Aerodynamic Countermeasure Schemes of Super Long-Span Suspension Bridges with Various Aspect Ratios

2020 ◽  
Vol 20 (05) ◽  
pp. 2050061 ◽  
Author(s):  
Yongxin Yang ◽  
Yaojun Ge ◽  
Rui Zhou ◽  
Shiguo Chen ◽  
Lihai Zhang
Keyword(s):  
Aspect Ratio ◽  
Suspension Bridges ◽  
Shape Variation ◽  
Control Effect ◽  
Long Span Bridges ◽  
Long Span ◽  
Aspect Ratios ◽  
Typical Aspect ◽  
Wind Barrier ◽  
Girder Bridge

The purpose of this study is to investigate the flutter control scheme of super long-span bridges with various aspect ratios (e.g. width to height (B/H)) using passive aerodynamic countermeasures. Through a series of wind tunnel testing and theoretical analysis, three types of passive aerodynamic countermeasures, i.e. vertical central stabilizer (VCS), wind barrier and inspection rail, were investigated for five typical aspect ratios of a closed-box girder bridge. The results show that both the aspect ratio and flutter critical wind speed generally increase with the decrease of the ratio of torsional and vertical frequencies of the bridge. In the case of an aspect ratio of 8.9, a downward VCS (DVCS) has a much better flutter performance than that of an upward VCS (UVCS) because aerodynamic damping of Part A and Part D could produce a higher heaving degree of freedom (DOF) participation level. Furthermore, the position variation of wind barriers is superior to their shape variation for the bridge with an aspect ratio of 8.3, and the flutter performance of the girder with a combination of the wind barrier (WB3P3) and UDVCS with 0.3[Formula: see text]h/H DVCS appears to be better than that without countermeasures. In addition, the installation of an inspection rail near the bottom point of an inclined-web (IR3) has the best flutter control effect among four positions of inspection rails.

Damper Optimization for Long-Span Suspension Bridges

2013 ◽  
pp. 112-125
Author(s):  
Hao Wang ◽  
Aiqun Li ◽  
Zhouhong Zong ◽  
Teng Tong ◽  
Rui Zhou
Keyword(s):  
Seismic Response ◽  
Optimization Method ◽  
Sensitivity Analyses ◽  
Suspension Bridges ◽  
Seismic Responses ◽  
Control Effect ◽  
Analytic Hierarchy ◽  
First Order ◽  
Traveling Wave Effect ◽  
Long Span

Long-span suspension bridges are becoming prevalent globally with the rapid progress in design methodologies and construction technologies. Although with apparent progress, the balance between excessive displacement and inner forces, under dynamic loads, is still a main concern because of increased flexibility and low structural damping. Therefore, effective controllers should be employed to control the seismic responses to ensure their normal operation. In this chapter, the combination of the analytic hierarchy process (AHP) and first-order optimization method are formulated to optimize seismic response control effect of the Runyang suspension bridge (RSB) under earthquakes, considering traveling wave effect. The compositive optimal parameters of dampers are achieved on the basis of 3-dimensional nonlinear seismic response analyses for the RSB and parameters sensitivity analyses. Results show that the dampers with rational parameters can reduce the seismic responses of the bridge significantly, and the application of the AHP and first-order optimization method can lead to accurate optimization effects.

scholarly journals Modeling and simulation of bridge-section buffeting response in turbulent flow

2019 ◽  
Vol 29 (05) ◽  
pp. 939-966 ◽  
Author(s):  
Tore A. Helgedagsrud ◽  
Yuri Bazilevs ◽  
Kjell M. Mathisen ◽  
Jinhui Yan ◽  
Ole A. Øseth
Keyword(s):  
Aspect Ratio ◽  
Modeling And Simulation ◽  
Turbulent Flows ◽  
Wind Engineering ◽  
Long Span Bridges ◽  
Buffeting Response ◽  
Long Span ◽  
Inflow Turbulence ◽  
Practical Impact ◽  
Good Agreement

Buffeting analysis plays an important role in the wind-resistant design of long-span bridges. While computational methods have been widely used in the study of self-excited forces on bridge sections, there is very little work on applying advanced simulation to buffeting analysis. In an effort to address this shortcoming, we developed a framework for the buffeting simulation of bridge sections subjected to turbulent flows. We carry out simulations of a rectangular bridge section with aspect ratio 10 and compute its aerodynamic admittance functions. The simulations show good agreement with airfoil theory and experimental observations. It was found that inflow turbulence plays an important role in obtaining accurate wind loads on the bridge sections. The proposed methodology is envisioned to have practical impact in wind engineering of structures in the future.

