Long-Span Bridge Dynamic Response due to Ground Motions Considering Phase Differences

2006 ◽  
Author(s):  
Wang Guoxin ◽  
Wang Donglei ◽  
Wang Dongsheng
Keyword(s):  
Dynamic Response ◽  
Ground Motions ◽  
Long Span ◽  
Long Span Bridge ◽  
Phase Differences

Numerical Simulations of Canyon Topography Effects on Long-Span Bridge with High Piers under Incident SH Seismic Waves

2011 ◽  
Vol 378-379 ◽  
pp. 789-794
Author(s):  
Guo Liang Zhou ◽  
Xiao Jun Li ◽  
Qing Li Meng
Keyword(s):  
Oblique Incidence ◽  
Seismic Waves ◽  
Seismic Analysis ◽  
Ground Motions ◽  
Ground Surface ◽  
Analysis And Design ◽  
Long Span ◽  
Rigid Frame ◽  
Long Span Bridge ◽  
Canyon Topography

To evaluate the influences of the canyon topography on large structures, based on a rigid frame bridge across a 137-meter-deep and 600-meter-wide canyon, the seismic response of the canyon topography is analyzed under seismic SH waves with the assumptions of vertical incidence and oblique incidence to obtain the surface ground motions, which are used as the excitations for the bridge. It indicates that canyon topography has significant and complex influences on the surface ground motions. The peak ground accelerations vary greatly from the bottom of the canyon to the upper corners. And the ground surface has been characterized by larger relative displacements in the case of oblique incidence. Compared with the uniform seismic excitations, it’s hard to find out any regularity on structural seismic responses considering the canyon topography effects. The canyon topography can enlarge or minish the structural responses in terms of the different structure members, and it should be a carefully considered factor in structural seismic analysis and design.

Influence of Random Multi-Point Seismic Excitations on the Safety Performance of a Train Running on a Long-Span Bridge

2020 ◽  
Vol 20 (04) ◽  
pp. 2050054
Author(s):  
Wei Wang ◽  
Yahui Zhang ◽  
Huajiang Ouyang
Keyword(s):  
High Speed ◽  
Ground Motions ◽  
Time History ◽  
Arma Model ◽  
Safety Performance ◽  
Seismic Excitations ◽  
Dynamic Reliability ◽  
Running Safety ◽  
Long Span ◽  
Long Span Bridge

The increasing use of bridges in high-speed railway (HSR) lines raises the possibility of train derailment on bridges under seismic excitations. In this paper, the influence of random multi-point earthquakes on the safe running of a train on a long-span bridge is studied in terms of the dynamic reliability, considering spatial seismic effects, and randomness of ground motions and train locations. The equations of motion for the train and the track/bridge as time-invariant subsystems under earthquakes are established, separately. The two subsystems are connected via the wheel–rail interface, for which a nonlinear contact model and detachment are considered. The time-history samples of nonstationary multi-point random earthquakes considering wave passage effects and incoherence effects are generated by the autoregressive moving average (ARMA) model. The ground motions are imposed on the bridge support points in terms of displacement and velocity. The train location at the time of earthquake is considered a uniformly distributed random variable. The running safety reliability of a train moving on a long-span bridge under earthquakes is determined by combining subset simulation (SS) with a prediction-based iterative solution method. Under different seismic components, train speeds, apparent seismic wave velocities and seismic intensities, the most unfavorable train location intervals are determined, which provides a reference for the safety performance assessment of trains traveling on bridges under earthquakes. Numerical results show that the influence of the lateral seismic component on the wheel derailment coefficient (WDC) is greater than the vertical seismic component, and the earthquake that occurs before the train’s arrival at 70% length of the bridge will significantly reduce its running safety.

Dynamic Response of Railway Vehicles Running on Long-Span Cable-Stayed Bridge Under Uniform Seismic Excitations

2016 ◽  
Vol 16 (05) ◽  
pp. 1550005 ◽  
Author(s):  
Yongle Li ◽  
Siyu Zhu ◽  
C. S. Cai ◽  
Cheng Yang ◽  
Shizhong Qiang
Keyword(s):  
Dynamic Response ◽  
Seismic Waves ◽  
Ground Motions ◽  
Spectral Characteristics ◽  
Seismic Action ◽  
Seismic Excitations ◽  
Railway Vehicles ◽  
Cable Stayed Bridge ◽  
Long Span ◽  
Bridge System

In order to evaluate the dynamic response of the train running on long-span cable-stayed bridges under uniform seismic excitations, a time-domain framework of analysis for the train–bridge system is established. The rail irregularities are treated as internal excitation and seismic loads as external excitation considering the inertia forces induced by the 3D seismic waves. The vehicles are modeled as mass-spring-damper systems, and the cable-stayed railway bridge is simulated by finite elements. A comprehensive analysis of the train–bridge system subjected to earthquake is conducted, focused on the effect of seismic ground motions on the dynamic response of the running train. Four kinds of seismic waves, each with three components, are simulated, with their spectral characteristics taken into account. To consider the stochastic characteristic of actual seismic waves, the effect of the incident angle and occurrence time of earthquakes on the bridge and vehicles is analyzed. Moreover, the earthquakes with various occurrence probability levels are also studied and the safety of the train running under the seismic action is evaluated, which may be used as the operation reference for the railway authority. The results demonstrate that the seismic ground motions have significant effects on the dynamic response of railway vehicles running on the long-span cable-stayed bridge under various spectrum characteristics, incident angles, occurrence times, and occurrence probabilities.

