Geometrical Nonlinear Analysis on Three-Tower Suspension Bridges under Live Load

2011 ◽  
Vol 255-260 ◽  
pp. 1209-1213
Author(s):  
Xiang Nan Wu ◽  
Yue Xu ◽  
Wan Heng Li ◽  
Peng Liang

Anti-slipping safety factor between the main cable and saddle, deflection-to-span ratio of main girder and force in the mid-tower, which are not important factors in two-tower suspension bridge design, yet becoming dominant ones in three-tower. Moreover, these factors are all controlled by live load. Thus geometrical nonlinearity under live load for three-tower suspension bridge becomes even more significant. This paper takes Taizhou Yangtze River Bridge as the study object, and uses linear deflection theory, incremental UL formulation and total CR formulation to study the geometrical nonlinearity of various key responses of the structure under live load. It is concluded that accuracy and efficiency of total CR formulation is the highest among the three as well as the maximum error of incremental UL formulation is no more than 0.3%; however, the error of widely used linear deflection theory is 6.6%, 4.5% and -2.64% respectively, which is conservative and can not meet the requirements of sophisticated analysis.

2013 ◽  
Vol 2013 ◽  
pp. 1-5 ◽  
Author(s):  
Wang Hui-Li ◽  
Tan Yan-Bin ◽  
Qin Si-Feng ◽  
Zhang Zhe

Geometric nonlinearity of self-anchored cable-stayed suspension bridges is studied in this paper. The repercussion of shrinkage and creep of concrete, rise-to-span ratio, and girder camber on the system is discussed. A self-anchored cable-stayed suspension bridge with a main span of 800 m is analyzed with linear theory, second-order theory, and nonlinear theory, respectively. In the condition of various rise-to-span ratios and girder cambers, the moments and displacements of both the girder and the pylon under live load are acquired. Based on the results it is derived that the second-order theory can be adopted to analyze a self-anchored cable-stayed suspension bridge with a main span of 800 m, and the error is less than 6%. The shrinkage and creep of concrete impose a conspicuous impact on the structure. And it outmatches suspension bridges for system stiffness. As the rise-to-span ratio increases, the axial forces of the main cable and the girder decline. The system stiffness rises with the girder camber being employed.


2015 ◽  
Vol 2015 ◽  
pp. 1-12 ◽  
Author(s):  
Shaorui Wang ◽  
Zhixiang Zhou ◽  
Yanmei Gao ◽  
Yayi Huang

The stiffening girder of self-anchored suspension bridge (SSB) is subjected to huge axial force because the main cable is directly anchored on the end of the stiffening girder. To obtain a simple model and accurately understand the mechanical behavior of the whole structure in preliminary design, this paper proposed an analytical calculation method considering the combined effects of the main cable-suspender-stiffening girder. On the basis of the deflection theory of the stiffening girder, the relation between the girder shape and the suspender force was explored. The relation between the main cable end force (MCEF) and the suspender force was derived through segmental catenary theory, and iteration method was further improved to avoid the divergence condition. Finally the solution was obtained through satisfying the compatibility condition. The proposed method does not need to iterate manually and can save calculation time. Examples are introduced to verify the applicability of this method, with the result that this method considers the combined effects of the main cable-suspender-stiffening girder, and the finished bridge state satisfies the minimum strain energy of the stiffening girder. Results also indicate that this method has fast convergence speed and high precision.


2017 ◽  
Vol 17 (04) ◽  
pp. 1750050
Author(s):  
Myung-Rag Jung ◽  
Min-Jung Jang ◽  
Mario M. Attard ◽  
Moon-Young Kim

To investigate the elastic buckling behavior of self-anchored suspension bridges subjected to proportionally increasing dead loads, a new stability procedure is proposed based on the deflection theory. For this purpose, a finite element buckling analysis is performed using the initial state solution based on the unstrained length method (ULM) (Ref. 1 ). The finite element solutions are compared with those by the deflection theory. It is shown that both the main girder and tower of the self-anchored suspension bridge are under compression, but their fundamental buckling modes are tower-dominant. Importantly, it is observed that local buckling within the main girder supported by hangers occurs without any geometric change of the main cable, in the higher buckling modes of the self-anchored suspension bridge.


2013 ◽  
Vol 405-408 ◽  
pp. 1616-1622
Author(s):  
Guo Hui Cao ◽  
Jia Xing Hu ◽  
Kai Zhang ◽  
Min He

In order to research on mechanical properties of flexible suspension bridges, a geometric nonlinear analysis method was used to simulate on the experimental results, and carried on static loading test finally. In the loading test process, the deformations were measured in critical section of the suspension bridge, and displacement values of measured are compared with simulation values of the finite element simulation. Meanwhile the deformations of the main cable sag are observed under classification loading, the results show that the main cable sag increment is basically linear relationship with the increment of mid-span loading and tension from 3L/8 and 5L/8 to L/2 section, the main cable that increasing unit sag required mid-span loads and tension are gradually reduce in near L/4 and 3L/4 sections and gradually increase in near L/8 and 7L/8 sections and almost equal in near L/2, 3L/8 and 5L/8 sections. From the experimental results, the flexible suspension bridge possess good mechanical properties.


