scholarly journals Arranging Parameters of Self-anchored Stressed Ribbon Supported on Arch Pedestrian Bridges

2017 ◽  
Vol 9 (5) ◽  
pp. 495-499 ◽  
Author(s):  
Vilius Karieta
Keyword(s):  
Twentieth Century ◽  
Construction Cost ◽  
Computational Scheme ◽  
Design Parameters ◽  
Suspension Bridges ◽  
Pedestrian Bridges ◽  
Major Disadvantage ◽  
Arch Structure ◽  
Support Reactions ◽  
Horizontal Support

Stressed ribbon pedestrian bridges are most graceful, efficient and economical strains of suspension bridges. However, these structures have a major disadvantage – very large horizontal support reactions, which result mainly to the construction cost. In order to discover new forms and to extend the limits of stressed ribbon bridges, in the end of twentieth century these constructions were started to combine with other bearing elements in cable­stayed, under­deck cable­stayed bridges and other structures. At the beginning of the twenty­first century stressed ribbon supported on arch structure was discovered. The paper presents reviews of suspension supported on arch footbridges and classification. Considered the main geometrical design parameters and their interdependence. The paper presents a method of how to balance self­anchored suspension supported on arch bridge design computational scheme.

scholarly journals Performance of a Suspension Bridge with Active Vibration Dampers

2018 ◽  
Vol 196 ◽  
pp. 01017
Author(s):  
Anatolij Konovalov ◽  
Marina Pustovalova
Keyword(s):  
Cross Sections ◽  
Dynamic Properties ◽  
Suspension Bridge ◽  
Suspension Bridges ◽  
Initial Model ◽  
Strain Behavior ◽  
Pedestrian Bridges ◽  
Active Vibration ◽  
Active Damper ◽  
Vibration Dampers

Suspended structures that are used extensively in construction of motorway and pedestrian bridges allow bridging wide spans without having to install intermediate supports. Being less stiff in comparison to girder and arch bridges, suspension bridges require their dynamic properties to be controlled [1, 2]. This is a vital task when it comes to suspension bridges. Several engineering arrangements are available to control the dynamic properties of the structures [3]. This paper addresses the use of active dampers [4] installed on the tops of the towers as the means to control vibrations of a suspension bridge. To this end, a planar 3D model of suspension bridge was built using ANSYS software. The authors compared stress-strain behavior and dynamic properties of the models with and without active vibration dampers. In contrast to the initial model, the model of a bridge equipped with active dampers exhibits less displacement in all cross-sections. Thus, the displacements are reduced 1.7 times in the middle of the central span of suspended stiffening truss; 2.7 times in the middle of the end span; and displacements of the top of the bridge tower are 1.6 times less. The modal analysis has shown that in the model with active dampers the frequency of transverse vibrations at the tower tops has increased 1.9 times, while vertical vibrations have increased within 23%. Under maximum applied overpressure in the active damper, torsional vibrations of the structure have increased 2.4 times as compared to the initial model. The results obtained by the authors allow for the conclusion that active dampers are useful tools for controlling the dynamic properties of a suspension bridge.

Building 8500+ Trail Bridges in the Himalayas

2021 ◽  
Author(s):  
Robert Groeli
Keyword(s):  
International Development ◽  
Technical Assistance ◽  
Local Level ◽  
Cost Effective ◽  
Suspension Bridge ◽  
Development Cooperation ◽  
Design Parameters ◽  
Suspension Bridges ◽  
Teaching Resources ◽  
Economic Output