Effects of Frequency Content of Earthquake Ground Motions on Probabilistic Seismic Demand Assessment of Long-Span Bridge Structures

2011 ◽  
Vol 255-260 ◽  
pp. 982-987
Author(s):  
Liang Chen ◽  
Jin Song Zhang
Keyword(s):  
Ground Motions ◽  
Geometric Mean ◽  
Response Spectra ◽  
Seismic Demand ◽  
Frequency Content ◽  
Earthquake Ground Motions ◽  
Long Span ◽  
Long Span Bridge ◽  
Demand Assessment ◽  
Probabilistic Seismic Demand

Earthquake ground motions were reasonally selected for the nonlinear dynamic time-history analysis conducted for a two-tower long-span cable-stayed bridge. The correlation between frequency content of earthquake ground motions and probabilistic seismic demands reveals that the geometric mean and dispersion of response spectra from earthquake ground motions have significant effects on probabilistic seismic demand assessment of long-span bridge stuctures and these effects are related to the difference of the shape of geometric mean spectra in the important period ranges where cumulative modal mass participation is significant. Response spectra of selected earthquake ground motions should match well with target spectra in the important period ranges. If input ground motions are reasonally selected, analytic results can be obtained more precisely and effectively and more amplitude parameters can be selected as intensity measures.

Dynamic Response of Concrete Arch Bridge under Blast Loading

2014 ◽  
Vol 501-504 ◽  
pp. 1283-1286
Author(s):  
Xing Jun Qi ◽  
Qing Liu ◽  
Fang Jian Shang
Keyword(s):  
Dynamic Response ◽  
Impact Load ◽  
Blast Loading ◽  
Calculation Model ◽  
Repair Work ◽  
Arch Bridge ◽  
Long Span ◽  
Damage Degree ◽  
Long Span Bridge ◽  
Explosion Accidents

In order to reduce loss of terrorist attacks or accidental explosion accidents to traffic facilities of the state and society, antiknock safety of long-span bridge needs to be further studied. A deck arch bridge calculation model of fluid-structure interaction was established, and explicit dynamic analysis was presented to study the dynamic response of long-span arch bridge under blast loading, and the explosion effect to the overall structure of the bridge was analysed. The results show that the area around explosion center, has local large deformation and heavy damage degree, while a little far region has low deformation and damage degree; When explosives is located on the deck, the damage of blast-impact load on the main arch ring can be neglected, which is advantageous to the late bridge repair work. The results of this article can be provided as important theoretical reference to antiknock and explosion-proof of bridges in the future work.

scholarly journals Dynamic response of long-span bridges subjected to nonuniform excitation: a state-of-the-art review

2019 ◽  
Vol 258 ◽  
pp. 05017
Author(s):  
Seplika Yadi ◽  
Bambang Suhendro ◽  
Henricus Priyosulistyo ◽  
Akhmad Aminullah
Keyword(s):  
Dynamic Response ◽  
State Of The Art ◽  
Ground Motions ◽  
Experimental Studies ◽  
Suspension Bridges ◽  
Long Span Bridges ◽  
Long Span ◽  
Numerical Studies ◽  
Multiple Support ◽  
Support Excitation

In recent years, considerable attention has been paid to the research of dynamic response of long-span bridges with particular emphasis on seismic behavior. Cable-stayed and suspension bridges are the most popular types. Since long-span bridges have multi-supports and extreme lengths, due to the spatial variation effects, the ground motions at different supports might be non-uniform. A state-of-the-art update review of the response of long-span bridges subjected to non-uniform excitation is presented. The review mainly focuses on the theoretical aspects of non-uniform excitation, numerical studies, and experimental studies to verify some of the theoretical findings. In this paper, a review of the use of shake-table in experimental studies of long-span bridges is also presented. The non-uniform cases considered include a time delay with the same support excitations, multiple support excitations, and the combination of the first and the later. The results are discussed and summarized in comparison to the cases of uniform support excitation.

scholarly journals Analysis of the dynamic response of long span bridges with GNSS under typhoon loading

2021 ◽  
Vol 4 (3) ◽  
pp. Manuscript
Author(s):  
Hongbo Wang ◽  
Xiaolin Meng ◽  
Chaohe Chen
Keyword(s):  
Dynamic Response ◽  
Real Time ◽  
Deformation Monitoring ◽  
Bridge Management ◽  
Time Data ◽  
Engineering Structures ◽  
Long Span Bridges ◽  
Long Span ◽  
Long Span Bridge ◽  
Cross Correlation Analysis

Nowadays, real-time bridge deformation monitoring has attracted more attention due to the development of bridge management system and land transportation safety. Huge civil engineering structures, such as long-span bridge, is susceptible to dynamic deflection caused by various loadings. Hence, precise dynamic response measurement becomes necessary to make structure more reliable and integrated. Currently, Global Navigation Satellite System (GNSS) positioning technology has been commonly used in this field to detect the dynamic displacement of long-span bridges. According to this, real-time data were collected from the Forth Road Bridge to observe the dynamic response of lang span bridges under extreme wind load conditions and this report has also verified the data processing technique of the real-time bridge deformation monitoring system. Compared with other monitoring methods, the method used in this report which combines GNSS and anemometer together has features of high frequency with low lag. Moreover, it also shows the superiority of post-processing and synchronization, background noises could be reduced by embedded software. Finally, according to the cross-correlation analysis, it was found that wind speed and bridge displacement in y-axis have the highest correlation. Also, the reliability of combining method to monitor the dynamic response of long-span bridge and noise reducing method proposed in this report has also been verified.

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