The document discusses the design and construction challenges of the Deh Cho Bridge in the Northwest Territories of Canada. Some key points:
- The bridge crosses the Mackenzie River and connects Yellowknife to Highway 1, replacing a ferry. Its remote northern location and extreme winter conditions of -40°C posed challenges.
- An innovative extradosed bridge design was used with a 1045m continuous superstructure and expansion joints only at the abutments.
- Construction methods like incremental launching and extensive prefabrication were employed to minimize field work during the short construction season.
- Rigorous shop trial assembly and quality control processes were required given the remote site and need to minimize repairs.
This document presents the design of a three-span precast pre-stressed concrete girder bridge with spans of 12.0015m, 24.140m, and 12.0015m. The objectives are to develop a cost-effective bridge design using LRFD methods that meets NMDOT standards. The design includes AASHTO Type III girders, a reinforced concrete deck, bearing pads, pier columns, drilled shaft foundations, and considers loads, reinforcement, and strength requirements. Analysis and design software such as CONSPAN and RC-PIER are used to optimize the superstructure and substructure elements.
Dr. F. Dejahang discusses the benefits of precast concrete bridges, including lower initial costs than other bridge types, minimal required maintenance, and fast/easy construction. Precast bridges have assured quality from manufacturing in a controlled plant environment, are durable, attractive, and allow for minimal traffic disruption during construction as precast elements can be quickly installed. Bridge piers and decks can be constructed from precast concrete segments assembled on site. Erection gantries are used to lift and install large precast concrete segments for viaduct construction.
Construction Challenges For Bridges In Hilly AreasShantanu Patil
Hilly region pose unique problem for bridge construction. In a restricted hilly area itself climatic condition, Geographical features and hydrological parameters affect considerably. Keeping in view the bridge site and various constraints, type of bridges and method of construction are to be selected carefully for safe, economical and successful completion of bridges construction.
Fast construction of bridges using precast concrete elements provides benefits to both owner agencies and contractors. For owners, it reduces the duration of work zones, lowering traffic handling costs and accident risks while causing less inconvenience to the public. Contractors benefit from reduced hazards, the ability to accomplish more work in less time with fewer weather delays, and lower costs. Examples are given of bridges constructed rapidly using precast concrete piles, pile caps, piers, abutments, beams, and other elements.
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 presentation summarizes the key aspects of an elevated road project in India. It includes three main points:
1. The elevated road project has a total length of 1250 meters with two lanes, crash barriers along the sides for safety, and approaches built with retaining walls.
2. The main components of the project are site clearance, earthworks, construction of foundations for piers and abutments, building the superstructure with pre-stressed concrete girders and deck slabs, and construction of service roads.
3. Testing was performed on site to check the workability and strength of concrete used in building the foundations, piers, and other structural elements. Slump tests were used to
This document presents the design of a three-span precast pre-stressed concrete girder bridge with spans of 12.0015m, 24.140m, and 12.0015m. The objectives are to develop a cost-effective bridge design using LRFD methods that meets NMDOT standards. The design includes AASHTO Type III girders, a reinforced concrete deck, bearing pads, pier columns, drilled shaft foundations, and considers loads, reinforcement, and strength requirements. Analysis and design software such as CONSPAN and RC-PIER are used to optimize the superstructure and substructure elements.
Dr. F. Dejahang discusses the benefits of precast concrete bridges, including lower initial costs than other bridge types, minimal required maintenance, and fast/easy construction. Precast bridges have assured quality from manufacturing in a controlled plant environment, are durable, attractive, and allow for minimal traffic disruption during construction as precast elements can be quickly installed. Bridge piers and decks can be constructed from precast concrete segments assembled on site. Erection gantries are used to lift and install large precast concrete segments for viaduct construction.
Construction Challenges For Bridges In Hilly AreasShantanu Patil
Hilly region pose unique problem for bridge construction. In a restricted hilly area itself climatic condition, Geographical features and hydrological parameters affect considerably. Keeping in view the bridge site and various constraints, type of bridges and method of construction are to be selected carefully for safe, economical and successful completion of bridges construction.
Fast construction of bridges using precast concrete elements provides benefits to both owner agencies and contractors. For owners, it reduces the duration of work zones, lowering traffic handling costs and accident risks while causing less inconvenience to the public. Contractors benefit from reduced hazards, the ability to accomplish more work in less time with fewer weather delays, and lower costs. Examples are given of bridges constructed rapidly using precast concrete piles, pile caps, piers, abutments, beams, and other elements.
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 presentation summarizes the key aspects of an elevated road project in India. It includes three main points:
1. The elevated road project has a total length of 1250 meters with two lanes, crash barriers along the sides for safety, and approaches built with retaining walls.
2. The main components of the project are site clearance, earthworks, construction of foundations for piers and abutments, building the superstructure with pre-stressed concrete girders and deck slabs, and construction of service roads.
3. Testing was performed on site to check the workability and strength of concrete used in building the foundations, piers, and other structural elements. Slump tests were used to
The Detail Project Report is an essential building block for any construction project. The DPR is to be prepared carefully and with sufficient details to ensure appraisal, approval, and subsequent implementation in a timely and efficient manner. The detailed project report gives us the clear idea about the existing site conditions and improvements needed to be accomplished. The DPR survey has been done for construction of a high level bridge on road pertaining @ km 6/2 (R&B) road to Kadapa district. The bridge crosses the river in normal crossing. It has total span of 50.80mts.This work has been executed under MNREGS scheme. The bridge has 3 vents of 6.37m effective span. The bridge is constructed across the stream to provide transportation facilities to people of Proddatur to various places of Kadapa District. This stream has an adequate discharge of 97.00 cusecs and it increases more during in rainy season. Traffic studies have been conducted on this road and the outcome was 120cvpd. The maximum flood level of this stream is 99.830.The linear water way is 18.00m. The design drawings and plans were given by MORT&H for execution of work. To calculate the discharge levels has been surveyed around 300mts both upstream and down streams. Funding for this project has been given by the government of A.P. The work has to be completed in a period of one year. The total estimate amount of the project is said to be 69.50 Lakhs.
The document provides a training report for a bridge construction project in Jaipur, India during May-June 2016. It summarizes the key components of the bridge, including pile foundations, substructures like piers and pedestals, and superstructures such as prestressed concrete girders and deck slabs. The training helped the author gain practical knowledge of bridge construction techniques and management that supplemented their theoretical classroom learning.
Modelling Analysis and Design of Self Anchored Suspension BridgeRohit Grandhi, EIT
The application of earlier course works in this project is summarized in Table 1.2:
Table 1.2 Application of earlier course work
Course Work Application in Project
Structural Analysis Analysis of loads, stresses and deformations of structural elements.
Structural Design Design of deck slab, girder, cables, suspenders as per codes.
Concrete Technology Design of M25 grade concrete mix.
Steel Structures Design of reinforcement details.
Geotechnical Engineering Foundation design not included in scope.
BSCPL Infrastructure Pvt. Ltd is constructing a four-lane bridge over the Mahanadi River in Chhattisgarh, India as part of a contract to reconstruct 250 km of National Highway 53. The segmental bridge is being built using the lanuching girder method, where precast concrete segments are placed using a launching girder and temporary supports. Segments are dry fitted, glued with epoxy, post-tensioned with 7-ply cable strands using hydraulic jacks, then grouted to form each span. Precast segments are lifted into place by the launching girder's gantry and secured to sliding supports. The launching girder is then advanced to the next pier to begin constructing
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.
