scholarly journals Quantification of Energy-Related Parameters for Near-Fault Pulse-Like Seismic Ground Motions

2020 ◽  
Vol 10 (21) ◽  
pp. 7578 ◽  
Author(s):  
Omar AlShawa ◽  
Giulia Angelucci ◽  
Fabrizio Mollaioli ◽  
Giuseppe Quaranta
Keyword(s):  
Ground Motions ◽  
Time History ◽  
High Energy ◽  
Reduction Factor ◽  
Hysteretic Behavior ◽  
Energy Reduction ◽  
Input Energy ◽  
Hysteretic Energy ◽  
Analysis And Design ◽  
Near Fault

An energy-based approach facilitates the explicit consideration of the damage associated with both maximum displacements and cumulative plastic deformations under earthquakes. For structural systems that can undergo pulse-like seismic ground motions close to causative faults, an energy-based approach is deemed especially appropriate with respect to well-established force- or displacement-based strategies. In such a case, in fact, most of the damage is attributable to the dominant pulse-like component, which usually occurs into the velocity time history of the seismic ground motion, thus implying high energy levels imparted to a structural system. In order to enable the implementation of an energy-based approach in the analysis and design of structures under near-fault pulse-like seismic ground motions, this study presents a comprehensive numerical investigation about the influence of seismological parameters and hysteretic behavior on the spectra of the following energy-related parameters: inelastic absolute and relative input energy; input energy reduction factor; hysteretic energy dissipation demand; hysteretic energy reduction factor; dimensionless cumulative plastic deformation ratio. Closed-form approximations are proposed for these spectra, and the numerical values of the corresponding parameters have been also calibrated (with reference to both mean and standard deviation values) as functions of earthquake magnitude, type of hysteretic behavior (i.e., non-degrading or degrading) and ductility level. The outcomes of this study are meant to support the derivation of design spectra for the energy-based seismic design of structures under near-fault pulse-like seismic ground motions.

Strength reduction factor of self-centering structures under near-fault pulse-like ground motions

2020 ◽  
Vol 24 (1) ◽  
pp. 119-133
Author(s):  
Huihui Dong ◽  
Qiang Han ◽  
Xiuli Du ◽  
Canxing Qiu
Keyword(s):  
Ground Motions ◽  
Time History ◽  
Reduction Factor ◽  
Strength Reduction ◽  
The Self ◽  
Hysteretic Behavior ◽  
Hysteretic Model ◽  
Strength Reduction Factor ◽  
Vibration Period ◽  
Near Fault

Many studies on the strength reduction factor mainly focused on structures with the conventional hysteretic models. However, for the self-centering structure with the typical flag-shaped hysteretic behavior, the corresponding study is limited. The main purpose of this study is to investigate the strength reduction factor of the self-centering structure with flag-shaped hysteretic behavior subjected to near-fault pulse-like ground motions by the time history analysis. For this purpose, the smooth flag-shaped model based on Bouc-Wen model which can show flag-shaped hysteretic behavior is first described. The strength reduction factor spectra of the flag-shaped model are then calculated under 85 near-fault pulse-like ground motions. The influences of the ductility level, vibration period, site condition, hysteretic parameter, and hysteretic model are investigated statistically. For comparison, the strength reduction factors under ordinary ground motions are also analyzed. The results show that the strength reduction factor from near-fault pulse-like ground motions is smaller. Finally, a predictive model is proposed to estimate the strength reduction factor for the self-centering structure with the flag-shaped model under near-fault pulse-like ground motions.

scholarly journals Seismic Energy Response of SDOF Systems Subjected to Long-Period Ground Motion Records

