The document summarizes research on developing new stress-ribbon pedestrian bridges that are stiffened by arches or cables. It describes two types of structures being studied: 1) A two-span stress-ribbon deck supported and stiffened by a central arch. 2) A suspension structure formed by a straight or arched stress-ribbon fixed at the abutments and stiffened by external bearing cables. The paper presents the structural solutions, analysis methods, and some preliminary results from testing scale models.
Stress ribbon and cable supported pedestrian bridgesMasum Majid
This document discusses the analysis and design of stress ribbon and cable supported pedestrian bridges. It begins with an introduction to stress ribbon bridges, which consist of tensioned cables embedded in a thin concrete deck that directly supports pedestrian loads. Several structural systems for cable supported bridges are then presented, including stress ribbon structures, suspension bridges, and cable-stayed bridges. The document focuses on analyzing the static and dynamic behavior of stress ribbon structures through modeling and examples. It evaluates how the stiffness of the concrete deck influences structural response to loading. The key findings are that a fully prestressed concrete deck provides both tension and bending stiffness, improving the bridge's load carrying ability and stiffness compared to alternatives like timber boards or partially prestressed concrete.
1. Stress-ribbon bridges consist of slender concrete deck segments placed over bearing cables in a catenary shape. The deck segments are prestressed to stiffen the structure and provide stability to the cables. These bridges have smooth, curved shapes that blend into the environment and clearly show the flow of internal forces.
2. A new type of stress-ribbon bridge combines the structure with an arch to support or suspend the deck. This helps address the disadvantage of large horizontal forces in classical stress-ribbon bridges. Physical models have proven the structural behavior of stress-ribbon bridges supported by arches.
3. Several stress-ribbon bridges have been built that combine the structure with an arch, including pedestrian
Design and analysis of stress ribbon bridgeseSAT Journals
Abstract
A stressed ribbon bridge (also known as stress-ribbon bridge or catenary bridge) is primarily a structure under tension. The tension cables form the part of the deck which follows an inverted catenary between supports. The ribbon is stressed such that it is in compression, thereby increasing the rigidity of the structure where as a suspension spans tend to sway and bounce. Such bridges are typically made RCC structures with tension cables to support them. Such bridges are generally not designed for vehicular traffic but where it is essential, additional rigidity is essential to avoid the failure of the structure in bending. A stress ribbon bridge of 45 meter span is modelled and analyzed using ANSYS version 12. For simplicity in importing civil materials and civil cross sections, CivilFEM version 12 add-on of ANSYS was used. A 3D model of the whole structure was developed and analyzed and according to the analysis results, the design was performed manually.
Keywords: Stress Ribbon, Precast Segments, Prestressing, Dynamic Analysis, Pedestrian Excitation.
The document discusses stress ribbon bridges, which are a type of suspension bridge where cables are embedded in the deck below the walking surface. Stress ribbon bridges follow a catenary profile and transmit loads via tension in the sagging deck to anchored abutments. The document outlines the history, form, construction techniques, applications, advantages, and recent advances of stress ribbon bridges. Stress ribbon bridges are economically efficient, aesthetically pleasing, require minimal maintenance, and can be erected without falsework.
Stress ribbon bridges are tension structures similar to suspension bridges. They transmit loads via tension in the deck to anchored abutments. Unlike simple spans, the ribbon is stressed in compression, adding stiffness. The first was built in Switzerland in the 1960s. They consist of precast concrete planks supported by bearing tendons and separate prestressing tendons to create the catenary shape. Stress ribbon bridges are economical, aesthetic, and require minimal maintenance.
A stressed ribbon bridge (also stress-ribbon bridge or catenary bridge) is a tension structure (similar in many ways to a simple suspension bridge). The suspension cables are embedded in the deck which follows a catenary arc between supports. Unlike the simple span, the ribbon is stressed in traction, which adds to the stiffness of the structure (simple suspension spans tend to sway and bounce).
what is a ribbon bridge
stress ribbon pedestrian bridges
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interesting civil engineering topics
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Suspension bridges are suspended from cables. The earliest suspension bridges were made of ropes or vines covered with pieces of bamboo. In modern bridges, the cables hang from towers that are attached to caissons or cofferdams. The caissons or cofferdams are implanted deep into the bed of the lake, river or sea. Sub-types include the simple suspension bridge, the stressed ribbon bridge, the underspanned suspension bridge, the suspended-deck suspension bridge, and the self-anchored suspension bridge. There is also what is sometimes called a "semi-suspension" bridge, of which the Ferry Bridge in Burton-upon-Trent is the only one of its kind in Europe.[19]
The longest suspension bridge in the world is the 3,909 m (12,825 ft) Akashi Kaikyō Bridge in Japan.
Stress ribbon and cable supported pedestrian bridgesMasum Majid
This document discusses the analysis and design of stress ribbon and cable supported pedestrian bridges. It begins with an introduction to stress ribbon bridges, which consist of tensioned cables embedded in a thin concrete deck that directly supports pedestrian loads. Several structural systems for cable supported bridges are then presented, including stress ribbon structures, suspension bridges, and cable-stayed bridges. The document focuses on analyzing the static and dynamic behavior of stress ribbon structures through modeling and examples. It evaluates how the stiffness of the concrete deck influences structural response to loading. The key findings are that a fully prestressed concrete deck provides both tension and bending stiffness, improving the bridge's load carrying ability and stiffness compared to alternatives like timber boards or partially prestressed concrete.
1. Stress-ribbon bridges consist of slender concrete deck segments placed over bearing cables in a catenary shape. The deck segments are prestressed to stiffen the structure and provide stability to the cables. These bridges have smooth, curved shapes that blend into the environment and clearly show the flow of internal forces.
