Technologies on Replacement of Structural Members in Prestressed Concrete Cable-Stayed Bridges

2012 ◽  
Vol 446-449 ◽  
pp. 1158-1166 ◽  
Author(s):  
Hong Jiang Li
Keyword(s):  
Prestressed Concrete ◽  
Engineering Application ◽  
Practical Experience ◽  
Structural Condition ◽  
Structural Members ◽  
Long Span Bridges ◽  
Long Span ◽  
Sustainable Operation ◽  
Key Techniques ◽  
Cable Stayed Bridges

Different from traditional strengthening methods, the technology on replacement of structural members is a new strengthening concept for solving the problem of local failures in prestressed concrete cable-stayed bridges. To clarify the characteristics and realization ways of this technology, practical experience and latest achievements of strengthening prestressed concrete cable-stayed bridges in recent years in China were summarized comprehensively, such as replacement of stay cables, replacement of closure segment, replacement of tension rocker bearing cables at subsidiary piers, et al. Forms of Special diseases were described, and their failure mechanisms were given. Then calculation methods and key techniques of these strengthening ways were introduced. Engineering application and practice showed, the technology on replacement of structural members is a system engineering, namely, not only new structural members should meet the mechanical requirements of their own, but also the structural condition of whole bridge should be improved through replacing structural members. Establishment and development of this technology had important and far-reaching significance to promote the technical level of strengthening long-span bridges under the condition of special diseases and ensure bridges in the sate of safe and sustainable operation.

scholarly journals Serviceability Assessment Method of Stay Cables with Vibration Control Using First-Passage Probability

2019 ◽  
Vol 2019 ◽  
pp. 1-9 ◽  
Author(s):  
Seunghoo Jeong ◽  
Young-Joo Lee ◽  
Sung-Han Sim
Keyword(s):  
Vibration Control ◽  
Control Method ◽  
Principal Component ◽  
Assessment Method ◽  
Stay Cable ◽  
First Passage ◽  
Long Span Bridges ◽  
Long Span ◽  
Stay Cables ◽  
Cable Stayed Bridges

As the construction of long-span bridges such as cable-stayed bridges increases worldwide, maintaining bridge serviceability and operability has become an important issue in civil engineering. The stay cable is a principal component of cable-stayed bridges and is generally lightly damped and intrinsically vulnerable to vibration. Excessive vibrations in stay cables can potentially cause long-term fatigue accumulation and serviceability issues. Previous studies have mainly focused on the mitigation of cable vibration within an acceptable operational level, while little attention has been paid to the quantitative assessment of serviceability enhancement provided by vibration control. This study accordingly proposed and evaluated a serviceability assessment method for stay cables equipped with vibration control. Cable serviceability failure was defined according to the range of acceptable cable responses provided in most bridge design codes. The cable serviceability failure probability was then determined by means of the first-passage problem using VanMarcke’s approximation. The proposed approach effectively allows the probability of serviceability failure to be calculated depending on the properties of any installed vibration control method. To demonstrate the proposed method, the stay cables of the Second Jindo Bridge in South Korea were evaluated and the analysis results accurately reflected cable behavior during a known wind event and show that the appropriate selection of vibration control method and properties can effectively reduce the probability of serviceability failure.

scholarly journals State-of-the-Art Review on Determining Prestress Losses in Prestressed Concrete Girders

2020 ◽  
Vol 10 (20) ◽  
pp. 7257
Author(s):  
Marco Bonopera ◽  
Kuo-Chun Chang ◽  
Zheng-Kuan Lee
Keyword(s):  
Prestressed Concrete ◽  
State Of The Art ◽  
Nondestructive Method ◽  
Prestress Loss ◽  
Prestress Losses ◽  
Long Span Bridges ◽  
Concrete Girders ◽  
Long Span ◽  
Vibration Responses ◽  
Prestressed Concrete Girders

