Damage detection of a cable-stayed bridge based on the variation of stay cable forces eliminating environmental temperature effects

2016 ◽  
Vol 17 (6) ◽  
pp. 859-880 ◽  
Author(s):  
Chien-Chou Chen ◽  
Wen-Hwa Wu ◽  
Chun-Yan Liu ◽  
Gwolong Lai
Keyword(s):  
Damage Detection ◽  
Temperature Effects ◽  
Environmental Temperature ◽  
Stay Cable ◽  
Cable Stayed Bridge ◽  
Cable Forces

The Second Maintenance and Strengthening of Yonghe Bridge

2011 ◽  
Vol 90-93 ◽  
pp. 1074-1081 ◽  
Author(s):  
Hong Jiang Li
Keyword(s):  
Safety Factor ◽  
Prestressed Concrete ◽  
Line Shape ◽  
Structural System ◽  
Stay Cable ◽  
Cable Stayed Bridge ◽  
Load Combination ◽  
Cable Forces ◽  
Main Girder ◽  
Cable Stayed Bridges

Tension rocker bearing (TRB) cables installed at auxiliary piers were critical members to sustain the structural system in a prestressed concrete cable-stayed bridge. Once these cables fractured or broken, its structural system would be transferred. Based on diseases caused by fracture of TRB cables in Yonghe Bridge, corresponding maintenance or strengthening measures were described in detail. These measures included replacement of TRB cables, strengthening of the closure segment of main girder at each side span, and adjustment of stay cable forces. Monitoring results showed that, its structural system was finally and completely rehabilitated, and the safety factor of new TRB cables is enough under the most unfavorable load combination. Moreover, the line shape of main girder and the inclined displacement at the top of each pylon were improved effectively. Thus, Yonghe Bridge accumulated some valuable experience for maintenance or strengthening of existing prestressed concrete cable-stayed bridges, and also made a useful exploration.

scholarly journals Replacement of Cable Stays in Yonghe Bridge in Tianjin, China

2020 ◽  
Vol 2020 ◽  
pp. 1-17
Author(s):  
Hongjiang Li
Keyword(s):  
Structural Changes ◽  
Structural Condition ◽  
Stay Cable ◽  
Cable System ◽  
Construction Monitoring ◽  
Cable Stayed Bridge ◽  
Cable Stays ◽  
Cable Forces ◽  
Replacement Design ◽  
Design Construction

Cable replacement is one of the most important approaches for retrofitting an existing cable-stayed bridge. The Yonghe Bridge opened to traffic in 1987 and was the largest concrete cable-stayed bridge in Asia at the time. After nearly 20 years in service, its stay-cable system was completely replaced. The present paper details the key technical points of cable replacement in this bridge, including causes of replacement, cable replacement design, construction monitoring during replacement, and cable tension tuning after replacement. Based on the measurements during construction, the variation in structural condition indexes was thoroughly investigated, such as cable forces throughout the bridge, geometry profile of bridge deck, and tower horizontal displacements. The structural changes due to cable replacement were evaluated, and then, a relatively desirable scheme of cable adjustment was correspondingly put forward. The measured results showed that, influenced by the accumulated tolerances of cable forces during construction, cable replacement may often lead to a further deviation of structural condition. In this instance, cable adjustment is an effective compensation measure to improve the overall structural condition of the bridge. The practice of cable replacement in the Yonghe Bridge has provided some valuable experience or beneficial references for the similar retrofitting cases.

scholarly journals Magnetic Properties and Environmental Temperature Effects on Battery Performance of Na 0.67 Mn 0.5 Fe 0.5 O 2

2021 ◽  
pp. 2001130
Author(s):  
Serdar Altin ◽  
Ali Bayri ◽  
Emine Altin ◽  
Erdinc Oz ◽  
Sedat Yasar ◽  
...  
Keyword(s):  
Magnetic Properties ◽  
Temperature Effects ◽  
Environmental Temperature

A prediction method for cable forces of cable-stayed bridges using fuzzy processing and Bayes estimation

2021 ◽  
Author(s):  
Li Dong ◽  
Bin Xie ◽  
Dongli Sun ◽  
Yizhuo Zhang
Keyword(s):  
Prediction Method ◽  
Practical Method ◽  
Bayes Estimation ◽  
Primary Data ◽  
Force Estimation ◽  
Element Analysis ◽  
Cable Stayed Bridge ◽  
Input Parameters ◽  
Cable Forces ◽  
Cable Stayed Bridges

<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>

Fast Tracking the Pulau Poh Cable-stayed Bridge

2018 ◽  
Author(s):  
Chet Chie Voon ◽  
Hiang Miang Goh ◽  
Chuan Seng Koo
Keyword(s):  
Cross Section ◽  
Fast Track ◽  
Rainfall Intensity ◽  
Stay Cable ◽  
Bridge Design ◽  
Environmental Challenges ◽  
High Rainfall ◽  
Fast Tracking ◽  
Cable Stayed Bridge ◽  
Design Life

<p>The construction of the Pulau Poh cable-stayed bridge has been challenging both technically and environmentally. The curved pylon shape in two planes, with changing cross section and heavily congested reinforcement pose constructability concerns. Accurate geometry control and positioning of stay cable anchorages within the pylon is crucial to ensure the bridge meets its intended design life. Located in an area with high rainfall intensity presents additional environmental challenges, where working areas are constantly submerged. To address the challenges and meet the project deadline, innovative construction methodologies are being adopted. The bridge design was also revisited, taking into consideration the construction approach. This paper aims to explain the challenges faced and methods used to fast track the construction of the Pulau Poh cable-stayed bridge.</p>

Insights into temperature effects on structural deformation of a cable-stayed bridge based on structural health monitoring

2018 ◽  
Vol 18 (3) ◽  
pp. 778-791 ◽  
Author(s):  
Yi Zhou ◽  
Limin Sun
Keyword(s):  
Thermal Expansion ◽  
Health Monitoring ◽  
Temperature Effects ◽  
Temperature Response ◽  
Field Measurements ◽  
Structural Deformation ◽  
Linear Superposition ◽  
Thermally Induced ◽  
Diurnal Cycles ◽  
Cable Stayed Bridge

Structural deformation is an important consideration in the health monitoring of bridges, and its dependence on temperature variations is quite complex. Based on field measurements performed for an operational cable-stayed bridge, the proposed study investigates mechanisms of thermally induced variations in girder length and mid-span deflection through plane geometric and finite element analyses. The objective of this study is to understand the behaviour of such bridges over annual and diurnal cycles. It has been observed that the girder length and mid-span deflection of a cable-stayed bridge exhibit different modes of the temperature–response correlation. Thermally induced changes in girder length are solely governed by the average girder temperature, and its annual variation in amplitude is significantly larger compared to the diurnal variation. However, thermally induced mid-span deflections are simultaneously influenced by the cable temperature and average girder temperature, and these do not vary monotonously with temperature, thereby resulting in nearly equal variation amplitudes over both annual and diurnal cycles. Temperature-induced deformations of a cable-stayed bridge could well be approximated through multiple linear superposition of thermal-expansion effects of individual components. Besides thermal-expansion coefficients of structural materials, the temperature dependency of mid-span deflection of a symmetrical twin-tower cable-stayed bridge is closely related to the ratio of tower height above the deck to central span of the girder as well as span ratio of the side span to central span. The proposed simplified formulae to estimate the sensitivities of temperature effects could be readily extended to other cable-stayed bridges with different geometric arrangements, thereby providing valuable insights into thermally induced deformation of such bridges.

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