A prediction method for cable forces of cable-stayed bridges using fuzzy processing and Bayes estimation

2021 ◽  
Author(s):  
Li Dong ◽  
Bin Xie ◽  
Dongli Sun ◽  
Yizhuo Zhang
Keyword(s):  
Prediction Method ◽  
Practical Method ◽  
Bayes Estimation ◽  
Primary Data ◽  
Force Estimation ◽  
Element Analysis ◽  
Cable Stayed Bridge ◽  
Input Parameters ◽  
Cable Forces ◽  
Cable Stayed Bridges

<p>Cable forces are primary factors influencing the design of a cable-stayed bridge. A fast and practical method for cable force estimation is proposed in this paper. For this purpose, five input parameters representing the main characteristics of a cable-stayed bridge and two output parameters representing the cable forces in two key construction stages are defined. Twenty different representative cable-stayed bridges are selected for further prediction. The cable forces are carefully optimized through finite element analysis. Then, discrete and fuzzy processing is applied in data processing to improve their reliability and practicality. Finally, based on the input parameters of a target bridge, the maximum possible output parameters are calculated by Bayes estimation based on the processed data. The calculation results show that the average prediction error of this method is less than 1% for the twenty bridges themselves, which provide the primary data and less than 3% for an under-construction bridge.</p>

scholarly journals Accounting for the effect of creep and shrinkage on the stress state of concrete structures of cable-stayed bridges in Myanmar

2020 ◽  
Vol 7 (2) ◽  
Author(s):  
Sherali Valiev ◽  
Maung Maung Win Aung ◽  
Ivan Shatilov
Keyword(s):  
Concrete Structures ◽  
Reinforced Concrete Beam ◽  
Element Analysis ◽  
Box Girder ◽  
Cable Stayed Bridge ◽  
Shrinkage And Creep ◽  
Cable Forces ◽  
Creep And Shrinkage ◽  
Cable Stayed Bridges

The article considers the finite element analysis of the influence of time-dependent processes (creep and shrinkage) of concrete on the structures of a concrete cable-stayed bridge according to Russian, European and American standards. For numerical calculation, the Midas/Civil software was used, which allowed us to take into account elastic short-term deformation and creep deformation, as well as changes in the strength of concrete over time. Long-term deformations in concrete elements could be 1.5~3.0 times higher than elastic deformations and were observed in the first few months, and most of them occurred within five years. The object of research was a cable-stayed bridge with a reinforced concrete beam with a box girder. Three calculation models were used to model concrete shrinkage and creep: according to Russian, European and American standards. The results of the study showed significant discrepancies between foreign and Russian standards for accounting for long-term processes in concrete structures of cable-stayed bridges. Creep and shrinkage processes led to increased displacements in the box girder and pylon. Moreover, with an increase in the humidity of the environment, the deflection of the girder decreased, and the displacement of the pylon slightly increased. The cable-forced was reduced by the shrinkage and creep of the concrete. It was found that the loss of cable forces decreased with increasing humidity of the environment.

scholarly journals Static Experiment and Finite Element Analysis of a Multitower Cable-Stayed Bridge with a New Stiffening System

2019 ◽  
Vol 2019 ◽  
pp. 1-8 ◽  
Author(s):  
Xiaowei Wang ◽  
Yingmin Li ◽  
Weiju Song ◽  
Jun Xu
Keyword(s):  
Finite Element Analysis ◽  
Finite Element ◽  
Internal Force ◽  
Element Analysis ◽  
Cable Stayed Bridge ◽  
Practical Engineering ◽  
Static Experiment ◽  
Stiffening Effect ◽  
Better Than ◽  
Cable Stayed Bridges

Based on the stiffness limitations of the midtower in multitower cable-stayed bridges, a new stiffening system (tie-down cables) is proposed in this paper. The sag effects and wind-induced responses can be reduced with the proposed system because tie-down cables are short and aesthetic compared with traditional stiffening cables. The results show that the stiffening effect of tie-down cables is better than that of traditional stiffening cables in controlling the displacement and internal force of the bridge based on a static experiment and finite element analysis. Therefore, the proposed system can greatly improve the overall stiffness of a bridge, and its stiffening effect is better than that of traditional stiffening cables in controlling the displacement and internal force. The results provide a reference for the application of such systems in practical engineering.