Wind Tunnel Studyon Vortex-Induced Vibration Characteristics of Long-Span Suspension Bridges with Single Cable Plane

2014 ◽  
Vol 633-634 ◽  
pp. 1263-1266
Author(s):  
Huang Yu
Keyword(s):  
Wind Tunnel ◽  
Suspension Bridge ◽  
Wind Tunnel Experiment ◽  
Vibration Characteristics ◽  
Torsional Stiffness ◽  
Suspension Bridges ◽  
Vortex Induced Vibration ◽  
Long Span Bridges ◽  
Wind Speeds ◽  
Long Span

For modern long-span bridges, both the optimization of aerodynamic shape and the increase of torsional stiffness according to the result of the wind tunnel experiment could avoid the flutter instability.Vortex-inducedvibration with relatively large amplitude happens easily at low wind speeds. In this paper, based on wind tunnel experiment, by studying on the vortex-induced vibration characteristics of a long-span suspension bridge with single cable plane, aerodynamic measures for easing the vortex-induced vibration are given.

Mechanics Characteristics Study for Cable-Stayed-Suspension Bridges

2011 ◽  
Vol 243-249 ◽  
pp. 1817-1825
Author(s):  
Jing Qiu ◽  
Rui Li Shen ◽  
Huai Guang Li
Keyword(s):  
Finite Element ◽  
Suspension Bridge ◽  
Simulation Method ◽  
Suspension Bridges ◽  
Preliminary Design ◽  
Structural System ◽  
Long Span Bridges ◽  
Long Span ◽  
Element Simulation ◽  
Mechanics Characteristics

As a composite structure, the cable-stayed-suspension bridge is characterized by relatively new structure, great overall stiffness and long-span capacity, which has been proposed for the design of some extra long-span bridges. In order to research further into the mechanics characteristics of this type of structural system, the proposed preliminary design of a cable-stayed-suspension bridge with a main span of 1800m is analyzed by means of finite element simulation method. The advantages on overall stiffness in the cable-stayed-suspension bridge are summarized in comparison with the three-span suspension bridge and the single-span suspension bridge. Then, the reasons for the fatigue of the longest suspension cables in the cable-stayed-suspension bridge are also discussed in this paper.

A Study on the Development of Slip Form System With Lightweight GFRP Panel

2013 ◽  
Author(s):  
Hyejin Yoon ◽  
Won Jong Chin ◽  
Hee Seok Kim ◽  
Young Jin Kim
Keyword(s):  
High Performance ◽  
High Strength ◽  
Suspension Bridges ◽  
Long Span Bridges ◽  
Long Span ◽  
Management Technology ◽  
Early Strength ◽  
Near Future ◽  
Form System ◽  
Design And Construction

Nowadays, many countries are competing in the erection of long-span bridges with main span longer than 2,000 m owing to the tremendous innovations realized in the domain of high performance and high strength materials as well as in the design and construction technologies. The near future will see a boom in the market of suspension bridges with main span longer than 3,000 m. Since three-dimensionally shaped high concrete pylons would be unavoidably required to construct these super long-span bridges, need is to develop advanced slip form systems for their erection. This paper presents the development of a slip form system applying lightweight GFRP panel. Improved slip form management technology is secured by introducing a slip-up technique using GPS-based verticality control and wireless early strength estimation. A mock-up test is conducted by designing and fabricating the slip form system based on the developed techniques.

Shaking Table Test of a Long-Span Continuous Girder Bridge

2012 ◽  
Vol 446-449 ◽  
pp. 242-246
Author(s):  
Yan Jiang Chen ◽  
Da Xing Zhou ◽  
Wei Ming Yan ◽  
Zhen Yun Tang
Keyword(s):  
Seismic Design ◽  
Shaking Table Test ◽  
Shaking Table ◽  
Technology Study ◽  
Long Span Bridges ◽  
Long Span ◽  
Test Technology ◽  
Continuous Girder Bridge ◽  
Girder Bridge ◽  
Support Excitation

Compared with middle-span bridges, seismic response of long-span bridges is more complicated, and so is seismic design. For example, influence of high order modes is obvious, as well as multi-support excitation, all kinds of nonlinear factors and soil and structure interaction (SSI). It is necessary to study on seismic behavior of a long-span continuous girder bridge. With the help of shake table array and substructure test technology, study on seismic performance of a long-span continuous girder bridge has been done and some useful conclusions have been got.

