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 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.

Main span closure for the New Samuel de Champlain Bridge (NSCB) - An innovative alternative closure using a temporary king-post to accelerate construction

2019 ◽  
Author(s):  
Gonzalo Osborne ◽  
Frederic Saleh
Keyword(s):  
Stay Cable ◽  
Project Completion ◽  
Long Span ◽  
Stay Cables ◽  
The Subject ◽  
Construction Schedule ◽  
Lifting Equipment ◽  
Main Bridge ◽  
Cable Stayed Bridges ◽  
Schedule Requirement

<p>Signature Saint Laurent (SSLC) is the consortium comprised of SNC Lavalin, Flatiron Constructors Canada, Dragados USA and EBC, that selected the design and construction for the New Samuel de Champlain Bridge (NSCB) in Montreal, Canada.</p><p>The NSCB’s construction schedule was the major challenge for a successful project completion. The geometry of the main bridge is complex, with an asymmetric stay cable arrangement and a unique transverse behavior with three independent corridors connected by crossbeams, involving the location of the stay cable anchorages. This geometry questioned the constructability and the stringent schedule requirement. The subject of this paper is relevant to this conference as it pertains to an innovative construction method for cable-stayed bridges.</p><p>The back span was fully erected on temporary towers in advance, followed by the main span which was to be built with heavy lifting equipment in cantilever sequentially from the main single pylon towards to the East approach. A set of three gantries erected the preassembled segments from the ground to the tip of the deck, where they were connected to the previous segment.</p><p>To expedite the construction, an innovative method was developed to erect some segments from the opposite end with cranes from the ground, with a stick-built conventional method. The closure location was therefore shifted by 50 meters (four segments) towards the pylon. These segments would be supported with temporary stay cables anchored to a 36-meter high king-post on top of the deck. The king-post would be sitting on top of the deck, supported temporarily by shoring towers to reduce the demands in the superstructure and adjacent pier.</p><p>This erection system can serve as an alternative method to expedite construction for long span single tower cable stayed bridges, by erecting segments with a temporary stay tower from the opposite end, therefore reducing schedule constraints.</p>

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.

The Analysis of Stayed Cable Wind-Induced Vibration Morphology and Damping Measures

2014 ◽  
Vol 501-504 ◽  
pp. 1174-1177
Author(s):  
Xiao Ming Du ◽  
Nan Li
Keyword(s):  
Time Effect ◽  
Stay Cable ◽  
Main Bearing ◽  
Cable Vibration ◽  
Cable Stayed Bridge ◽  
Long Span ◽  
Stay Cables ◽  
Long Span Bridge ◽  
Long Time ◽  
Wind Induced Vibration

The stayed cable is the key part of the cable-stayed bridge and the main bearing section. Stay cables are prone to vibration under the loads of the rains winds, earthquakes and transportation for the long-span bridge is very flexible and the damping is small. A long time effect of cable vibration on the structure durability has become a serious problem of cable-stayed bridge in the development and operation. Wind induced vibration of stay cable shape is analyzed, and some common damping measures are expounded in the article and it provides the basis for further study in the future.

Experimental Study on Multi-Mode Vibration Control of a Stay Cable with a Passive Magnetorheological Damper

2013 ◽  
Vol 361-363 ◽  
pp. 1402-1405
Author(s):  
Zhi Hao Wang
Keyword(s):  
Vibration Control ◽  
Mr Damper ◽  
Magnetorheological Damper ◽  
Test Results ◽  
Stay Cable ◽  
Mr Dampers ◽  
Stay Cables ◽  
Modal Damping ◽  
Mode Vibration ◽  
Multi Mode

Effective vibration control technology for stay cables is extremely critical to safe operations of cable-stayed bridges. For super-long cables, passive linear damper cannot provide sufficient damping since it can be only optimum for a given mode of cable, while a long cable may vibrate with several modes. This paper focuses on multi-mode vibration control of stay cables with passive magnetorheological (MR) dampers. Firstly, a 21.6m-long model cable was designed and established in the laboratory.Then, control performance of the cable with a passive MR damper was tested. The test results show that modal damping ratios of the cable in the first four modes can be improved significantly with the MR damper. It is further demonstrated that optimal tuned passively operated MR damper can outperform the passive viscous damper.

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>

Deviation saddles for cables bridges: development and qualification ofstay cable technology

2019 ◽  
Author(s):  
Julien-Erdem Erdogan ◽  
Ivica Zivanovic ◽  
Matthieu Guesdon
Keyword(s):  
Corrosion Protection ◽  
High Performance ◽  
Cost Effective ◽  
Stay Cable ◽  
Stay Cables ◽  
Accurate Definition ◽  
High Performance Fiber ◽  
Definition Of ◽  
Bridge Aesthetics ◽  
Cable Stayed Bridges

<p>Deviation saddles for cables are regularly used in projects such as cable stayed bridges, suspended bridges or extradossed bridges. The choice of a deviation saddle may be imposed to improve the bridge aesthetics with a slender pylon and to simplify the construction with a solid pylon section. Saddles are a proper anchorage and must be designed such as to ensure a safe transfer of vertical forces and of differential forces of stay cables into the pylon structure.</p><p>For parallel strand cables, since grouted stay cable tends to disappear from commonly accepted design and technologies, due to corrosion protection and fatigue issues, the most widely used concept of saddle is made of a battery of individual tubes, placed inside a guide pipe poured of concrete.</p><p>The most recent saddle system developed consists in allowing the passage of the strands through the saddle without individual tubes. Strands go directly through concrete recesses within the Ultra High Performance Fiber Concrete (UHPFC) matrix. Recesses are made thanks to reusable rubber bars removed after poured concrete is hardened. Thanks to an optimized cross section of the recesses, individual holes maximize the friction between the concrete and specially sheathed strands with local application of a cohesive sheathing (Cohestrand®), which allow strands to transfer important asymmetrical loads to the saddle without sliding. Meanwhile, a continuous corrosion protection is ensured by the strand sheathing from one deck anchorage to the other.</p><p>This make the use of saddle a cost-effective and durable mean to deviate and anchor parallel strand cables, that suits Owners needing simple but robust design for stay cable or extradossed bridges. Such saddle bridge design is nowadays clearly described in the 7<span>th</span> edition of the PTI recommendations, that specifies the qualification process of saddle technologies, especially in regards to the accurate definition of a minimum friction coefficient.</p>

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