Composite construction in Bridge Deck systems by Suhas Khedkar Kishore SaxenaSuhas Khedkar
This document discusses the use of prefabricated structural steel girders with composite reinforced concrete deck slabs for bridge construction in congested urban environments. Some key advantages include reduced construction time since superstructure elements can be prefabricated off-site while foundations are constructed. Structural steel options also allow for lighter prefabricated elements that are easier to transport and erect compared to precast concrete. The document presents various structural steel girder configurations that have been used successfully for urban flyovers.
Stress ribbon bridges stiffened by arches or cablesMasum Majid
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.
The document discusses the balanced cantilever method of bridge construction. It begins by explaining that this method is used for bridges with spans between 50-250m, and involves attaching precast or cast-in-place segments in an alternating manner from each end of cantilevers supported by piers. This method is well-suited for irregular spans, congested sites, and environmentally sensitive areas. It also discusses advantages like determinacy and reduced cracking risks. The document then goes into detail about construction sequences, member proportioning, superstructure types, and analysis of a specific balanced cantilever bridge in Kochi, India.
This document provides guidance on designing balanced cantilever bridges. It discusses:
1) Typical span configurations including 3 or more spans of varying lengths.
2) Construction sequence where segments are cast and cantilevered out from the preceding segment to form balanced cantilevers on both sides.
3) Design checks that are required at various construction stages and during service life, accounting for time-dependent effects like creep and shrinkage.
Undergraduate major project_-_design_ofVijay Singh
This document describes the design of a T-beam rail-over-bridge submitted by 9 students for their Bachelor of Technology degree in Civil Engineering. It includes an introduction to bridge types and T-beam bridges. It then outlines the contents which will cover the design of the deck slab, cantilever slab, longitudinal and cross girders, and bearings. Design calculations and reinforcement details will be provided for each component.
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.
The document describes a topographic survey conducted for the construction of a new railway bridge. It discusses using a topographic map to identify potential alignment options for the railway track. A field survey was then carried out using a total station to determine the central line alignment and elevation levels at different points. Soil exploration work, including lab testing, was also performed. Following this, the land acquisition process began by contacting local authorities to purchase the necessary land from owners. Foundation excavation work then commenced based on the ground conditions. Piers were constructed using a total station to ensure proper alignment. Bed blocks were then marked for placing precast girders. Sleepers were later laid to allow for track alignment along the central line.
This document provides details about a practical training project completed on the construction of a high flood level bridge across the Mahi River from May 23, 2016 to July 23, 2016. The key aspects summarized are:
- The bridge was 360m long with 12 spans of 30m each and cost approximately 12 crore rupees to construct.
- Foundations included excavating for and constructing rafts for the abutments and piers. Piers and pier caps were also constructed to support the girder spans.
- Precast prestressed concrete girders were launched into place using cranes and temporary bearings. The girders rested on pot/PTFE bearings.
- The
This document discusses bridges in hilly areas and the various challenges associated with their construction. It outlines different types of bridges suitable for hilly regions, including beam bridges, truss bridges, cantilever bridges, arch bridges, tied-arch bridges, suspension bridges, and cable-stayed bridges. For each bridge type, it provides a brief definition and example image. It also discusses challenges like foundation construction, substructure, superstructure, plant and materials management, and financing.
Construction methods of Bridges and its typesprathiekraj1
This presentation holds the various types of bridge construction and its methods in detail with real time examples and the source links are included in each slide.
The document describes the process of designing and testing models of a truss bridge made of fettuccine. Four truss bridge models were constructed and tested to evaluate their load bearing efficiency. The final design adopted the Warren truss pattern and used an I-beam structure to strengthen the beams. Various materials and methods were tested to optimize the bridge's strength and weight. Load testing provided data to analyze failures and improve subsequent designs.
The document discusses different viaduct systems used for Delhi Metro. It analyzes precast systems like single segmental U girder and segmental box, cast in-situ systems like single segmental box girder and I girder and slab, and balanced cantilever systems like extra-dosed bridge and BCLC viaduct. Parameters compared for each system include length studied, cost, construction speed, clear span, depth, site constraints, and aesthetics. Balanced cantilever and single segmental U girder scored highest based on these criteria for different viaduct conditions.
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
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 discusses the benefits of exercise for mental health. Regular physical activity can help reduce anxiety and depression and improve mood and cognitive functioning. Exercise causes chemical changes in the brain that may help protect against mental illness and improve symptoms.
- Worldwide Logistics Group (WWL) was founded in 2001 in Shanghai and has expanded to have 28 branch offices across China and overseas.
- WWL has over 1200 employees and annual turnover of over 3.8 billion RMB. It provides integrated logistics services including sea, land, and air freight, warehousing, and customs brokerage.
- WWL has a global network covering China and 78 other countries through agents and partners. It is recognized as a top Chinese logistics company.
The Detail Project Report is an essential building block for any construction project. The DPR is to be prepared carefully and with sufficient details to ensure appraisal, approval, and subsequent implementation in a timely and efficient manner. The detailed project report gives us the clear idea about the existing site conditions and improvements needed to be accomplished. The DPR survey has been done for construction of a high level bridge on road pertaining @ km 6/2 (R&B) road to Kadapa district. The bridge crosses the river in normal crossing. It has total span of 50.80mts.This work has been executed under MNREGS scheme. The bridge has 3 vents of 6.37m effective span. The bridge is constructed across the stream to provide transportation facilities to people of Proddatur to various places of Kadapa District. This stream has an adequate discharge of 97.00 cusecs and it increases more during in rainy season. Traffic studies have been conducted on this road and the outcome was 120cvpd. The maximum flood level of this stream is 99.830.The linear water way is 18.00m. The design drawings and plans were given by MORT&H for execution of work. To calculate the discharge levels has been surveyed around 300mts both upstream and down streams. Funding for this project has been given by the government of A.P. The work has to be completed in a period of one year. The total estimate amount of the project is said to be 69.50 Lakhs.
The document provides a training report for a bridge construction project in Jaipur, India during May-June 2016. It summarizes the key components of the bridge, including pile foundations, substructures like piers and pedestals, and superstructures such as prestressed concrete girders and deck slabs. The training helped the author gain practical knowledge of bridge construction techniques and management that supplemented their theoretical classroom learning.
Modelling Analysis and Design of Self Anchored Suspension BridgeRohit Grandhi, EIT
The application of earlier course works in this project is summarized in Table 1.2:
Table 1.2 Application of earlier course work
Course Work Application in Project
Structural Analysis Analysis of loads, stresses and deformations of structural elements.
Structural Design Design of deck slab, girder, cables, suspenders as per codes.
Concrete Technology Design of M25 grade concrete mix.
Steel Structures Design of reinforcement details.
Geotechnical Engineering Foundation design not included in scope.
BSCPL Infrastructure Pvt. Ltd is constructing a four-lane bridge over the Mahanadi River in Chhattisgarh, India as part of a contract to reconstruct 250 km of National Highway 53. The segmental bridge is being built using the lanuching girder method, where precast concrete segments are placed using a launching girder and temporary supports. Segments are dry fitted, glued with epoxy, post-tensioned with 7-ply cable strands using hydraulic jacks, then grouted to form each span. Precast segments are lifted into place by the launching girder's gantry and secured to sliding supports. The launching girder is then advanced to the next pier to begin constructing
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.
Composite construction in Bridge Deck systems by Suhas Khedkar Kishore SaxenaSuhas Khedkar
This document discusses the use of prefabricated structural steel girders with composite reinforced concrete deck slabs for bridge construction in congested urban environments. Some key advantages include reduced construction time since superstructure elements can be prefabricated off-site while foundations are constructed. Structural steel options also allow for lighter prefabricated elements that are easier to transport and erect compared to precast concrete. The document presents various structural steel girder configurations that have been used successfully for urban flyovers.
