Effects of Near Fault and Far Fault Ground Motions on Nonlinear Dynamic Response and Seismic Improvement of Bridges

In this study, the dynamic response of bridges to earthquakes near and far from the fault has been investigated. With respect to available data and showing the effects of key factors and variables, we have examined the bridge’s performance. Modeling a two-span concrete bridge in CSI Bridge software and ability of this bridge under strong ground motion to near and far from fault has been investigated. Nonlinear dynamic analysis of time history includes seven records of past earthquakes on models and it was observed that the amount of displacement in the near faults is much greater than the distances far from faults. Bridges designed by seismic separators provide an acceptable response to a far from fault. This means that in bridges using seismic separators, compared to bridges without seismic separators, Acceleration rate on deck, base shearing and the relative displacement of the deck are decrease. This issue is not seen in the response of the bridges to the near faults. By investigating earthquakes near faults, it was observed that near-fault earthquakes exhibit more displacements than faults that are far from faults. These conditions can make seismic separators critical, so to prevent this conditions FDGM should be used to correct the response of these bridges. Based on these results, it can be said that the displacement near faults with forward directivity ground motion is greater than far from faults. So that by reducing the distance from the faults, the maximum value of the shearing and displacement of the deck will be greater.

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Nonlinear Dynamic Analysis of a Masonry Arch Bridge Accounting for Damage Evolution

Geosciences ◽

10.3390/geosciences11080343 ◽

2021 ◽

Vol 11 (8) ◽

pp. 343

Author(s):

Daniela Addessi ◽

Cristina Gatta ◽

Mariacarla Nocera ◽

Domenico Liberatore

Keyword(s):

Dynamic Response ◽

Nonlinear Dynamic ◽

Damage Index ◽

Nonlinear Dynamic Analysis ◽

Time History ◽

Damage Variable ◽

Constitutive Law ◽

Masonry Arch ◽

Nonlinear Dynamic Response ◽

History Of

This study investigates the nonlinear dynamic response of the masonry bridge ‘Ponte delle Torri’ in Spoleto, aiming at assessing the seismic performance of the structure and evaluating the occurring damaging mechanisms. A 3D Finite Element (FE) macromechanical procedure implemented in the FE program FEAP is adopted to model the bridge. To reproduce the typical nonlinear microcracking process evolving in masonry material when subjected to external loads, an isotropic damage model is used. This is based on a scalar damage variable introduced in the stress-strain constitutive law and equally degrading all the components of the elastic constitutive operator. A nonlocal integral definition of the damage associated variable, that is the equivalent strain measure governing its evolution, is adopted to overcome the mesh dependency problems of the FE solution typically occurring in the presence of strain softening behavior. Based on the results of a recent study by some of the authors, a single equivalent pier is analyzed, whose geometry and boundary conditions are selected so that its response can provide useful information on the out-of-plane dynamic behavior of the overall bridge. To perform the seismic assessment, a set of recorded accelerograms is properly selected to simulate the seismic history of the Spoleto site. The nonlinear dynamic response of the structure is evaluated and monitored in terms of top displacement time history, evolution of the global damage index, and distribution of the damage variable. First, a set of analyses is performed by imposing the selected ground motions one by one on the initial undamaged configuration for the structure with the aim of emphasizing the damaging effects on its dynamic response. Then, the accelerograms are arranged in sequence to reproduce the seismic history of the site and analyze the influence of accumulated damage on the dynamic amplification of the response. A critical comparison of the bridge response to the sequence of accelerograms and the single records is made, and the interaction between the damaged structure dynamic response and the signal characteristic is highlighted, as well.

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Effects of near-fault and far-fault ground motions on nonlinear dynamic response and seismic damage of concrete gravity dams

Soil Dynamics and Earthquake Engineering ◽

10.1016/j.soildyn.2013.07.014 ◽

2013 ◽

Vol 53 ◽

pp. 217-229 ◽

Cited By ~ 62

Author(s):

Sherong Zhang ◽

Gaohui Wang

Keyword(s):

Dynamic Response ◽

Nonlinear Dynamic ◽

Ground Motions ◽

Seismic Damage ◽

Gravity Dams ◽

Nonlinear Dynamic Response ◽

Near Fault ◽

Concrete Gravity Dams ◽

Far Fault

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Seismic Response of a Viaduct under near-Fault Earthquakes

Applied Mechanics and Materials ◽

10.4028/www.scientific.net/amm.166-169.2368 ◽

2012 ◽

Vol 166-169 ◽

pp. 2368-2372

Author(s):

Yan Jiang Chen ◽

Yu Bo Zhang ◽

Wei Ming Yan ◽

Yong Li

Keyword(s):

Dynamic Response ◽

Seismic Response ◽

Time History ◽

Response Patterns ◽

Structural Dynamic ◽

Near Fault ◽

Large Velocity ◽

Time History Response ◽

Near Fault Earthquakes ◽

Periodic Components

Abundant long-periodic components endue near-fault earthquakes with large velocity pulses while the viaducts owe long periodic fundamental period. To explore the seismic response patterns of viaducts under near-fault earthquakes, the paper analyzed the time history response of a viaduct under near-fault seismograms including TCU 1063, TCU 065, El centro and Artificial wave via FEM software Civil. The analysis shows a significant boost in near-fault seismic response as the value of PGV/PGA increased accordingly, indicates that the near-fault pulse affects strongly on the structural dynamic response of the viaducts.

