Effect of Pounding at Expansion Joints on Seismic Response of Long-Span Suspension Bridge under Strong Earthquakes

2010 ◽  
Vol 163-167 ◽  
pp. 4373-4377
Author(s):  
Yu Lin Deng ◽  
Xiong Jun He
Keyword(s):  
Time History ◽  
Suspension Bridge ◽  
Relative Displacement ◽  
Suspension Bridges ◽  
Seismic Responses ◽  
Expansion Joints ◽  
Strong Earthquakes ◽  
Seismic Displacement ◽  
Long Span ◽  
History Analysis

For a long-span suspension bridge, owing to a flexible structure system, the seismic displacement at the end of the deck may severely exceed the allowance under earthquake which due to the occurrence of the pound between the main span and the approach span usually which can causes the collision of falling-beams and structures. In this paper, based on the pounding phenomenon at expansion joints of long-span suspension bridge under strong earthquake and employing a typical long-span suspension bridges. With the time history analysis method of determining the nonlinear seismic responses, the pounding effects of adjacent girders at expansion joints on seismic responses of long-span cable-stayed bridge were studied. The results indicate that pounding can amplify the seismic demand of piers of the approach span and can also amplify the displacement of beam of the approach span, the relative displacement between main span and approach span and the hinge seat width of beam of approach span obviously and it causes easily the collision of falling-beams and structures under earthquakes.

Compositive Optimal Control for the Seismic Response of a Long-Span Triple-Tower Suspension Bridge

2018 ◽  
Vol 18 (08) ◽  
pp. 1840009 ◽  
Author(s):  
Hao Wang ◽  
Yifeng Wu ◽  
Ben Sha ◽  
Wenzhi Zheng ◽  
Yuqi Gao
Keyword(s):  
Optimal Control ◽  
Suspension Bridge ◽  
Suspension Bridges ◽  
Seismic Responses ◽  
Viscous Dampers ◽  
Analytic Hierarchy ◽  
Expansion Joints ◽  
Elastic Links ◽  
Long Span ◽  
Floating System

In the design of super-long-span suspension bridges, the floating system is commonly adopted. However, this system may lead to the excessive earthquake-excited longitudinal displacement (LD) at the end of the main girder, which in return could result in pounding damage at expansion joints. In this paper, Taizhou Bridge, the triple-tower suspension bridge with the longest main span in the world, is taken as an example to demonstrate the effectiveness of three different approaches (elastic links, viscous dampers, and their combination) of mitigating the possible excessive LD. The finite element code ABAQUS is used to build the numerical model of the bridge and calculate the dynamic characteristics as well as the seismic responses. Then, 24 cases with different parameters of elastic links and viscous dampers are investigated and it is observed that the mitigation effect of the 24 cases varies significantly with different parameters. To obtain the optimized mitigation effect for seismic responses, including the LD of the girder, the LD and shear force of all towers, in the 24 cases, the modified analytic hierarchy process (AHP) method is introduced to realize the compositive optimal control of the triple-tower suspension bridge. Results show that the 24th case is the optimal one in which the LD of the girder is reduced significantly while the inner force of towers does not get excessive increase.

Research on Optimization of Shock Absorption Design of the Self-Anchored Cable-Stayed Suspension Bridge

2011 ◽  
Vol 243-249 ◽  
pp. 1722-1726 ◽  
Author(s):  
Wei Zhi Zhu ◽  
Zheng Zheng Wang ◽  
Zhe Zhang ◽  
Hao Ran Chen
Keyword(s):  
Time History ◽  
Suspension Bridge ◽  
Relative Displacement ◽  
Seismic Effect ◽  
Suspension Bridges ◽  
Bridge Structure ◽  
Viscous Dampers ◽  
History Analysis ◽  
Non Linear ◽  
Dynamic Time

Combining the scientific research project- the study on cable-stayed suspension bridges, with the engineering background of Dalian Gulf Bridge to be built, this paper focuses on the seismic effect of non-linear viscous dampers on Self-anchored Cable-stayed Suspension Bridge. Based on the non-linear dynamic time-history analysis, the parameter sensitivity of damping coefficient and velocity exponent is analyzed. Through the analysis results, the proper dampers are decided. The seismic response result of before setting dampers is compared with that of after setting dampers. The results show that viscous dampers not only can greatly reduce the relative displacement and inner force under seismic effect of key positions of Self-anchored Cable-stayed Suspension Bridge, but can efficiently minimize the damage caused by earthquakes on bridge structure without changing static force behavior, which can provide evidence of seismic design for similar bridges.

Analysis of Linear Viscous Damper Parameters and Shock Absorption for Long-Span Cable-Stayed Bridge

2011 ◽  
Vol 243-249 ◽  
pp. 3858-3862
Author(s):  
Hong Yu Jia ◽  
Shi Xiong Zheng ◽  
Ming Qiang Xia ◽  
Lei Yang
Keyword(s):  
Vertical Direction ◽  
Time History ◽  
Longitudinal Direction ◽  
Relative Displacement ◽  
Sensitivity Study ◽  
Viscous Dampers ◽  
Long Span ◽  
Behavior Study ◽  
History Analysis ◽  
Dynamic Time

The seismic behavior study of Fengdu Bridge will be conducted on a parameter of damping coefficient C of linear viscous dampers through linear dynamic time-history analysis. Simultaneously, the results are compared with the seismic response without viscous dampers. The parameter sensitivity study indicates that setting damper in longitudinal direction of bridge can reduce the relative displacement of key positions and the response of the bridge, the beneficial effect of the isolation in the longitudinal direction, but important amplification occurs in the vertical direction for relatively high frequency components. Moreover, the reference of application of linear viscous dampers will be provided for similar projects.

