scholarly journals The Application of the Grey Neural Network in the Deflection Control of PC Rigid Frame Continuous Box Girder Bridges

2014 ◽  
Vol 8 (1) ◽  
pp. 416-419
Author(s):  
Lifeng Wang ◽  
Hongwei Jiang ◽  
Dongpo He
Keyword(s):  
Neural Network ◽  
Prestressed Concrete ◽  
Control Process ◽  
Construction Control ◽  
Box Girder Bridges ◽  
Girder Bridges ◽  
Rigid Frame ◽  
Continuous Girder Bridge ◽  
Girder Bridge ◽  
Cantilever Construction

Deflection control is the crucial procedure in construction control of cantilever prestressed concrete continuous girder bridge. This paper summarizes the advantages of Grey theory’s poor information processing and abilities of Neural Network’s self-learning and adaption, and the combinational algorithm of grey Neural Network is applied to the prestressed concrete bridge cantilever construction control process. Firstly, GM (1, 1) model and BP artificial Neural Network algorithm to predict the elevation of construction process are introduced respectively. In addition, the elevation prediction model of rigid-framed-continuous girder bridge is established. By practicing in the construction control project of LongHua Bridge, the method is testified to be feasible. The results indicate that, the combinational algorithm of Gray Neural Network to predict the construction elevation has higher reliability and accuracy which can be an effective tool of construction control for the same type bridges.

Influence of Tensioning Stress to Web Cracking of Rigid Frame Bridge in Cantilever Construction

2014 ◽  
Vol 919-921 ◽  
pp. 560-563
Author(s):  
Dong Jia Yin ◽  
Xiong Jun He ◽  
De Quan You ◽  
Bing Kai Liu
Keyword(s):  
Prestressed Concrete ◽  
Main Mode ◽  
Box Girder Bridges ◽  
Box Girder ◽  
Girder Bridges ◽  
Rigid Frame ◽  
Under Construction ◽  
Cantilever Construction ◽  
Rigid Frame Bridge

Cantilever construction is main mode for prestressed concrete continuous rigid frame box-girder bridges, but the diagonal cracks on web are often appeared in construction. The prestressed tension is an important part of the construction beyond doubt. This article takes a bridge under construction as the background to analyze the variation of stressed in the process of construction by MIDAS FEA. The result shows that the vertical steel stretch-drawn in advance has to be a consensus in future.

Study on Crack Causes and Strengthening Measures of Large Span PC Continuous Box Girder Bridges

2010 ◽  
Vol 163-167 ◽  
pp. 3551-3554
Author(s):  
Wei Peng ◽  
Zhi Xiang Zha
Keyword(s):  
Prestressed Concrete ◽  
Load Test ◽  
Box Girder Bridges ◽  
Element Analysis ◽  
Box Girder ◽  
Girder Bridges ◽  
Long Span ◽  
Concrete Box Girder Bridges ◽  
Girder Bridge ◽  
Engineering Projects

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.

Assessment and identification of concrete box-girder bridges

2019 ◽  
Author(s):  
Edward A. Baron
Keyword(s):  
Neural Network ◽  
Health Monitoring ◽  
Concrete Bridge ◽  
Fe Model ◽  
Box Girder Bridges ◽  
Box Girder ◽  
Damage Scenarios ◽  
Girder Bridges ◽  
Concrete Box Girder Bridges ◽  
Girder Bridge

<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>

Optimization on Closure Scheme of Multi-Span Prestressed Concrete Box-Girder Bridge

2010 ◽  
Vol 163-167 ◽  
pp. 2369-2375 ◽  
Author(s):  
Ming Yuan ◽  
Dong Huang Yan
Keyword(s):  
Stress State ◽  
Prestressed Concrete ◽  
Box Girder ◽  
Rigid Frame ◽  
Closure Scheme ◽  
Concrete Box Girder ◽  
Box Girder Bridge ◽  
Girder Bridge ◽  
Cantilever Construction ◽  
Rigid Frame Bridge