2021 ◽  
Vol 2021 ◽  
pp. 1-20
Author(s):  
Yu Cheng ◽  
Yao-Rong Dong ◽  
Li Qin ◽  
Yuan-Yuan Wang ◽  
Ye-Xue Li
Keyword(s):  
Ground Motions ◽  
Seismic Energy ◽  
Response Spectra ◽  
Design Parameters ◽  
Far Field ◽  
Input Energy ◽  
Energy Response ◽  
Hysteretic Energy ◽  
Near Fault ◽  
Long Period

To provide an important reference for the energy-based seismic design of long-period structures, the elastoplastic dynamic analysis program is employed to study the seismic energy response of single-degree-of-freedom (SDOF) systems under two types of typical long-period ground motions. Then, the influencing relationships of external and internal factors on the energy response spectra under near-fault pulse-like and far-field harmonic ground motions are analyzed one by one. Study results are obtained as follows: within the whole period, all the input energy, hysteretic energy and damping energy spectra of SDOF systems under near-fault pulse-like and far-field harmonic ground motions, are larger than those under common ground motions, even the seismic energy response under far-field harmonic ground motions is larger than that under near-fault pulse-like ground motions. From the aspect of energy concept, the energy response spectra and energy distribution rule of SDOF systems are evaluated based on the intensity and spectral distribution under near-fault pulse-like and far-field harmonic ground motions. If the ratio of hysteretic energy to input energy (RHEIE) is determined, the hysteretic energy which must be dissipated by a structure would be derived by the method of energy-based design. The input energy and hysteretic energy are mainly influenced by damping ratio and ductility coefficient, while the yield stiffness ratio exerts minor effects. It indicates that reasonable structural design parameters would contribute to the hysteretic energy of a structure itself.

EVALUATION OF SEISMIC DEMANDS IN A CONTINUOUS BRIDGE

2001 ◽  
Vol 01 (02) ◽  
pp. 235-246 ◽  
Author(s):  
CHIN-HSIUNG LOH ◽  
SHIUAN WAN ◽  
YI-WEN CHANG
Keyword(s):  
Earthquake Engineering ◽  
Ground Motions ◽  
Hysteretic Behavior ◽  
Earthquake Ground Motion ◽  
Far Field ◽  
Base Shear ◽  
Near Fault ◽  
Seismic Design Code ◽  
Cyclic Loading Tests ◽  
Earthquake Characteristics

This paper examines the dynamic behavior of a highway RC-bridge subjected to both near-fault and far-field ground motions. The bridge consists of a hinge supported continuous girder with six concrete piers and the bridge is designed according to the Taiwan seismic design code. To investigate the hysteretic behavior of the bridge piers, cyclic loading tests were carried out at the National Center for Research on Earthquake Engineering (NCREE). The Chi-Chi earthquake ground motion record was adopted as the near-fault earthquake characteristics whereas another earthquake record was selected for the far-field earthquake characteristics. The ductility demands and base shear demands due to the near-fault and the far-field earthquake ground motions are compared and conclusions drawn from the study. The stipulation of code limitations and the present calculated demands are discussed.

Simulation of Palu IV Bridge Collapse using Near-Fault Ground Motions

2019 ◽  
Author(s):  
Iswandi Imran ◽  
Budi Santoso ◽  
Ary Pramudito ◽  
Muhammad Kadri Zamad
Keyword(s):  
Spatial Variation ◽  
Ground Motions ◽  
Time History ◽  
Seismic Demand ◽  
Fault Line ◽  
Near Fault ◽  
Failure Simulation ◽  
Bridge Collapse ◽  
Pulse Type ◽  
Bridge Bearing

<p>The earthquake near Palu, Sulawesi (Indonesia) on September 28, 2018 with a magnitude of M7.4 was caused by a shallow strike-slip of Palu-Koro fault. The earthquake and the subsequent tsunami have caused the collapse of the Ponulele Bridge (Palu IV Bridge). The steel box bowstring arch bridge was located near-fault regions (within 1,5 km from fault line) that have not been identified during the design process. This bridge may have been damaged by the presence of fling-step pulses in the near-fault pulse-type ground motions that increases the damaging potential of such ground motions. This paper presents the failure simulation of the bridge subjected to the near fault pulse type time history with spatial variation ground motions applied on multiple bridge supports. From the simulation, it is concluded that the near fault effects and the spatial variation of the ground motion have increased significantly the seismic demand on the bridge. This increase causes the failure in the anchorage of the bridge bearing system.</p>