Prestressing methods were used to realize long-span bridges in the last few decades. For their predictive maintenance, devices and dynamic nondestructive procedures for identifying prestress losses were mainly developed since serviceability and safety of Prestressed Concrete (PC) girders depend on the effective state of prestressing. In fact, substantial long term prestress losses can induce excessive deflections and cracking in large span PC bridge girders. However, old unsolved problematics as well as new challenges exist since a variation in prestress force does not significantly affect the vibration responses of such PC girders. As a result, this makes uncertain the use of natural frequencies as appropriate parameters for prestress loss determinations. Thus, amongst emerging techniques, static identification based on vertical deflections has preliminary proved to be a reliable method with the goal to become a dominant approach in the near future. In fact, measured vertical deflections take accurately and instantaneously into account the changes of structural geometry of PC girders due to prestressing losses on the equilibrium conditions, in turn caused by the combined effects of tendon relaxation, concrete creep and shrinkage, and parameters of real environment as, e.g., temperature and relative humidity. Given the current state of quantitative and principled methodologies, this paper represents a state-of-the-art review of some important research works on determining prestress losses conducted worldwide. The attention is principally focused on a static nondestructive method, and a comparison with dynamic ones is elaborated. Comments and recommendations are made at proper places, while concluding remarks including future studies and field developments are mentioned at the end of the paper.

Sustainability design strategies for cable-stayed bridges

2019 ◽  
Author(s):  
Juan A. Sobrino
Keyword(s):  
Economic Benefits ◽  
Design Strategies ◽  
Long Span Bridges ◽  
Long Span ◽  
Sustainability Strategies ◽  
The Social ◽  
Relevant Role ◽  
Magdalena River ◽  
Local Materials ◽  
Cable Stayed Bridges

<p>Sustainability design considerations play a relevant role in long span bridges. In addition to the social and economic benefits to communities, a good design must be respectfully integrated into the environment and implement other sustainability strategies: prioritizing the use of local materials and labour, and design for durability to extend its lifetime. Minimization of the amount of materials, even with solutions that require more labour, is also an unrecognized strategy to reduce the carbon print.</p><p>The paper presents the sustainability strategies utilized in the design of two cable-stayed bridges recently completed in Colombia: The Hisgaura Bridge and the Magdalena River crossing at Honda. The design of both bridges has been driven by a combination of various factors, all aligned with sustainability practices, such as minimum impact on the natural environment, use of light-weight structures to minimize consumption of materials, use of local materials and labor, along with constructability and cost considerations.</p><p>The Hisgaura bridge is a concrete cable-stayed structure with a main span of 330 m and 148 m tall pylons that is one of the tallest bridges in Latin-America. The Honda bridge is a similar structure with a main span of 247 m over the longest river in Colombia.</p>

Research on Temperature Influences in Cable-Stayed Bridges’ Health Monitoring

2012 ◽  
Vol 188 ◽  
pp. 162-167 ◽  
Author(s):  
Chang Rong Yao ◽  
Ya Dong Li
Keyword(s):  
Health Monitoring ◽  
Temperature Fields ◽  
Effect Of Temperature ◽  
Long Span Bridges ◽  
Bridge Health Monitoring ◽  
Long Span ◽  
Monitoring Strategies ◽  
Structure Monitoring ◽  
Structural Responses ◽  
Cable Stayed Bridges

The health monitoring for long-span bridges has become a hotspot in civil engineering. However, because of the complexity and particularity in bridge structure, monitoring variables are greatly influenced by environmental factors, which results in more difficulties in evaluation. The paper analyzes structural responses in different temperature fields, and the results show that effect of temperature difference among members and temperature gradient are remarkable on structures. The results may be of reference for formulation of bridge health monitoring strategies.

scholarly journals Condition Diagnosis of Long-Span Bridge Pile Foundations Based on the Spatial Correlation of High-Density Strain Measurement Points