Stress ribbon bridges stiffened by arches or cablesMasum Majid
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.
The document discusses the balanced cantilever method of bridge construction. It begins by explaining that this method is used for bridges with spans between 50-250m, and involves attaching precast or cast-in-place segments in an alternating manner from each end of cantilevers supported by piers. This method is well-suited for irregular spans, congested sites, and environmentally sensitive areas. It also discusses advantages like determinacy and reduced cracking risks. The document then goes into detail about construction sequences, member proportioning, superstructure types, and analysis of a specific balanced cantilever bridge in Kochi, India.
This document provides guidance on designing balanced cantilever bridges. It discusses:
1) Typical span configurations including 3 or more spans of varying lengths.
2) Construction sequence where segments are cast and cantilevered out from the preceding segment to form balanced cantilevers on both sides.
3) Design checks that are required at various construction stages and during service life, accounting for time-dependent effects like creep and shrinkage.
Undergraduate major project_-_design_ofVijay Singh
This document describes the design of a T-beam rail-over-bridge submitted by 9 students for their Bachelor of Technology degree in Civil Engineering. It includes an introduction to bridge types and T-beam bridges. It then outlines the contents which will cover the design of the deck slab, cantilever slab, longitudinal and cross girders, and bearings. Design calculations and reinforcement details will be provided for each component.
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.
The document describes a topographic survey conducted for the construction of a new railway bridge. It discusses using a topographic map to identify potential alignment options for the railway track. A field survey was then carried out using a total station to determine the central line alignment and elevation levels at different points. Soil exploration work, including lab testing, was also performed. Following this, the land acquisition process began by contacting local authorities to purchase the necessary land from owners. Foundation excavation work then commenced based on the ground conditions. Piers were constructed using a total station to ensure proper alignment. Bed blocks were then marked for placing precast girders. Sleepers were later laid to allow for track alignment along the central line.
This document provides details about a practical training project completed on the construction of a high flood level bridge across the Mahi River from May 23, 2016 to July 23, 2016. The key aspects summarized are:
- The bridge was 360m long with 12 spans of 30m each and cost approximately 12 crore rupees to construct.
- Foundations included excavating for and constructing rafts for the abutments and piers. Piers and pier caps were also constructed to support the girder spans.
- Precast prestressed concrete girders were launched into place using cranes and temporary bearings. The girders rested on pot/PTFE bearings.
- The
This document discusses bridges in hilly areas and the various challenges associated with their construction. It outlines different types of bridges suitable for hilly regions, including beam bridges, truss bridges, cantilever bridges, arch bridges, tied-arch bridges, suspension bridges, and cable-stayed bridges. For each bridge type, it provides a brief definition and example image. It also discusses challenges like foundation construction, substructure, superstructure, plant and materials management, and financing.
Construction methods of Bridges and its typesprathiekraj1
This presentation holds the various types of bridge construction and its methods in detail with real time examples and the source links are included in each slide.
The document describes the process of designing and testing models of a truss bridge made of fettuccine. Four truss bridge models were constructed and tested to evaluate their load bearing efficiency. The final design adopted the Warren truss pattern and used an I-beam structure to strengthen the beams. Various materials and methods were tested to optimize the bridge's strength and weight. Load testing provided data to analyze failures and improve subsequent designs.
The document discusses different viaduct systems used for Delhi Metro. It analyzes precast systems like single segmental U girder and segmental box, cast in-situ systems like single segmental box girder and I girder and slab, and balanced cantilever systems like extra-dosed bridge and BCLC viaduct. Parameters compared for each system include length studied, cost, construction speed, clear span, depth, site constraints, and aesthetics. Balanced cantilever and single segmental U girder scored highest based on these criteria for different viaduct conditions.
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
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 discusses the benefits of exercise for mental health. Regular physical activity can help reduce anxiety and depression and improve mood and cognitive functioning. Exercise causes chemical changes in the brain that may help protect against mental illness and improve symptoms.
- Worldwide Logistics Group (WWL) was founded in 2001 in Shanghai and has expanded to have 28 branch offices across China and overseas.
- WWL has over 1200 employees and annual turnover of over 3.8 billion RMB. It provides integrated logistics services including sea, land, and air freight, warehousing, and customs brokerage.
- WWL has a global network covering China and 78 other countries through agents and partners. It is recognized as a top Chinese logistics company.
The document discusses strategies for effective classroom discussions based on the Constructive Classroom Conversations (CCC) model from Stanford University. It outlines some of the challenges students face in discussions, such as lack of background knowledge or academic vocabulary. The solution is to consistently teach discussion norms and vocabulary, model discussions using various tools, and provide rubrics to assess students. Resources like discussion prompts, vocabulary posters, and transcripts can help build students' discussion skills.
How businesses can use Facebook, Twitter, Instagram and Pinterest to market their businesses. This was presented at the Small Business Development Center in Anchorage by Kathy Day and Debbie Rinckey, Authorized Leading Experts (ALEs) in Constant Contact for Alaska.
Xerox is a global corporation that employs 150,000 people and provides business services and document technology products. It currently underutilizes social media platforms like Facebook, Twitter, and YouTube, with low engagement and infrequent posts. The document recommends increasing social media presence by posting more personalized videos and expanding to Instagram and Pinterest. It also suggests better promoting the GoLA transportation app in Los Angeles and targeting millennials rather than older generations to accomplish goals of growing social media followers, app downloads, and shifting sales more toward business services.
Kati graham life tec presentation don't stop doing the things you love kgLifeTec
LifeTec is a social enterprise that exists to enable people and their communities to achieve their goals through the correct application of assistive technology.
We provide everyone with everyday solutions to everyday activities.
This document provides a detailed summary and analysis of three parables told by Jesus: the Parable of the Prodigal Son, the Parable of the Rich Fool, and the Parable of the Good Samaritan. For each parable, the document outlines the story, the moral lesson conveyed, and the overall message being taught. The key messages are that God eagerly forgives those who repent, material wealth means nothing without spiritual riches, and that we must help others in need regardless of differences.
This short document promotes the creation of Haiku Deck presentations on SlideShare by including an image of a nature scene and the text "Inspired? Create your own Haiku Deck presentation on SlideShare! GET STARTED". It encourages the viewer to be inspired by the photo and get started making their own Haiku Deck presentation by using the provided platform.
The Grand Blossoms It is Chennai's only full moon party destination!
THE Grand Blossoms rewrites the philosophy of ultimate leisure with The Grand Blossoms Red Hills. Bringing in carefully designed spaces on the shores of a wide and tranquil lake. To give you the best of family recreation and splendid isolation. Forget your cares. Forget yourself. Enjoy.
Tim Smith's portfolio summarizes his marketing responsibilities and experiences for various BYU sports teams. He assisted with promotions, social media, attendance, and rebranding efforts for baseball, women's basketball, softball, and men's volleyball. Under his leadership, social media followings grew significantly and attendance increased for several teams. He demonstrated skills in event coordination, promotions, graphic design, and social media management.
This document outlines 5 test slides. Slides 1 through 5 are briefly described to test an unknown topic. The slides progress sequentially from the first to the fifth test slide with no other details provided.
This document provides an outline and overview of attention deficit hyperactivity disorder (ADHD), oppositional defiant disorder (ODD), and conduct disorder (CD) within the child and adolescent population. It defines ADHD and its three main presentations (inattentive, hyperactive-impulsive, combined). Statistics on ADHD prevalence are provided. Common ADHD symptoms and impacts in school-aged children and adolescents are outlined. A multi-modal treatment approach is recommended, including medications, behavioral therapies, and psychoeducation. Common stimulant and non-stimulant medications used to treat ADHD are defined, including considerations for selection. ODD and CD are briefly mentioned regarding risk factors and medications.
