scholarly journals A New Multiconstraint Method for Determining the Optimal Cable Stresses in Cable-Stayed Bridges

2014 ◽  
Vol 2014 ◽  
pp. 1-9 ◽  
Author(s):  
B. Asgari ◽  
S. A. Osman ◽  
A. Adnan
Keyword(s):  
Design Procedure ◽  
Unit Load ◽  
Structural Behaviour ◽  
Long Span Bridges ◽  
Long Span ◽  
Moment Distribution ◽  
Final Design ◽  
Unit Load Method ◽  
Cable Forces ◽  
Cable Stayed Bridges

Cable-stayed bridges are one of the most popular types of long-span bridges. The structural behaviour of cable-stayed bridges is sensitive to the load distribution between the girder, pylons, and cables. The determination of pretensioning cable stresses is critical in the cable-stayed bridge design procedure. By finding the optimum stresses in cables, the load and moment distribution of the bridge can be improved. In recent years, different research works have studied iterative and modern methods to find optimum stresses of cables. However, most of the proposed methods have limitations in optimising the structural performance of cable-stayed bridges. This paper presents a multiconstraint optimisation method to specify the optimum cable forces in cable-stayed bridges. The proposed optimisation method produces less bending moments and stresses in the bridge members and requires shorter simulation time than other proposed methods. The results of comparative study show that the proposed method is more successful in restricting the deck and pylon displacements and providing uniform deck moment distribution than unit load method (ULM). The final design of cable-stayed bridges can be optimised considerably through proposed multiconstraint optimisation method.

Optimization of Pre-Tensioning Cable Forces in Highly Redundant Cable-Stayed Bridges

2015 ◽  
Vol 15 (01) ◽  
pp. 1540005 ◽  
Author(s):  
Banafsheh Asgari ◽  
Siti Aminah Osman ◽  
Azlan Bin Adnan
Keyword(s):  
Structural Performance ◽  
Fe Model ◽  
Optimization Strategy ◽  
Unit Load ◽  
Long Span Bridges ◽  
Long Span ◽  
Moment Distribution ◽  
Unit Load Method ◽  
Cable Forces ◽  
Cable Stayed Bridges

Cable-stayed bridges have been developing rapidly in the last decade and have become one of the most popular types of long-span bridges. One of the important issues in the design and analysis of cable-stayed bridges is determining the pre-tensioning cable forces that optimize the structural performance of the bridge. Appropriate pre-tensioning cable forces improve the damaging effect of unbalanced loading due to the deck dead load. Because the cable-stayed structure is a highly undetermined system, there is no unique solution for directly calculating the initial cable forces. Numerous studies have been conducted on the specification of cable pre-tensioning forces for cable-stayed bridges. However, most of the proposed methods are limited in their ability to optimize the structural performance. This paper presents an effective multi-constraint optimization strategy for cable-stayed bridges based on the application of an inverse problem through unit load method (ULM). The proposed method results in less stresses in the bridge members, more stability and a shorter simulation time than the existing approaches. The finite element (FE) model of the Tatara Bridge in Japan is considered in this study. The results show that the proposed method successfully restricts the pylon displacement and establishes a uniform deck moment distribution in the simulated cable-stayed bridge; thus, it might be a useful tool for designing other long-span cable-stayed bridges.

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.

Monitored structural behavior of a long span cable-stayed bridge under environmental effects

2018 ◽  
Vol 4 (4) ◽  
pp. 137 ◽  
Author(s):  
Alemdar Bayraktar ◽  
Ashraf Ashour ◽  
Halil Karadeniz ◽  
Altok Kurşun ◽  
Arif Erdiş
Keyword(s):  
Air Temperature ◽  
Environmental Effects ◽  
Monitoring Data ◽  
Structural Behavior ◽  
Steel Cable ◽  
Daily Monitoring ◽  
Cable Stayed Bridge ◽  
Long Span ◽  
Cable Forces ◽  
Cable Stayed Bridges

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.