2. A new type of stress-ribbon bridge combines the structure with an arch to support or suspend the deck. This helps address the disadvantage of large horizontal forces in classical stress-ribbon bridges. Physical models have proven the structural behavior of stress-ribbon bridges supported by arches.
3. Several stress-ribbon bridges have been built that combine the structure with an arch, including pedestrian
Design and analysis of stress ribbon bridgeseSAT Journals
Abstract
A stressed ribbon bridge (also known as stress-ribbon bridge or catenary bridge) is primarily a structure under tension. The tension cables form the part of the deck which follows an inverted catenary between supports. The ribbon is stressed such that it is in compression, thereby increasing the rigidity of the structure where as a suspension spans tend to sway and bounce. Such bridges are typically made RCC structures with tension cables to support them. Such bridges are generally not designed for vehicular traffic but where it is essential, additional rigidity is essential to avoid the failure of the structure in bending. A stress ribbon bridge of 45 meter span is modelled and analyzed using ANSYS version 12. For simplicity in importing civil materials and civil cross sections, CivilFEM version 12 add-on of ANSYS was used. A 3D model of the whole structure was developed and analyzed and according to the analysis results, the design was performed manually.
Keywords: Stress Ribbon, Precast Segments, Prestressing, Dynamic Analysis, Pedestrian Excitation.
The document discusses stress ribbon bridges, which are a type of suspension bridge where cables are embedded in the deck below the walking surface. Stress ribbon bridges follow a catenary profile and transmit loads via tension in the sagging deck to anchored abutments. The document outlines the history, form, construction techniques, applications, advantages, and recent advances of stress ribbon bridges. Stress ribbon bridges are economically efficient, aesthetically pleasing, require minimal maintenance, and can be erected without falsework.
Stress ribbon bridges are tension structures similar to suspension bridges. They transmit loads via tension in the deck to anchored abutments. Unlike simple spans, the ribbon is stressed in compression, adding stiffness. The first was built in Switzerland in the 1960s. They consist of precast concrete planks supported by bearing tendons and separate prestressing tendons to create the catenary shape. Stress ribbon bridges are economical, aesthetic, and require minimal maintenance.
A stressed ribbon bridge (also stress-ribbon bridge or catenary bridge) is a tension structure (similar in many ways to a simple suspension bridge). The suspension cables are embedded in the deck which follows a catenary arc between supports. Unlike the simple span, the ribbon is stressed in traction, which adds to the stiffness of the structure (simple suspension spans tend to sway and bounce).
what is a ribbon bridge
stress ribbon pedestrian bridges
cancer symbols and colors
bridge materials for sale
materials used to build bridges
used bridge
material used in construction
interesting civil engineering topics
civil engineering topics for presentation
seminar topics pdf
best seminar topics for civil engineering
civil seminar topics ppt
civil engineering seminar topics 2019
seminar topics for mechanical engineers
mechanical engineering seminar topics 2018
Suspension bridges are suspended from cables. The earliest suspension bridges were made of ropes or vines covered with pieces of bamboo. In modern bridges, the cables hang from towers that are attached to caissons or cofferdams. The caissons or cofferdams are implanted deep into the bed of the lake, river or sea. Sub-types include the simple suspension bridge, the stressed ribbon bridge, the underspanned suspension bridge, the suspended-deck suspension bridge, and the self-anchored suspension bridge. There is also what is sometimes called a "semi-suspension" bridge, of which the Ferry Bridge in Burton-upon-Trent is the only one of its kind in Europe.[19]
The longest suspension bridge in the world is the 3,909 m (12,825 ft) Akashi Kaikyō Bridge in Japan.
The document discusses stress ribbon bridges, which are tension structures similar to suspension bridges. Stress ribbon bridges are characterized by smooth, catenary curves and have pre-tensioned cables anchored into supporting structures. They can be supported by flexible saddles, parabolic haunches, or intermediate arch supports. Precast deck segments are slid into place and joined with cast-in-place composite slabs. Post-tensioning of tendons occurs after hardening to finalize the bridge's shape and determine sag. Stress ribbon bridges provide an economical and aesthetically pleasing option with minimal maintenance needs.
This document discusses stress ribbon bridges. It provides an introduction to stress ribbon bridges, describing them as slender concrete deck segments placed on bearing cables shaped like a catenary curve. It explains their construction, comparing them to simple suspension bridges. Advantages include being economical, aesthetic, environmentally friendly structures that require little material and can be erected without falsework. Stress ribbon bridges transfer loads via tension in the thin, precast concrete deck between cable-anchored abutments.
This document provides an overview of reinforced concrete slab bridge design. It discusses the types of reinforced concrete bridges, including slab, beam and slab, arch, box girder, cable-stayed, and integral bridges. It also outlines the loads that must be considered in slab bridge design, including truck, other roadway, sidewalk, and impact loads. Finally, it details the design steps for slab and edge beam components, including calculating bending moments from dead and live loads, determining the effective depth, area of main and distributed reinforcement, and designing the edge beam reinforcement.
Group 06 presents information on suspension bridges. The document includes:
1. A definition of a suspension bridge as a type of bridge where the deck is hung below suspension cables on vertical suspenders.
2. Details about some of the oldest suspension bridges still in service today, including the Roebling Bridge constructed in 1847.
