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.

Seismic Response Analysis of Long Span Cable-Stayed Bridge under Non-Uniform Excitation

2012 ◽  
Vol 246-247 ◽  
pp. 131-135
Author(s):  
Bao Fu Wang ◽  
Zhong Ren Feng ◽  
Xiong Jiang Wang ◽  
Bai Ben Chen
Keyword(s):  
Dynamic Analysis ◽  
Ground Motion ◽  
Ground Motions ◽  
Time History ◽  
Large Mass ◽  
Response Analysis ◽  
Cable Stayed Bridge ◽  
Long Span ◽  
History Analysis ◽  
Large Mass Method

In this paper, non-uniform dynamic analysis of a cable-stayed bridge is carried out using the large mass method. The Ed Yangtze River highway bridge, constructed in Hubei province, is chosen as a numerical example. In the non-uniform dynamic analysis, various wave velocities are used for the travelling ground motion. Displacements and internal forces solutions obtained for the spatially varying ground motions are compared with those of the uniform excitation. It is observed that the velocity of the ground motion greatly influences the response of the bridge and the variability of the ground motions should be included in the time-history analysis of cable-stayed bridges.

Dynamic response limit of high-speed railway bridge under earthquake considering running safety performance of train

2021 ◽  
Vol 28 (3) ◽  
pp. 968-980
Author(s):  
Xiang Liu ◽  
Li-zhong Jiang ◽  
Ping Xiang ◽  
Zhi-peng Lai ◽  
Yu-lin Feng ◽  
...  
Keyword(s):  
Dynamic Response ◽  
High Speed ◽  
Safety Performance ◽  
Railway Bridge ◽  
High Speed Railway ◽  
Running Safety

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.

Dynamic Time-History Deformation Response Analysis of Long-Span Beam Bridge Subjected to Flowing Ice

2010 ◽  
Vol 163-167 ◽  
pp. 2830-2834
Author(s):  
Zhi Ping Bai ◽  
Xie Dong Zhang ◽  
Cheng Lin Han
Keyword(s):  
Yellow River ◽  
Time History ◽  
Response Analysis ◽  
Soil Function ◽  
Action Mode ◽  
Deformation Response ◽  
Long Span ◽  
Long Span Bridge ◽  
Dynamic Time ◽  
Beam Bridge

Based on the pile-soil function and damper boundary condition influence by Finite Element Method, taking Bao-Shu yellow river extra long-span bridge as the project object, the deformation effect of the bridge subjected to flowing and melting ice in spring was analyzed considering dynamical action mode. The results revealed that the deformation from this kind of action is tittly small and the bridge structure is reliable and stable. Then the calculation and analysis have been put into design and construction stage.

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.

Study on Mechanical Properties and Field Monitoring of Ballastless CWR on the Bridge in High-Speed Railway

2013 ◽  
Vol 361-363 ◽  
pp. 1449-1454
Author(s):  
Bo Jing Chen ◽  
Xiao Pei Cai ◽  
Xiao Bo Shi
Keyword(s):  
High Speed ◽  
Design Parameters ◽  
Fiber Grating ◽  
High Speed Railway ◽  
Finite Element Software ◽  
Long Span ◽  
Long Span Bridge ◽  
Deformation Law ◽  
Testing Technology ◽  
Beam Track

In the design of long-span bridge , it is necessary to lay the expansion regulator in order to reduce the beam-track interaction. Take the Zhengzhou-Xi’an high-speed railway as an example, the paper created a CWR mechanical model on the bridge using the finite element software ANSYS, proposed the deformation law of the structure and its stress characteristics. Based on the fiber grating testing technology, many monitoring points were laid on the Weihe bridge, to make a long-term monitoring. Processed the monitoring data about rail temperature and temperature force of the regulator, the CWR service conditions were assessed. The study shows that the scheme laying a set of regulator on the longest span Weihe bridge has greatly decreased the beam-rail interaction. All of its design parameters are reasonable. The operation safety indexes can completely meet the need of limits.

Response Spectrum Characteristics of Near-Fault Ground Motions and Influence to CFST Arch Bridge

2013 ◽  
Vol 671-674 ◽  
pp. 1367-1371
Author(s):  
Fan Xing ◽  
Rui Kang
Keyword(s):  
Response Spectrum ◽  
Ground Motions ◽  
Time History ◽  
Arch Bridge ◽  
Response Characteristics ◽  
Near Fault ◽  
Long Span ◽  
History Analysis ◽  
Cfst Arch Bridge ◽  
The Common

Near-fault ground motions are more complex than the common far field, and it can significantly change the response characteristics of the structure. The records of Taiwan chi-chi earthquake associating with velocity pulse are selected, and the seismic accelerate response spectrum of different site are studied in deep. On the basis of time-history analysis, the seismic responses of a long-span CFST (concrete-filled steel tubular) arch bridge are discussed. Weakness section of the CFST arch rib are also indicated, providing a valuable reference for aseismic design.

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