Simplified Method of Isolated Structure Collapse Capacity Part, (I): Ground Motion Intensity Measure

2013 ◽  
Vol 275-277 ◽  
pp. 1466-1470
Author(s):  
Yang Liu ◽  
Wen Guang Liu ◽  
Wen Fu He ◽  
Qiao Rong Yang
Keyword(s):  
Correlation Coefficient ◽  
Ground Motion ◽  
Ground Motions ◽  
Near Field ◽  
Far Field ◽  
Intensity Measure ◽  
Maximum Deformation ◽  
Average Value ◽  
Short Period ◽  
Ground Motion Intensity Measure

The equivalent velocity spectrum as a new ground motion intensity measure (IM) characterization parameter is proposed in this paper. 44 far field ground motions and 20 near-field high-speed pulse seismic waves were used for single-degree-freedom (SDOF) nonlinear time history analysis, respectively. The correlations between five IMs and maximum deformation for SDOF at various periods and different yield coefficients were analyzed. The results show that for the structures with medium-to-long period, the correlation coefficient average value of the proposed equivalent speed and maximum deformation is more than 0.6, and maximum of those is more than 0.9. The correlation coefficient average value by using the proposed equivalent speed under far field ground motions is more than those under near field ground motions. The P-delta effect on the correlation coefficients between proposed IM for the structures with medium-to-short period is significant

A Far-Field Ground-Motion Model for the North Australian Craton from Plate-Margin Earthquakes

2021 ◽  
Author(s):  
Trevor I. Allen
Keyword(s):  
Ground Motion ◽  
Ground Motions ◽  
Peak Ground Velocity ◽  
Far Field ◽  
Motion Model ◽  
Ground Acceleration ◽  
Depth Dependence ◽  
Ground Motion Model ◽  
Plate Margin ◽  
Short Period

ABSTRACT The Australian territory is just over 400 km from an active convergent plate margin with the collision of the Sunda–Banda Arc with the Precambrian and Palaeozoic Australian continental crust. Seismic energy from earthquakes in the northern Australian plate-margin region are channeled efficiently through the low-attenuation North Australian craton (NAC), with moderate-sized (Mw≥5.0) earthquakes in the Banda Sea commonly felt in northern Australia. A far-field ground-motion model (GMM) has been developed for use in seismic hazard studies for sites located within the NAC. The model is applicable for hypocentral distances of approximately 500–1500 km and magnitudes up to Mw 8.0. The GMM provides coefficients for peak ground acceleration, peak ground velocity, and 5%-damped pseudospectral acceleration at 20 oscillator periods from 0.1 to 10 s. A strong hypocentral depth dependence is observed in empirical data, with earthquakes occurring at depths of 100–200 km demonstrating larger amplitudes for short-period ground motions than events with shallower hypocenters. The depth dependence of ground motion diminishes with longer spectral periods, suggesting that the relatively larger ground motions for deeper earthquake hypocenters may be due to more compact ruptures producing higher stress drops at depth. Compared with the mean Next Generation Attenuation-East GMM developed for the central and eastern United States (which is applicable for a similar distance range), the NAC GMM demonstrates significantly higher short-period ground motion for Banda Sea events, transitioning to lower relative accelerations for longer period ground motions.

scholarly journals Performance of Concrete MRF at Near-Field Earthquakes Compared to Far-Field Earthquakes

2019 ◽  
Vol 5 (4) ◽  
pp. 759-766 ◽  
Author(s):  
Farzaneh Raji ◽  
Amir Naeiji
Keyword(s):  
Ground Motion ◽  
Ground Motions ◽  
Near Field ◽  
Analytical Models ◽  
Far Field ◽  
Building Structures ◽  
Drift Ratio ◽  
Story Drift ◽  
Two Parameters ◽  
Floor Acceleration

The characteristic of near-field earthquake records has been investigated in the previous studies. However, the effects of the near-field earthquakes on the response of the building structures need to be further investigated. Engineering demand parameters like inter-story drift ratio and floor acceleration can provide a good means for comparing the response of structures to the near-field and the far-field earthquakes. The main objective of this paper was to apply these two parameters to compare the behavior of the concrete Moment Resistant Frame (MRF) subjected to near-field and far-field ground motions. In this study, non-linear numerical simulations were performed on concrete MRF office buildings subjected to two sets of 14 near-field records and 14 far-field records. The analytical models simulated 4-story, 8-story, and 16 story buildings. The obtained results indicated that the near-field effects can increase the inter-story drift ratio and floor acceleration at lower stories of low and mid-rise building subjected to high ground motion intensities.

Ground-Motion Intensity Measure Correlations on Interface and Intraslab Subduction Zone Earthquakes Using the NGA-Sub Database

2021 ◽  
Author(s):  
Jorge Macedo ◽  
Chenying Liu
Keyword(s):  
Subduction Zone ◽  
Ground Motion ◽  
Ground Motions ◽  
Correlation Coefficients ◽  
Intensity Measure ◽  
Cumulative Absolute Velocity ◽  
Tectonic Settings ◽  
Subduction Zone Earthquakes ◽  
Good Agreement ◽  
Ground Motion Intensity Measure

