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.

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.

Inspection and Assessment of Stay Cables in Cable Stayed Bridges

2014 ◽  
Vol 638-640 ◽  
pp. 954-960 ◽  
Author(s):  
Wei Zhen Chen ◽  
Jian Xi Yang
Keyword(s):  
Cross Sections ◽  
Systematic Research ◽  
Bridge Management ◽  
Distribution Law ◽  
Stay Cables ◽  
Two Factors ◽  
Connection System ◽  
Assessing Method ◽  
Mechanical Change ◽  
Cable Stayed Bridges

That stayed cables are prone to corrosion fails to draw enough attention of bridge management until corrosion leads to damage of cables. Corrosion is usually allowed to develop for lack of accurate detection method or rather for lack of matured method of assessing tensile capacity of existing stayed cables. The tensile capacity of corroded stayed cables are affected by main factors such as cable specifications, mechanical properties of wires, extent of corrosion, and distribution of corroded wires in stayed cables. The last two factors are especially in need of systematic research. Therefore, this paper, taking advantage of the project of displacing stayed cables of Shimen Bridge, attempts an investigation of the two factors from the following perspectives: The investigation starts with measurement of corroded cable wires of the bridge to understand mechanical property of the wires and then makes an empirical fitting curve according to the mechanical change caused by corrosion. Severely corroded stayed cables are cut into several parts to expose cross sections, every wire in which is numbered for test of corrosion extent. Thus, radial distribution law of corroded cable wires is well examined. In light of the above investigation, a model is proposed to assess tensile capacity of stayed cable based on the series-parallel connection system. To verify practicality of the theory governing the investigation, one specimen made from a corroded stayed cable with the old anchor terminal on one end is tensioned and assessed using the assessing method proposed in this paper to see if the method is applicable to assessment of tensile capacity of other corroded stayed cables.

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 Shear Lag Effect of a PC Box Girder Bridge with Corrugated Steel Webs under Self Weight

2014 ◽  
Vol 638-640 ◽  
pp. 1092-1098 ◽  
Author(s):  
Rui Juan Jiang ◽  
Qi Ming Wu ◽  
Yu Feng Xiao ◽  
Xiao Wei Yi ◽  
Wei Ming Gai
Keyword(s):  
Bending Moment ◽  
Shear Lag ◽  
Shear Lag Effect ◽  
Element Analysis ◽  
Box Girder ◽  
Lag Effect ◽  
Box Girder Bridge ◽  
Girder Bridge ◽  
Effective Flange Width ◽  
Width Coefficient

In the present paper, based on the three-dimensional finite element analysis for a three-span continuous PC box girder bridge with corrugated steel webs and the corresponding conventional box girder bridge with concrete webs, a comparative study on the shear lag effect under self-weight is carryied out together with the analyslis on the coefficient of the effective flange width. The results show that At the sections in the negative bending moment near the intermediate piers, the shear lag effect in the bridge with corrugated steel webs is more obvious than that in the bridge with concrete webs by 8%; and the corresponding effective flange width coefficient in the bridge with corrugated steel webs is even smaller than 0.9, so the shear lag effect at these sections should be considered in the design of this type of bridges. At the mid-span section of the middle span of a three-span continuous bridge either with corrugated steel webs or concrete webs, the shear lag effect can be omitted since the corresponding effective flange width coefficient there is close to 1.0.

Shear Lag Effect in Single Plane Cable-Stayed Bridge

1998 ◽  
Vol 1 (4) ◽  
pp. 301-306 ◽  
Author(s):  
Shih Toh Chang ◽  
Qiwei Zhang ◽  
Shiduo Zhang
Keyword(s):  
Axial Force ◽  
Beam Theory ◽  
Test Results ◽  
Shear Lag ◽  
Shear Lag Effect ◽  
Single Plane ◽  
Cable Stayed Bridge ◽  
Lag Effect ◽  
Combined Action ◽  
Minimum Potential

The shear lag effect in thin-walled trapezoidal box sections with inclined stiffeners within the cell is analyzed using the principle of minimum potential energy. Due to the combined action of axial force and moment in a cable-stayed bridge, the normal stress in the pylon is given by [Formula: see text]. The coefficient of shear lag can be written as [Formula: see text], where σ is the actual stress taking shear deformation of slabs into account and [Formula: see text] is the stress evaluated by elementary beam theory. In this paper, the longitudinal displacement under axial force is assumed to vary parabolically transversely across the section. Due to moment, a quartic variation is adopted. Two sets of differential equations with boundary conditions are theoretically derived. An example is illustrated by theoretical analysis and test results.

