Ground Motion Selection for Liquefaction Evaluation Analysis of Earthen Levees

2012 ◽  
Vol 28 (4) ◽  
pp. 1331-1351 ◽  
Author(s):  
Adda Athanasopoulos-Zekkos ◽  
Mustafa Saadi
Keyword(s):  
Ground Motion ◽  
Cross Sections ◽  
Ground Motions ◽  
Cyclic Stress ◽  
Cyclic Stress Ratio ◽  
Ground Motion Selection ◽  
Liquefaction Susceptibility ◽  
Wide Range ◽  
Dynamic Analyses ◽  
The Mean

Guidelines for selecting ground motions for liquefaction evaluation analysis of earthen levees are proposed. These guidelines were developed based on results from dynamic analyses of characteristic earthen levee cross sections using a wide range of ground motions (~1,500). The effect of a number of ground motion parameters on the dynamic response of the levees in terms of liquefaction susceptibility was studied, and the parameters that correlated best to the response were identified. For the liquefaction triggering evaluation, the mean period of the ground motion ( Tm) is best correlated to the cyclic stress ratio (CSR). Regression relationships between CSR and Tm are proposed for a series of levee types and shaking intensities.

Ground Motion Selection for Seismic Slope Displacement Evaluation Analysis of Earthen Levees

2016 ◽  
Vol 32 (1) ◽  
pp. 217-237 ◽  
Author(s):  
Adda Athanasopoulos-Zekkos ◽  
Heidi Pence ◽  
Adam Lobbestael
Keyword(s):  
Slope Stability ◽  
Ground Motion ◽  
Cross Sections ◽  
Ground Motions ◽  
Peak Ground Velocity ◽  
Seismic Slope Stability ◽  
Ground Motion Selection ◽  
Specific Analysis ◽  
Wide Range ◽  
Slope Displacement

Guidelines for selecting ground motions for evaluation of seismic slope displacements for earthen levees are proposed. These guidelines were developed based on results from two-dimensional equivalent-linear dynamic analyses of characteristic earthen levee cross sections using a wide range of ground motions (∼1 ;500). The effect of a number of ground motion parameters on the dynamic response of the levees in terms of seismic slope stability was studied, and the parameters that correlated best to the response were identified. For the seismic slope stability evaluation, the peak ground velocity ( PGV) best correlates to the seismic slope displacements ( u). Regression relationships between u and PGV are proposed for a series of levee types and shaking intensity levels, which are used in the proposed methodology for selecting ground motions for site specific analysis of levees.

scholarly journals Challenges in Evaluating Seismic Collapse Risk for RC Buildings

2021 ◽  
Vol 15 (1) ◽  
Author(s):  
Jin Zhou ◽  
Zhelun Zhang ◽  
Tessa Williams ◽  
Sashi K. Kunnath
Keyword(s):  
Ground Motion ◽  
Seismic Vulnerability ◽  
Ground Motions ◽  
Primary System ◽  
Fragility Functions ◽  
Reinforced Concrete Frame ◽  
Ground Motion Selection ◽  
Concrete Frame ◽  
Frame Building ◽  
Seismic Collapse

AbstractThe development of fragility functions that express the probability of collapse of a building as a function of some ground motion intensity measure is an effective tool to assess seismic vulnerability of structures. However, a number of factors ranging from ground motion selection to modeling decisions can influence the quantification of collapse probability. A methodical investigation was carried out to examine the effects of component modeling and ground motion selection in establishing demand and collapse risk of a typical reinforced concrete frame building. The primary system considered in this study is a modern 6-story RC moment frame building that was designed to current code provisions in a seismically active region. Both concentrated and distributed plasticity beam–column elements were used to model the building frame and several options were considered in constitutive modeling for both options. Incremental dynamic analyses (IDA) were carried out using two suites of ground motions—the first set comprised site-dependent ground motions, while the second set was a compilation of hazard-consistent motions using the conditional scenario spectra approach. Findings from the study highlight the influence of modeling decisions and ground motion selection in the development of seismic collapse fragility functions and the characterization of risk for various demand levels.