Este documento discute el uso de selfies, groufies e imágenes en la orientación educativa y vocacional. Explica que las imágenes pueden usarse para comprender los intereses, grupos, estados de ánimo y opciones de estudio de los estudiantes. También proporciona estrategias como hacer preguntas y guiar la lectura de imágenes para que los estudiantes puedan analizarlas y sacar nuevos significados. Finalmente, señala que las imágenes son útiles recursos pedagógicos que pueden mejorar la comprensión, present
1. The author attends an experimental music performance at Roulette, an arts space in Brooklyn.
2. The performance includes traditional Korean and Indian tabla music followed by experimental electronic music.
3. The author is intrigued by Roulette's unique musical experiences and supportive community of performers.
Every sector has a unique style of logos, here are some logo designs created for the education industry.
You could also view them at - http://bit.ly/EduLogoDesign
The Eastside Youth Athletic Association (EYAA) is a nonprofit organization dedicated to developing youth in St. Paul, Minnesota through athletics and academics. It operates youth football and cheerleading programs and is run entirely by volunteers. The EYAA aims to expand programming and increase participation from the local community through improved funding, partnerships, and marketing of their brand. Their goals include developing sustainable funding sources and expanding membership to better serve Eastside youth.
1) The financial close of the $899 million Pennsylvania Rapid Bridge Replacement Project was a landmark public-private partnership deal in the US. It involved the largest Private Activity Bond financing for a P3 to date.
2) According to the World Bank's methodology, having the right partnership governance model is crucial for PPP success. A key part of this is properly allocating risks to the party best able to manage them.
3) For partnerships to be sustainable over the long term, the various partners must be able to define their respective roles and ensure an optimal organizational fit that addresses sustainable development issues. This helps prevent loss of interest or disputes between partners.
Presentation by Ms. Karuna Gokhale at Seminar on 'Women's Issues- Forms and Challenges' as part of a seminar series 'Maharashtra-2025' organised by Yashwantrao Chavan Pratishthan.
The Downtown Crossing bridge project in Louisville, Kentucky is progressing ahead of schedule. Steel work is expected to be completed by late October 2015 and the bridge is scheduled to open to traffic in January 2016. The 642m, $860 million cable-stayed bridge will connect Louisville to Covington, Indiana, doubling traffic capacity across the Ohio River. Its design incorporates measures like flexible tower foundations and a three-tower arrangement to allow for movement, as well as aesthetic elements like unobstructed tower views. Service life modeling was used to design the bridge to last 100 years with minimal maintenance.
Case study: Widening an existing bridge structure Challenges and solutionsIRJET Journal
This document summarizes the process of widening an existing bridge in the UAE. It faced several challenges, including replacing deteriorated bearings, repairing cracks and defects found after removing pavement, constructing approach slabs where there were none previously, addressing differences in cross-slope between the existing and new structures, protecting the deck from chemicals, and strengthening an existing pier with carbon fiber reinforced polymer sheets. These challenges were addressed through methods like jacking the bridge to replace bearings, repairing cracks, constructing new approach slabs, using leveling concrete to create uniform cross-slope, applying waterproofing, and installing CFRP sheets to strengthen the pier according to product specifications. The widening resulted in two bridges with four
This document summarizes a seminar presentation on stress ribbon bridges. It defines a stress ribbon bridge as a tension structure similar to a simple suspension bridge, where the suspension cables are embedded in the deck which follows a catenary arc between supports. This provides stiffness to prevent excessive swaying. Such bridges use pre-tensioned concrete reinforced by steel cables. The document outlines the history and theory behind stress ribbon bridges, describes their construction process, and provides examples of existing stress ribbon bridges along with their advantages and disadvantages.
The document discusses the design and construction of a 4-lane 90m railway over bridge in Chand Sarai, Lucknow. Key steps in the construction process include surveying, engineering design, laying pile foundations, installing bearings and girders, shuttering, and concreting. Tests were conducted on materials and foundations to ensure quality. The bridge was designed to allow road traffic to safely pass over the railway line.
This document provides details about the Samuel Beckett Bridge in Dublin, Ireland. It is a cable-stayed steel structure with a 123m main span across the River Liffey. The bridge rotates 90 degrees to allow ship traffic. It has an asymmetric shape influenced by maintaining the navigable river channel. The bridge structure transfers loads through a box girder deck, cable stays in tension, and a curved pylon foundation. Live loads include traffic and wind. Value engineering identified cost savings such as using steel blocks instead of lead shot for ballast.
Review on studies and research on widening of existing concrete bridgesIRJET Journal
This document summarizes several studies that have been conducted on widening existing concrete bridges. It describes a study from China that examined load distribution factors for a bridge widened with composite steel-concrete girders. It also outlines challenges and solutions for widening a bridge in the UAE, including replacing bearings and stitching the new and existing structures. Additionally, it discusses two bridge widening projects in New Zealand that involved adding precast beams and stitching to connect structures. Finally, safety measures and challenges for strengthening a historic bridge in Switzerland under live traffic are presented.
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.
challanges made for construction of bridge in hilly areasSwapnali Kunjir
This document discusses the challenges of constructing bridges in hilly areas. Key challenges include constructing bridges across deep gorges with large height differences, on rivers with unstable beds, in areas with extreme temperatures or landslides. Proper site selection and bridge type choice are important considering geological and weather conditions. Foundations can be difficult to build in areas with mixed soil types. Management of construction activities, materials, quality, safety, and equipment are also discussed. Common bridge types for hilly areas described include beam, truss, cantilever, arch, tied arch, suspension, and cable-stayed bridges.
Influence line diagram for model arch bridgekunalsahu9883
The Lupu Bridge in Shanghai, China is a steel box section tied arch bridge with a main span of 550m, making it the largest arch bridge in the world when it was completed. A tied arch bridge design was used because the ground conditions on either side of the river were unsuitable for the large forces from a normal arch bridge. The bridge was analyzed using structural analysis software to determine member forces and deformations under load. The bridge is an impressive engineering feat that helped advance Chinese bridge engineering.
The document summarizes a technical seminar presentation on Accelerated Bridge Construction techniques. It discusses how ABC uses innovative methods to reduce mobility impacts during bridge replacement or rehabilitation. Key benefits of ABC include improved constructability, reduced construction time, higher quality materials, and increased work zone safety. The presentation outlines various prefabricated bridge elements and structural placement methods used in ABC, such as full depth and partial depth precast bridge decks, precast pier elements, spread footings, pile caps, and precast pier box cofferdams. Placement methods covered include horizontal skidding, use of self-propelled modular transporters, longitudinal launching, and heavy lifting equipment.
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This document summarizes segmental bridge construction techniques. Segmental bridges are constructed using precast concrete segments rather than a single continuous pour. This allows construction over bodies of water without needing intermediate supports. Two common techniques are discussed - cantilever construction where segments are cast out from each pier, and incremental launching where precast segments are erected on a launching girder. A case study of the Ganga bridge in India is provided, which used both precast and cast-in-place segments to span over 1,000 meters. Segmental construction enables longer bridge spans while reducing impacts to river traffic during construction.
