scholarly journals Force Analysis of Self-Anchored Suspension Bridges after Cable Clamp Slippage

Symmetry ◽  
2021 ◽  
Vol 13 (8) ◽  
pp. 1514
Author(s):  
Hongfeng Li ◽  
Yancheng Liu ◽  
Chunwei Li ◽  
Hao Hu ◽  
Quansheng Sun

The slippage of cable clamps during the long-term operation of suspension bridges is a common and detrimental phenomenon. From an experimental point of view, the cable clamp slippage of a suspension bridge was investigated to reveal the effect of this sliding on the force acting on the full bridge. The forces acting on the bridge before and after the slippage were analyzed using a finite element model. The calculation results showed that the cable clamp slippage directly affects the cable forces of the hangers. The hanger cable force decreased by 19.2% when the slippage reached 10.2 cm, while the maximum increase in the cable force of adjacent hangers was 147.7 kN, an increase of 7.25%. The variation of forces in the hanger cable disrupted the force balance of the main girder, thereby producing a torque effect at the corresponding position in the girder, i.e., increased torque. Meanwhile, the slippage affected the axial tension in the main cable and the main girder. The impact of the tower internal force was less than 1%. Hence, the study concluded that the effect of cable clamp slippage is better understood, ensuring the safety of the suspension bridge.

2012 ◽  
Vol 446-449 ◽  
pp. 1277-1282
Author(s):  
Jia Xing Zhou ◽  
Qing Tian Su ◽  
Chong Wu ◽  
Guo Tao Yang

Main cables of self-anchored suspension bridge are anchored at each end of main girder, thus producing a self-balancing system. In order to transfer the cable force to main girder safely and smoothly, the anchorage region is one of the most critical issues in design of a self-anchored suspension bridge. It is hard to fully understand the mechanical behavior only by spatial beam and column model, so a 3D shell finite element model is established to overcome the limitation of spatial beam and column model. The mechanical behavior of initial designed anchorage structure is then analyzed and a modified anchorage fabrication is proposed to improve the stress distribution. Analysis results show that: the modified anchorage system effectively reduces the stress level of anchorage structure and enhances the efficiency of anchorage structure.


2021 ◽  
Vol 2021 ◽  
pp. 1-10
Author(s):  
Hao Tian ◽  
Jiji Wang ◽  
Sugong Cao ◽  
Yuanli Chen ◽  
Luwei Li

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.


2013 ◽  
Vol 694-697 ◽  
pp. 476-480
Author(s):  
Hai Qing Zhu ◽  
Xie Dong Zhang

The type of suspension bridge is used all over the world because of its long span. But the cable system which forced the main load is vulnerable to damage and corrosion. In order to discuss the dynamic characteristics of typical long-span suspension bridges, a finite-element model of a typical long-span bridge was set up with ANSYS, and its top ten frequencies and vibration types were calculated. What’s more the dynamic characteristics under the variations such as modulus of elasticity, sectional size of the cable system, initial strain of the cable, as well as the deficiency of suspender cable were discussed. According to the analysis, the researchers got the conclusion that how the cable system impacts the whole bridge and which suspender cable plays the most significant role. Moreover, the results could serve as some valuable references for the optimization design and preservation of long-span suspension bridges.


2021 ◽  
Vol 12 (1) ◽  
pp. 305
Author(s):  
Guanyuan Zhao ◽  
Xiaopei Cai ◽  
Wanli Liu ◽  
Tielin Wang ◽  
Tao Wang

In order to ensure driving safety and comfort, it is necessary to figure out the complex interaction between continuous welded rail (CWR) and suspension bridges for high-speed railway. A spatial finite element model for a 1092 m main span suspension bridge was established based on the bridge-track interaction theory. A specific correction method was put forward to keep the rail in a zero-stress state when just laid. Three rail expansion joint (REJ) layout schemes were proposed according to practical engineering experience. Both static and dynamic analysis methods were used to evaluate the feasibility of these schemes. The results show that the REJ should be laid at the position with a distance away from the primary beam end, and the beam with more substantial integral stiffness should be preferentially selected. For the recommended scheme, the REJ expansion reaches more than 380 mm under expansion load. The factors affecting the REJ expansion from major to minor are temperature, earthquake, rail fracture, braking, and bending load. The superposition effect of the above factors is suggested to be considered in the selection of REJ range.


2011 ◽  
Vol 243-249 ◽  
pp. 1540-1548
Author(s):  
Yu Zhao ◽  
Jia Le Wei ◽  
Shuan Hai He

Based on the object of self-anchored suspension bridge constructed with long segment hoist method, the load-carrying characteristics and construction technique which is different from other self-anchored suspension bridge is analyzed, and the method of calculation and control on steel box girder configuration during the construction course of long segment hoisted are proposed. For different calculation methods of girder configuration lifting, the influences of the three manners of pre-cambering for steel girders on the configuration and internal force of finished bridge are analyzed. The results show that inverse erection— forward erection—unstressed state synthetic method can guarantee the minimum deviation of steel girder configuration of finished bridge with the design, and it is not necessary to adjust the suspension cable force, and there is no change in main cable configuration and internal force.