3. Mentions some famous modern suspension bridges like the Golden Gate Bridge and Clifton Suspension Bridge.
This document summarizes the testing and analysis of multiple fettuccine truss bridge designs. It describes the construction and load testing of initial bridges with varying heights and numbers of trusses. The first bridge design had a height of 9cm and 6 trusses, and was able to withstand a maximum load of 1337g before failing when the bottom members broke. Subsequent bridge designs were analyzed and improved based on the weaknesses identified in previous tests, with the goal of optimizing the design to support the greatest load while minimizing weight.
This document provides details on the design of a cable-stayed bridge project over the Suez Canal. The key aspects are:
1) The bridge has a total length of 730m with a 165m side span and 400m main span. It consists of a concrete box girder deck, H-shaped concrete pylons that are 150m tall, and 16 pre-tensioned steel strand cables on each side.
2) Analyses were conducted to determine cable forces, member forces and deformations due to self-weight, live loads, wind, and earthquakes. The bridge was found to meet design criteria.
3) The main components of the deck, pylons, and cables are
This is just an overview about the Reinforced Concrete Deck Girder Bridge
(RCDG Bridge)
the Presentation includes:
Materials for Construction,
Parts of a typical RCDG bridge,
The Forces Acting on the bridge, etc.
BRIDGE CONSTRUCTION ATLAS TE ENSEÑA TODO TIPO DE PUENTES GIGANTES QUE HAY EN TODO EL MUNDO PERO SON MUY CAROS TODOS MAYOR DE 100 MILLONES DE DOLARES A 1 000 MILLONES DE DOLARES CADA UNO.
Cable stay bridges, summary of a lecture delivered at Uni of Surrey, UKDavid Collings
Cable stay bridges, summary of a lecture delivered as part of MSc course at University of Surrey UK. Outlines key issues for sizing major bridges. The work draws on Manual of bridge Enginnering, the authors book Steel Concrete composite bridges - which has a chapter on cable stay bridges, and recent research on cable stay and extradosed bridges.
This document provides information about the design of a composite deck bridge. It includes an abstract describing the key components of a composite deck bridge. The introduction defines different bridge types. The main body describes the structural components of a composite deck bridge, including the RC slab, steel girders, and shear connectors. It outlines the design procedure and provides literature references. The conclusion indicates that site data will be collected and a composite deck bridge will be analyzed and designed using MIDAS software.
STATIC AND DYNAMIC ANALYSIS OF CABLE-STAYED SUSPENSION HYBRID BRIDGE & VALIDA...IAEME Publication
The requirement of long span bridge is increase with development of infrastructure facility in every nation. Long span bridge could be achieved with use of high strength materials and innovative techniques for analysis of bridge. Generally, cable supported bridges comprise both suspension and cable-stayed bridge. Cable supported bridges are very flexible in behavior. These flexible systems are susceptible to the dynamic effects of wind and earthquake loads. The cable-stayed bridge could provide more rigidity due to presence of tensed cable stays as a force resistance element. The suspension bridge could assigned more span in the field of bridge. So, combination of above two structural system the innovative form of cable-stayed suspension hybrid bridge could be the better option to provide more span. Here, attempt is made to analyse long span cable-stayed suspension hybrid bridge. The literature survey on the topic of analysis of cable-stayed suspension hybrid bridge is presented in the current paper. Modeling of cable-stayed suspension hybrid bridge in SAP2000 software and its validation is carried out. The nonlinear static analysis and modal time history analysis of cable-stayed suspension hybrid bridge is carried out in SAP2000 software. The time period of bridge for different mode shape is presented to compare the result of research paper with Sap 2000 software.
The document provides information about the analysis of a pre-stressed bridge construction project. It discusses what a bridge is, classifications of bridges, materials used, and components involved in bridge construction. It also describes the Danyang–Kunshan Grand Bridge in China, the world's longest rail-road bridge. The document outlines the process of post-tensioning bridges and provides field data from the construction of a bridge across Chhokra nalla on the Saddu-Urkura Road.
This document provides an analysis of a truss bridge submitted by SK Abdul Kaium. It includes introductions to trusses and their structural assumptions. It describes different types of trusses like Pratt and Warren trusses. It discusses the motivation for using trusses, their common uses, structural members, loads, load combinations, and methods of analysis. The document analyzes the design of a specific truss structure using STAAD-Pro software and concludes that truss structures are useful, stable, economical, and meet client needs for bridges and other applications.
About Suspension Bridges:
A suspension bridge is a type of bridge in which the deck (the load-bearing portion) is hung below suspension cables on vertical suspenders. The first modern examples of this type of bridge were built in the early 19th century. Bridges without vertical suspenders have a long history in many mountainous parts of the world.
This document discusses reinforced concrete (RC) girder bridges. It begins by defining girder bridges as the simplest bridge type, consisting of horizontal beams supported at each end. RC girder bridges are comprised of deck slabs that vehicles drive on, supported by main girders. There are three main types of girder bridges: box girders, which can handle twisting forces and are suitable for longer spans; concrete girders made of pre-stressed concrete; and I-beam girders made of steel. RC girder bridges must be designed to support dead loads from the structure itself, live loads from traffic, and dynamic loads from wind and weather.
M.Tech Structural Engineering Project on Voided and Cellular Bridge introductionvaignan
This document discusses the analysis of voided and cellular bridge deck structures using the Midas-Civil software. It provides background on voided slab and cellular slab bridges, including their advantages and disadvantages. The literature review found that no previous studies have analyzed these deck types specifically using Midas-Civil. Therefore, the project aims to perform this analysis and compare the manual and Midas-Civil results. The schedule outlines initial manual analysis followed by modeling in Midas-Civil to validate the hand calculations.