Control of Vibrations due to Moving Loads on Suspension Bridges

2006 ◽  
Vol 11 (3) ◽  
pp. 293-318 ◽  
Author(s):  
M. Zribi ◽  
N. B. Almutairi ◽  
M. Abdel-Rohman
Keyword(s):  
Bridge Deck ◽  
Suspension Bridge ◽  
Lyapunov Theory ◽  
Dynamic Responses ◽  
Suspension Bridges ◽  
Control Force ◽  
Moving Loads ◽  
Hydraulic Actuator ◽  
Long Span ◽  
Suspended Cables

The flexibility and low damping of the long span suspended cables in suspension bridges makes them prone to vibrations due to wind and moving loads which affect the dynamic responses of the suspended cables and the bridge deck. This paper investigates the control of vibrations of a suspension bridge due to a vertical load moving on the bridge deck with a constant speed. A vertical cable between the bridge deck and the suspended cables is used to install a hydraulic actuator able to generate an active control force on the bridge deck. Two control schemes are proposed to generate the control force needed to reduce the vertical vibrations in the suspended cables and in the bridge deck. The proposed controllers, whose design is based on Lyapunov theory, guarantee the asymptotic stability of the system. The MATLAB software is used to simulate the performance of the controlled system. The simulation results indicate that the proposed controllers work well. In addition, the performance of the system with the proposed controllers is compared to the performance of the system controlled with a velocity feedback controller.

scholarly journals Probabilistic Assessment of the Safety of Main Cables for Long-Span Suspension Bridges considering Corrosion Effects

2021 ◽  
Vol 2021 ◽  
pp. 1-10
Author(s):  
Hao Tian ◽  
Jiji Wang ◽  
Sugong Cao ◽  
Yuanli Chen ◽  
Luwei Li
Keyword(s):  
Probability Model ◽  
Steel Wire ◽  
Suspension Bridge ◽  
Element Model ◽  
Traffic Load ◽  
Suspension Bridges ◽  
Accelerated Corrosion ◽  
Long Span ◽  
Accelerated Corrosion Tests ◽  
Main Cables

This paper presents a reliability analysis to assess the safety of corroded main cables of a long-span suspension bridge. A multiscale probability model was established for the resistance of the main cables considering the length effect and the Daniels effect. Corrosion effects were considered in the wire scale by relating the test results from accelerated corrosion tests to the corrosion stages and in the cable scale by adopting a corrosion stage distribution of the main cable section in NCHRP Report 534. The load effects of temperature, wind load, and traffic load were obtained by solving a finite element model with inputs from in-service monitoring data. The so-obtained reliability index of the main cables reduces significantly after operation for over 50 years and falls below the design target value due to corrosion effects on the mechanical properties of the steel wire. Multiple measures should be taken to delay the corrosion effects and ensure the safety of the main cables in the design service life.

Probabilistic Fatigue Damage Analysis of Long Span Suspension Bridge Due to Wind Induced Buffeting

2020 ◽  
Vol 980 ◽  
pp. 275-281
Author(s):  
Hu Jun
Keyword(s):  
Fatigue Life ◽  
Fatigue Damage ◽  
Time History ◽  
Suspension Bridge ◽  
Wind Load ◽  
Strong Wind ◽  
Fatigue Reliability ◽  
Long Span ◽  
Fatigue Damage Analysis ◽  
Fluctuating Wind

In order to consider the fluctuating wind load induced fatigue problem of long span suspension bridge, fatigue reliability formula is modified by assuming the fatigue life is accord with the weibull distribution. Based on the accurate bridge buffeting analysis of time history, the stress time history of components of a suspension bridge in east sea China is simulated, and then the fatigue damages and reliabilities are calculated. The results indicate that the main cables and hangers have enough fatigue reliability under the fluctuating wind load, the fatigue failure will not occur; the stiffening girder has larger fatigue damage, under 40 / (m.s-1) mean wind speed action, the girder of mid-support section’s average fatigue life is only 3.103 years, so the girder’s damage under strong wind action should be taken seriously.

scholarly journals A Master Digital Model for Suspension Bridges

2020 ◽  
Vol 10 (21) ◽  
pp. 7666
Author(s):  
Ngoc-Son Dang ◽  
Gi-Tae Rho ◽  
Chang-Su Shim
Keyword(s):  
Suspension Bridge ◽  
Geometrical Model ◽  
Information Modeling ◽  
Digital Model ◽  
Suspension Bridges ◽  
Actual Behavior ◽  
Data Generation ◽  
Element Analysis ◽  
Long Span ◽  
Bridge System

Long-span suspension bridges require accumulated design and construction technologies owing to challenging environmental conditions and complex engineering practices. Building information modeling (BIM) is a technique used to federate essential data on engineering knowledge regarding cable-supported bridges. In this study, a BIM-based master digital model that uses a data-driven design for multiple purposes is proposed. Information requirements and common data environments are defined considering international BIM standards. A digital inventory for a suspension bridge is created using individual algorithm-based models, and an alignment-based algorithm is used to systematize them and generate the entire bridge system. After assembling the geometrical model, metadata and various BIM applications are linked to create the federated master model, from which the mechanical model is derived for further stages. During the construction stage, the advantage of this digital model lies in its capability to perform efficient revisions and updates with respect to varying situations during the erection process. Stability analyses of the bridge system can be performed continuously at each erection step while considering the geometric control simulation. Furthermore, finite element analysis models for any individual structural member can be extracted from the master digital model, which is aimed at estimating the actual behavior of bridge members. In addition, a pilot master digital model was generated and applied to an existing suspension bridge; this model exhibited significant potential in terms of bridge data generation and manipulation.

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