2019 ◽  
Vol 9 (12) ◽  
pp. 2576 ◽  
Author(s):  
Guangpan Zhou ◽  
Aiqun Li ◽  
Jianhui Li ◽  
Maojun Duan ◽  
Zhiyuan Xia ◽  
...  

The present work is aimed at studying the determination method and implementation process of reasonable completion state for the Hunan Road Bridge, which is currently the widest concrete self-anchored suspension bridge in China. The global finite element model and the cable analytic program BNLAS were integrated. The synthesis algorithm of completion state determination was proposed. The contact relationships between the cable and saddles were captured using the refined FE discretization method. The concrete shrinkage and creep effects during the construction and operation periods were predicted using the CEB-FIP 90 model and the age-adjusted effective modulus method. The cable alignments under the free cable state, system transformation condition, and completion state were obtained. Moreover, the multiple-control method for the whole process of system transformation was proposed. The multiple parameters included the hanger tensioning force, exposed amount of hanger anchor cup, and tag line position. A detailed system transformation procedure was formulated and well preformed in the construction site. In addition, the further optimization analysis of final hanger force was conducted based on the actual completion state. The influence on the stress and geometry evolution of girder brought by the final girder alignment was investigated. The measured results of structural alignment and stress show that the target completion state was well implemented. The accuracy and efficiency of the proposed multiple-control method were verified by checking the tag line position of each step. In addition, the optimized final hanger force and girder lifting amount were obtained, which can provide feedback and reference for the construction control and service safety of the similar concrete self-anchored suspension bridges.


2013 ◽  
Vol 444-445 ◽  
pp. 173-177
Author(s):  
Xiao Chun Wang ◽  
Ben Ning Qu ◽  
Jiao Long Peng ◽  
Meng Xi Geng

Under the background of a stable type suspension bridge (A suspension bridge with a inverse-tensional system), the effect of inverse-tensional system for suspension bridge is studied. Using finite element method, three-dimensional finite element model of stable type suspension bridge and a common suspension bridge is established by fish bone model consisting of beam elements respectively. The finite element characteristic equation of two bridges is solved with Block Lanczos method respectively. 20 order eigenpairs of two kind of suspension bridges are obtained. The inherent characteristics of the two type bridges are analyzed comparatively. The results showed that due to the effect of inverse-tensional structures, the overall stiffness of the stable suspension bridge is better than common suspension bridge obviously, which can effectively suppress the torsional vibration of the suspension bridge.


2021 ◽  
Vol 2 (1) ◽  
Author(s):  
Hongyu Jia ◽  
Kang Jia ◽  
Caizhi Sun ◽  
Yanqiang Li ◽  
Chao Zhang ◽  
...  

AbstractThe objective of this paper is to expediently expose the seismic performance pertinent to demand and capacity of general long-span suspension bridges crossing active faults. Firstly three dimensional finite element model of the ordinary long-span suspension bridge is established based on the powerful and attractive finite element software ANSYS. Secondly a series of appropriate fault ground motions with different target final permanent displacements (Tectonic displacements or ground offset) in the direction perpendicular to the fault plane are assumed and applied to the employed long-span suspension bridge. And then the Newmark method is utilized to solve the equation of motion of the long-span suspension bridge structure subjected to fault ground motions in the elastic range. Finally some important conclusions are drawn that the final permanent displacements in the direction perpendicular to the fault plane has significant influence on the seismic responses and demands of general long-span suspension bridges crossing active faults. And the resultant conclusions deliver explicitly and directly specifications and guidelines for seismic design of ordinary long-span suspension bridges across fault-rupture zones.


2014 ◽  
Vol 1020 ◽  
pp. 124-129
Author(s):  
Zhi Gang Qi ◽  
Jun Dong ◽  
Bo Qiang Yao

As a bridge with a large span, suspension bridge has obvious advantage in the current cross-sea engineering. In order to achieve longer span capacity, long-span multi-tower suspension bridge programs were repeatedly proposed. Due to the increase in the number of tower, the mechanical behavior would be inevitably different with the ordinary two-tower suspension bridge. For better grasp the difference of the mechanical properties, Midas civil 2011 is used to model to analyze. Suspension bridge models whose spans are 1080m with different towers (two, three, four, five, six,) are established to analyze the change in the mechanical properties under the action of vehicle load. The results show that the mechanical properties of multi-tower suspension bridge are quietly different from two-tower suspension bridge and with the increase in the number of bridge tower, the displacements of main girder and main tower have large difference. When the number of tower is more than or equal to four, multi-tower suspension bridges have little difference in the mechanical properties and that means multi-tower effect is not obvious.


2010 ◽  
Vol 43 ◽  
pp. 594-598
Author(s):  
Bang Sheng Xing ◽  
Changlun Du ◽  
Xue Feng Wang

In this paper Ansys, the difite element analysis software, is used to make model analysis on self-anchored suspension bridges achieve the intrinsic frequency and inherent vibrating mode of its first ten bands. Simutaneously, a transient dynamic analysis is made to research the impact of the deformation of the self-suspension bridge under a moving load with the change of the speed, which will be playing a pivotal role in the design and construction of the self-anchored suspension bridges.


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