Running Head BRIDGE DESIGN1BRIDGE DESIGN31.docxtoddr4
Running Head: BRIDGE DESIGN 1
BRIDGE DESIGN 31
Title:
Student Name:
Institution:
Course:
Date:
BRIDGE DESIGN FOR THE MOTOR WAY BELOW
8m
Embankment
A
Motorway
16m
10m
Central Reservation
Motorway
16m
Grass Verge
Existing Factory Units
Footway
A
Carriagewaym
Existing Factory Units
Fixed Factory Entrance
Fixed Factory Entrance
3m
2m
3m
2m
10mm
Existing Highway to Proposed Bridge
Existing Development
Proposed Development
Existing Development
Existing Retaining Wall – 500mm thick rc construction indicated by old record drawings
Central Reservation
10m
10m
Section A-A
2m footway
1.2m high parapets
10m carriageway
Bridge Deck Section
Figure 1
Bridge design
Most suitable bridge forms
· Beam bridge
· Arch bridge
The beam bridge: Beam and slab with ladder decks
This form of bridges comprises of slab which sits on top of steel I-beams. This form is mostly used for mid span highway bridge which is where our required bridge falls in.
Slab in this system is supported on tow main girders with a spacing of about 3.5m and it lies longitudinally between the girders as per the below diagram.
Figure 1
The bridge will use plate girders giving us a scope to vary the flange and web sizes to fit and suit the bridge load carrying capabilities. In the design process, ability of the bridge to carry the maximum load expected and the loading at the various stages of construction will guide on the proportion of girders that is their depth, width of tension and compression flanges and web thickness.
The girders are erected firmly on the ground and have stud connectors welded on the top flange to provide composite action between the slab and girder. The number of studs and spacing vary depending on expected level of shear flow between steel girder and concrete slab.
The girders rest on bearings fastened to the bottom flange. The girders are stiffened to carry the bearing loads at these points. Some cases apply bracing between the girders at support to carry lateral forces and provide torsional restraint.
Bridge description
· The bridge will have a span of 50m.
· The bridge will be raised to a height of 10m on both sides to be in level with the existing highway. The girders will have constant height.
· The bridge cross section will have the reinforced concrete slab sitting on top of two main abutment substructures and an extra substructure which will be on the central reservation. The main substructure will be located at the embarkment of the road.
Construction sequence
Abutment substructure construction
Girder construction
The bridge will consist of two main girder I beams. The girders will be of the same height. To make the I-beam, steel plates will be used. The steel plate is cut into the required sizes for the bottom flange and top flange and for the web. The cut pieces are then fillet welded into the I-section. This is done either by machine manual assembling in jig or through improved pressing machine .
The Temple Mills Bridge in London was reconstructed from 2004-2006. The original 1963 bridge had deteriorated due to water ingress and reinforcement corrosion. The reconstruction involved demolishing the old bridge down to the existing foundations and riverbed, then constructing new piers, abutments, and a precast concrete deck. Environmental considerations like flood risk, habitat creation, and noise/pollution mitigation played a key role. Careful planning and risk management were needed due to the bridge's strategic location and need to maintain traffic flow during construction. The reconstruction secured this important transport link in advance of nearby Olympic development works.
Sustainable Solution for Shoring Method of Cross-Creek Bridge in Ankeng MRT S...Dr. Amarjeet Singh
In the Ankeng Light Rail MRT system (ALRMS) project, the U7 box girder passes crossing the Erbads creek and needs a temporary supporting system for the construction work. In this study, three temporary shoring system options were proposed to be the construction method. The D-B Contractor, New Asia construction and Development Corporation, evaluated and selected the optimal choice, The Steel truss frame with supporting beams, to serve as the temporary supporting system. Compare the deflection of Δmax and Δactual, which are 1.609 cm and 1.59 cm, respectively. This result presented that the shoring system composed of the H912*302*18*37 supporting beams and steel truss frame had achieved outstanding performance and work to construct the U7 box girder. This paper presents how the three options are evaluated and the detailed construction processes along with the survey verification for the method.
The document provides details about the Bandra-Worli Sea Link bridge project in Mumbai, India. It discusses the objectives of reducing traffic and travel time. Key aspects summarized include that it is the longest sea bridge in India at 5.6 km long, with cable-stayed towers up to 128 meters high, and construction from 2000-2010 with challenges that delayed completion. Foundations included over 50 piles up to 663 meters deep, and precast concrete segments were used for the superstructure.
Future fast track model for new road over bridge spanning over railway yard- ...Rajesh Prasad
Implementation of 4 lane cable stayed road over bridge is nearing completion. It is felt that it could be a future fast track model for construction of ROB over busy railway yard in India
Three futuristic composite bridge technologies - Bridge in a Backpack, Hybrid-Composite Beam, and ProCoBeam - are described that result in fast-track construction and more sustainable bridges with expected lifespans over 100 years. The Bridge in a Backpack uses fiber reinforced polymer tubes filled with self-consolidating concrete as main load-bearing elements. The Hybrid-Composite Beam has a fiber reinforced polymer shell housing a self-consolidating concrete arch tied by galvanized prestressing strands. ProCoBeam uses a shear composite dowel to connect a bottom steel T-section to a top concrete T-section.
Futuristic Composite Bridges-ING IABSE June 2016-pp 1-11
Deh Cho Bridge
1. 1
Design and Construction of the Deh Cho Bridge
Challenges, Innovation, and Opportunities
Author and Presenter
Matthias SCHUELLER
Principal, Ph.D. MBA P.Eng.
Infinity Engineering Group
North Vancouver, BC, Canada
MSchueller@infinity-engineers.com
Co-Author
Prabhjeet Raj SINGH
Vice-President, P.Eng. PE
Infinity Engineering Group
North Vancouver, BC, Canada
PSingh@infinity-engineers.com
Paper prepared for presentation
at the “Bridges – Innovations” Session
of the 2012 Conference of the
Transportation Association of Canada
Fredericton, New Brunswick
2. 2
Design and Construction of the Deh Cho Bridge
Challenges, Innovation, and Opportunities
Keywords
Extradosed Bridge System; Value Engineering; Assembly-line Design Approach; Conceptual
Bridge Design; Failure Mechanism Concept; Fuse Design Philosophy; Fast-tracked Erection
Methods; Ecological Light-weight Design Principals; Optimization of Structural
Performance.
Fig. 1: Deh Cho Bridge under construction (Photo: Dennis Hicks, Associated Engineering)
Abstract
The Deh Cho Bridge will be the first bridge structure crossing the Mackenzie, Canada’s
longest river. When the bridge is opened it will permanently replace ferry and ice road
services along Highway 3 connecting Yellowknife in the Northwest Territories with Highway
1 in the South. The bridge’s remote location in the North with severe winter conditions of up
to -40 °C requires meticulous planning and is an extraordinary challenge for men and
equipment (see Figure 1).
Innovative design methods led to the design of a unique 1045 m long continuous cable
supported superstructure with expansion joints only at the abutments. The design employs
ecological light-weight design principles as well as fast-tracked fabrication and erection
methods. Structural performance of the superstructure has been optimized for construction
and service scenarios allowing a high degree of repetition as well as aesthetic proportions and
rhythm.
Serious design challenges often require new philosophies and strategies. On the other hand,
they provide exceptional opportunities for innovation. The Assembly-line Design Approach,
the Failure Mechanism Concept, and the Fuse Design Philosophy have been specifically
developed for the Deh Cho Bridge with the purpose to cope with extraordinary schedule and
design requirements.
3. 3
Fig. 2: Rendering of the Deh Cho Bridge near Fort Providence (Infinity)
1. Introduction
The Deh Cho Bridge near Fort Providence is the largest bridge project ever undertaken in the
Northwest Territories (see Figure 2). Construction of the bridge is now in full swing after
steel fabrication was halted in 2008 when superstructure design and construction deficiencies
were discovered by an independent review team. In spring 2009 Infinity Engineering Group
(Infinity) was retained by the design coordinator Sargent & Associates to develop a new
superstructure design complying with the project requirements and compatible with the
substructure that had already been built in the river. The redesign was completed in a
compressed design schedule of six months. Superstructure fabrication started in early 2010.
