Are Bridges Safe Under Near-Fault Pulse-Type Ground Motions Considering the Vertical Component?

Near-fault (NF) earthquakes cause severe bridge damage, particularly urban bridges subjected to light rail transit (LRT), which could affect the safety of the light rail transit vehicle (“light rail vehicle” or “LRV” for short). Now when a variety of studies on the fault fracture effect on the working protection of LRVs are available for the study of cars subjected to far-reaching soil motion (FFGMs), further examination is appropriate. For the first time, this paper introduced the LRV derailment mechanism caused by pulse-type near-fault ground motions (NFGMs), suggesting the concept of pulse derailment. The effects of near-fault ground motions (NFGMs) are included in an available numerical process developed for the LRV analysis of the VBI system. A simplified iterative algorithm is proposed to assess the stability and nonlinear seismic response of an LRV-reinforced concrete (RC) viaduct (LRVBRCV) system to a long-period NFGMs using the dynamic substructure method (DSM). Furthermore, a computer simulation software was developed to compute the nonlinear seismic responses of the VBI system to pulse-type NFGMs, non-pulse-type NFGMs, and FFGMs named Dynamic Interaction Analysis for Light-Rail-Vehicle Bridge System (DIALRVBS). The nonlinear bridge seismic reaction determines the impact of pulses on lateral peak earth acceleration (Ap) and lateral peak land (Vp) ratios. The analysis results quantify the effects of pulse-type NFGMs seismic responses on the LRV operations' safety. In contrast with the pulse-type non-pulse NFGMs and FFGMs, this article's research shows that pulse-type NFGM derail trains primarily via the transverse velocity pulse effect. Hence, this study's results and the proposed method can improve the LRT bridges' seismic designs.

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

IABSE Congress, New York, New York 2019: The Evolving Metropolis ◽

10.2749/newyork.2019.1314 ◽

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>

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Application of the Incremental Modal Analysis for Bridges (IMPAb) Subjected to Near-Fault Ground Motions

10.20944/preprints202009.0023.v1 ◽

2020 ◽

Author(s):

Alessandro Vittorio Bergami ◽

Gabriele Fiorentino ◽

Davide Lavorato ◽

Bruno Briseghella ◽

Camillo Nuti

Keyword(s):

Ground Motion ◽

Ground Motions ◽

Pushover Analysis ◽

Vertical Component ◽

Vertical Motion ◽

Strong Motion ◽

Seismic Action ◽

Near Fault ◽

Benchmark Solutions

Near-fault ground motions can cause severe damage to civil structures, including bridges. Safety assessment of these structures for near fault ground motion is usually performed through Non-Linear Dynamic Analyses, while faster methods are often used. IMPAb (Incremental Modal Pushover Analysis for Bridges) permits to investigate the seismic response of a bridge by considering the effects of higher modes, which are often relevant for bridges. In this work, IMPAb is applied to a bridge case study considering near-fault pulse-like ground motion records. The records were analyzed and selected from the European Strong Motion Database and the pulse parameters were evaluated. In the paper results from standard pushover procedures and IMPAb are compared with nonlinear Response-History Analysis (NRHA), considering also the vertical component of the motion, as benchmark solutions and incremental dynamic analysis (IDA). Results from the case study demonstrate that the vertical seismic action has a minor influence on the structural response of the bridge. Therefore IMPAb, which can be applied considering vertical motion, remains very effective conserving the original formulation of the procedure, and can be considered a well performing procedure also for near-fault events.

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Identification Methods of Important Parameters for Near-Fault Pulse-Type Ground Motions

Advanced Materials Research ◽

10.4028/www.scientific.net/amr.594-597.1688 ◽

2012 ◽

Vol 594-597 ◽

pp. 1688-1691

Author(s):

Ming Li ◽

Qiao Jin ◽

Yong Liu ◽

He Yuan ◽

Zhe Zhe Sun

Keyword(s):

Ground Motion ◽

Peak Velocity ◽

Ground Motions ◽

Velocity Pulse ◽

Identification Methods ◽

Near Fault ◽

Pulse Type ◽

Pulse Peak ◽

Motion Parameters ◽

Near Fault Ground Motion

during the process of fitting or synthesizing near-fault ground motion，parameters of the equivalent velocity pulse need to be decided based on seismic records．Thus, it is a key problem that how to identify these parameters from the records．Pulse period and pulse peak velocity are important parameters in the equivalent velocity pulse models．In this study，various methods on identifying these parameters are reviewed．It is shown that all the existing methods have limitations，especially for the irregular seismic records．Finally，problems need to be further studied is pointed out.