Monitored structural behavior of a long span cable-stayed bridge under environmental effects

2018 ◽  
Vol 4 (4) ◽  
pp. 137 ◽  
Author(s):  
Alemdar Bayraktar ◽  
Ashraf Ashour ◽  
Halil Karadeniz ◽  
Altok Kurşun ◽  
Arif Erdiş
Keyword(s):  
Air Temperature ◽  
Environmental Effects ◽  
Monitoring Data ◽  
Structural Behavior ◽  
Steel Cable ◽  
Daily Monitoring ◽  
Cable Stayed Bridge ◽  
Long Span ◽  
Cable Forces ◽  
Cable Stayed Bridges

An accurate numerical analysis of the behavior of long-span cable-stayed bridges under environmental effects is a challenge because of complex, uncertain and varying environmental meteorology. This study aims to investigate in-situ experimental structural behavior of long-span steel cable-stayed bridges under environmental effects such as air temperature and wind using the monitoring data. Nissibi cable-stayed bridge with total length of 610m constructed in the city of Adıyaman, Turkey, in 2015 is chosen for this purpose. Structural behaviors of the main structural elements including deck, towers (pylons) and cables of the selected long span cable-stayed bridge under environmental effects such as air temperature and wind are investigated by using daily monitoring data. The daily variations of cable forces, cable accelerations, pylon accelerations and deck accelerations with air temperature and wind speed are compared using the hottest summer (July 31, 2015) and the coldest winter (January 1, 2016) days data.

scholarly journals PC Cable-Stayed Bridge Main Girder Shear Lag Effects: Assessment of Single Cable Plane in Construction Stage

2020 ◽  
Vol 2020 ◽  
pp. 1-16
Author(s):  
Yan-feng Li ◽  
Xing-long Sun ◽  
Long-sheng Bao
Keyword(s):  
Bending Moment ◽  
Main Beam ◽  
Shear Lag ◽  
Distribution Law ◽  
Element Analysis ◽  
Cable Stayed Bridge ◽  
Action Point ◽  
Cable Force ◽  
Beam Section ◽  
Cable Forces

A model test and finite element analysis were conducted in this study to determine the distribution law of shear lag effect in the main beam section, a box girder, during the cable-stayed bridge construction process. The experimental and theoretical results were compared in an example of loading the control section. The stress value of the cable tension area of the main beam upper edge was found to markedly change when tensiling the cable force and was accompanied by prominent shear lag effect. After a hanging basket load was applied, the main beam of certain sections showed alternating positive and negative shear lag characteristics. The shear lag distribution law in the box girder of the single-cable-plane prestressed concrete cable-stayed bridge along the longitudinal direction was determined in order to observe the stress distribution of the girder. The results show that finite element analysis of the plane bar system should be conducted at different positions in the bridge under construction; the calculated shear lag coefficient of the cable force acting at the cable end of the cantilever reflects the actual force. In the beam segments between the cable forces, the shear lag coefficient determined by the ratio of the bending moment to the axial force reflects the actual stress at the cable force action point. In the midspan beam section between the action points of cable forces, the shear lag coefficient of the bending moment reflects the actual stress. The section shear lag coefficient can be obtained by linear interpolation of the beam section between the cable action point and the middle of the span.