The bridge is predicted to open in late 2012.
2. Design Features
The symmetrical superstructure consists of two vertical Warren trusses which are connected
by Chevron cross frames and wind bracings at top and bottom chord levels. This adaptation
of an “open” steel box girder is designed to carry two lanes of traffic while acting
compositely with an 11.3 m wide and 235 mm thick precast concrete deck. The new joint-less
superstructure has a span arrangement of 90 m – 3 x 112.5 m – 190 m (navigation channel) –
3 x 112.5 m – 90 m with a total length of 1,045 m (see Figure 3). The 190 m long main span
is cable assisted allowing a constant superstructure depth of only 4.5 m over the entire length
of the bridge. This corresponds to a maximum slenderness value of 42 (span to depth ratio).
Fig. 3: Span arrangement and articulation scheme (Infinity)
4. 4
The articulation scheme (see Figure 3) utilizes disk bearings at the piers and abutments. The
bearings guide the superstructure in the transverse bridge direction but allow longitudinal
movements due to temperature changes. Pier 4 North (one of the main span piers) is the only
location where the superstructure is longitudinally restrained. At the remaining piers, except
the piers nearest to each abutment, Lock-up Devices (LUD or shock transmission units) are
employed (see Figure 4, Elevation). The Lock-up Devices allow temperature displacements
without generating noteworthy restraining effects, but for longitudinal impact forces due to
gusty winds or braking loads, the devices rigidly connect the superstructure to the piers and
permit load sharing between engaged piers.
Two steel A-pylons located at the tallest piers flank the navigation channel located in the
bridge center. Each A-pylon is supported by two spherical bearings that allow a pendulum
movement of the pylon in longitudinal bridge direction (see Figure 4, Elevation). Four groups
of three stays each, arranged in two cable planes, are anchored at each pylon head using cast
steel sockets with pin connections. The stays (locked coil cables with 100 mm diameter) are
anchored at the third points of the main span and at the centres of the back spans using steel
truss outrigger systems.
The eight piers of the Deh Cho Bridge are founded on concrete spread footings which are
cast into the Mackenzie River bed using cofferdams. Each pier consists of a lower solid
concrete cone (reinforced with an outer steel shell protecting the concrete against ice forces)
and an upper steel head. The steel head has a base, two inclined legs, and a tie-beam
connecting the legs. The lower concrete cone and the steel head are connected at the pier’s
bottle-neck (called the Pier Connection Detail). Post-tensioned high-strength bars ensure that
the critical connection stays tight and sealed for service loads.
Fig. 4: Pier 4 South with A-pylon and superstructure (Infinity)
5. 5
The Deh Cho Bridge can be classified as an Extradosed Bridge System. [1, 2, 3] Similar to
conventional extradosed concrete box girders the “open” steel box girder has significant
bending stiffness and is only locally reinforced with stays and “king posts”. As such, the Deh
Cho Bridge has a very different structural behaviour than similar looking cable-stayed
bridges which typically do not require stiffening girders due to their multi-stay configuration
in combination with anchor cables. [4, 5]
3. Challenges
3.1 Site
The extreme temperature conditions at the bridge site of up to -40 °C permit reasonable
construction conditions only during short periods between June and December. Ice breakup
occurs between April and May and requires full removal of any works supported by
temporary foundations in the river (see Figure 5). Material delivery to the North shore
depends on ferry or ice road service since no alternative route is available. Between ice road
closure and ice breakup no river crossings via truck are possible. For those reasons erection
stages along the critical path had to be carefully planned and executed.
3.2 Design
For complex bridges, it is good design practice to investigate and present at least one feasible
erection method as part of the design. This is imperative for major bridges with extraordinary
site conditions because an economical fabrication, transportation and construction scheme
typically governs the design. Based on economy, the following five aspects were identified as
the most critical design parameters for the Deh Cho Bridge: (1) Site conditions, (2) Erection
method, (3) Transportation aspects, (4) Fabrication preferences, and (5) Shop trial assembly.
Fig. 5: Piers 3N and 4N with temporary works during winter 2011/2012 (Photo: Arndt Becker, Infinity)
6. 6
The special site conditions, especially the low temperatures and the remote location, led to a
design that minimizes field activities through maximum shop prefabrication. This principle
has been applied to most bridge components. Only abutments, curbs, and wearing surface
have been designed for conventional construction methods.
Incremental launching was determined as the most effective and economical superstructure
erection method (see Figure 6). This technique reduces the contractor’s risk and accelerates
construction progress when compared to other methods such as the span-by-span erection
scheme or the balanced cantilever technique.
A high degree of prefabrication typically requires a careful consideration of transportation
aspects. The location of the bridge site and potential fabrication shops as well as possible
access routes, transportation limitations and traffic restrictions have been considered. It was
decided to design all prefabricated components in such a manner that shipment via road and
rail is possible. Standard transportation means were utilized to avoid oversized loads and
special permits.
Fabrication of steel and precast concrete followed the industry’s preferred methods allowing
a high degree of repetition and an effective assembly-line fabrication process. Both principles
are beneficial from a cost, schedule and quality perspective, especially when many identical
or similar pieces are produced (analogous to mass production in the car industry).
Because of the bridge’s remote location and the short periods of reasonable construction
conditions, it was essential to minimize quality issues that require repair in the field.
Therefore, it was decided to enforce a rigorous shop trial assembly combined with a thorough
quality control (QC) and quality assurance (QA) process for all superstructure and pylon steel
work. Extra time and cost for those activities are compensated by faster onsite construction
speed and savings as delays due to field repair work are minimized. Steel trial assembly is
addressed by the Canadian Highway Bridge Design Code CAN/CSA-S6 and should reflect
camber, alignment, accuracy of holes as well as fit-up of welded joints and milled surfaces.
Fig. 6: Truss launching utilizing temporary bents (Photo: Dennis Hicks, Associated Engineering)
7. 7
3.3 Budget
In order to meet the budget the new design for the superstructure had to consider economical
design principles as well as cost effective fabrication and erection methods. To verify the
economy of the newly proposed superstructure concept a value engineering assignment was
conducted.
“Value Engineering uses a combination of creative and analytical techniques to identify
alternative ways to achieve objectives.” [6] As such value engineering is an important task
often conducted for major bridges to ensure that the selected design is a viable solution
meeting design criteria and budget. During a typical value engineering process different
bridge proposals are analysed, discussed, and evaluated by experienced engineers who
identify and weigh considerable technical and financial aspects. For instance, material
quantities are a characteristic and measurable evaluation criterion. Other aspects such as
construction cost, risk, and schedule or durability, adaptability, inspection and maintenance
requirements may be considered as well but are difficult to quantify.
Infinity conducted a value engineering assignment for the Deh Cho Bridge superstructure by
comparing the original with a newly developed design optimized for structural performance
(see chapter 4.4). [7] The result clearly showed that the new superstructure design would
permit significant material savings of more than 20% for structural steel and up to 30% for
deck concrete. More importantly designer (Infinity) and reviewers (T.Y. Lin International,
URS Corporation, and BPTEC-DNW Engineering) confirmed that the new design meets the
design criteria and allows superstructure launching. Because of the budget constraints and
other significant advantages (e.g. lower expected maintenance costs) it was decided to
abandon the original design and realize Infinity’s superstructure design.
3.4 Schedule
The new superstructure design task had to be performed in a timely manner to avoid further
delays and extra costs. Infinity agreed to deliver a fully designed, checked, and reviewed
design within six months after receiving the notice to proceed. One of the greatest challenges
was drafting. Over hundred of unique design drawings had to be prepared, checked, and
reviewed following a rigorous QC and QA procedure before the design could be sealed,
signed, and released as “Issued for Construction”.