<p>Mobility is one of the most challenging fundamentals of rural livelihood in the Himalayan hills and mountains. More than 8500 trail bridges, comprising an overall span-length of about 650 kilometers have been constructed to date, saving millions of walking hours for people living in the rural Himalayan areas. Previously, crossing rivers was dangerous and sometimes impossible, especially in the rainy season. These bridges created vital connections which enabled children to go to school and people to access public services and visit medical centers and sanctuaries. They also boost local economic output by reducing the effort required to run local farms, gather crops and visit regional markets.</p><p>Fig. 1:The struggles and dangers of crossing a river and its solution</p><p>Swiss technical assistance for rural trail bridges started in the early sixties with the construction of a few suspension bridges in the hill areas of Nepal. In 1964 the Nepalese Government established the Suspension Bridge Division (SBD), and starting in 1972 the Swiss Government began providing continuous technical and financial assistance. Similarly, the Public Works Department in Bhutan initiated a country wide trail bridge construction program in 1971 for which assistance was provided from 1985-2010. Exchanges of experiences between these programs created a collaborative environment where new ideas could be evaluated and tested in the field. After SBD initially developed the basic technical norms, design parameters and standard designs suitable for long-span bridges, demand for simpler shorter span bridges rose tremendously. This prompted the program to develop “community executable bridge designs” adapted to the local skills and materials while conforming to established engineering standards. As a result, cost-effective, easy to implement technologies and community-based approaches were developed, which have been replicated in numerous countries leading to multiple successful partnerships in international development cooperation.</p><p>The purpose of this paper is to highlight the following outcomes of the trail bridge-program:</p><ul><li><p>Standardized cost-effective trail bridge designs based on local capabilities and bridge-building techniques</p></li><li><p>Published of manuals, technical drawings and teaching resources for design, construction and fabrication</p></li><li><p>Engaged local communities in the construction, operation and maintenance of trail bridges</p></li><li><p>Compiled comprehensive trail bridge directory for planning, monitoring and maintenance</p></li><li><p>Established Sector Wide Approach (SWAp) with institutional frameworks at national and local level</p></li><li><p>‘South-South Cooperation’ with Bhutan, Tanzania, Ethiopia, Indonesia, Laos, Burundi, Honduras, Guatemala</p></li></ul>

scholarly journals Influence of catwalk design parameters on the galloping of constructing main cables in long-span suspension bridges

2017 ◽  
Vol 19 (6) ◽  
pp. 4671-4684 ◽  
Author(s):  
Shengli Li ◽  
Pan Guo ◽  
Chaoqun Wang ◽  
Yanan Hu ◽  
Dongwei Wang
Keyword(s):  
Design Parameters ◽  
Suspension Bridges ◽  
Long Span ◽  
Main Cables

Post-Critical Behavior of Suspension Bridges Under Nonlinear Aerodynamic Loading

2015 ◽  
Vol 11 (1) ◽  
Author(s):  
Andrea Arena ◽  
Walter Lacarbonara ◽  
Pier Marzocca
Keyword(s):  
Reduction Process ◽  
Design Parameters ◽  
Suspension Bridges ◽  
Long Span ◽  
Fold Bifurcation ◽  
Speed Up ◽  
The Stability ◽  
Parametric Analyses ◽  
Bifurcation Behavior ◽  
Nonlinear Aerodynamic

The limit cycle oscillations (LCOs) exhibited by long-span suspension bridges in post-flutter condition are investigated. A parametric dynamic model of prestressed long-span suspension bridges is coupled with a nonlinear quasi-steady aerodynamic formulation to obtain the governing aeroelastic partial differential equations adopted herewith. By employing the Faedo–Galerkin method, the aeroelastic nonlinear equations are reduced to their state-space ordinary differential form. Convergence analysis for the reduction process is first carried out and time-domain simulations are performed to investigate LCOs while continuation tools are employed to path follow the post-critical LCOs. A supercritical Hopf bifurcation behavior, confirmed by a stable LCO, is found past the critical flutter condition. The analysis shows that the LCO amplitude increases with the wind speed up to a secondary critical speed where it terminates with a fold bifurcation. The stability of the LCOs within the range bracketed by the Hopf and fold bifurcations is evaluated by performing parametric analyses regarding the main design parameters that can be affected by uncertainties, primarily the structural damping and the initial wind angle of attack.

scholarly journals Effect of Modification of Deck Properties on Suspension Bridges

2017 ◽  
Vol 12 (1) ◽  
pp. 39-50
Author(s):  
Jagat Kumar Shrestha
Keyword(s):  
Three Dimensional ◽  
Suspension Bridge ◽  
Design Parameters ◽  
Suspension Bridges ◽  
Finite Element Models ◽  
Real World Problem ◽  
Dimensional Finite Element ◽  
Design Requirements ◽  
Three Dimensional Finite Element ◽  
Steel Deck

Different type of deck configuration has been used for suspension bridge depending upon different design requirements. Changes in deck properties lead to changes in behavior of a suspension bridge. In this study, effect of deck modification of a existing bridge from timber to steel deck is considered. Three dimensional finite element models is developed and analyzed changing the deck material from timber to steel which causes reduction in weight and changes in design parameters. This changes the dynamic behavior of the bridge and affects the performance of bearings. The study has been carried out in real world problem encountered in Mugling Suspension Bridge over Trishuli River in Nepal. The study has come up with conclusions and recommendations to increase mass of deck material and replacement of bearings for better performance.Journal of the Institute of Engineering, 2016, 12(1): 39-50

scholarly journals DECREASING DISPLACEMENTS OF PRESTRESSED SUSPENSION BRIDGE

2012 ◽  
Vol 18 (6) ◽  
pp. 858-866 ◽  
Author(s):  
Vadims Goremikins ◽  
Karlis Rocens ◽  
Dmitrijs Serdjuks
Keyword(s):  
Suspension Bridge ◽  
Point Of View ◽  
Small Scale ◽  
Suspension Bridges ◽  
Long Span ◽  
Long Span Bridge ◽  
Major Disadvantage ◽  
Load Carrying ◽  
Vertical Displacements ◽  
The Cross

