scholarly journals Automatic Management and Monitoring of Bridge Lifting: A Method of Changing Engineering in Real-Time

Sensors ◽  
2019 ◽  
Vol 19 (23) ◽  
pp. 5293
Author(s):  
Fang ◽  
Chou ◽  
Hoang ◽  
Lee
Keyword(s):  
Global Climate ◽  
Computer Software ◽  
Element Model ◽  
Earthquake Resistance ◽  
Bridge Foundations ◽  
Construction Period ◽  
Bridge Model ◽  
Temporary Support ◽  
Lower Structure ◽  
Bridge Foundation

In recent years, owing to the increase of extreme climate events due to global climate change, the foundational erosion of old bridges has become increasingly serious. When typhoons have approached, bridge foundations have been broken due to the insufficient bearing capacity of the bridge column. The bridge bottoming method involves rebuilding the lower structure while keeping the bridge surface open, and transferring the load of the bridge temporarily to the temporary support frame to remove the bridge base or damaged part with insufficient strength. This is followed by replacing the removed bridge base with a new bridge foundation that meets the requirements of flood and earthquake resistance. Meanwhile, monitoring plans should be coordinated during construction using the bottoming method to ensure the safety of the bridge. In the case of this study, the No. 3 line Wuxi Bridge had a maximum bridge age of 40 years, where the maximum exposed length of the foundation was up to 7.5 m, resulting in insufficient flood and earthquake resistance. Consequently, a reconstruction plan was carried out on this bridge. This study took the reconstruction of Wuxi Bridge as the object and established a finite element model using the SAP 2000 computer software based on the secondary reconstruction design of the Wuxi Bridge. The domestic bridge design specification was used as the basis for the static and dynamic analyses of the Wuxi Bridge model. As a result of the analysis, the management value of the monitoring instrument during construction was determined. The calculated management values were compared with the monitoring data during the construction period to determine the rationality of the management values and to explore changes in the behavior of the old bridges and temporary support bridges.

Investigation on three-directional dynamic interaction between a heavy-duty vehicle and a curved bridge

2017 ◽  
Vol 21 (5) ◽  
pp. 721-738 ◽  
Author(s):  
Shaohua Li ◽  
Jianying Ren
Keyword(s):  
Interaction Model ◽  
Element Model ◽  
Driver Model ◽  
Impact Factors ◽  
Lateral Impact ◽  
Heavy Duty ◽  
Vehicle Model ◽  
Curved Bridge ◽  
Bridge Model ◽  
The Impact

Considering the nonlinear property of suspension damping and tire stiffness, a full-vehicle model is built for a heavy-duty truck. A modified preview driver model with nonlinear time delay is inserted into the vehicle model to compute the suitable steering angle of the front wheel and to make the vehicle follow the required route. Next, the finite element model of a five-span continuous curved highway bridge is established, and the bridge’s inherent frequencies and modes are obtained. The curved bridge and the vehicle are coupled by three-directional tire forces, and a three-directional driver–vehicle–bridge interaction model is presented. The presented vehicle model and bridge model are verified by comparing with the published works. The dynamic impact factors of vertical, lateral, and torsional displacements of the bridge are calculated when a vehicle is traversing through the bridge, and the impact factors’ distributions along the bridge are analyzed. The effects of vehicle driving conditions on impact factors are also researched. It is found that the impact factor calculated from the present specification for a straight bridge is smaller than that from the three-directional driver–vehicle–bridge interaction model, and the vertical and torsional impact effects at the third span midpoint are greater than the lateral impact effect.