This document summarizes a semester project to design a truss bridge using wooden sticks. A group of 5 students designed a bridge combining features of Bonhill and Whipple Arc bridges, using wooden sticks as materials. The bridge is 61 cm long, 14 cm high, and 11 cm wide. Force calculations were performed assuming the bridge would support a mass hanging at the center. Forces were calculated for each truss member, with some in compression and some in tension. A video was also taken to document the project.
With the increase of span length of steel box truss
arch bridge,the problem of nonlinear effect becomes even more
promient.The ultimate bearing capacity is an important means of
evaluate the performance of bridge safety.So it is significant
important in the practical engineering to study the ultimate
bearing capacity of long-span half-through steel box truss arch
bridge.A Yangtze River Highway Brige is a long-span
half-through steel box truss arch bridge with a main span 519
m.The ultimate bearing capacity of the structure are analyzed
using the spatial finite element model.The results show that the
influence of nonlinearities must be considered in the analysis of
ultimate bearing capacity.
In order to facilitate large containerships through the Albert Canal, four lock bridges needed to be elevated and refurbished. SCIA Engineer proofed once more to be an excellent software to do the modelling and dimensioning of the bridges.
The document discusses stress ribbon bridges, which are tension structures similar to suspension bridges. Stress ribbon bridges are characterized by smooth, catenary curves and have pre-tensioned cables anchored into supporting structures. They can be supported by flexible saddles, parabolic haunches, or intermediate arch supports. Precast deck segments are slid into place and joined with cast-in-place composite slabs. Post-tensioning of tendons occurs after hardening to finalize the bridge's shape and determine sag. Stress ribbon bridges provide an economical and aesthetically pleasing option with minimal maintenance needs.
This document discusses stress ribbon bridges. It provides an introduction to stress ribbon bridges, describing them as slender concrete deck segments placed on bearing cables shaped like a catenary curve. It explains their construction, comparing them to simple suspension bridges. Advantages include being economical, aesthetic, environmentally friendly structures that require little material and can be erected without falsework. Stress ribbon bridges transfer loads via tension in the thin, precast concrete deck between cable-anchored abutments.
This document provides an overview of reinforced concrete slab bridge design. It discusses the types of reinforced concrete bridges, including slab, beam and slab, arch, box girder, cable-stayed, and integral bridges. It also outlines the loads that must be considered in slab bridge design, including truck, other roadway, sidewalk, and impact loads. Finally, it details the design steps for slab and edge beam components, including calculating bending moments from dead and live loads, determining the effective depth, area of main and distributed reinforcement, and designing the edge beam reinforcement.
Group 06 presents information on suspension bridges. The document includes:
1. A definition of a suspension bridge as a type of bridge where the deck is hung below suspension cables on vertical suspenders.
2. Details about some of the oldest suspension bridges still in service today, including the Roebling Bridge constructed in 1847.
3. Mentions some famous modern suspension bridges like the Golden Gate Bridge and Clifton Suspension Bridge.
This document summarizes the testing and analysis of multiple fettuccine truss bridge designs. It describes the construction and load testing of initial bridges with varying heights and numbers of trusses. The first bridge design had a height of 9cm and 6 trusses, and was able to withstand a maximum load of 1337g before failing when the bottom members broke. Subsequent bridge designs were analyzed and improved based on the weaknesses identified in previous tests, with the goal of optimizing the design to support the greatest load while minimizing weight.
This document provides details on the design of a cable-stayed bridge project over the Suez Canal. The key aspects are:
1) The bridge has a total length of 730m with a 165m side span and 400m main span. It consists of a concrete box girder deck, H-shaped concrete pylons that are 150m tall, and 16 pre-tensioned steel strand cables on each side.
2) Analyses were conducted to determine cable forces, member forces and deformations due to self-weight, live loads, wind, and earthquakes. The bridge was found to meet design criteria.
3) The main components of the deck, pylons, and cables are
This is just an overview about the Reinforced Concrete Deck Girder Bridge
(RCDG Bridge)
the Presentation includes:
Materials for Construction,
Parts of a typical RCDG bridge,
The Forces Acting on the bridge, etc.
BRIDGE CONSTRUCTION ATLAS TE ENSEÑA TODO TIPO DE PUENTES GIGANTES QUE HAY EN TODO EL MUNDO PERO SON MUY CAROS TODOS MAYOR DE 100 MILLONES DE DOLARES A 1 000 MILLONES DE DOLARES CADA UNO.
Cable stay bridges, summary of a lecture delivered at Uni of Surrey, UKDavid Collings
Cable stay bridges, summary of a lecture delivered as part of MSc course at University of Surrey UK. Outlines key issues for sizing major bridges. The work draws on Manual of bridge Enginnering, the authors book Steel Concrete composite bridges - which has a chapter on cable stay bridges, and recent research on cable stay and extradosed bridges.
This document provides information about the design of a composite deck bridge. It includes an abstract describing the key components of a composite deck bridge. The introduction defines different bridge types. The main body describes the structural components of a composite deck bridge, including the RC slab, steel girders, and shear connectors. It outlines the design procedure and provides literature references. The conclusion indicates that site data will be collected and a composite deck bridge will be analyzed and designed using MIDAS software.