Key to success was a meticulously planned project management approach involving the
entire design, drafting, and review team right from the start. Numerous internal and external
face-to-face meetings were held to achieve agreement and approval as fast as possible during
all critical design stages.
4. Innovation
4.1 Assembly-line Design Approach
Infinity’s design scope included the following design items: (1) steel truss superstructure, (2)
composite concrete deck, (3) stay system, (4) steel A-pylons, (5) deck sealing and asphalt
wearing surface, (6) concrete curbs and steel railing, (7) bearings and Lock-up Devices, (8)
expansion joints, (9) erection feasibility, and (10) superstructure/substructure compatibility.
8. 8
Fig. 7: Assembly-line Design Approach used for the Deh Cho Bridge (Infinity)
Fig. 8: Gantt chart picturing the Assembly-line Design Approach (Infinity)
9. 9
The Assembly-line Design Approach is an evolved design strategy that significantly
accelerates the design through the development of interdependent but individually treated
design components (e.g. steel superstructure, concrete deck, stay system, A-pylons). Because
of their interdependence, interfaces between design components must be given top priority.
The lead designer identifies, develops, and documents critical interfaces and shares the
information with the design team. Right from the beginning special emphasis must be laid on
the compatibility of the individually executed design components. The definition of design
components and their interfaces is a vital part of the conceptual bridge design phase and
should be addressed immediately after the bridge concept is developed and approved (see
chapter 4.2). This way many design and drafting tasks can be simultaneously executed
without compromising quality (see Figures 7 and 8).
In the final set of sealed and signed design drawings (Sealed Package) each design
component has its own chapter (analogous to a book). Drawings in each chapter strictly
follow predefined hierarchy levels starting with very general content (lowest hierarchy level)
to very complex details in shop drawing quality (highest hierarchy level). Cross references to
other chapters and hierarchy levels within the same chapter are required but only permitted in
the drawing notes that can be found on each drawing in the same corner.
As mentioned before drafting was identified as the most challenging design task along the
critical path because its progress directly depends on the outcome of all other design tasks.
The Assembly-line Design Approach bypasses most tasks as far as possible and gets drafting
started long before other important design tasks (e.g. Analysis and Final Design) are
completed (see Figure 8). This has the following advantages: (1) Design Criteria, Geometry,
and Drawing Layout are properly laid out, well documented right from the beginning, and
continuously updated, (2) drafters directly support designers with relevant information (e.g.
Geometry), and (3) early drawings are kept as simple and concise as possible enhancing
familiarization and comprehension.
During the Delivering Stage the Assembly-line Design Approach allows drafting to focus on
templates (Data Sheets to be filled with designers’ specifications) and the task Detailing (see
Figure 8). The predefined templates significantly reduce drafting work, permit quick
revisions, improve transparency, and support QC.
4.2 Conceptual Bridge Design
The conceptual design phase is the most important design stage because key design decisions
are made during this early stage. The lead designer focuses on the general concept and
ensures that the newly developed design is feasible, complies with relevant design criteria,
and satisfies the owner’s expectations. Infinity defined for the conceptual design of Deh Cho
Bridge superstructure the following priorities: (1) compatibility with the constructed piers, (2)
proven fast-tracked fabrication and erection methods for the superstructure, (3) economic and
ecological light-weight design principles, as well as (4) an inexpensive and reliable deck.
The compatibility with the existing piers was established using the Failure-Mechanism-
Concept (see chapter 4.3). This innovative technique was developed for the Deh Cho Bridge
and used to verify that the 1045 m long superstructure could be built as a single continuous
unit with expansion joints only at the abutments. As a result, two complex and costly
expansion joints originally proposed for the 190 m long main span of the bridge were
eliminated.
10. 10
For erection of the steel superstructure the incremental launching method was selected.
Consequently, cross sections of the steel truss were designed to optimize the structure’s
performance during launching and service [8]. The structural depth of the truss and its chords
was kept uniform over the entire bridge length allowing a high degree of repetition during
design, fabrication and erection as well as respecting aesthetic proportions and rhythm.
Light-weight design principles were thoroughly employed minimizing mass of structural
members and saving resources. Generally trusses and cable supported structures have been
used over centuries by bridge engineers in order to reduce dead load and material. [9, 10, 11]
However, the consequent application of light-weight design principles for the Deh Cho
Bridge led to an innovative composite extradosed truss bridge that has not much in common
with post-tensioned extradosed concrete box girders designed by French and Japanese
engineers in the last century. [1]
The concrete deck of the Deh Cho Bridge has an average thickness of only 235 mm (see
Figure 9). This light-weight deck was achieved using two-way action and the yield-line
theory for the Ultimate Limit State. [12] Upper truss chords and floor beams between chords
act compositely together with the deck slab creating a very efficient structural system for the
governing local wheel and axle loads. The cantilevering deck portions are strengthened by
structurally integrated cast-in-place concrete curbs which serve as edge beams redistributing
wheel loads. These largely forgotten design principles, widely used by François Hennebique
(1842-1921) and Eduard Züblin (1850-1916) for their “cassette slabs”, allow designing
extremely efficient concrete slabs reinforced with mild steel only. [13, 14]
Fig. 9: Precast deck panels stored onsite (Photo: Arndt Becker, Infinity)
11. 11
4.3 Failure Mechanism Concept
The I-35 Mississippi River Bridge in Minneapolis, Minnesota, USA [15] and the Boulevard
De La Concorde Overpass in Laval, Quebec, Canada [16] are regrettable examples of sudden
bridge collapses causing the loss of human lives. We are convinced that those unpredicted
incidents are avoidable when the consequences of critical failure mechanisms are investigated
and appropriately addressed during the design phase.
The design philosophy of the Failure Mechanism Concept (FMC) goes beyond the traditional
Ultimate Limit State design approach adopted by modern codes. [17, 18] In addition to
modern code requirements the FMC focuses on the weakest sections along primary load
paths. A primary load path is hereby defined as the structure’s preferred way of resisting
loads. The objective of the concept is the development of a structure that announces a serious
problem long before a fatal chain reaction is triggered.
Structural integrity and redundancy are fundamental principles when applying the FMC. The
entire structure (foundations, abutments, piers, superstructure, etc) shall be considered as a
whole. This new view point will provide designers with valuable information about probable
failure mechanisms and the structure’s ultimate behaviour when reaching its structural
capacity. Unpredicted failures along primary load paths shall be avoided by deliberately
defining weak sections. The predefined weak sections shall act as fuses allowing significant
deformations and the activation of redundant load paths long before the structure forfeits its
structural resistance. The so called Fuse Design Philosophy is the “backbone” of the FMC;
noticeable deformations shall be triggered so that the structure’s critical condition can be
recognized before lives are endangered and the investment is put at risk. [19]
The FMC has been developed for the Deh Cho Bridge during the conceptual design phase to
allow a continuous superstructure over the entire bridge length. The basic problem was to
accommodate temperature movements with the necessity to absorb longitudinal forces such
as wind, earthquake, and braking loads. The piers had been identified with such a stiff
behaviour that only one pier could be equipped with longitudinally fixed bearings. Other
piers required sliding bearings to allow temperature movements in a nearly unrestrained
manner. This meant that a traditional articulation scheme would rely only on one pier to
provide longitudinal stability of the 1045 m long superstructure. None of the piers had
enough capacity to satisfy this requirement alone. Therefore, it was decided to employ Lock-
up Devices which allow load sharing between piers for dynamically applied loads but do not
restrain slow acting temperature movements occurring over a relative long period of time.