scholarly journals Cable Interlayer Slip Damage Identification Based on the Derivatives of Eigenparameters

Sensors ◽  
2018 ◽  
Vol 18 (12) ◽  
pp. 4456
Author(s):  
Jintu Zhong ◽  
Quansheng Yan ◽  
Liu Mei ◽  
Xijun Ye ◽  
Jie Wu
Keyword(s):  
Damage Identification ◽  
Bending Stiffness ◽  
Tikhonov Regularization Method ◽  
Suspension Bridges ◽  
Damage State ◽  
Long Span Bridges ◽  
Long Span ◽  
Stiffness Reduction ◽  
Interlayer Slip ◽  
Fixed End

Cables are the main load-bearing structural components of long-span bridges, such as suspension bridges and cable-stayed bridges. When relative slip occurs among the wires in a cable, the local bending stiffness of the cable will significantly decrease, and the cable enters a local interlayer slip damage state. The decrease in the local bending stiffness caused by the local interlayer slip damage to the cable is symmetric or approximately symmetric for multiple elements at both the fixed end and the external load position. An eigenpair sensitivity identification method is introduced in this study to identify the interlayer slip damage to the cable. First, an eigenparameter sensitivity calculation formula is deduced. Second, the cable is discretized as a mass-spring-damping structural system considering stiffness and damping, and the magnitude of the cable interlayer slip damage is simulated based on the degree of stiffness reduction. The Tikhonov regularization method is introduced to solve the damage identification equation of the inverse problem, and artificial white noise is introduced to evaluate the robustness of the method to noise. Numerical examples of stayed cables are investigated to illustrate the efficiency and accuracy of the method proposed in this study.

scholarly journals Dynamic response of long-span bridges subjected to nonuniform excitation: a state-of-the-art review

2019 ◽  
Vol 258 ◽  
pp. 05017
Author(s):  
Seplika Yadi ◽  
Bambang Suhendro ◽  
Henricus Priyosulistyo ◽  
Akhmad Aminullah
Keyword(s):  
Dynamic Response ◽  
State Of The Art ◽  
Ground Motions ◽  
Experimental Studies ◽  
Suspension Bridges ◽  
Long Span Bridges ◽  
Long Span ◽  
Numerical Studies ◽  
Multiple Support ◽  
Support Excitation

In recent years, considerable attention has been paid to the research of dynamic response of long-span bridges with particular emphasis on seismic behavior. Cable-stayed and suspension bridges are the most popular types. Since long-span bridges have multi-supports and extreme lengths, due to the spatial variation effects, the ground motions at different supports might be non-uniform. A state-of-the-art update review of the response of long-span bridges subjected to non-uniform excitation is presented. The review mainly focuses on the theoretical aspects of non-uniform excitation, numerical studies, and experimental studies to verify some of the theoretical findings. In this paper, a review of the use of shake-table in experimental studies of long-span bridges is also presented. The non-uniform cases considered include a time delay with the same support excitations, multiple support excitations, and the combination of the first and the later. The results are discussed and summarized in comparison to the cases of uniform support excitation.

Analysis of Structural Parameters of Cable-Stayed Suspension Bridges

2010 ◽  
Vol 163-167 ◽  
pp. 2068-2076
Author(s):  
Jing Qiu ◽  
Rui Li Shen ◽  
Huai Guang Li ◽  
Xun Zhang
Keyword(s):  
Structural Parameters ◽  
Three Dimensional ◽  
Suspension Bridge ◽  
Suspension Bridges ◽  
Analysis Method ◽  
Long Distance ◽  
Long Span Bridges ◽  
Long Span ◽  
And Behavior ◽  
Selection Of

The cable-stayed suspension bridge is a novel composite structure with great overall stiffness and the capacity to span a long distance, which has been proposed for the design of some extra long-span bridges. To take further research on mechanical properties and behavior of this type of structure, the proposed preliminary design of a cable-stayed suspension bridge with a main span of 1800m is analyzed. The three-dimensional nonlinear analysis method is used to investigate systematically the influence of various principal structural parameters on the static and dynamic behavior of bridges. These parameters include the rise-span ratio, the suspension-to-span ratio, the constraint condition of the stiffened girder, the number of auxiliary piers at side spans, the layout of suspension cables, and the elastic modulus of suspension cables. Meanwhile, the selection of the rational values of these parameters is discussed.

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