STATIC AND DYNAMIC ANALYSIS OF CABLE-STAYED SUSPENSION HYBRID BRIDGE & VALIDA...IAEME Publication
The requirement of long span bridge is increase with development of infrastructure facility in every nation. Long span bridge could be achieved with use of high strength materials and innovative techniques for analysis of bridge. Generally, cable supported bridges comprise both suspension and cable-stayed bridge. Cable supported bridges are very flexible in behavior. These flexible systems are susceptible to the dynamic effects of wind and earthquake loads. The cable-stayed bridge could provide more rigidity due to presence of tensed cable stays as a force resistance element. The suspension bridge could assigned more span in the field of bridge. So, combination of above two structural system the innovative form of cable-stayed suspension hybrid bridge could be the better option to provide more span. Here, attempt is made to analyse long span cable-stayed suspension hybrid bridge. The literature survey on the topic of analysis of cable-stayed suspension hybrid bridge is presented in the current paper. Modeling of cable-stayed suspension hybrid bridge in SAP2000 software and its validation is carried out. The nonlinear static analysis and modal time history analysis of cable-stayed suspension hybrid bridge is carried out in SAP2000 software. The time period of bridge for different mode shape is presented to compare the result of research paper with Sap 2000 software.
The document provides information about the analysis of a pre-stressed bridge construction project. It discusses what a bridge is, classifications of bridges, materials used, and components involved in bridge construction. It also describes the Danyang–Kunshan Grand Bridge in China, the world's longest rail-road bridge. The document outlines the process of post-tensioning bridges and provides field data from the construction of a bridge across Chhokra nalla on the Saddu-Urkura Road.
This document provides an analysis of a truss bridge submitted by SK Abdul Kaium. It includes introductions to trusses and their structural assumptions. It describes different types of trusses like Pratt and Warren trusses. It discusses the motivation for using trusses, their common uses, structural members, loads, load combinations, and methods of analysis. The document analyzes the design of a specific truss structure using STAAD-Pro software and concludes that truss structures are useful, stable, economical, and meet client needs for bridges and other applications.
About Suspension Bridges:
A suspension bridge is a type of bridge in which the deck (the load-bearing portion) is hung below suspension cables on vertical suspenders. The first modern examples of this type of bridge were built in the early 19th century. Bridges without vertical suspenders have a long history in many mountainous parts of the world.
This document discusses reinforced concrete (RC) girder bridges. It begins by defining girder bridges as the simplest bridge type, consisting of horizontal beams supported at each end. RC girder bridges are comprised of deck slabs that vehicles drive on, supported by main girders. There are three main types of girder bridges: box girders, which can handle twisting forces and are suitable for longer spans; concrete girders made of pre-stressed concrete; and I-beam girders made of steel. RC girder bridges must be designed to support dead loads from the structure itself, live loads from traffic, and dynamic loads from wind and weather.
M.Tech Structural Engineering Project on Voided and Cellular Bridge introductionvaignan
This document discusses the analysis of voided and cellular bridge deck structures using the Midas-Civil software. It provides background on voided slab and cellular slab bridges, including their advantages and disadvantages. The literature review found that no previous studies have analyzed these deck types specifically using Midas-Civil. Therefore, the project aims to perform this analysis and compare the manual and Midas-Civil results. The schedule outlines initial manual analysis followed by modeling in Midas-Civil to validate the hand calculations.
This document summarizes a semester project to design a truss bridge using wooden sticks. A group of 5 students designed a bridge combining features of Bonhill and Whipple Arc bridges, using wooden sticks as materials. The bridge is 61 cm long, 14 cm high, and 11 cm wide. Force calculations were performed assuming the bridge would support a mass hanging at the center. Forces were calculated for each truss member, with some in compression and some in tension. A video was also taken to document the project.
With the increase of span length of steel box truss
arch bridge,the problem of nonlinear effect becomes even more
promient.The ultimate bearing capacity is an important means of
evaluate the performance of bridge safety.So it is significant
important in the practical engineering to study the ultimate
bearing capacity of long-span half-through steel box truss arch
bridge.A Yangtze River Highway Brige is a long-span
half-through steel box truss arch bridge with a main span 519
m.The ultimate bearing capacity of the structure are analyzed
using the spatial finite element model.The results show that the
influence of nonlinearities must be considered in the analysis of
ultimate bearing capacity.
In order to facilitate large containerships through the Albert Canal, four lock bridges needed to be elevated and refurbished. SCIA Engineer proofed once more to be an excellent software to do the modelling and dimensioning of the bridges.
Time history analysis of braced and unbraced steel StructuresSoumitra Das
This document summarizes a study that analyzed the behavior of braced and unbraced steel structures under earthquake loading through time history analysis. A 10-story steel building was designed and analyzed with no bracing, concentric bracing, and eccentric bracing. Earthquake records from Imperial Valley of varying magnitudes were applied. Results showed that the cross-braced structure experienced the highest bending moments and shear forces at the base of corner columns compared to other bracing types. While the concentric braced structure was found to be safer with smaller displacements, the eccentric braced structure was determined to be the most economical option.
The document presents a finite element analysis of concrete filled steel tube (CFT) beams subjected to flexure. A numerical model was developed using ANSYS to predict the flexural behavior and moment capacity of circular and rectangular CFT beams. The model considered the material properties of steel and concrete, and incorporated the interaction between concrete and steel. Results of the numerical analysis for moment capacity were compared to experimental data. For circular CFT beams, the predicted capacities matched well with experimental values. The analysis showed rectangular CFTs can provide good confinement of the concrete core.
Design and analysis of stress ribbon bridgeseSAT Journals
Abstract
A stressed ribbon bridge (also known as stress-ribbon bridge or catenary bridge) is primarily a structure under tension. The tension cables form the part of the deck which follows an inverted catenary between supports. The ribbon is stressed such that it is in compression, thereby increasing the rigidity of the structure where as a suspension spans tend to sway and bounce. Such bridges are typically made RCC structures with tension cables to support them. Such bridges are generally not designed for vehicular traffic but where it is essential, additional rigidity is essential to avoid the failure of the structure in bending. A stress ribbon bridge of 45 meter span is modelled and analyzed using ANSYS version 12. For simplicity in importing civil materials and civil cross sections, CivilFEM version 12 add-on of ANSYS was used. A 3D model of the whole structure was developed and analyzed and according to the analysis results, the design was performed manually.
