Effects Analysis of Bending Stiffness of Cables on Stress Distribution and Curve Shape in Super-Long Single Suspension Cable Structures

2010 ◽  
Vol 163-167 ◽  
pp. 173-176
Author(s):  
Tian Hu Jing ◽  
Qing Ning Li
Keyword(s):  
Stress Distribution ◽  
Cross Sections ◽  
Suspension Bridge ◽  
Bending Stiffness ◽  
Structural Safety ◽  
Curve Shape ◽  
Cable Structures ◽  
Long Span ◽  
Suspension Cable ◽  
Main Cables

The design scheme of a suspension bridge with a super-long-span of 3300 m was taken as an example, and calculating results from 3 mechanics models are compared with each other to study the effects of bending stiffness of cables on stress distribution and curve shape in super-long single suspension cable structures on the basis of the Finite Element Method (FEM) algorithm of ANSYS and the analytical segmental catenary method for cables’ shape-finding. The study shows that the influence of bending stiffness on curve shape-finding of cables is negligible; Although its effects on stress distribution in cross sections of main cables due to dead loads is small, the error of horizontal forces probably results in great one for the calculation of bending moments at the bottom cross-sections of bridge pylons, which needs attention to ensure the structural safety.

scholarly journals Parametric analysis of the dynamic characteristics of a long-span three-tower self-anchored suspension bridge with a composite girder

2020 ◽  
Vol 1 (1) ◽  
Author(s):  
Feifei Shao ◽  
Zhijun Chen ◽  
Hanbin Ge
Keyword(s):  
Finite Element ◽  
Dynamic Characteristics ◽  
Suspension Bridge ◽  
Bending Stiffness ◽  
Torsional Stiffness ◽  
Design Parameters ◽  
Long Span ◽  
Bending Mode ◽  
Main Cables ◽  
Central Buckle

Abstract Three-tower self-anchored suspension bridge (TSSB) is more and more favored because of its beautiful structure and strong adaptability to terrain and geological conditions. However, there are few engineering practices and related researches on super long-span three-tower self-anchored suspension bridges. A three-dimensional finite element model for the Fenghuang Yellow River Bridge, with the world’s longest span of its kind under construction, is established using the ANSYS finite element program, and the structural dynamic characteristics of the super long-span TSSB are studied and compared with those of several bridges of the same type or with similar spans. In addition, the influence of the key design parameters such as the stiffening girder stiffness, tower stiffness, main cable and suspender stiffness, central buckle, and longitudinal constraint system on the dynamic characteristics of the structure is analyzed. The results show that the first mode of the TSSB is longitudinal floating, the lower-order modes are dominated by vertical bending modes, while the higher-order modes are primarily vibration modes of the main cables, and the torsional modes exhibit strong coupling with the lateral sway of the towers and main cables. The frequency of the first antisymmetric vertical bending mode of the TSSB has an inversely proportional relationship with the main span length. Compared with a double-tower ground-anchored suspension bridge and cable-stayed bridge with similar spans, the TSSB has the lowest frequency for the first antisymmetric vertical bending mode and the highest frequency for the first symmetric vertical bending mode, with a more pronounced coupling with the towers and main cables in the torsional modes. Analysis of the structural parameters shows that the frequencies of the longitudinal floating mode, first antisymmetric vertical bending mode, first symmetric vertical bending mode, and first torsional mode are most sensitive to the longitudinal bending stiffness of the side tower, central buckle, vertical bending stiffness of the stiffening girder, and torsional stiffness of the stiffening girder, respectively. The research findings and relevant conclusions can provide basic data for response analysis of long-span TSSBs under dynamic loads and offer an engineering reference for the design of similar bridges around the world.

scholarly journals Probabilistic Assessment of the Safety of Main Cables for Long-Span Suspension Bridges considering Corrosion Effects

2021 ◽  
Vol 2021 ◽  
pp. 1-10
Author(s):  
Hao Tian ◽  
Jiji Wang ◽  
Sugong Cao ◽  
Yuanli Chen ◽  
Luwei Li
Keyword(s):  
Probability Model ◽  
Steel Wire ◽  
Suspension Bridge ◽  
Element Model ◽  
Traffic Load ◽  
Suspension Bridges ◽  
Accelerated Corrosion ◽  
Long Span ◽  
Accelerated Corrosion Tests ◽  
Main Cables

This paper presents a reliability analysis to assess the safety of corroded main cables of a long-span suspension bridge. A multiscale probability model was established for the resistance of the main cables considering the length effect and the Daniels effect. Corrosion effects were considered in the wire scale by relating the test results from accelerated corrosion tests to the corrosion stages and in the cable scale by adopting a corrosion stage distribution of the main cable section in NCHRP Report 534. The load effects of temperature, wind load, and traffic load were obtained by solving a finite element model with inputs from in-service monitoring data. The so-obtained reliability index of the main cables reduces significantly after operation for over 50 years and falls below the design target value due to corrosion effects on the mechanical properties of the steel wire. Multiple measures should be taken to delay the corrosion effects and ensure the safety of the main cables in the design service life.

scholarly journals Review on the Service Safety Assessment of Main Cable of Long Span Multi-Tower Suspension Bridge

2021 ◽  
Vol 11 (13) ◽  
pp. 5920
Author(s):  
Dagang Wang ◽  
Jihong Ye ◽  
Bo Wang ◽  
Magd Abdel Wahab
Keyword(s):  
Corrosion Fatigue ◽  
Safety Assessment ◽  
Failure Mechanisms ◽  
Suspension Bridge ◽  
Research Trends ◽  
Structural Safety ◽  
Suspension Bridges ◽  
Long Span ◽  
Main Cable ◽  
Bridge Failure