ABSTRACT The NGA-Sub (subduction zone earthquake) database developed by the Pacific Earthquake Engineering Research center is used to derive new correlation coefficients for a number of ground-motion intensity measure (IM) parameters from ground motions in subduction zone earthquakes, considering both interface and intraslab tectonic settings. The IMs include peak ground acceleration, pseudospectral accelerations with periods from 0.01 to 10 s, Arias intensity, cumulative absolute velocity, peak ground velocity, and significant duration. Comparisons of the estimated correlation coefficients for ground motions from the interface and intraslab tectonic settings generally show a good agreement. Our estimations are also in good agreement with correlation coefficients estimated in previous studies that used ground motions from shallow crustal earthquakes, supporting the concept that any variation in correlation coefficients comes from spectral shape (i.e., the distribution of peaks and troughs) rather than tectonic region. This study also explores the influence of parameters such as magnitude, distance, and site conditions on the estimated correlation coefficients. We did not find apparent trends of the correlation coefficients with respect to these parameters. Finally, we propose analytical models to estimate correlation coefficients between the IMs explored in this study, considering both subduction interface and intraslab tectonic settings.

scholarly journals Seismic Fragility Analysis of Mid-Story Isolation Buildings

2021 ◽  
Keyword(s):  
Fragility Curves ◽  
Ground Motions ◽  
Near Field ◽  
Fragility Analysis ◽  
Seismic Fragility ◽  
Plastic State ◽  
Far Field ◽  
Analysis Method ◽  
Isolation System ◽  
Isolation Layer

Abstract. Seismic fragility analysis is essential for seismic risk assessment of structures. This study focuses on the damage probability assessment of the mid-story isolation buildings with different locations of the isolation system. To this end, the performance-based fragility analysis method of the mid-story isolation system is proposed, adopting the maximum story drifts of structures above and below the isolation layer and displacement of the isolation layer as performance indicators. Then, the entire process of the mid-story isolation system, from the initial elastic state to the elastic-plastic state, then to the limit state, is simulated on the basis of the incremental dynamic analysis method. Seismic fragility curves are obtained for mid-story isolation buildings with different locations of the isolation layer, each with fragility curves for near-field and far-field ground motions, respectively. The results indicate that the seismic fragility probability subjected to the near-field ground motions is much greater than those subjected to the far-field ground motions. In addition, with the increase of the location of the isolation layer, the dominant components for the failure of mid-story isolated structures change from superstructure and isolation system to substructure and isolation system.

Spatial attenuation of intensities for central U.S. earthquakes

1976 ◽  
Vol 66 (3) ◽  
pp. 743-751
Author(s):  
Indra N. Gupta ◽  
Otto W. Nuttli
Keyword(s):  
United States ◽  
Ground Motion ◽  
Epicentral Distance ◽  
Near Field ◽  
Mississippi Valley ◽  
Average Value ◽  
Anelastic Attenuation ◽  
Central United States ◽  
Using Data ◽  
Spatial Attenuation

abstract Attenuation of ground motion in the central United States has to be determined principally using the Modified Mercalli (MM) intensity observations because of the absence of instrumental strong ground-motion data. Nuttli's previous studies of Mississippi Valley earthquakes indicate that higher-mode surface waves produce the largest ground motion except possibly in the near-field region. Particle velocity rather than acceleration correlates directly with intensity and the coefficient of anelastic attenuation has an average value of 0.10 per degree. Using data from isoseismals of the November 9, 1968, southern Illinois and the December 16, 1811, New Madrid, Missouri earthquakes and assuming a linear relationship between log(A/T) and MM intensity, attenuation is expressed by the equation, valid for I(R) ≧IV (MM), I ( R ) = I 0 + 3.7 − 0.0011 R − 2.7 log ⁡ R ; for R ≧ 20 k m where R is the epicentral distance in kilometers. This relationship shows fairly good agreement with isoseismals of many large earthquakes in the central United States and may therefore be useful in providing realistic estimates of spatial attenuation and hence of design earthquakes for a given site. It can also be sometimes useful in estimating the epicentral intensity of an earthquake whose maximum intensity is not reliably known.

Simulation and analysis of a vertically irregular building subjected to near-fault ground motions

2020 ◽  
Vol 36 (3) ◽  
pp. 1485-1516
Author(s):  
Jui-Liang Lin ◽  
Wen-Hui Chen ◽  
Fu-Pei Hsiao ◽  
Yuan-Tao Weng ◽  
Wen-Cheng Shen ◽  
...  
Keyword(s):  
Numerical Model ◽  
Seismic Response ◽  
Ground Motion ◽  
Ground Motions ◽  
Far Field ◽  
Near Fault ◽  
Study Results ◽  
Rc Building ◽  
Near Fault Ground Motion ◽  
Story Building

A shaking table test of a three-story reinforced concrete (RC) building was conducted. The tested building is vertically irregular because of the first story’s elevated height and the third story’s added RC walls. In addition to far-field ground motions, near-fault ground motions were exerted on this building. A numerical model of the three-story building was constructed. Comparing with the test results indicates that the numerical model is satisfactory for simulating the seismic response of the three-story building. This validated numerical model was then further applied to look into two issues: the effective section rigidities of RC members and the effects of near-fault ground motions. The study results show the magnitude of the possible discrepancy between the actual seismic response and the estimated seismic response, when the effective section rigidities of the RC members are treated as in common practice. An incremental dynamic analysis of the three-story RC building subjected to one far-field and one near-fault ground motion, denoted as CHY047 and TCU052, respectively, was conducted. In comparison with the far-field ground motion, the near-fault ground motion is more destructive to this building. In addition, the effect of the selected near-fault ground motion (i.e. TCU052) on the building’s collapse is clearly identified.

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