Experiment Research and Numerical Simulation of an Innovative Seismic Isolating System Designed for Long-Span Continuous Girder Bridges

2011 ◽  
Vol 311-313 ◽  
pp. 2192-2199
Author(s):  
Cong Sun ◽  
Ri Gao

To enhance the earthquake resistance capacity of long-span continues bridge, theory and design of a new seismic isolating system are proposed based on the utilization of improved carbon structural steel material. Pseudo-static test result of the damping tenon, one essential energy dissipation component, proved the system’s excellent characteristic of consuming earthquake energy. Comparative experiments of three models reflect the working stability of the damping tenon confronted with different stimulation. Finite Element simulation further validates accuracy of the experiment and helps analyzing the material’s elastic and plastic developing status due to different load steps. Finally, this new seismic isolating system is recommended to long-span continues girder bridge designed on the basis of high level earthquake resistant standard.

2010 ◽  
Vol 163-167 ◽  
pp. 3551-3554
Author(s):  
Wei Peng ◽  
Zhi Xiang Zha

This template Based on cracks observation and finite element analysis of real engineering projects as well as bridge load test after reinforcement, causes and types of cracks in prestressed concrete box girder bridges and treating measurements are systematically studied. The results obtained from the calculation are presented to demonstrate the effect of sensitive factors, such as arrangement of longitudinal prestressed tendons, the magnitude of vertical prestressed force, temperature gradient, etc. The results show that the arrangement of longitudinal prestressed tendons and the magnitude of vertical prestressed force take key roles in cracks control of box girder webs. Lots of treating measurements are presented in accordance with different types of cracks, some of them are applied to a reinforcement engineering of a long span pretressed concrete continuous box girder bridge with cracks. Load test after reinforcement of the bridge demonstrates the reasonability of the treating measurements. Several design recommendations and construction measures about reinforcements and some sensitive factors mentioned above are proposed to control cracks.


Author(s):  
Yitong Gu ◽  
Wancheng Yuan ◽  
Xinzhi Dang

<p>In China, most of the support systems applied by short/medium span bridges are elastomeric pad bearings (EPBs). This type of support system has no reliable connections between bearings and girders as well as bearings and piers, which will cause structural damages due to large lateral displacement of bearings under earthquakes. The restrainers used currently could restrict the deformation of bridges under normal service conditions and could only restrict unidirectional displacement. Considering the disadvantages of these restrainers, a new restrainer called Connected Cable Restrainer (CCR), which can be used in short/medium span bridges supported by EPBs, is developed in this paper. The design principle, basic configuration, isolation mechanism and the design method of CCR are introduced. A pseudo static test to study the seismic performance of CCR is conducted. Seismic responses of a 3-span continuous girder bridge with CCR are simulated using OpenSees platform and parametric analyses of the two main parameters, lateral restraining displacement and restraining stiffness, are also carried out. Results show that the deformation of bridges under normal service conditions would not be restrained using CCR and the displacement responses can be mitigated effectively by using CCR through parameter optimization.</p>


2011 ◽  
Vol 255-260 ◽  
pp. 1290-1294 ◽  
Author(s):  
Yan Wei Niu

The analysis and mechanism of excessive long-term deflection of long-span prestressed concrete (PC) box girder bridges is concentrated recently. However, because of the lack of computing method, three dimensional (3D) analysis of PC continuous bridge especially including long-term shear lag effect is hard to analyze. According to this, a 3D creep analysis method for long-span PC bridges is illustrated in this paper first. The shear lag analysis of loads, prestress and their combination effect is carried out respectively. Based on this, the effect of shear lag to the long-term deflection of mid-span and whole-shape of the bridge is demonstrated. At the end, the different of computing between analysis with or without considering shear lag is discussed and some suggestion is proposed.


Author(s):  
Jianqing Bu ◽  
Jincan Cui

In order to analyze the impacts of pre-stress loss on the long-term deflection for long-span PC continuous girder bridges, this paper presents a numerical analysis using the finite element analysis software MIDAS/Civil based on a long-span PC continuous box-section girder bridge in Shijiazhuang. Once the 3-D finite element model was established, the influences of different pre-stress loss levels and locations were analyzed in a numerical simulation. Pre-stress loss is often the key reason for long-term deflection in long-span PC continuous girder bridges, so we can estimate the development of deflection by considering these factors during the operation.


2011 ◽  
Vol 268-270 ◽  
pp. 557-560
Author(s):  
Shi Ruo Yang

The train and the continuous truss girder bridge are coupled together as one composite system. Truss girder bridge is idealized as an assemblage of finite truss element. The equations of the train and truss girder bridges time varying system are set up by using the principle of total potential energy with stationary value in elastic system dynamics and the“set-in-right-position”rule for forming structural matrices. This method is more convenient than the finite elements. The vibration responses of the train and bridge are calculated when the the passenger trains pass through a continuous truss girder bridge at speeds of 90km/h and 120km/h The results show that the passenger train can pass it safely and comfortably


Author(s):  
Ryoga Oura ◽  
Takashi Yamaguchi ◽  
Kentaro Arimura

<p>Bridges are composed by many structural members which interact with each other to resist against various load combinations. Considering damage repair of one of its structural members, the relationship between the recovery of the individual load-carrying capacity due to the repair of a single member and the improvement of the load-carrying capacity of the structural system is not clear. In the present study, a full-scale FE analysis has been conducted for a steel I-girder bridge system with corrosion damages which have been repaired. The analysis considered, the structural system behavior, varying the repaired areas and the type of patch members. From the analytical results, it was found that, compared to the method in which the damaged portion is completely repaired, the amount of repair can be reduced by taking into account the structural system behavior and partially repair both the damaged and the adjacent intact girders.</p>


Author(s):  
Edward A. Baron

<p>This work consists in identify and assess the properties related to material, geometry and physic sources, in a pre-stressed concrete bridge through a surrogate model. The use of this mathematical model allows to generate a relationship between bridge properties and its dynamic response, with the purpose to develop a tool to predict the analytical values of the studied properties from measured eigenfrequencies. Therefore, it is introduced the identification of damage scenarios, giving the application for validate the generated metamodel (Artificial Neural Network). A FE model is developed to simulate the studied structure, a Colombian bridge called "El Tablazo", one of the higher in the country of this type (box-girder bridge). Once the damage scenarios are defined, this work allows to indicate the basis for futures plans of structural health monitoring.</p>


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