Keywords: Stress Ribbon, Precast Segments, Prestressing, Dynamic Analysis, Pedestrian Excitation.
International Journal of Engineering and Science Invention (IJESI) is an international journal intended for professionals and researchers in all fields of computer science and electronics. IJESI publishes research articles and reviews within the whole field Engineering Science and Technology, new teaching methods, assessment, validation and the impact of new technologies and it will continue to provide information on the latest trends and developments in this ever-expanding subject. The publications of papers are selected through double peer reviewed to ensure originality, relevance, and readability. The articles published in our journal can be accessed online.
Comparative Analysis between Tube in Tube Structure and Conventional Moment R...IRJET Journal
This document compares the performance of a conventional moment resisting frame structure to a tube-in-tube steel structure through computer modeling and analysis. Five 50-story building models are analyzed: a conventional frame, two tube-in-tube structures with different column spacing, and two tube-in-tube structures with additional X bracing. The analyses indicate that the tube-in-tube structures perform better in resisting lateral loads but have greater displacements. Reducing column spacing and adding bracing in the tube-in-tube models increases their stiffness and decreases displacements and drift, while increasing base shear and accelerations. The tube-in-tube structure with close column spacing and bracing provides the best performance against static and dynamic loads
This paper involves an experimental investigation on the flexural behaviour of curved beams and comparison of its results with conventional beams. Curved beams of size 1200 x 150 x 100 mm with varying initial curvature as 4000mm, 2000mm and the concrete strength as M40 is considered. Various reinforcement are provided in the curved beams to predict which reinforcement detail would give more resistant over maximum loading. The material properties of cement, fine aggregate, coarse aggregate and the compressive strength of concrete cube were found out. A total of 12 specimens of curved beams were casted with various combination of reinforcement along with three control specimens. The beams are tested under two point loading both horizontally and vertically. The deflection and maximum moment carrying capacity are investigated to understand its strength. Also analytical modelling is done to determine the ultimate moment carrying capacity using Finite Element Software ABAQUS to compare with the experimental model.
The document discusses the design and construction of composite bridge piers made of steel pipes and concrete. Experimental tests on scaled pier models showed that the composite piers had higher deformation performance and more stable seismic behavior than conventional reinforced concrete hollow piers. The composite piers exceeded maximum deformation but had relatively small residual displacement after earthquakes. The analytical models of composite piers showed lower deformation performance than experimental results because they could not account for the contribution of ductile steel pipes and high-strength strands. A new construction method called Hybrid Slipform Method provides rapid construction and reduced labor for the composite piers.
Rail Structure Interaction Analysis of Steel Composite Metro BridgeIRJET Journal
This document summarizes a study on rail structure interaction analysis of a steel composite metro bridge in Mumbai, India. The study uses 3D finite element modeling software to analyze stresses in the rails due to temperature variations and train loads. The total bridge length analyzed is 743.43 meters, of which 260.43 meters is steel composite. The objectives are to determine additional rail stresses and bearing forces, and check if stresses are within permissible limits set by standards. Nonlinear springs are used to model the connection between rails and deck, and results will show axial rail stresses along the bridge length.
Long term strain gage monitoring was conducted on the reconstructed silo PC1 to track stress changes in the walls from variations in clinker loading levels and temperatures. Over one year, 16 strain gages at different heights measured stresses as the silo was filled from 5 to 47 meters and discharged. Results showed stresses increased with filling from -52 to 85 MPa and decreased from -29 to -59 MPa with discharge. Stresses also varied by height. Finite element modeling in ANSYS generally matched measured stresses but showed higher dispersion at greater heights. Monitoring provided data to evaluate stresses in the reconstructed silo under working conditions.
This document presents the results of a study comparing the abilities of ABAQUS and OpenSees finite element software to model the pinching and softening behavior observed in an experimental cyclic loading test of a reinforced concrete frame. The test was conducted on a full-scale frame in India. Both software were able to generally capture the strength envelope, but OpenSees was better able to model the pinching effect and strength/stiffness degradation seen in the experimental hysteretic curves. The pinching material model in OpenSees accounted for unloading, reloading and strength degradation in a way that improved the accuracy of the numerical simulation results compared to the experimental data.
A THEORETICAL STUDY ON COLLAPSE MECHANISM AND STRUCTURAL BEHAVIOR OF MULTI-ST...nhandoan10
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Stress ribbon bridges stiffened by arches or cables
1. 1
2nd Int. PhD Symposium in Civil Engineering 1998 Budapest
STRESS-RIBBON BRIDGES STIFFENED BY ARCHES OR
CABLES
Tomas Kulhavy
Technical University of Brno, Department of Concrete and Masonry Structures
Udolni 53
61200 Brno, Czech Republic
SUMMARY
At present research on the development of new stress-ribbon pedestrian bridges is being
carried out. The classical stress-ribbon deck is combined with arches or cables. The
studied structures are two span stress-ribbon supported and stiffened by an arch and
suspension structure formed by a straight or arched stress-ribbon. The paper presents
structural solutions, methods of static and dynamic analysis as well as some results.