Application of the R-Curve Concept to Fatigue Crack Growth

1978 ◽  
Vol 100 (4) ◽  
pp. 416-420 ◽  
Author(s):  
D. P. Wilhem ◽  
M. M. Ratwani
Keyword(s):  
Fatigue Crack ◽  
Fatigue Crack Growth ◽  
Crack Growth ◽  
Crack Extension ◽  
Stress Ratio ◽  
Cyclic Stress ◽  
Crack Growth Resistance ◽  
Resistance Curve ◽  
Cyclic Stress Ratio ◽  
Wide Range

Crack growth resistance for both static (rising load) and for cyclic fatigue crack growth has been shown to be a continuous function over a range of 0.1 μm to 10 cm in crack extension for 2024-T3 aluminum. Crack growth resistance to each fatigue cycle of crack extension is shown to approach the materials ordinary undirectional static crack resistance value when the cyclic stress ratio is zero. The fatigue crack extension is averaged over many cycles and is correlated with the maximum value of the crack tip stress intensity, Kmax. A linear plot of crack growth resistance for fatigue and static loading data shows similar effects of thickness, stress ratio, and other parameters. The effect of cyclic stress ratio on crack growth resistance for 2219 aluminum indicates the magnitude of differences in resistance when plotted to a linear scale. Prediction of many of these trends is possible using one of several available crack growth data correlating techniques. It appears that a unique resistance curve, dependent on material, crack orientation, thickness, and stress/physical environment, can be developed for crack extensions as small as 0.076 μm (3 μ inches). This wide range, crack growth resistance curve is seen of immense potential for use in both fatigue and fracture studies.

Evaluation of SCEC CyberShake Ground Motions for Engineering Practice

2019 ◽  
Vol 35 (3) ◽  
pp. 1311-1328 ◽  
Author(s):  
Ganyu Teng ◽  
Jack Baker
Keyword(s):  
Los Angeles ◽  
Ground Motion ◽  
Ground Motions ◽  
Response Spectra ◽  
Building Design ◽  
Empirical Models ◽  
Soil Conditions ◽  
Engineering Practice ◽  
Ground Motion Selection ◽  
Promising Source

This paper evaluates CyberShake (version 15.12) ground motions for potential application to high-rise building design in the Los Angeles region by comparing them against recordings from past earthquakes as well as empirical models. We consider two selected sites in the Los Angeles region with different underlying soil conditions and select comparable suites of ground motion records from CyberShake and the NGA-West2 database according to the ASCE 7-16 requirements. Major observations include (1) selected ground motions from CyberShake and NGA-West2 share similar features, in terms of response spectra and polarization; (2) when selecting records from Cyber-Shake, it is easy to select motions with sources that match the hazard deaggregation; (3) CyberShake durations on soil are consistent with the empirical models considered, whereas durations on rock are slightly shorter; (4) occasional excessive polarization in ground motion is produced by San Andreas fault ruptures, though those records are usually excluded after the ground motion selection. Results from this study suggest that CyberShake ground motions are a suitable and promising source of ground motions for engineering evaluations.

Consideration and Propagation of Ground Motion Selection Epistemic Uncertainties to Seismic Performance Metrics

2018 ◽  
Vol 34 (2) ◽  
pp. 587-610 ◽  
Author(s):  
Karim Tarbali ◽  
Brendon A. Bradley ◽  
Jack W. Baker
Keyword(s):  
Seismic Hazard ◽  
Seismic Response ◽  
Ground Motion ◽  
Seismic Performance ◽  
Performance Metrics ◽  
Epistemic Uncertainty ◽  
Seismic Demand ◽  
Intensity Measures ◽  
Ground Motion Selection ◽  
The Mean

This paper investigates various approaches to propagate the effect of epistemic uncertainty in seismic hazard and ground motion selection to seismic performance metrics. Specifically, three approaches with different levels of rigor are presented for establishing the conditional distribution of intensity measures considered for ground motion selection, selecting ground motion ensembles, and performing nonlinear response history analyses (RHAs) to probabilistically characterize seismic response. The mean and distribution of the seismic demand hazard is used as the principal means to compare the various results. An example application illustrates that, for seismic demand levels significantly below the collapse limit, epistemic uncertainty in seismic response resulting from ground motion selection can generally be considered as small relative to the uncertainty in the seismic hazard itself. In contrast, uncertainty resulting from ground motion selection appreciably increases the uncertainty in the seismic demand hazard for near-collapse demand levels.

The Stability of Ground Motions Randomly Synthesized for an Engineering Site

2013 ◽  
Vol 477-478 ◽  
pp. 1069-1074
Author(s):  
Hai Ming Liu ◽  
Xiaxin Tao ◽  
Li Yuan Wang
Keyword(s):  
Ground Motion ◽  
Response Spectrum ◽  
Ground Motions ◽  
Source Models ◽  
The Mean ◽  
The Stability

The ground motions at two rock stations where motions were recorded during the great Wenchuan earthquae are randomly synthsized for 10 times. The mean response spectrum and mean PGA of each synthesis and the general mean spectrum and PGA after each synthesis are calculated. The result shows the fact that the general mean spectrum after 10 syntheses, and the general mean PGA could be improved just a little. It means that it is not necessary to synthsize ground motion many times for an engineering site in practice, if the mean spectrum and PG are taken from the syntheses by 30 source models.