Novelty detection of cable-stayed bridges based on cable force correlation exploration using spatiotemporal graph convolutional networks

2021 ◽  
pp. 147592172098866
Author(s):  
Shunlong Li ◽  
Jin Niu ◽  
Zhonglong Li
Keyword(s):  
Novelty Detection ◽  
The State ◽  
Spatial Dependency ◽  
Sensor Fault ◽  
Spatiotemporal Model ◽  
Convolutional Networks ◽  
Cable Stayed Bridge ◽  
Adjacency Matrices ◽  
Cable Forces ◽  
Cable Stayed Bridges

The novelty detection of bridges using monitoring data is an effective technique for diagnosing structural changes and possible damages, providing a critical basis for assessing the structural states of bridges. As cable forces describe the state of cable-stayed bridges, a novelty detection method was developed in this study using spatiotemporal graph convolutional networks by analysing spatiotemporal correlations among cable forces determined from different cable dynamometers. The spatial dependency of the sensor network was represented as a directed graph with cable dynamometers as vertices, and a graph convolutional network with learnable adjacency matrices was used to capture the spatial dependency of the locally connected vertices. A one-dimensional convolutional neural network was operated along the time axis to capture the temporal dependency. Sensor faults and structural variations could be distinguished based on the local or global anomalies of the spatiotemporal model parameters. Faulty sensors were detected and isolated using weighted adjacency matrices along with diagnostic indicators of the model residuals. After eliminating the effect of the sensor fault, the underlying variations in the state of the cable-stayed bridge could be determined based on the changing data patterns of the spatiotemporal model. The application of the proposed method to a long-span cable-stayed bridge demonstrates its effectiveness in sensor fault localization and structural variation detection.

scholarly journals Designing and 3-D Modelling of a Sustainable Cable Stayed Bridge-A Case Study

2020 ◽  
Vol 220 ◽  
pp. 01070
Author(s):  
Priyanka Singh ◽  
Mirza Jahangir Baig ◽  
Bhumika Pandey ◽  
Kartik Papreja
Keyword(s):  
The Past ◽  
Cable Stayed Bridge ◽  
Symmetrical Design ◽  
The World ◽  
Tensile Forces ◽  
Cable Forces ◽  
Design Options ◽  
World Development ◽  
Cable Stayed Bridges

In the world of Civil Engineering, bridges are an example of structural art expressing how much the structures have evolved till present times. The concept and design of bridges has been evolved over the past years, having numerous amounts of different geometrical models and methods to construct bridges. As the development and innovation has reached so far, the concept of bridges has made a great impact on global infrastructure by creating sustainable, effective, and aesthetical bridges around the world. development of the finest aesthetical and sustainable designs for bridges which are known as Cable Stayed BridgesThe bridge form in which the weight of the deck is supported by a number of nearly straight diagonal cables in tension running directly to one or more vertical towers. The towers transfer the cable forces to the foundations through vertical compression. The tensile forces in the cables also put the deck into horizontal compression. Cable stayed bridges are the types of bridges those are best suited for connecting wide-span crossings. Construction of cable stayed bridge is widely promoted all over the world and construction of more than 600 cable stayed bridges are recorded till date. This type of bridge is preferred over any other type due to its possible construction to the indefinite length, availability of multiple design options with the possibility of symmetrical design and excellent strength. In this paper we shall discuss numerous case studies of the cable stayed bridges, compile all the beneficial data for most of the cable stayed bridges located in India.

Conceptual Design of balanced Cable-Stayed Bridges

2019 ◽  
Author(s):  
Sami Soppela ◽  
Esko Järvenpää
Keyword(s):  
Longitudinal Direction ◽  
Design Stage ◽  
Span Length ◽  
Early Design Stage ◽  
Cable Stayed Bridge ◽  
Permanent Load ◽  
Live Loads ◽  
Cable Forces ◽  
Optimum Solution ◽  
Cable Stayed Bridges

<p>The cables are the major loadbearing cost components in the longitudinal direction of a cable-stayed bridge. The quantity of the cables reflects directly to the comparative costs of different alternative layouts. The cable forces, calculated for permanent load balance lead to a reliable cable quantity estimation. For a long-term durability it is important that the bridge is in balance for permanent loads. The influence of the live loads can be estimated separately.</p><p>The purpose of this article is to estimate cable quantities in an early design stage when finding the optimum solution for the bridge. A simple solution method is carried out mathematically using vector algebra and the force length method. This article sets a clear path for determining the preliminary cable forces and cable quantities for two-pylon and single-pylon cable-stayed bridges. The variables are the span length relation, pylon height relation to the main span length, optimum cable anchorage distance at the pylon and the permanent load of the deck.</p><p>Also, the cable quantities of single-pylon bridges can be calculated, even for bridges with highly asymmetric spans. It is noted that the single-pylon cable-stayed bridge has remarkably bigger cable quantity than the two- pylon bridge with equal length.</p><p>The results reveal that the optimum cable anchorage distance in the pylon depends on the pylon height. The higher the pylon is, the greater the optimum anchorage distance should be.</p><p>For the durable bridge an optimum layout and a good balance for gravity loads with minimized bending moments are an important design target. The article helps in reaching that target.</p>