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Failure Mechanism of Reinforced Concrete Rib Arch Bridge under Near-Fault Earthquakes

Applied Mechanics and Materials ◽

10.4028/www.scientific.net/amm.90-93.940 ◽

2011 ◽

Vol 90-93 ◽

pp. 940-945

Author(s):

Wen Jun Gao ◽

Guang Wu Tang ◽

Yi Da Kong

Keyword(s):

Reinforced Concrete ◽

Nonlinear Response ◽

Plastic Hinge ◽

Seismic Damage ◽

Arch Bridge ◽

2008 Wenchuan Earthquake ◽

Near Fault ◽

Pulse Type ◽

Near Fault Earthquakes ◽

Far Fault

A typical reinforced concrete rib arch bridge was chosen to investigate its nonlinear response to near-fault ground motions recorded in 2008 Wenchuan earthquake. Results showed that significant seismic damage may occur, maximum demands were higher for near-fault records having forward directive than far-fault motions, and the rotational capacity of rib plastic hinge is not enough for the large compression force of arch rib. While backward-directivity motions, typically do not exhibit pulse-type motions, only have medium seismic damage to the arch bridge.

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Acceleration amplification due to rotational components of near-fault earthquakes in triple concave friction pendulum base-isolated structures

Canadian Journal of Civil Engineering ◽

10.1139/cjce-2016-0354 ◽

2018 ◽

Vol 45 (4) ◽

pp. 314-327

Author(s):

Hamed Tajammolian ◽

Faramarz Khoshnoudian

Keyword(s):

Dynamic Analysis ◽

Ground Motion ◽

Nonlinear Dynamic Analysis ◽

Maximum Acceleration ◽

Nonstructural Components ◽

Geometrical Properties ◽

Near Fault ◽

Rotational Components ◽

Seismic Force ◽

Friction Pendulum

Recent studies show that rotational components of earthquakes can amplify the floor acceleration in a base-isolated structure. As a result, the seismic force of nonstructural components could be significantly increased. In this paper, a simple rectangular deck with various geometrical properties mounted on triple concave friction pendulum (TCFP) bearings is examined. At first a set of three translational components from 25 near-fault ground motion records are considered. Then, three rotational components, i.e., torsional and two rocking motions are computed for each earthquake. The results of nonlinear dynamic analysis in a rectangular structure with an aspect ratio in plan equal to 3, demonstrate that the acceleration approximately intensifies 3.4 times in presence of all six ground motion components compared to three translational ones. Finally, a new formula is proposed to determine the maximum acceleration of base-isolated structure without performing the dynamic analysis due to rotational components of ground motions.

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Nonlinear dynamic response of a tall building to near-fault pulse-like ground motions

Bulletin of Earthquake Engineering ◽

10.1007/s10518-019-00570-y ◽

2019 ◽

Vol 17 (6) ◽

pp. 2989-3013 ◽

Cited By ~ 11

Author(s):

Necmettin Güneş ◽

Zülfü Çınar Ulucan

Keyword(s):

Dynamic Response ◽

Nonlinear Dynamic ◽

Ground Motions ◽

Tall Building ◽

Nonlinear Dynamic Response ◽

Near Fault

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Probabilistic sensitivity analysis of two suspension bridges in Istanbul, Turkey to near- and far-fault ground motion

Natural Hazards and Earth System Science ◽

10.5194/nhess-12-459-2012 ◽

2012 ◽

Vol 12 (2) ◽

pp. 459-473 ◽

Cited By ~ 5

Author(s):

Ö. Çavdar

Keyword(s):

Ground Motion ◽

Dynamic Responses ◽

Suspension Bridges ◽

Near Fault ◽

Internal Forces ◽

Ground Motion Records ◽

Far Fault ◽

Sensitivity Method ◽

Mcs Method ◽

Strong Ground

Abstract. The aim of this paper is to compare the near-fault and far-fault ground motion effects on the probabilistic sensitivity dynamic responses of two suspension bridges in Istanbul. Two different types of suspension bridges are selected to investigate the near-fault (NF) and far-fault (FF) ground motion effects on the bridge sensitivity responses. NF and FF strong ground motion records, which have approximately identical peak ground accelerations, of the Kocaeli (1999) earthquake are selected for the analyses. Displacements and internal forces are determined using the probabilistic sensitivity method (PSM), which is one type of stochastic finite element method. The efficiency and accuracy of the proposed algorithm are validated by comparison with results of the Monte Carlo Simulation (MCS) method. The displacements and internal forces obtained from the analyses of suspension bridges subjected to each fault effect are compared with each other. It is clearly seen that there is more seismic demand on displacements and internal forces when suspension bridges are subjected to NF and FF ground motion.

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Adjustments of Ground Motion Input Based on Ground Micro Tremor Test to Determine Ground Dynamic Characteristics and its Anisotropy

Applied Mechanics and Materials ◽

10.4028/www.scientific.net/amm.90-93.1447 ◽

2011 ◽

Vol 90-93 ◽

pp. 1447-1453

Author(s):

Jun Zuo

Keyword(s):

Dynamic Response ◽

Ground Motion ◽

Structure Analysis ◽

Dynamic Characteristics ◽

Seismic Anisotropy ◽

Time History ◽

Test Analysis ◽

Analysis Process

According to the seismic anisotropy theory and the test observation, this paper puts forward the conception of the ground micro tremor anisotropy, and researches the method of the micro tremor test analysis about the anisotropy of the ground dynamic characteristics. Given the anisotropic characteristics of the ground motion, it analyzes the influence of the ground motion anisotropy on the seismic dynamic response of the structure, and the existent problems about the selection and adjustment of the existing seismic time history in the structure analysis process. Finally, this paper puts forward the new selection and adjustment solution of ground motion input based on the ground micro tremor test to determine the ground dynamic characteristics and the ground anisotropy.

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