Numerical Simulation of Pile Foundations of Qinghai-Tibet Power Transmission Line: Influence of Temperature Region

2014 ◽  
Vol 501-504 ◽  
pp. 218-223 ◽  
Author(s):  
Lin Chen ◽  
Wen Bing Yu ◽  
Wei Bo Liu ◽  
Xin Yi
Keyword(s):  
Climate Warming ◽  
Pile Foundation ◽  
Power Transmission ◽  
Global Climate ◽  
Element Model ◽  
Pile Foundations ◽  
Thermal Fields ◽  
Global Climate Warming ◽  
Thaw Depth ◽  
Permafrost Regions

To analyze the thermal effect of the pile foundation of permafrost, a two-dimensional transient finite element model of the thermal fields with phase change were established. The developments of heat influence limit and maximum thawed depth with and without climate warming were predicted and analyzed. Results indicate that (1) the heat influence limit and maximum thaw depth in permafrost regions enlarge with time elapse, while the global climate warming will have a greater influence to full-space pile foundation compared with the cone-cylinder pile foundation; (2) Considering the global climate warming, heat influence limit (Lmax) and maximum thaw depth (Hmax) in 50th year for full-space pile foundation, cone-cylinder pile foundation are 10.1m, 5.2m, 4.1m, 3.7m, respectively; the maximum thaw depth of full-space pile foundation during the operation will have exceeded the depth of structure (2.5m), which might put the structure at risk; (3) the structure of cone-cylinder pile foundation could effectively preserve permafrost and avoid pile foundations failure; (4) the spacing of cone-cylinder pile foundations is reasonable and the interaction of temperature distribution among cone-cylinder pile foundations can be negligible.

Modal Analysis of a Simple Supported Beam Steel Bridge Based on ANSYS

2012 ◽  
Vol 594-597 ◽  
pp. 2867-2870
Author(s):  
Dong Li Wang ◽  
Tong Li ◽  
Chun Yu Wang
Keyword(s):  
Modal Analysis ◽  
Health Monitoring ◽  
Element Model ◽  
Rate Of Change ◽  
Mode Shapes ◽  
Steel Bridge ◽  
Bridge Health Monitoring ◽  
Bridge Model ◽  
Set Up ◽  
Index Value

The purpose and significance of bridge health monitoring is described in this paper. In order to study bridge health monitoring, Firstly, a finite element model for simply supported steel beam is set up on the basis of the Infinite Element Theory and the software ANSYS in response to laboratory experient. Through adding instantaneous excitation to the mid-span, do modal analysis for different injury of steel bridge model to reveal the natural frequency and mode shapes of the different injury of steel bridges, identify the different injury by comparing the index value and the rate of change.

Development of a Seismic-Performance Assessment Method and Retrofitting Technology Against the Liquefaction of Existing Bridges

2019 ◽  
Vol 14 (2) ◽  
pp. 269-278 ◽  
Author(s):  
Michio Ohsumi ◽  
◽  
Toshiaki Nanazawa ◽  
Shunsuke Tanimoto ◽  
Mitsuhiko Nakata
Keyword(s):  
Performance Assessment ◽  
Seismic Performance ◽  
Assessment Method ◽  
Shaking Table ◽  
Seismic Performance Assessment ◽  
Bridge Foundations ◽  
The Past ◽  
Existing Bridges ◽  
Bridge Foundation

In the past, earthquakes have caused critical damage to bridges built on liquefiable ground, resulting in their collapse or long-term closures. In particular, for existing bridges designed in an age when the liquefaction influence was not considered, appropriate measures should be taken as necessary. However, there are many existing stocks of bridges, which require expensive foundation reinforcement. Therefore, it is crucial to appropriately choose bridge foundations for which anti-seismic measures are a high priority and implement the measures efficiently and successively. The present study aims to develop a seismic-performance assessment method and retrofitting technology for coping with liquefiable ground. For this purpose, a large shaking-table experiment was conducted to determine the effects of the liquefiable ground on bridge-foundation behavior and verify the effect of the retrofitting technology. Based on disaster-case analyses and the results of the shaking-table experiment, a seismic-performance assessment method applicable to practical designing was proposed.

scholarly journals Alternative Load Path Analysis for Assessing the Geometric Agreement of a Cable-Stayed Bridge with Steel Truss Girders

2021 ◽  
Vol 2021 ◽  
pp. 1-13
Author(s):  
Xiaobo Zheng ◽  
Gang Zhang ◽  
Yongfei Zhang ◽  
Leping Ren
Keyword(s):  
Computer Software ◽  
Element Model ◽  
Load Path ◽  
Brittle Damage ◽  
Cable Stayed Bridge ◽  
Load Paths ◽  
Vehicle Loading ◽  
Bridge Collapse ◽  
Steel Truss ◽  
Collapse Behavior