The stress state of finished bridge and service stage is influenced by various closure schemes in cantilever construction of multi-span prestressed concrete box-girder bridge. Two typical bridges—multi-span prestressed concrete continuous rigid frame bridge and girder bridge are investigated, The stress state in different closure schemes are analyzed using finite element(FE) analysis. Meanwhile, compared the healthy monitoring data, it has been found that taking the closure sequence from side span to middle span in cantilever construction of multi-span prestressed concrete box-girder bridge can lower stress of girder and pier in finished bridge stage, as well as reducing deformation of girder in service stage. Hence, the closure sequence from side span to middle span is more suitable for cantilever construction of multi-span prestressed concrete box-girder bridge.

Installation Technology of Webs in the Construction of PC Box-Girder Bridge with Corrugated Steel Webs

2012 ◽  
Vol 204-208 ◽  
pp. 2209-2213 ◽  
Author(s):  
Ya Jiang Du ◽  
Bing Wen Yang ◽  
Shui Wan
Keyword(s):  
Prestressed Concrete ◽  
Box Girder Bridges ◽  
Box Girder ◽  
Girder Bridges ◽  
Section Shape ◽  
Out Of Plane ◽  
Box Girder Bridge ◽  
Corrugated Steel Web ◽  
Girder Bridge ◽  
Installation Technology

In the construction of prestressed concrete(PC) box-girder bridge with corrugated steel webs used cast-in-place cantilever method, the key component-corrugated steel webs are fabricated in factory first and then transported to the construction site. Because of the low out-of plane stiffness, corrugated steel webs are easy to deform in the construction, which brings many difficulties for construction. The precision of installing the corrugated steel web has a direct effect on the cross-section shape of the box-girder. So it is a key step to monitor the orientation and installation of corrugated steel web during construction. Based on the experience of some PC box-girder bridges with corrugated steel webs having been built, a method to control the installation accuracy of corrugated steel webs is proposed and some quality assurance measures are introduced in order to ensure the accuracy, reliability and security of the installation of corrugated steel web. The method can be taken as a reference in the construction of this kind of bridge.

Study on Vehicle-Bridge Coupling Vibration of Equal Span Girder Bridge of Different Span Number

2013 ◽  
Vol 540 ◽  
pp. 63-68
Author(s):  
Wei Zhao Li ◽  
Zong Lin Wang ◽  
Hang Sun ◽  
Yan Li
Keyword(s):  
Surface Roughness ◽  
Influencing Factor ◽  
Dynamic Responses ◽  
Box Girder Bridges ◽  
Coupling Vibration ◽  
Average Value ◽  
Girder Bridges ◽  
Continuous Girder Bridge ◽  
Girder Bridge ◽  
Traveling Speed

The vehicle-bridge coupling vibration of girder bridge has been widely investigated. But most of previous work focused on the influencing factor of the vibration, such as traveling speed of vehicle, deck surface roughness and vehicle-bridge frequency ratio etc. Taking the box girder bridges of different span number with 20m single span length for example, applying the separated iterative method to multi-sample analysis the vehicle-bridge coupling vibration. The study considered the influence of the vehicle, traveling speed and the random deck surface roughness and then took the average value of the sample to discuss the influence of the span number on the dynamic responses. Results show that the continuous girder form can effectively decrease the dynamic responses of the equal span girder bridge than the simple-supported form. But the influence of the span number on the responses of equal span continuous girder bridge is not obvious.

Long Span Prestressed Concrete Continuous Rigid-Frame Bridge ANN Construction Control

2012 ◽  
Vol 204-208 ◽  
pp. 2261-2264
Author(s):  
Geng Feng Ren ◽  
Cun Jun Zou ◽  
Yue Xu
Keyword(s):  
Neural Network ◽  
Artificial Neural Network ◽  
Prestressed Concrete ◽  
Construction Control ◽  
Bridge Construction ◽  
Long Span ◽  
Continuous Rigid Frame Bridge ◽  
Rigid Frame ◽  
Artificial Neural ◽  
Rigid Frame Bridge

