Probabilistic determination of initial cable forces of cable-stayed bridges under dead loads

2004 ◽  
Vol 17 (2) ◽  
pp. 267-279 ◽  
Author(s):  
Jin Cheng ◽  
Ru-Cheng Xiao ◽  
Jian-Jing Jiang
2015 ◽  
Vol 10 (2) ◽  
pp. 141-150 ◽  
Author(s):  
Antonino Recupero ◽  
Michele Fabio Granata

The determination of initial cable forces in cable-stayed bridges is an important first step in design and analysis of the structure under external loads. Adjustments of stay forces are often required during construction in order to assure the requested behaviour of the bridge in terms of final geometrical configuration and internal force distribution. An accurate assessment of the stay tensioning system allows designers to obtain a good result at the end of construction, by considering the parameters involved as deterministic quantities, assuring the observance of the execution tolerances during works. Actual loads and their variations need instead a stochastic approach which can give useful indications about the effects of parameter variations. Particularly, the measurement on site of the actual values of stay elongations contains errors and the actual values of prestressing forces and working site loads are subjected to unknown variations. In this paper a procedure is implemented which takes into account the stochastic variation of stay elongations and the related uncertainties. The presented method does not require large computational efforts or computer memory. By approximating the probability density distribution of the variables involved by the Gaussian curve, a closed form expression of the imposed elongations given to stays and their variations during erection is provided. The main aim is to obtain an accurate prediction of the differences between the deterministic quantities found by the design analyses and the actual values of deck deformations and stresses in the erection of steel cable-stayed bridges.


2012 ◽  
Vol 44 ◽  
pp. 248-259 ◽  
Author(s):  
M.M. Hassan ◽  
A.O. Nassef ◽  
A.A. El Damatty

2021 ◽  
Author(s):  
Li Dong ◽  
Bin Xie ◽  
Dongli Sun ◽  
Yizhuo Zhang

<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>


Author(s):  
Sami Soppela ◽  
Esko Järvenpää

<p>In the cable-stayed bridges the primary cost components of the load-bearing material, in the longitudinal direction of the bridge, are the cables. The longer the bridge, the higher the share of the costs of the load-bearing material. The quantity of the cables and the cost optimized cable and tower topology can be reliably solved, already in very early design stages, using a simple calculation method proposed in this article. The cables are considered as a curtain structure and the cable forces are calculated for the permanent load balance. The solutions are performed mathematically by using integral calculus based on a force length method and a unit bridge concept. The results provide a good idea of the optimum pylon height for both one-pylon and two-pylon bridges. The optimum pylon height depends on the span ratio and the chosen cable system.</p>


2018 ◽  
Vol 4 (4) ◽  
pp. 137 ◽  
Author(s):  
Alemdar Bayraktar ◽  
Ashraf Ashour ◽  
Halil Karadeniz ◽  
Altok Kurşun ◽  
Arif Erdiş

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.


2016 ◽  
Vol 8 (4) ◽  
Author(s):  
Han Yuan ◽  
Eric Courteille ◽  
Dominique Deblaise

This paper addresses the force distribution of redundantly actuated cable-driven parallel robots (CDPRs). A new and efficient method is proposed for the determination of the lower-boundary of cable forces, including the pose-dependent lower-boundaries. In addition, the effect of cable sag is considered in the calculation of the force distribution to improve the computational accuracy. Simulations are made on a 6DOF CDPR driven by eight cables to demonstrate the validity of the proposed method. Results indicate that the pose-dependent lower-boundary method is more efficient than the fixed lower-boundary method in terms of minimizing the motor size and reducing energy consumption.


2001 ◽  
Vol 25 (12) ◽  
pp. 1099-1115 ◽  
Author(s):  
F.T.K. Au ◽  
Y.S. Cheng ◽  
Y.K. Cheung ◽  
D.Y. Zheng

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