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.

Study on the Effective Slab Width of Composite Cable-Stayed Bridge under Axial Force

2012 ◽  
Vol 568 ◽  
pp. 200-203
Author(s):  
Xiang Nan Wu ◽  
Xiao Liang Zhai ◽  
Ming Min Zhou
Keyword(s):  
Axial Force ◽  
Shear Lag ◽  
Distribution Law ◽  
Slab Width ◽  
Cable Stayed Bridge ◽  
Stay Cables ◽  
Transmission Angle ◽  
Effective Flange Width ◽  
Width Coefficient ◽  
Cable Stayed Bridges

There exist evident shear-lag phenomena in large-span composite cable-stayed bridges under the action of axial force, especially in the deck with double main girders. In order to discuss the distribution law of the effective flange width coefficient along the span, caused by axial force, finite element computations of five composite cable-stayed bridges and theoretical analysis have been performed. The transmission angle of axial force caused by the axial compression of stay cables was given, meanwhile the formulas for computation effective slab width coefficient under axial force were suggested.

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>

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.

Optimization of Stay Cables in the Double-Set Arch Pylon Cable-Stayed Bridge

2014 ◽  
Vol 711 ◽  
pp. 495-498
Author(s):  
Shi Xiang Hu ◽  
Wen Gang Ma ◽  
Min Luo
Keyword(s):  
Bending Moment ◽  
Original Design ◽  
Finite Element Software ◽  
Cable Stayed Bridge ◽  
Stay Cables ◽  
Bending Strain ◽  
The Difference ◽  
Negative Bending ◽  
Cable Forces

The determination of post-tensioning cable forces is one of the most important issues for the design of arch pylon cable stayed bridge. In this paper, the optimization module implemented in MATLB, together with the commercial finite element software MIDAS, were employed to evaluate the minimum bending strain energy of the bridge. After optimizing the cable forces, the bending moment of the pylons were bigger than the values of original design. The bending moment of the main arch pylon within 55m to 70m height increased by 7280 kN•m, and the bending moment of the auxiliary arch pylon within 30m to 60m height increased by 3926 kN•m .The stress of the pylons was still far below the allowance value when the obtained cable forces were applied. However, for the girder, the difference between the maximum positive and maximum negative bending moments due to dead load can be lessened greatly by the application of the obtained cable forces. The results obtained revealed that the method presented could make full use of cable forces and lead to optimal structural performance.

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>

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.

Deck-stay interaction with appropriate initial shapes of cable-stayed bridges

2014 ◽  
Vol 31 (4) ◽  
pp. 634-655
Author(s):  
Ming-Yi Liu ◽  
Li-Chin Lin ◽  
Pao-Hsii Wang
Keyword(s):  
Mode Shapes ◽  
Coupled Modes ◽  
Initial Shape ◽  
Content Type ◽  
Cable Stayed Bridge ◽  
Stay Cables ◽  
Modal Coupling ◽  
Degree Of Coupling ◽  
Cable Stayed Bridges ◽  
Tower System

Purpose – The purpose of this paper is to provide a variety of viewpoints to illustrate the mechanism of the deck-stay interaction with the appropriate initial shapes of cable-stayed bridges, which is validated by a symmetrical structure. Design/methodology/approach – Based on the smooth and convergent bridge shapes obtained by the initial shape analysis, the one-element cable system (OECS) and multi-element cable system (MECS) models of the symmetric harp cable-stayed bridge are developed to verify the applicability of the analytical model and numerical formulation from the field observations in the authors’ previous work. For this purpose, the modal analyses of the two finite element models are conducted to calculate the natural frequency and normalized mode shape of the individual modes of the bridge. The modal coupling assessment is also performed to obtain the generalized mass ratios among the structural components for each mode of the bridge. Findings – The findings indicate that the coupled modes are attributed to the frequency loci veering and mode localization when the “pure” deck-tower frequency and the “pure” stay cable frequency approach one another, implying that the mode shapes of such coupled modes are simply different from those of the deck-tower system or stay cables alone. The distribution of the generalized mass ratios between the deck-tower system and stay cables are useful indices for quantitatively assessing the degree of coupling for each mode. For each identical group of stay cables in the MECS model, the local modes with similar natural frequencies and normalized mode shapes consist of the participation of one or more stay cables. These results are demonstrated to fully understand the mechanism of the deck-stay interaction with the appropriate initial shapes of cable-stayed bridges. Originality/value – It is important to investigate the deck-stay interaction with the appropriate initial shape of a cable-stayed bridge. This is because such initial shape not only reasonably provides the geometric configuration as well as the prestress distribution of the bridge under the weight of the deck-tower system and the pretension forces in the stay cables, but also definitely ensures the satisfaction of the relations for the equilibrium conditions, boundary conditions and architectural design requirements. However, few researchers have studied the deck-stay interaction considering the initial shape effect. The objective of this paper is to fully understand the mechanism of the deck-stay interaction with the appropriate initial shapes of cable-stayed bridges, which is validated by a symmetrical structure. The modal coupling assessment is also performed for quantitatively assessing the degree of coupling for each mode of the bridge.

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