Estimating Cable Forces in a Large Cable-Stayed Bridge

2016 ◽  
Vol 101 ◽  
pp. 26-34
Author(s):  
Sara Casciati ◽  
Lorenzo Elia
Keyword(s):  
Numerical Model ◽  
Extreme Event ◽  
Large Dataset ◽  
Cable Stayed Bridge ◽  
Stay Cables ◽  
Complex Boundary ◽  
Cable Forces ◽  
Main Cables ◽  
Acceleration Signals ◽  
Cable Stayed Bridges

The presence of complex boundary conditions makes the estimation of cable forces in cable-stayed bridges quite difficult when using conventional model-based force identification methodologies. A large dataset of recorded acceleration signals is available for the Ting Kau Bridge (TKB) in Hong Kong. The dataset is used together with a numerical model of the bridge to reconstruct the tension forces in the main cables. A part of the data is used to calibrate the model. The remaining data are used for validation. The created numerical model permits an investigation of the tensions distribution in the stay-cables during a typhoon, based on the observed increase of some of the bridge frequencies during this extreme event.

The Second Maintenance and Strengthening of Yonghe Bridge

2011 ◽  
Vol 90-93 ◽  
pp. 1074-1081 ◽  
Author(s):  
Hong Jiang Li
Keyword(s):  
Safety Factor ◽  
Prestressed Concrete ◽  
Line Shape ◽  
Structural System ◽  
Stay Cable ◽  
Cable Stayed Bridge ◽  
Load Combination ◽  
Cable Forces ◽  
Main Girder ◽  
Cable Stayed Bridges

Tension rocker bearing (TRB) cables installed at auxiliary piers were critical members to sustain the structural system in a prestressed concrete cable-stayed bridge. Once these cables fractured or broken, its structural system would be transferred. Based on diseases caused by fracture of TRB cables in Yonghe Bridge, corresponding maintenance or strengthening measures were described in detail. These measures included replacement of TRB cables, strengthening of the closure segment of main girder at each side span, and adjustment of stay cable forces. Monitoring results showed that, its structural system was finally and completely rehabilitated, and the safety factor of new TRB cables is enough under the most unfavorable load combination. Moreover, the line shape of main girder and the inclined displacement at the top of each pylon were improved effectively. Thus, Yonghe Bridge accumulated some valuable experience for maintenance or strengthening of existing prestressed concrete cable-stayed bridges, and also made a useful exploration.

Seismic Vulnerability Assessment of Long-Span Cable-Stayed Bridges

2011 ◽  
Vol 255-260 ◽  
pp. 2612-2617
Author(s):  
Gang Jin Li ◽  
Wen Hua Zhang
Keyword(s):  
Vulnerability Assessment ◽  
Seismic Vulnerability ◽  
Practical Method ◽  
Transportation System ◽  
Anhui Province ◽  
Seismic Fragility ◽  
Seismic Vulnerability Assessment ◽  
Cable Stayed Bridge ◽  
Long Span ◽  
Cable Stayed Bridges

As important junction in lifeline transportation system, bridges are the most seismic vulnerable components. Based on the capacity/demand (C/D) analysis of bridge components, a practical method is established for seismic fragility assessment of long-span cable-stayed bridges. Depending on this approach, the seismic vulnerability assessment of the Wangdong Bridge, a cable-stayed bridge with a main span of 638m in Anhui Province, is conducted, and the feasibility of the approach is verified.

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