A parametric study on reliability-based tuned-mass damper design against bridge flutter

2015 ◽  
Vol 23 (9) ◽  
pp. 1518-1534 ◽  
Author(s):  
Filippo Ubertini ◽  
Gabriele Comanducci ◽  
Simon Laflamme
Keyword(s):  
Design Procedure ◽  
Tuned Mass Damper ◽  
Computationally Efficient ◽  
Long Span Bridges ◽  
Long Span ◽  
Mass Damper ◽  
Supplemental Damping ◽  
Damper Design ◽  
Reducing Costs ◽  
First Order Method

We present a probabilistic methodology for designing tuned mass dampers for flutter suppression in long-span bridges. The procedure is computationally efficient and computes the probability of flutter occurrence based on a modified first-order method of reliability analysis, a reduced-order representation of the structure and a time domain formulation of aeroelastic loads. Results of a parametric investigation show that the proposed methodology is preferable to a deterministic design procedure, which relies on nominal values of mechanical and aerodynamic parameters and does not guarantee the maximum safety. Furthermore, the reliability-based approach can be effectively used in the design of multiple tuned mass damper configurations by enhancing robustness against frequency mistuning and by reducing costs associated with supplemental damping for a given safety performance level.

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.

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>

MULTI-MODE COUPLED BUFFETING ANALYSIS OF CABLE-STAYED BRIDGES

2001 ◽  
Vol 01 (03) ◽  
pp. 429-453 ◽  
Author(s):  
YEONG-BIN YANG ◽  
SU-VAI MAC ◽  
CHERN-HWA CHEN
Keyword(s):  
Wind Velocity ◽  
Complex Geometry ◽  
Coupling Effect ◽  
Conventional Approach ◽  
Long Span Bridges ◽  
Long Span ◽  
Asymmetric Shape ◽  
Critical Wind Velocity ◽  
Multi Mode ◽  
Cable Stayed Bridges

A procedure for the spectral analysis of buffeting response of long span bridges under unsteady wind loads is developed, with emphasis placed on inclusion of the multi-mode vibrations. The effect of mean wind velocity is considered through the aerodynamic stiffness and damping matrices using the flutter derivatives, while the effect of buffeting through the auto- and cross-power spectral densities. Compared with the conventional approach, the present approach is featured by the fact that no selection has to be made concerning the dominant modes. It can be reasonably used in analyzing cable-stayed bridges of complex geometry or of asymmetric shape, such as the Kao-Ping-Hsi Bridge, where the conventional approach has its limitations. The numerical studies indicate that using the conventional approach, by which the coupling effect is ignored, may significantly overestimate the critical wind velocity, while underestimating the buffeting responses of cable-stayed bridges.

scholarly journals Automated Real-Time Assessment of Stay-Cable Serviceability Using Smart Sensors

2019 ◽  
Vol 9 (20) ◽  
pp. 4469 ◽  
Author(s):  
Seunghoo Jeong ◽  
Young-Joo Lee ◽  
Do Hyoung Shin ◽  
Sung-Han Sim
Keyword(s):  
Real Time ◽  
Damping Ratio ◽  
Assessment System ◽  
Smart Sensors ◽  
Stay Cable ◽  
Long Span Bridges ◽  
Long Span ◽  
Stay Cables ◽  
High Flexibility ◽  
Cable Stayed Bridges

The number of cable-stayed bridges being built worldwide has been increasing owing to the increasing demand for long-span bridges. As the stay-cable is one of critical load-carrying members of cable-stayed bridges, its maintenance has become a significant issue. The stay-cable has an inherently low damping ratio with high flexibility, which makes it vulnerable to vibrations owing to wind, rain, and traffic. Excessive vibration of the stay-cable can cause long-term fatigue problems in the stay-cable as well as the cable-stayed bridge. Therefore, civil engineers are required to carry out maintenance measures on stay-cables as a high priority. For the maintenance of the stay-cables, an automated real-time serviceability assessment system using wireless smart sensors was developed in this study. When the displacement of the cable in the mid-span exceeds either the upper or the lower bound provided in most bridge design codes, it is considered as a serviceability failure. The system developed in this study features embedded on-board processing, including the measurement of acceleration, estimation of displacement from measured acceleration, serviceability assessment, and monitoring through wireless communication. A series of laboratory tests were carried out to verify the performance of the developed system.

Sign in / Sign up

Export Citation Format

Share Document