A Study on Dissipation of Cumulative Hysteretic Energy in Reinforced Concrete Frame Structures

2010 ◽  
Vol 163-167 ◽  
pp. 4301-4308
Author(s):  
Min Sheng Guan ◽  
Da Jian Han ◽  
Hong Biao Du ◽  
Xin Wang
Keyword(s):  
Reinforced Concrete ◽  
Distribution Pattern ◽  
Ground Motion ◽  
Time History ◽  
Frame Structure ◽  
Input Energy ◽  
Reinforced Concrete Frame ◽  
Hysteretic Energy ◽  
Concrete Frame ◽  
Reinforced Concrete Frame Structures

Earthquake input energy and structural energy dissipation are key indicators to assess the seismic performance of structures. To study the rules of distribution of hysteretic energy within structures, a 6-storey regular reinforced concrete frame structure model is analyzed through elasto-plastic time-history dynamic analysis using the El Centro and Northridge accelerograms. Based on the comparison between numerical results for the earthquake input energy and structural hysteretic energy under the minor, moderate and major earthquakes of Grade 8 and 9, the distribution of the ratio of the storey hysteretic energy to the total hysteretic energy through the height was further studied. It shows that the computed results corresponding to the two earthquake records are in good agreement under different ground motion severity. And the percentage of structural hysteretic energy to input energy is basically stable. The distribution pattern of storey hysteretic energy through the height is that the value of the upper stories is smaller than the value of the lower stories. And the ground motion severity has a minor influence on the distribution pattern when the plasticity of structure develops more sufficiently.

DAMAGE EVOLUTION SPECTRA FOR SEISMIC ANALYSIS OF HIGH-RISE BUILDINGS

2012 ◽  
Vol 06 (03) ◽  
pp. 1250021
Author(s):  
Y. B. HO ◽  
J. S. KUANG
Keyword(s):  
Damage Evolution ◽  
Seismic Analysis ◽  
Ground Motions ◽  
Time History ◽  
Tall Buildings ◽  
Response Spectra ◽  
Seismic Damage ◽  
Analysis And Design ◽  
High Rise ◽  
Earthquake Ground Motions

Seismic response spectra are amongst one of the most important tools for characterizing earthquake ground motions. In design practice, the response spectra are presented without including any load history, hence the nonlinear analysis of structures based solely on conventional earthquake response spectra is theoretically unsound, particularly for long-period or vertically irregular high-rise buildings. In this paper, a concept of seismic damage evolution is introduced and the method of analysis for characterizing the process of seismic damage to structures under earthquakes is presented. Seismic damage evolution spectra for analysis and design of high-rise buildings are then developed as an effective means of describing and simplifying earthquake ground motions. These spectra are shown to be very useful in selecting the ground motion-time history and, particularly, validating the equivalent static-load analysis and design of high-rise buildings under near-fault pulse-like ground motions. Case studies of the seismic inelastic performance of two vertically irregular, tall buildings are presented considering the seismic damage evolution spectra.

scholarly journals Seismic Design of Bridges against Near-Fault Ground Motions Using Combined Seismic Isolation and Restraining Systems of LRBs and CDRs

2019 ◽  
Vol 2019 ◽  
pp. 1-11
Author(s):  
Xiaoli Li ◽  
Yan Shi
Keyword(s):  
Control System ◽  
Seismic Design ◽  
High Intensity ◽  
Seismic Isolation ◽  
Ground Motions ◽  
Time History ◽  
Nonlinear Time History Analysis ◽  
Near Fault ◽  
Combined Control ◽  
Quantitative Design

