately correlated with medium to long-period SA (i.e., [Formula: see text] for vibration periods 0.5-3.0 seconds), and also moderately correlated with short period SA, PGA and ASI ([Formula: see text]). A simple example is used to illustrate one possible application of the developed correlation equations for ground motion selection.

scholarly journals New Ground Motion to Intensity Conversion Equations for China

2021 ◽  
Vol 2021 ◽  
pp. 1-21
Author(s):  
Xiufeng Tian ◽  
Zengping Wen ◽  
Weidong Zhang ◽  
Jie Yuan
Keyword(s):  
Ground Motion ◽  
Correction Term ◽  
Strong Motion ◽  
Seismic Intensity ◽  
Peak Ground Velocity ◽  
Ground Acceleration ◽  
Strong Earthquakes ◽  
Hypocentral Distance ◽  
Peak Ground Motion ◽  
Pseudo Spectral

In this study, we use the strong motion records and seismic intensity data from 11 moderate-to-strong earthquakes in the mainland of China since 2008 to develop new conversion equations between seismic intensity and peak ground motion parameters. Based on the analysis of the distribution of the dataset, the reversible conversion relationships between modified Mercalli intensity (MMI) and peak ground acceleration (PGA), peak ground velocity (PGV), and pseudo-spectral acceleration (PSA) at natural vibration periods of 0.3 s, 1.0 s, 2.0 s, and 3.0 s are obtained by using the orthogonal regression. The influence of moment magnitude, hypocentral distance, and hypocentral depth on the residuals of conversion equations is also explored. To account for and eliminate the trends in the residuals, we introduce a magnitude-distance-depth correction term and obtain the improved relationships. Furthermore, we compare the results of this study with previously published works and analyze the regional dependence of conversion equations. To quantify the regional variations, a regional correction factor for China, suitable for adjustment of global relationships, has also been estimated.

A Seismic Intensity Survey of the 16 April 2016 Mw 7.8 Pedernales, Ecuador, Earthquake: A Comparison with Strong-Motion Data and Teleseismic Backprojection

2021 ◽  
Author(s):  
Ellen M. Smith ◽  
Walter D. Mooney
Keyword(s):  
Emergency Response ◽  
Strong Motion ◽  
Seismic Intensity ◽  
Peak Ground Velocity ◽  
Ground Acceleration ◽  
Motion Data ◽  
Contour Maps ◽  
Crustal Earthquakes ◽  
Maximum Value ◽  
Large Earthquakes

Abstract We conducted a seismic intensity survey in Ecuador, following the 16 April 2016 Mw 7.8 Pedernales earthquake, to document the level of damage caused by the earthquake. Our modified Mercalli intensities (MMIs) reach a maximum value of VIII along the coast, where single, two, and multistory masonry and concrete designed buildings partially or completely collapsed. The contours of our MMI maps are similar in shape to the contour maps of peak ground acceleration (PGA) and peak ground velocity (PGV). A comparison of our seismic intensities with the recorded PGA and PGV values reveals that our MMI values are lower than predicted by ground-motion intensity conversion equations that are based on shallow crustal earthquakes. The image of the earthquake rupture obtained using teleseismic backprojection at 0.5–2.0 Hz is coincident with the region of maximum MMI, PGA, and PGV values, Thus, rapid calculation of backprojection may be a useful tool for guiding the deployment of emergency response teams following large earthquakes. The most severe damage observed was, primarily, due to a combination of poorly constructed buildings and site conditions.

Ground Motion from Mw 1.5 to 3.9 Aftershocks of the 2014 Mw 6.2 Jinggu Earthquake at Hypocentral Distances < 45 km in Yunnan, China

2019 ◽  
Author(s):  
Mengyao Sun ◽  
Huiyu Zhu ◽  
Jie Zhang ◽  
Haohuan Fu ◽  
Xiao Tian
Keyword(s):  
Ground Motion ◽  
Yunnan Province ◽  
Strong Motion ◽  
Spectral Ratio ◽  
Prediction Equation ◽  
Peak Ground Velocity ◽  
Induced Earthquakes ◽  
Ground Acceleration ◽  
Hypocentral Distance ◽  
Fundamental Frequencies

ABSTRACT The ground motion from small aftershocks of the 2014 Mw 6.2 Jinggu earthquake in Yunnan Province is analyzed. With the seismic records, we assess the site conditions and develop a ground‐motion prediction equation (GMPE) for this region. The strong‐motion duration is also calculated to further understand the potential seismic hazard to nearby structures. The dataset includes 504 events with Mw 1.5–3.9 and 2956 three‐component records at hypocentral distances <45  km from 10 stations operated by the Earthquake Administration of Yunnan Province. The ground‐motion amplification factor derived from the horizontal‐to‐vertical (H/V) spectral ratio of each station ranges from 1.1 to 5.2 (0.04–0.72 in log units). The time‐averaged shear‐wave velocity to 30 m depth (VS30) for seismographic stations is estimated using fundamental frequencies associated with peak H/V ratios. GMPE is obtained using the entire dataset. The values of the geometrical spreading coefficient for the pseudoabsolute response spectral acceleration (PSA) at a frequency of 10 Hz suggest higher decay than those for the peak ground velocity, peak ground acceleration (PGA), and PSA at other frequencies. The significant duration (Ds) of strong ground motion systematically decreases with PGA but increases with hypocentral distance. However, no strong correlation is observed for Ds and magnitude or for Ds and VS30. The results of this study are compared with analogous research (Babaie Mahani and Kao, 2018) on induced earthquakes with the same distance–magnitude range. The comparison indicates that the decay of ground‐motion amplitudes with hypocentral distance in our case is generally lower than that in the other study. The Ds trends are consistent in the two studies, although the longest strong‐motion duration in the two cases apparently differs.

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