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Study on inelastic displacement ratio spectra for near-fault pulse-type ground motions

Earthquake Engineering and Engineering Vibration ◽

10.1007/s11803-007-0755-x ◽

2007 ◽

Vol 6 (4) ◽

pp. 351-355 ◽

Cited By ~ 20

Author(s):

Changhai Zhai ◽

Shuang Li ◽

Lili Xie ◽

Yamin Sun

Keyword(s):

Ground Motions ◽

Inelastic Displacement ◽

Near Fault ◽

Displacement Ratio ◽

Pulse Type ◽

Inelastic Displacement Ratio

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Seismic Response of Skewed Integral Abutment Bridges under Near-Fault Ground Motions, Including Soil–Structure Interaction

Applied Sciences ◽

10.3390/app11073217 ◽

2021 ◽

Vol 11 (7) ◽

pp. 3217

Author(s):

Qiuhong Zhao ◽

Shuo Dong ◽

Qingwei Wang

Keyword(s):

Seismic Response ◽

Soil Structure ◽

Ground Motions ◽

Integral Abutment ◽

Skew Angle ◽

Nonlinear Dynamic Response ◽

Integral Abutment Bridges ◽

Near Fault ◽

Abutment Bridges ◽

Pulse Type

Studies on the seismic response of skewed integral abutment bridges have mainly focused on response under far-field non-pulse-type ground motions, yet the large amplitude and long-period velocity pulses in near-fault ground motions might have significant impacts on bridge seismic response. In this study, the nonlinear dynamic response of an skewed integral abutment bridge (SIAB) under near-fault pulse and far-fault non-pulse type ground motions are analyzed considering the soil–structure interaction, along with parametric studies on bridge skew angle and compactness of abutment backfill. For the analyses, three sets of near-fault pulse ground motion records are selected based on the bridge site conditions, and three corresponding far-field non-pulse artificial records are fitted by their acceleration response spectra. The results show that the near-fault pulse type ground motions are generally more destructive than the non-pulse motions on the nonlinear dynamic response of SIABs, but the presence of abutment backfill will mitigate the pulse effects to some extent. Coupling of the longitudinal and transverse displacements as well as rotation of the bridge deck would increase with the skew angle, and so do the internal forces of steel H piles. The influence of the skew angle would be most obvious when the abutment backfill is densely compacted.

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Amplification of seismic demands in inter-storey-isolated buildings subjected to near fault pulse type ground motions

Soil Dynamics and Earthquake Engineering ◽

10.1016/j.soildyn.2021.106771 ◽

2021 ◽

Vol 147 ◽

pp. 106771

Author(s):

Arijit Saha ◽

Sudib Kumar Mishra

Keyword(s):

Ground Motions ◽

Seismic Demands ◽

Near Fault ◽

Pulse Type

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Characterization of the Dynamic Response of Structures to Damaging Pulse-type Near-fault Ground Motions

Meccanica ◽

10.1007/s11012-005-7965-y ◽

2006 ◽

Vol 41 (1) ◽

pp. 23-46 ◽

Cited By ~ 27

Author(s):

Fabrizio Mollaioli ◽

Silvia Bruno ◽

Luis D. Decanini ◽

Giuliano F. Panza

Keyword(s):

Dynamic Response ◽

Ground Motions ◽

Near Fault ◽

Pulse Type

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Inelastic response spectra of self-centering structures with the flag-shaped hysteretic response subjected to near-fault pulse-type ground motions

Earthquake Spectra ◽

10.1177/87552930211000359 ◽

2021 ◽

pp. 875529302110003

Author(s):

Huihui Dong ◽

Qiang Han ◽

Xiuli Du ◽

Shoushan Cheng ◽

Haifang He

Keyword(s):

Ground Motion ◽

Ground Motions ◽

Response Spectra ◽

Displacement Velocity ◽

Hysteretic Behavior ◽

Hysteretic Model ◽

Inelastic Response ◽

Inelastic Displacement ◽

Near Fault ◽

Pulse Type

Many studies on the inelastic response spectra have mainly focused on structures with the conventional hysteretic behavior. However, for self-centering structures with the flag-shaped (FS) hysteretic behavior, the corresponding study is limited. The primary aim of this study is to investigate the inelastic response spectra of self-centering structures with FS hysteretic behavior subjected to the near-fault pulse-type ground motion. To this end, the smooth FS hysteretic model based on Bouc–Wen model is developed, and the characteristics of pulse-type ground motions are described in detail. It is found that the general features of inelastic response spectra of the FS model are sensitive to the acceleration-, velocity-, and displacement-sensitive spectral regions of the ground motion. The inelastic displacement, velocity, acceleration, and ductility factor spectra of the FS hysteretic model for pulse-type ground motions are much larger than those for ordinary ground motions, while the residual displacement spectra under the two types of ground motions are both very small due to its self-centering capacity. Moreover, the inelastic response spectra are affected by the ground motion characteristics and structural hysteresis behavior, especially the large pulse period and peak ground velocity (PGV) significantly increase the inelastic displacement, velocity, and acceleration spectra.

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