A suspension bridge is the most suitable type for a long-span bridge due to rational use of structural materials. Increased deformability, which is conditioned by the appearance of the elastic and kinematic displacements, is the major disadvantage of suspension bridges. The problem of increased kinematic displacements under the action of symmetrical and non-symmetrical load can be solved by the prestressing. A prestressed suspension bridge with span of 200 m was considered as an object of investigations. The cable truss with the cross web was considered as the main load carrying structure of prestressed suspension bridges and was compared with the single cable. The considered prestressed suspension bridge was investigated by the FEM program ANSYS 12 and by the small scale physical model. Rational, from the point of view of minimal vertical kinematic displacements, main load-carrying structure of prestressed suspension bridge was developed. The obtained results shows, that usage of cable truss with the cross web as the main load carrying structures of prestressed suspension bridge in comparison with the single cable, reduces vertical displacements upwards by 63.1%, downwards by 1.8% and total displacements by 29.6% under the action of worth situated load.

Revisiting storey enclosure method for early estimation of structural building construction cost

2018 ◽  
Vol 25 (7) ◽  
pp. 877-895 ◽  
Author(s):  
Chau Ngoc Dang ◽  
Long Le-Hoai
Keyword(s):  
Regression Analysis ◽  
Residential Building ◽  
Construction Cost ◽  
Design Parameters ◽  
Cumulative Probability ◽  
Range Estimation ◽  
Building Projects ◽  
Content Type ◽  
Enclosure Method ◽  
The Cost

Purpose The purpose of this paper is to develop several predictive models for estimating the structural construction cost and establish range estimation for the structural construction cost using design information available in early stages of residential building projects. Design/methodology/approach Information about residential building projects is collected based on project documents from construction companies with regard to the design parameters and the actual structural construction costs at completion. Storey enclosure method (SEM) is fundamental for determining the building design parameters, forming the potential variables and developing the cost estimation models using regression analysis. Nonparametric bootstrap method is used to establish range estimation for the structural construction cost. Findings A model which is developed from an integration of advanced SEM, principle component analysis and regression analysis is robust in terms of predictability. In terms of range estimation, cumulative probability-based range estimates and confidence intervals are established. While cumulative probability-based range estimates provide information about the level of uncertainty included in the estimate, confidence intervals provide information about the variability of the estimate. Such information could be very crucial for management decisions in early stages of residential building projects. Originality/value This study could provide practitioners with a better understanding of the uncertainty and variability included in the cost estimate. Hence, they could make effective improvements on cost-related management approaches to enhance project cost performance.

Post-Flutter Bifurcation Behavior in Long-Span Suspension Bridges

2013 ◽  
Author(s):  
Andrea Arena ◽  
Walter Lacarbonara ◽  
Pier Marzocca
Keyword(s):  
Limit Cycle ◽  
Equations Of Motion ◽  
Suspension Bridge ◽  
Sensitivity Analyses ◽  
Design Parameters ◽  
Suspension Bridges ◽  
Limit Cycle Oscillations ◽  
Stability Range ◽  
Long Span ◽  
Fold Bifurcation

A linearized parametric continuum model of a long-span suspension bridge is coupled with a nonlinear quasi-steady aerodynamic model giving the aeroelastic partial differential equations of motion reduced to the state-space ordinary differential form by adopting the Galerkin method. Numerical time-domain simulations are performed to investigate the limit cycle oscillations occurring in the range of post-flutter wind speeds. Continuation tools are thus employed to path follow the limit cycles past the flutter speed where the Hopf bifurcation occurs. The stable post-flutter behavior, which can significantly affect the bridge by fatigue, terminate at a fold bifurcation. This result represents an important assessment of the conducted aeroelastic investigations. The stability range of the limit cycle oscillations is evaluated by carrying out sensitivity analyses with respect to the main design parameters, such as the structural damping and the initial wind angle of attack.

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