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.

Measuring Methods of Cable Tension in Cable-Stayed Bridges

2011 ◽  
Vol 295-297 ◽  
pp. 1230-1235
Author(s):  
Jiang Bo Sun ◽  
Zuo Zhou Zhao ◽  
Hong Hua Zhao
Keyword(s):  
Natural Vibration ◽  
String Model ◽  
Beam Model ◽  
Stay Cable ◽  
Fem Model ◽  
Cable Tension ◽  
Cable Stayed Bridge ◽  
Stay Cables ◽  
Beam Bending ◽  
Cable Stayed Bridges

This paper presents several methods usually used for measuring cable tension in cable-stayed bridges, especially frequency vibration method. Taken two different length stay-cables under given tension forces in a real cable-stayed bridge as an example, different modeling methods in finite element methods (FEM) were used to solve their natural vibration frequencies. The results by FEM were compared with those from other available theoretical predicting method. It was found that FEM based on tightening string model is more suitable for a long stay-cable. For a short stay-cable under given tension force, beam bending stiffness can be ignored in predicting its first five natural frequencies using a hinged beam model in FEM. While the predicted lower frequency using clamped beam FEM model is more accurate and reasonable.

Feasibility of Using a Negative Stiffness Damper to Two Interconnected Stay Cables for Damping Enhancement

2019 ◽  
Vol 19 (06) ◽  
pp. 1950058 ◽  
Author(s):  
Peng Zhou ◽  
Min Liu ◽  
Huigang Xiao ◽  
Hui Li
Keyword(s):  
Dynamic Behavior ◽  
Dynamic Responses ◽  
Negative Stiffness ◽  
Cable Stayed Bridge ◽  
Long Span ◽  
Stay Cables ◽  
Modal Damping ◽  
Vibration Responses ◽  
White Noises ◽  
Cable Stayed Bridges

The dynamic behavior of stay cables has a significant impact on the safety and serviceability of cable-stayed bridges. As tuning such dynamic behavior could be effectively achieved by a damping increase on stay cables, this paper investigates on the feasibility of increasing damping on two stay cables simultaneously through interconnecting them with a negative stiffness damper (NSD). It presents the passive realization of the NSD through the following process. First, under harmonic excitations, the steady-state dynamic responses of the two cables in the network are derived. Then, the asymptotic solutions for the additional modal damping ratios are formulated with the critical viscous damping and negative stiffness determined approximately. Subsequently, a parametric analysis is performed to verify the theoretical derivations using two stay cables of a real long-span cable-stayed bridge, under a series of numerical evaluations consisting of sinusoidal excitations and white noises vibrational responses for both cables. Both the theoretical and numerical results show superior damping enhancement by the NSD, in that the vibration responses of the two cables are reduced remarkably.

Dynamic Behavior of Cable-Stayed Bridge under Moving Vehicle and Train

2014 ◽  
Vol 1065-1069 ◽  
pp. 870-874
Author(s):  
Yong Myung Park ◽  
Ji Hoon Kang ◽  
Sung Hun Cho ◽  
Hee Soon Kim
Keyword(s):  
Dynamic Behavior ◽  
Parametric Analysis ◽  
Interaction Analysis ◽  
Span Length ◽  
Moving Vehicle ◽  
Cable Stayed Bridge ◽  
Stay Cables ◽  
Dynamic Amplification ◽  
Cable Stayed Bridges

In this study, dynamic behavior of cable-stayed bridge under moving vehicle and train was analyzed. The parameters considered are the main span length of bridge and the existence of intermediate pier at side span. For the parametric analysis, cable-stayed bridges with 400m and 700m main span (with and without the intermediate pier at side span) were selected. From the vehicle/train-bridge interaction analysis, the intermediate pier was found very effective to reduce the dynamic amplification of girder and stay-cables.

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