2012 ◽  
Vol 461 ◽  
pp. 151-154
Author(s):  
Dai Yong Jia ◽  
Lu Yan Sui ◽  
Ming Lai He

In this study, an experiment platform was built up to determine the key parameter, mass transfer coefficient, of the ventilation and dehumidification process in main cable of suspension bridge. On the basis of experimental studies, an empirical formula of the mass transfer coefficient was obtained, which can greatly contribute to control the content of moisture in the main cable of suspension bridges.


2020 ◽  
Vol 2020 ◽  
pp. 1-18
Author(s):  
Pengfei Cao ◽  
Hai Fang ◽  
Weiqing Liu ◽  
Yong Zhuang ◽  
Yuan Fang ◽  
...  

A composite wrapping system for main cable protection of suspension bridges was designed by using prepreg fiber-reinforced composites and nitrile rubber. The circumferential expansion performance of the system was tested, and the curves of circumferential bearing capacity and radial displacement of the components were obtained. Failure modes of each group of components were compared and analyzed. The results show that most of the components are vertically fractured at the lap transition. The increase of the number of prepreg layers contributed the most to the circumferential bearing capacity of components, with a growth rate of 65.31%~109.01%. The increase of rubber belt layers had the most significant effect on the radial displacement of the components, with a growth rate of 7.06%~23.5%. In the initial stage of the test, the strain of each part of the component was smaller due to the compaction by the loading device, and the strain value of the component was generally linearly increased during the loading process, during which the strain of the overlap was the smallest. The calculated cross-sectional temperature deformation of the main cable is in good agreement with the experimental data. The application of the rubber belt increases the deformation of the main cable; therefore, the protection system for the main cable could have more deformation redundancy and delay the arrival of the ultimate strain of the outer prepreg wrap.


2013 ◽  
Vol 671-674 ◽  
pp. 1988-1992
Author(s):  
Xi Jiang ◽  
Tian Qing Yu

The Yangxi main bridge for 49+120+49 m the self-anchored suspension bridge, the main girder procedure full framing in situ girder construction, bridge tower using piecewise casting method construction, use scaffolding as construction operation platform. Main cable construction using prefabricated parallel wire strand method (PPWS), first within the plant into steel wire strand, roll in the drum on delivery to the bridge site erection points, with traction rope by stock installation in place. Saddle the fission lifting, cable clamp installed application to the calibration of jack import screw tension 420 kn, and three times repeated tension, sling the factory-made after installation in place. Can be used as the same bridge comparison and reference.


2012 ◽  
Vol 178-181 ◽  
pp. 2281-2284 ◽  
Author(s):  
Qing Tian Su ◽  
Dong Fang Wang

Self-anchored suspension bridge is a self-balancing system by anchored the main cable at each end of main girder. With complicated configuration and important rule of transferring tension in main cable to main girder, the anchorage region is one of the most critical issues during designing a self-anchored suspension bridge. It is impossible to fully understand the mechanical behavior only by spatial beam and column model but spatial refined model. Because the behavior of anchorage region is greatly influenced by its boundary condition, in this paper, reasonable length of main girder in calculation model is discussed based on the spatial refined model. The mechanical behavior of initial anchorage structure is calculated. A modified anchorage configuration is proposed according to the stresses distribution of anchorage zone. Calculation results show the modified anchorage configuration can make the force transferring smoothly and decrease the stresses of anchorage structure, and it can be referenced to similar bridges.


2015 ◽  
Vol 2015 ◽  
pp. 1-14 ◽  
Author(s):  
Myung-Rag Jung ◽  
Dong-Ju Min ◽  
Moon-Young Kim

A simplified analytical method providing accurate unstrained lengths of all structural elements is proposed to find the optimized initial state of self-anchored suspension bridges under dead loads. For this, equilibrium equations of the main girder and the main cable system are derived and solved by evaluating the self-weights of cable members using unstrained cable lengths and iteratively updating both the horizontal tension component and the vertical profile of the main cable. Furthermore, to demonstrate the validity of the simplified analytical method, the unstrained element length method (ULM) is applied to suspension bridge models based on the unstressed lengths of both cable and frame members calculated from the analytical method. Through numerical examples, it is demonstrated that the proposed analytical method can indeed provide an optimized initial solution by showing that both the simplified method and the nonlinear FE procedure lead to practically identical initial configurations with only localized small bending moment distributions.


2014 ◽  
Vol 543-547 ◽  
pp. 3977-3981
Author(s):  
Jian Yuan Sun ◽  
Cheng Zhang Yin ◽  
Zeng Bao Ma

With the increase of the span of suspension bridge, the weight of the main cable increases, and the safety margin becomes smaller. Thus high accuracy is necessary for the construction control analysis of suspension bridges. The traditional finite element software cannot meet the accuracy requirement because of temperature, cable saddle and other factors, which influence the construction control. Based on the modified segmental catenary method, this paper has come up with a fine analysis method for the construction control of suspension bridges. And a software program called ZambisSC has been developed using object-oriented programming language combined with a number of the latest software development technologies. Compared with the monitoring results of Nancha suspension bridge in Guangzhou, China, it shows that ZambisSC can predict the main cable shape with high accuracy.


Sign in / Sign up

Export Citation Format

Share Document