The long-span multi-tower suspension bridge is widely used in the construction of river and sea crossing bridges. The load-bearing safety and anti-sliding safety of its main cable are directly related to the structural safety of a suspension bridge. Failure mechanisms of the main cable of a long-span multi-tower suspension bridge are discussed. Meanwhile, the tribo-corrosion-fatigue of main cable, contact, and slip behaviors of the saddle and service safety assessment of the main cable are reviewed. Finally, research trends in service safety assessment of main cable are proposed. It is of great significance to improve the service safety of the main cable and thereby to ensure the structural safety of long-span multi-tower suspension bridges.

scholarly journals Materials Consumption Decrease for Long-Span Prestressed Cable Roof

2015 ◽  
Vol 1 ◽  
pp. 209
Author(s):  
Arturs Stuklis ◽  
Dmitrijs Serdjuks ◽  
Vadims Goremikins
Keyword(s):  
Cross Sections ◽  
Raw Materials ◽  
Energy Resources ◽  
Load Carrying Capacity ◽  
Polynomial Equations ◽  
Material Consumption ◽  
Cable Structures ◽  
Long Span ◽  
Load Carrying ◽  
Vertical Displacements

<p class="R-AbstractKeywords"><span lang="EN-US">Limited raw materials and energy resources are actual national economy problems which can be solved by the decrease of weight, increase of span and durability of load bearing structures. The largest structural spans were achieved by application of cable structures. The roofs are one of the most widely used in practice type of cable structures.  However, increased deformability and necessity of the special methods of stabilizing are significant cable roofs disadvantages. The prestressing of one or several groups of cables is one of the probable methods for stabilizing of cable roofs. According to the recommendations available in the literature, all cables of the roof must be prestressed by the equal forces. But after applying of design vertical load, values of the forces, acting in the cables of the roof, changes within the wide limits. So, using of structural materials will not be rational in this case, taking into account, that the cables cross-sections are constant because the cables cross-sections were determined basing on the maximum axial force, acting in the all cables.</span></p><p class="R-AbstractKeywords"><span lang="EN-US">Possibility to decrease materials consumption by the changing of prestressing forces for cables of the roof was checked on the example of saddle-shaped cable roof with the rigid support contour and dimensions 60x60 m in the plan. Initial deflections of main suspension and stressing cables of the roof were equal to 7m.  Suspension and stressing cables of the net were placed with the step equal to 2.828 m. Steel ropes with modulus of elasticity in 1.5∙105 MPa  were considered as a material of suspension and stressing cables of the roof. Suspension and stressing cables were divided into the groups, which are differed by the prestressing forces. Amount of cables groups changes within the limits from 1 to 27. Values of prestressing forces for cables groups change within the limits from 20 to 80% from the cables breaking force.  </span></p><p class="R-AbstractKeywords"><span lang="EN-US">The dependences of material consumption and maximum vertical displacements of cable roof on the amount of cables groups and prestressing forces were determined as second power polynomial equations. It was stated, that division of suspension and stressing cables on the 18 groups enables to decrease cables material consumption by 19.2%. Values of prestressing forces for suspension and stressing cables of the roof were equal to 57 and 80 %, from it load-carrying capacity, correspondingly</span><span lang="EN-US">. </span></p>

Bridges with multiple structural systems: The example of Trilj Bridge reconstruction in Croatia

2021 ◽  
Vol 17 (1-2) ◽  
pp. 65-75
Author(s):  
Jure Radnić ◽  
Domagoj Matešan ◽  
Ivan Banović
Keyword(s):  
Suspension Bridge ◽  
Structural Safety ◽  
Structural Systems ◽  
Paper Briefly ◽  
Suspension Cable ◽  
Bridge Reconstruction ◽  
Existing Bridges ◽  
Design Ideas ◽  
The City ◽  
Bearing Structure

Development of multiple structural systems for bridges is useful in the design of new bridges and rehabilitation of existing bridges. This paper briefly presents some existing bridges with multiple structural systems and succinctly discusses design ideas for bridges with such systems. As an example of a bridge with multiple structural systems, the paper presents the reconstruction of a pedestrian suspension bridge in the City of Trilj, Croatia. The new bridge’s load-bearing structure is composed of several structural systems. Namely, the reconstructed bridge is a combination of suspension, cable-stayed and stress-ribbon bridge, which is laterally restrained with horizontal tensioned ropes. Numerical analysis was conducted on the renovated bridge. The results have shown an acceptable levels of stresses and deflections verifying the structural safety of the restored bridge. It is believed that this example of the bridge renovation may be useful in the design of new and strengthening of existing similar bridges.

Probability Evaluation Method for Cable Safety of Long Span Suspension Bridges under Extreme Wind Load

2010 ◽  
Vol 163-167 ◽  
pp. 3223-3229 ◽  
Author(s):  
Jun Hu ◽  
Jin Ping Ou
Keyword(s):  
Safety Assessment ◽  
Evaluation Method ◽  
Suspension Bridge ◽  
Wind Load ◽  
Structural Safety ◽  
Suspension Bridges ◽  
Type I ◽  
Attenuation Relations ◽  
Long Span ◽  
Extreme Wind

The cable is the main load-bearing component of suspension bridge and its safety assessment under extreme wind load is a key issue to the structure. Take a long-span suspension bridge in the East Sea China as an example, the standard of extreme wind load for structural safety evaluation is established; the wire’s strength model is established by the type I extreme value distribution; cable’s safety assessment function under wind load is established and the Monte Carlo method is used to get the cable’s reliability and reliable indicators. The bridge’s re-service term is taken for 90 years as an example, the results indicate that the wire’s serial effects can’t be ignored, the cable’s reliable indicator decreases as the number of broken wires increases in approximately the linear attenuation relations, the critical percentage of broken wires is about 10%.

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