Keywords: stress-ribbon, arch, suspension stress-ribbon, modelling, load test
1. INTRODUCTION
Stress-ribbon pedestrian bridges are very economical, aesthetical and almost
maintenance-free structures. They require minimal quantities of materials. They are
erected independently from the existing terrain and therefore they have a minimum
impact upon the environment during construction. One disadvantage of the traditional
stress-ribbon type structures is the need to resist very large horizontal forces at the
abutments. It determines the cost of that solution in many cases. Another characteristic
feature of the stress-ribbon type structures, in addition to their very slender concrete
decks, is that the stiffness and stability are given by the whole structural system using
predominantly the geometric stiffness of the deck. At present research on the
development of new structures combining classical stress-ribbon deck with arches or
cables is being carried out.
The first studied type is a stress-ribbon structure supported by an arch designed by Prof.
Strasky (Fig.1). The stress-ribbon deck is fixed into the side struts. Both the arch and
struts are founded on the same footings. Due to the dead load the horizontal force both
in the arch and in the stress-ribbon have the same magnitude, but they act in opposite
Nnnn
Fig.1 Stress-ribbon stiffened by an arch
2. 2
directions. Therefore the foundation is loaded only by vertical reactions. This self-
anchoring system allows a reduction in the costs of substructure.
The second type of studied structures is a suspension structure formed by a straight or
arched stress-ribbon fixed at the abutments (Fig.2). External bearing cables stiffen the
structure both in the vertical and horizontal directions. Horizontal movements caused by
live load are eliminated by stoppers, which only allow horizontal movement due to
temperature changes and creep and shrinkage of concrete.
2. STRESS-RIBBON STIFFENED BY AN ARCH
The structure in Fig.3 was designed for study purposes. The structure combines a steel
tube arch with a span length of 77 m with a modified stress-ribbon type deck. The arch
is formed by two steel tubes. The steel tubes are supported on concrete foundations. The
tubes have a diameter of 0.60 m and a thickness of 30 mm. The steel arches support the
deck formed by a stress-ribbon of two spans assembled from precast segments. The
deck is fix-connected at midspan with the arch. Steel plates supporting the deck extend
for a short distance from the midspan outwards towards the sides to help keep a
maximum variability in the slope of 8%. At both ends, the stress-ribbon is fixed to a
diaphragm supported by two inclined cast-in-place concrete struts fixed in the
foundations of the arch. The diaphragm is supported by tension pin piles. The
foundation is supported by compression pin piles. The structure forms a self-anchoring
system, where the horizontal forces from the stress-ribbon are transferred by the
inclined concrete struts to the foundation where they are balanced against the horizontal
component of the arch.
Fig.2 Suspension stress-ribbon
Fig.3 Studied structure
3. 3
3. MODELLING OF THE STRESS-RIBBON STIFFENED BY AN ARCH
The development of the structure is carried out in two basic ways. The first type of
development is based on detailed mathematical modelling. The bridge is analyzed by
Ansys as a geometrically non-linear structure for both static and dynamic loads. In the
beginning a preliminary plane frame model was prepared to design the dimensions of
the members. At present a detailed three-dimensional model of the structure is being
prepared.
Model tests are the second type of development. The dynamic response of the structure
to wind load was tested using a scaled aeroelastic model. Tests were performed by Prof.
Pirner at the Institute of Theoretical and Applied Mechanics, Academy of Sciences of
the Czech Republic. The aerodynamic stability of the bridge was checked in a wind
tunnel. At present a test model built to a scale of 1:10 is also being assembled in our
department. The behaviour of the structural members and new details will be verified
using this model by a static load test.
3.1 Model 1:10 - similitude
Similitude is based on conservation of the geometry of the model in its deformed state.
This assumption allows the same level of stresses in the model as in the real structure.
Parameter Real structure Model Scale
Length L Lm L Lm/ = 10
Displacement d dm d dm/ = 10
Area A Am A Am/ = 102
Moment of inertia I Im I Im/ = 104
Modulus of elasticity E Em E Em/ = 1
Force F Fm F Fm/ = 102
Bending moment M Mm M Mm/ = 103
Linear force g gm g gm/ = 10
Stress σ σm σ σ/ m = 1
Strain ε εm ε ε/ m = 1
Tab.1 Similitude scales
According to the scales in Tab.1 geometry, cross-sections and additional loads were
determined. Additional dead load was calculated as follows:
concrete deck g mm add, . /= 2 250 kN
steel arch gm add, .= 0 759 kN / m
4. 4
3.2 Structural solution of the model
Fig.4 General view of the model - elevation and plan
The model approximately 10 m long is fixed to a steel frame anchored to a test room
floor (Fig.4). The height of the model above the floor is sufficient to apply the
additional dead load determined by the previous calculations. The arch is formed by
using two steel tubes 60 mm in diameter and a wall 3 mm thick. Transfer of the
horizontal component of the stress-ribbon axial force to the arch foundation is ensured
by two inclined steel struts. The vertical reaction of the deck is anchored to the steel
5. 5
frame using steel ties. The bearing and prestressing cables are modelled by two
monostrands 15.5 mm in diameter. The deck is assembled from precast segments and
monolithically connected to the end diaphragm. The cross section shape was simplified
to a rectangle 0.50 m in width and 18 mm thickness. Considering the similitude (Tab.1),
the cross section area of the scaled segments corresponds to the real structure cross
section area. The additional load will be applied through the steel bars anchored to the
segments (Fig.5). Three segments are connected to the steel arch at midspan. The
connection provides a sufficient stability of the arch and transfers the stress-ribbon axial
force caused by an unsymmetrical live load to the arch.
Fig.5 Cross-section of the model
3.3 Measurement
The strains of the concrete and steel will be measured at selected measuring points
during the loading of the model. Furthermore, deflections of the deck and arch will be
measured. The model will be loaded in two phases. Firstly the load test for standard
load will be performed after the deck assembling and prestressing. The structure will be
checked for several live load positions. The second phase of the test will be delayed to
involve the influence of creep and shrinkage. A test of the ultimate bearing capacity will
be carried out at the end of the experiment.