2021 ◽  
Vol 13 (22) ◽  
pp. 12498
Author(s):  
Feng Liu ◽  
Qianen Xu ◽  
Yang Liu
Keyword(s):  
Spatial Correlation ◽  
Strain Measurement ◽  
Pile Foundation ◽  
Brillouin Scattering ◽  
Density Measurement ◽  
Structural Condition ◽  
High Density ◽  
Pile Foundations ◽  
Long Span Bridges ◽  
Long Span

Pile foundations of long-span bridges are often deeply buried in soil, and their structural condition is difficult to accurately diagnose by conventional methods. To address this issue, a method for diagnosing the structural condition of bridge pile foundations based on the spatial correlation of high-density strain measurement points is proposed. The strain data of the high-density measurement points of a bridge pile foundation are obtained by using distributed optical fiber sensing technology based on Brillouin scattering, and then an algorithm for diagnosing the structural condition of the pile foundation based on geographically weighted regression analysis is presented. On this basis, aiming at the scour of the pile foundation of long-span bridges, an algorithm for estimating the scour depth of the pile foundation based on sliding plane clustering is proposed. Finally, the effectiveness of the proposed method is verified by numerical simulation and actual bridge data.

Large Bridges Recently Built in Poland

2018 ◽  
Author(s):  
Robert Toczkiewicz ◽  
Jan Biliszczuk ◽  
Marco Teichgraeber
Keyword(s):  
Construction Technology ◽  
Structural Configuration ◽  
Arch Bridge ◽  
Long Span Bridges ◽  
The Road ◽  
Long Span ◽  
Railway Infrastructure ◽  
Cable Stayed Bridges

<p>The road and railway infrastructure in Poland has been intensively developed and modernized for the last years. Around 300 new bridges are built annually. Among the new structures there is a group of modern long span bridges.</p> <p>This paper presents examples of selected, most interesting large road bridges built in recent years in Poland. The following structures are described:</p><ul><li> <p>two largest extradosed bridges in Europe – with spans exceeding 200 m;</p></li><li> <p>the largest arch bridge in Poland with 270 m long fixed arches and an expressway bridge with 200 m long arch span;</p></li><li> <p>two cable-stayed bridges.</p> <p>Structural configuration and construction technology of the above mentioned bridges are described.</p>

scholarly journals Long-Term Deflection of Prestressed Concrete Bridge Considering Nonuniform Shrinkage and Crack Propagation by Equivalent Load Approach

2020 ◽  
Vol 10 (21) ◽  
pp. 7754
Author(s):  
Fiseha Nega Birhane ◽  
Sung-Il Kim ◽  
Seung Yup Jang
Keyword(s):  
Prestressed Concrete ◽  
Three Dimensional ◽  
Simplified Approach ◽  
Long Span Bridges ◽  
Long Span ◽  
Dimensional Finite Element ◽  
Current Design ◽  
Equivalent Load ◽  
Three Dimensional Finite Element

Long-span prestressed concrete (PSC) bridges often suffer excessive deflection during their service lives. The nonuniform shrinkage strains of concrete caused by uneven moisture distributions can induce significant additional deflections, when combined with the creep and cracking of the concrete. Current design practices usually overlook these factors, and the few proposed approaches to consider them are complex and computationally expensive. This study proposes a simplified approach for considering the effect of nonuniform shrinkage by using the equivalent load concept in combination with a nonlinear analysis of the creep and cracking using three-dimensional finite element models. The long-term deflections of short-, medium-, and long-span PSC bridges are calculated under the combined effects of creep, shrinkage, and cracking. The results show that the nonuniform shrinkage effect is significant in medium- to long-span bridges, and that the cracking of the concrete reduces the stiffness, thereby increasing the long-term deflection of the bridges (more severely so in combination with creep and shrinkage). The predicted long-term deflections reasonably agree with the measured data. Thus, the equivalent load approach is effective for calculating long-term deflections considering nonuniform shrinkage strains, without the complicated and expensive coupling of moisture transport and structural analyses.

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