Based on the theory of ANN (Artificial Neural Network),The paper raised the method of construction control, and introduced the common forecasting method. According to the characteristic of ANN itself and the complexity of factors which influence the elevation, the paper analysed the influence aspects of ANN. On the promise of bridge construction precision, the paper raised section measure、elasticity model、temperature、delay of construction and cantilever for neural network’s input vector in bridge construction process. With the help of Graphical User Interface, built ANN, made the forecast function in the bridge construction into reality. Introduce the theory of Artificial Neural Network(ANN) into long span prestressed concrete continuous rigid-frame bridge construction control.

scholarly journals Load Distribution In Adjacent Precast "Deck Free" Concrete Box-Girder Bridges

2021 ◽  
Author(s):  
Waqar Khan
Keyword(s):  
Prestressed Concrete ◽  
Precast Concrete ◽  
Box Girders ◽  
Box Girder Bridges ◽  
Box Girder ◽  
Girder Bridges ◽  
Concrete Box Girder ◽  
Concrete Box Girder Bridges ◽  
Girder Bridge ◽  
The Moment

Bridges built with adjacent precast, prestressed concrete box-girders are a popular and economical solution for short-span bridges because they can be constructed rapidly. The top flanges of the precast box girders form the bridge deck surface. A shear key is introduced between the adjacent boxes over the depth of the top flange (i.e. 225 mm thick as the thickness of the box's top flange). Canadian Highway Bridge Design Code, CHBDC specifies empirical equations for the moment and shear distribution factors for selected bridge configurations but not for adjacent precast concrete box-girder bridge type. In this study, a parametric study was conducted, using the 3D finite-element modeling, and a set of simplified equations for the moment, shear and deflection distribution factors for the studied bridge configuration was developed.

Influence of Cracks Parameters on Bearing Capacity for Prestressed Concrete Box Girder

2012 ◽  
Vol 166-169 ◽  
pp. 1963-1966
Author(s):  
Zhao Ning Zhang
Keyword(s):  
Bearing Capacity ◽  
Prestressed Concrete ◽  
Operations Management ◽  
Box Girder Bridges ◽  
Box Girder ◽  
Girder Bridges ◽  
Long Span ◽  
Continuous Rigid Frame Bridge ◽  
Rigid Frame ◽  
Rigid Frame Bridge

For long-span pre-stressed concrete continuous box girder bridges, cracks and other damage problem are often found because of influence of loads, climate, operations management and other factors during operation. The problem of cracking is serious increasingly, which has a direct impact on usability, durability and security. In order to analyze the bearing capacity of the bridge with cracks under different parameters, such as cracks width, cracks height and cracks spacing and provide the basis for the safety assessment and reinforcement, the paper puts forward the cracking reduction coefficient that evaluates the bearing capacity of the damaged bridge based on the tensile stress control. A three-span continuous rigid frame bridge is analyzed and the result shows that the bearing capacity of the bridge is in inverse proportion to cracks width and cracks height. The bearing capacity of the bridge is in direct proportion to cracks spacing.

Analysis of the Causes of the Formation of Crack in Inclined Web of Prestressed Concrete Continuous Girder Bridge in Cantilever Construction

2012 ◽  
Vol 256-259 ◽  
pp. 1614-1617
Author(s):  
Li Hua Lu ◽  
Peng Tian ◽  
Tao Yu
Keyword(s):  
Prestressed Concrete ◽  
Paper Analysis ◽  
Additional Stress ◽  
Different Temperatures ◽  
Continuous Girder Bridge ◽  
Girder Bridge ◽  
Cantilever Construction ◽  
The Way

The crack in inclined web of the prestressed concrete continuous girder bridge which is constracted by the way of cast-in-place cantilever method that become one problem that should be more cared about[1-2]. This paper analysis the bridge in three different conditions which are according to the pratical and special engineering to find the causes of the formation of crack in inclined web of prestressed concrete continuous girder bridge in cantilever construction. The results of the analysis show that the additional stress caused by the different temperatures between internal and external components leads to the formation of the crack in inclined web of the bridge.

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