4. SUSPENSION STRESS-RIBBON
Pedestrian bridges formed by a suspension stress-ribbon are very slender structures.
Structural stiffness and response of the structure to static and dynamic loads is given
especially by a structural solution. A form of connection between the deck and external
bearing cables, a kind of boundary condition at pylons or abutments and geometry of
bearing cables influence structural behaviour. Slender suspension structure is especially
sensitive to a live load placed on a part of the suspension span and to a wind load.
Support of the deck in a horizontal direction provided by a stopper was designed and
analyzed during the study and development of this structural type. This device allows
horizontal movement due to temperature changes and due to the creep and shrinkage of
concrete. At the same time the device stops horizontal movement due to short-term
loads like a live load, wind load or earthquake. Deck deflection and bending moments
6. 6
are reduced due to zero or very small horizontal movement. Natural frequencies and
mode shapes were also determined during the dynamic analysis. The influence of the
aforementioned structural arrangements on frequencies and mode shapes was studied.
The structure allows one to place an observation platform at midspan. But dynamic
behavior is influenced by platform positioning, weight and area. For this reason the
aerodynamic stability of the structure was checked in a wind tunnel.
4.1 Parametric study
Fig.6 Geometry of the studied structure
Fig.7 Load cases
A suspension pedestrian bridge formed by a straight stress-ribbon deck, external bearing
cables and suspenders with a span length L = 99 m was analyzed in this parametric
study (Fig.6). The structure was analyzed as a geometrically non-linear two-dimensional
frame structure. Two basic types of deck-cable connection were designed. The deck was
connected to the cable through the suspenders along the whole span length in the first
variant. In the second one the cable was fixed to the deck at midspan. Both variants
were analyzed for three different initial sags of the bearing cable : F = L / 8, F = L /10
and F = L / 12. In addition fixed hinge or sliding hinge supports of the deck together
7. 7
with four values of the deck moment of inertia were considered. All the structures were
loaded by three basic load cases (Fig.7).
4.2 Results of the parametric study
The obtained results are here presented in graph form. The study was very extensive and
that is why only some conclusions are presented in this paper. The influence of deck-
cable connection at midspan is showed in Fig.8. The reduction of the deck deflection is
the most important in load case 3. The deflection of flexible decks is positively
influenced by fixed hinge supports (Fig.9). It is caused by an activation of higher deck
axial force due to larger deflections (Fig.10). The same conclusion can be reached
regarding deck bending stresses.
Fig.8 Influence of fixed deck-cable connection - fixed supports - F = L / 8
Fig.9 Influence of fixed hinge supports - variant 1 - F = L / 8
5. CONCLUSIONS
The main disadvantage of stress-ribbon pedestrian bridges is the large horizontal forces,
which must be anchored to the ground. A new structural type combining stress-ribbon
with a slender arch and eliminating this disadvantage is presented in this paper. The
process of the development includes both mathematical modelling and experimental
0
50
100
150
200
250
300
350
I 10 x I 100 x I 1000 x I
Deck moment of inertia : I = 0.005 m
4
Max.deckdeflection[mm]
LC3-var.1
LC3-var.2
0
100
200
300
400
500
I 10 x I 100 x I 1000 x I
Deck moment of inertia : I = 0,005 m
4
Max.deckdeflection[mm]
LC3
LC4
LC3-fix.supp.
LC4-fix.supp.
8. 8
methods. The main goal of the research is to check the structural response to static and
dynamic loads, design of structural members and finally design of new details. The
results of the performed analyses and experiments will make a practical design of this
aesthetic structure easier in the future.
Fig.10 Influence of fixed deck-cable connection - fixed supports - F = L / 8
Different parametric studies were performed during the study of pedestrian bridges
formed by a suspension stress-ribbon. The studies were focused on different structural
arrangements and their comparisons. The bending stresses of the slender deck
assembled from precast segments can be efficiently reduced by using stoppers. An
appropriate choice of support type and bearing cable geometry can significantly stiffen
the structure both in longitudinal and in transverse directions.
6. ACKNOWLEDGEMENTS
The new stress-ribbon structures described in this paper are studied under the financial
support of the Czech Grant Project No.103/96/35 ‘Stress-Ribbon Bridges Stiffened by
Arches or Cables’. Tomas Kulhavy also wishes to thank his supervisor, Prof. Jiri
Strasky, for his leadership during the PhD study.
7. REFERENCES
Fischer, O., Kolousek, V., Pirner, M. (1977), “Aeroelasticity of structures“ (in Czech),
Akademia, Prague
Gimsing, N. J. (1983), “Cable supported bridges“, John Wiley & Sons, New York
Schlaich, J., Engelsmann, S. (1996), “Stress Ribbon Concrete Bridges“, Structural
Engineering International, No. 4, pp. 271-274
Walther, R. (1988), “Cable stayed bridges with slender deck“, Test report No. 81.11.03,
Lausanne
Strasky, J. (1995), “Pedestrian Bridge at Lake Vranov, Czech Republic“, Civil
Engineering, August 1995, pp. 111-122
Strasky, J., Pirner, M. (1986), “DS-L stress-ribbon footbridges“, Dopravni stavby,
Olomouc
0
500
1000
1500
2000
2500
3000
3500
4000
I 10 x I 100 x I 1000 x I
Deck moment of inertia : I = 0,005 m4
Deckaxialforce[kN]
LC3-var.1
LC3-var.2