Consequently, it was recognized that the weakest pier section, the pier bottleneck (see Figure
3, Elevation, Pier Connection Detail), would form an excellent fuse. If designed properly
with a ductile failure mechanism (providing sufficient rotational capacity) the fuse would
allow the engagement of Lock-up Devices installed at other piers. This way additional
redundant load paths could be activated before the capacity of the single pier with fixed
bearings is exhausted. Therefore, the degree of pre-stress in the Pier Connection Detail (fuse
section) was chosen as low as possible (for safety reasons) but high enough to avoid
decompression during service (for durability reasons).
4.4 Optimization of Structural Performance
Construction stages are critical for bridges and require investigation. Erection engineers are
inclined to push the structure to permitted limits. Erection engineering involves much
knowledge about various erection techniques, processes, and state-of-the-art equipment.
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Fig. 10: Truss supported by the tallest temporary bent in the main span (Photo: Arndt Becker, Infinity)
Realization often directly depends on the feasibility of proven and accepted construction
techniques. For that reason, bridge designers require an excellent understanding of available
construction techniques to ensure their designs will endure envisioned construction stages
without increasing the construction budget.
Cost efficient bridge designs are often solutions that utilize synergy effects by concurrently
addressing relevant construction stages and code prescribed serviceability and ultimate limit
states. Plastic design methods (such as the yield-line theory, the Failure Mechanism Concept
or the Fuse Design Philosophy) are very helpful in pushing the limits without compromising
safety and quality. In other words, plastic design principles allow an optimization of
structural performance for construction and final conditions. This in turn means significant
savings for owners and contractors.
The Deh Cho Bridge truss members have been optimized for structural performance. Cross
sections of chords, diagonals, and posts have been carefully designed to use steel material as
efficient as possible by combining structural requirements during construction and service
(see Figure 10). For instance, truss bottom chords have been particularly designed to
accommodate the incremental launching erection method. Local bending and shear as well as
lateral guiding effects combined with global demands (derived from a detailed investigation
of a staged erection sequence) have been included. This fine tuning led to an optimized cross
section which does not require any extra material to satisfy anticipated launching stages.
High strength steel (485 MPa yield strength) has been locally utilized to keep truss chord
cross sections and superstructure depth constant over the entire bridge length. At piers the
chord cross sections have been boxed. This helped to control stresses and buckling effects.
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5. Opportunities
5.1 Design
The design of the Deh Cho Bridge had to deal with many unique problems directly related to
the remote site and the extreme weather conditions. However, these extraordinary
circumstances offered excellent opportunities to design the structure in an innovative way
leading to the development of new techniques in bridge design and construction. From this
viewpoint the Deh Cho Bridge is one of the few engineering achievements that promote new
design philosophies avoiding unpredictable collapses, enhancing durability, and achieving
higher returns on investment.
5.2 Fabrication
Fabrication of the 1045 m long superstructure was performed under enormous time pressure.
One of the design priorities was to focus on a fast-tracked fabrication method. The Lego™
system realized by the designer for truss fabrication allowed the fabricator to produce
segments using the assembly-line fabrication method for shop processes and during trial
assembly. Up to six shops were simultaneously employed before pieces were trial assembled
in Quebec, Canada. In average one truss segment per week (55 segments total) was delivered
to site. Launching of the North approach commenced after one third of the superstructure was
fabricated.
5.3 Erection
Onsite erection followed the same principles of mass production. Repetition and
prefabrication significantly helped the contractor to standardize erection methods, processes,
and onsite QC. The high degree of prefabrication allowed construction to proceed even in
harsh winter conditions although construction speed was reduced. For example, installation
of twelve fully assembled locked coil cables was performed at -25 °C with a team of four
specialists in only three weeks (see Figure 11).
Fig. 11: Cable installation with ferry “Merv Hardie” in the background (Photo: Chad Amiel, Infinity)
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5.4 Investment
The cost of a new vehicle is not just the price tag on the dashboard. The same is true for
bridges. Inspection, maintenance, and repair require additional funds that can easily triple the
construction cost over the life span of the structure. Even more funds are required when for
various reasons the design service life cannot be achieved and an early replacement is
required. For that reason, designers and owners must consider the overall return on
investment. This is particularly true for major bridges because they are often paid by
generations to come. Adaptability, durability, robustness, inspection, and maintenance need to
be carefully considered because replacement of a major bridge cannot be achieved overnight
(neither technically nor financially).
The Deh Cho Bridge follows best design practices by addressing those points. For example, a
comprehensive maintenance manual has been developed for the entire bridge. A system
similar to a car inspection and maintenance program will help the owner and its inspectors to
recognize potential deficiencies in an early state so that progressive deterioration and costly
repairs can be avoided. This customized and systematic effort of reducing maintenance cost
and extending service life is an attempt to increase the overall return on investment for the
Deh Cho Bridge and bridges in general.
6. Conclusions
Bridges like the Deh Cho Bridge are “lighthouses of our engineering discipline”. They mirror
the never ending desire of mankind to overcome obstacles of any nature. But the Deh Cho
Bridge is more; it is a meaningful investment and an outstanding opportunity to prove that
modern progress in an industrialized society is possible in a responsible manner and in
harmony with Canada’s Aboriginal people and Mother Nature.
Fig. 12:”Lighthouse of the bridge engineering discipline” (Photo: Arc Rajtar, Levelton)
15. 15
7. References
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Department of Civil Engineering, University of Toronto, 2008, pp. 1-40.
[2] MEISS K.U., Anwendung von Strukturoptimierungsmethoden auf den Entwurf mehrfeldriger
Schrägseilbrücken und Extradosed Bridges, Ph.D. Thesis, University of Stuttgart, Verlag
Grauer, Beuren und Stuttgart, 2007, pp. 2-3 and pp. 5-26 (in German).
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81-83 (in German).
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[5] PODOLNY W. and SCALZI J.B., Construction and Design of Cable-Stayed Bridges, John
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[6] Ontario Ministry of Transportation, “Value Engineering”, Retrieved on March 28, 2012 from
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2010, pp. 30-31.
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Larsa’s 4D Journal, October, 2009, p. 1 and pp. 4-6.
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[12] BRAESTRUP M.W., “Yield Line Theory and Concrete Plasticity”, Morley Symposium on
Concrete Plasticity and its Application, University of Cambridge, 2007, pp. 43-48.
[13] HAHN V., “Eduard Züblin – Leben und Werk eines Ingenieurs in der Entwicklungszeit des
Stahlbetons”, Wegbereiter der Bautechnik, VDI Verlag, Düsseldorf, 1990, pp. 25-45 (in
German).
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Betonbrücken”, Beton- und Stahlbetonbau, Vol. 99, No. 10, Ernst & Sohn, Berlin 2004, pp.
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[15] National Transportation Safety Board, Collapse of I-35W Highway Bridge, Minneapolis,
Minnesota, August 1, 2007, Highway Accident Report NTSB/HAR-08/03, Washington DC,
2008, p. xiii.
[16] Commission d’Enquête sur le Viaduc de la Concorde, Commission of Inquiry into the
Collapse of a Portion of the de la Concorde Overpass, Government of Quebec, 2007, pp. 5-7.
[17] CAN/CSA-S6-06 Canadian Highway Bridge Design Code, Canadian Standards Association,
Mississauga, 2006.
[18] AASHTO LRFD Bridge Design Specifications, Fifth Edition, American Association of State
Highway and Transportation Officials, Washington, 2010.
[19] SCHUELLER M., “The Failure Mechanism Concept – An Innovative ULS Design
Approach”, IABSE-IASS Symposium Taller, Longer, Lighter, London, 2011.