Ground Motion Selection in the Near-Fault Region considering Directivity-Induced Pulse Effects

2019 ◽  
Vol 35 (2) ◽  
pp. 759-786 ◽  
Author(s):  
Karim Tarbali ◽  
Brendon A. Bradley ◽  
Jack W. Baker
Keyword(s):  
Seismic Hazard ◽  
Ground Motion ◽  
Hazard Analysis ◽  
Ground Motions ◽  
Seismic Hazard Analysis ◽  
Response Analysis ◽  
Seismic Demand ◽  
Ground Motion Selection ◽  
Near Fault ◽  
Fault Region

This paper focuses on the selection of ground motions for seismic response analysis in the near-fault region, where directivity effects are significant. An approach is presented to consider forward directivity velocity pulse effects in seismic hazard analysis without separate hazard calculations for ‘pulse-like’ and ‘non-pulse-like’ ground motions, resulting in a single target hazard (at the site of interest) for ground motion selection. The ability of ground motion selection methods to appropriately select records that exhibit pulse-like ground motions in the near-fault region is then examined. Applications for scenario and probabilistic seismic hazard analysis cases are examined through the computation of conditional seismic demand distributions and the seismic demand hazard. It is shown that ground motion selection based on an appropriate set of intensity measures (IMs) will lead to ground motion ensembles with an appropriate representation of the directivity-included target hazard in terms of IMs, which are themselves affected by directivity pulse effects. This alleviates the need to specify the proportion of pulse-like motions and their pulse periods a priori as strict criteria for ground motion selection.

scholarly journals Orientation effects of horizontal seismic components on longitudinal reinforcement in R/C frame elements

2012 ◽  
Vol 12 (1) ◽  
pp. 1-10 ◽  
Author(s):  
K. G. Kostinakis ◽  
A. M. Athanatopoulou ◽  
I. E. Avramidis
Keyword(s):  
Ground Motion ◽  
Cross Sections ◽  
Linear Response ◽  
Ground Motions ◽  
Longitudinal Reinforcement ◽  
Analysis And Design ◽  
History Analysis ◽  
Response History Analysis ◽  
Internal Forces ◽  
Horizontal Ground Motion

Abstract. The present paper investigates the influence of the orientation of recorded horizontal ground motion components on the longitudinal reinforcement of R/C frame elements within the context of linear response history analysis. For this purpose, three single-story buildings are analyzed and designed for 13 recorded bi-directional ground motions applied along the horizontal structural axes. The analysis and design is performed for several orientations of the recording angle of the horizontal seismic components. For each orientation the longitudinal reinforcement at all critical cross sections is calculated using four methods of selecting the set of internal forces needed to compute the required reinforcement. The results show that the reinforcement calculated by three of the applied methods is significantly affected by the orientation of the recording angle of ground motion, while the fourth one leads to results which are independent of the orientation of the recording angle.

scholarly journals Selection of Compatible Ground Motions with the Seismic Characteristics of Erbil City, the Capital of the Kurdistan Region of Iraq

2020 ◽  
Vol 10 (1) ◽  
pp. 110-120
Author(s):  
Zina A. AbdulJaleel ◽  
Bahman O. Taha
Keyword(s):  
Ground Motion ◽  
Earthquake Engineering ◽  
Risk Evaluation ◽  
Ground Motions ◽  
Imperial Valley ◽  
Engineering Research ◽  
Ground Motion Selection ◽  
Seismic Characteristics ◽  
Time Histories ◽  
Selection Of

Erbil city characterized by the risk of earthquakes generated by Zagros-Taurus Belt. The central objective of this study is to obtain a compatible input ground motion within the seismicity of Erbil city since which is considered an essential component of seismic risk evaluation and vulnerability studies. The real records obtained from the online database Pacific Earthquake Engineering Research Next Generation Attenuation. Four sets of ground motion selection and modification methods proposed to obtain fifteen records, where each record scaled and matched with the defined target spectra and seismic characteristics in Erbil city. Based on the greatest number of repetition and different events, ten compatible ground motions with earthquake name and NGA record number are selected: Gazli_Ussr (#126), Imperial Vally_06 (#183), El Mayor-Cucapah_Maxico (#5827), Christchurch_New Zealand (#8124), Imperial Valley (#6), Darfield_NewZealand (#6893), Duzce Turkey (#1602), Northridge_01 (#1082), Loma Prieta (#761), and Spitak_Armenia (#730). Seismosoft application utilized to obtain the graphs of acceleration, velocity, and displacement time histories for three components, in addition to determine the important parameters to characterize the amplitude, frequency content, and duration of the selected ground motion.

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