This paper focuses on the seismic isolation design of near-fault bridges under the seismic excitations of near-fault ground motions in high-intensity earthquake zones and proposes a combined control system using lead rubber bearings (LRBs) and cable displacement restrainers (CDRs) along with ductility seismic resistance for the reinforced concrete piers. As part of the performance-based seismic design framework, this study provides the quantitative design criteria for multilevel performance-based objectives of a combined control system under conditions of frequent earthquake (E1), design earthquake (medium earthquake), and rare earthquake (E2). Moreover, in this study, a preliminary performance-based seismic isolation design for a near-fault actual highway bridge in high-intensity earthquake zones (basic peak of ground acceleration 0.4 g) was developed. Using nonlinear time-history analysis of the actual bridge under near-fault ground motions, the feasibility of a performance-based design method was validated. Furthermore, to ensure the predicted performance of the isolated bridges during a strong earthquake, a relatively quantitative design in structural details derived from the stirrup ratio of piers, expansion joints gap, supported length of capping beams, and limited vertical displacement response was obtained.

A Stochastic Model for Simulating Vertical Pulseless Near-Fault Seismic Ground Motions

2021 ◽  
Author(s):  
Xi Zhong Cui ◽  
Yong Xu Liu ◽  
Han Ping Hong
Keyword(s):  
Stochastic Model ◽  
Ground Motion ◽  
Ground Motions ◽  
Time History ◽  
Structural Deformation ◽  
Time Frequency ◽  
Motion Models ◽  
Near Fault ◽  
Simulation Techniques ◽  
Ground Motion Records

ABSTRACT The vertical near-fault seismic ground-motion component can cause significant structural deformation and damage, which can be evaluated from time history analysis using actual or synthetic ground-motion records. In this study, we propose a new stochastic model for the vertical pulseless near-fault ground motions that depends on earthquake magnitude, rupture distance, and site condition. The proposed model is developed based on the time–frequency characteristics of 606 selected actual vertical record components in strike-slip earthquakes. The use and validation of the model are presented using simulated records obtained by two simulation techniques. For the validation, the statistics of time–frequency-dependent power spectral acceleration estimated from the simulated records using the proposed stochastic model are compared with those from the actual records and the ground-motion models available in the literature.

SEISMIC RESPONSE OF A FLAG-SHAPED HYSTERETIC BEHAVIOR UNDER GROUND MOTIONS

2014 ◽  
Vol 1 (1) ◽  
Author(s):  
Daniel I. Silva ◽  
Cheng Chen
Keyword(s):  
Earthquake Engineering ◽  
Parametric Study ◽  
Ground Motions ◽  
Hysteretic Behavior ◽  
Far Field ◽  
Displacement Ductility ◽  
Engineering Research ◽  
Sdof System ◽  
Residual Drift ◽  
Near Fault

Self-centering systems have attracted significant interest in earthquake-engineering research, due to their excellent performance under simulated seismic loading through their self-centering capabilities. A comprehensive parametric study is presented to compare the ductility demands on single-degree-of-freedom (SDOF) systems, when subjected to ground motions with a probability of exceedance of 10% in 50 years in California. The influences of different parameters were analyzed under SDOF structural responses in terms of displacement ductility and absolute acceleration. The responses of the flag-shaped hysteretic SDOF systems were also compared against the responses of similar bilinear elasto-plastic hysteretic SDOF systems. Two ensembles of far-field and near-fault historical earthquake records, corresponding to ordinary earthquakes, were used for the parametric study to compare the ductility demands. Although a flag-shaped hysteretic SDOF system of equal or lesser strength can often match or better the response of an elasto-plastic hysteretic SDOF system with almost no residual drift, the analysis shows that seismic design of self-centering systems should account for the difference between far-field and near-fault ground motion.

Sign in / Sign up

Export Citation Format

Share Document