The geometric agreement, commonly hailed as load-transferring paths withinbridge structures, is significantly crucial to the bridge structural mechanicalperformance, such as capacity, deformation, and collapse behavior. This paperpresents a methodology dependent on alternative load paths to investigate thecollapse behavior of a double-pylon cable-stayed bridge with steel truss girderssubjected to excess vehicle loading. The cable-stayed bridge with steel trussgirders is simplified using a series-parallel load-bearing system. This researchmanifests that the enforced vehicle loading can be transferred to alternativepaths of cable-stayed bridges in different load-structure scenarios. A 3-Dfinite element model is established utilizing computer software ANSYS to explorethe collapse path of cable-stayed bridge with steel truss girders, taking intoaccount chord failure, loss of cables together with corrosion in steel trussgirders. The results show that chord failures in the mid-portion of the mainspan result in brittle damage in truss girders or even sudden bridge collapse. Further,the loss of long cables leads to ductile damage with significant displacement.The corrosion in steel truss girders has a highly slight influence on the collapsebehavior of cable-stayed bridge. The proposed methodology can be reliably usedto assess and determine the vulnerability of cable-stayed bridge with steeltruss girders during their service lifetime, thus preventing structural collapsesin this type of bridge.

A Meta-Modeling Procedure for Updating the Finite Element Model of an Arch Bridge Model

2013 ◽  
Vol 540 ◽  
pp. 79-86
Author(s):  
De Jun Wang ◽  
Yang Liu
Keyword(s):  
Finite Element ◽  
Finite Element Model ◽  
Dynamic Analysis ◽  
Large Scale ◽  
Model Updating ◽  
Element Model ◽  
Fe Model ◽  
Large Scale Structures ◽  
Bridge Model ◽  
Scale Structures

Finite element (FE) model updating of structures using vibration test data has received considerable attentions in recent years due to its crucial role in fields ranging from establishing a reality-consistent structural model for dynamic analysis and control, to providing baseline model for damage identification in structural health monitoring. Model updating is to correct the analytical finite element model using test data to produce a refined one that better predict the dynamic behavior of structure. However, for real complex structures, conventional updating methods is difficult to be utilized to update the FE model of structures due to the heavy computational burden for the dynamic analysis. Meta-model is an effective surrogate model for dynamic analysis of large-scale structures. An updating method based on the combination between meta-model and component mode synthesis (CMS) is proposed to improve the efficiency of model updating of large-scale structures. The effectiveness of the proposed method is then validated by updating a scaled suspender arch bridge model using the simulated data.

Optimal structure control for earthquake resistance

2021 ◽  
pp. 1-7
Author(s):  
Xianyang Yang ◽  
James D. Lee
Keyword(s):  
Optimal Control ◽  
Structural Control ◽  
Algorithm Design ◽  
Computer Software ◽  
Earthquake Resistance ◽  
Control Law ◽  
State Variables ◽  
Optimal Control Strategy ◽  
Earthquake Excitation ◽  
History Of

This work developed the optimal and active control algorithms applicable to structural control for earthquake resistance. [Lewis, F. L., Vrabie, D. and Syrmos, V. L. [2012] Optimal Control (John Wiley & Sons)] developed a rigorous and comprehensive procedure for the derivation of an optimal control strategy based on the calculus of variation. This work is an application of Lewis’ formulation to the control of a structure for earthquake resistance. We developed a computer software which can be used to generate a dynamic model to simulate a planar structure and to construct the control law. This model also includes the tendon driven actuators, sensors and true history of earthquake excitation. The control law has two parts: (I) the feedback control which depends on the estimate state variables (Kalman filter) and (II) the record of the realistic earthquake excitation. The optimal control problem eventually leads to a two-point boundary value problem whose solution hinges on the knowledge of the entire history of the earthquake excitation. We employ true records of earthquake excitation as input. This approach enables one to solve the Riccati equations rigorously. Then, from the simulation results, one may study the relations between the control algorithm design and the characteristics (frequency, amplitude and duration) of earthquake excitation.

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