bluuebunny/crossref_metadata_2025 huggingface dataset:
COST TU1406 – An overview of European Standardization on Quality Control of Road Bridges
Authors: Matos José , Casas Joan R. , Fernandes Sérgio
Published: February 2021

Road asset management is a task of great responsibility, since it involves vital assets to the community. An efficient transportation network is essential for the modern society from the economic, societal and environmental point of view. Today, it is a challenge for operators to manage road infrastructures under their responsibility in an efficient way, meeting the present and future needs of the community they serve. For this purpose, authorities need to produce an asset management plan which should not only define the goals to be achieved by exploiting the roadway bridge network, but should also identify investment needs and priorities based on a life cycle cost criteria. In addition, a proper condition assessment of these assets must be conducted to support the decision-making process regarding their preservation. COST Action TU1406 aims to quantify performance indicators, define standardized performance goals and develop a guideline to establish quality control plans at a European level.
Development of a modular footbridge system with pre-tensioned CFRP reinforcement
Authors: Perse Sophia , Stark Alexander , Will Norbert , Hegger Josef
Published: February 2021

A common problem of concrete bridges are corrosion damages of the steel reinforcement. The related loss of capacity as well as visual effects often require expensive and elaborate refurbishment or even reconstruction. To overcome these drawbacks, a modular footbridge system without steel reinforcement is developed. The application of non-corrosive carbon fiber reinforced polymer (CFRP) reinforcement is suitable for building slender constructions which are durable and long- lasting. To enhance the durability and reduce costs, high strength concrete (HSC) with high density is applied. Hence, no additional surface is required. The modular construction method allows for fast assembly and disassembly of the footbridge. This paper presents the dimensioning and flexural pre-design of the modular footbridge system.
IZMIT Bay Suspension Bridge – Wind Induced Vibrations
Authors: Inoue Manabu , Takai Yusuke , Uzun Mecit Kerem , Kawakami Takeshi
Published: February 2021

This paper describes the studies and the countermeasures against the vibrations on the cables of IZMIT Bay bridge (now named “Osman Gazi Bridge”) in Turkey. First, the vibrations observed in the structure are summarized together with the data measured on site by accelerometers, GPS etc. Through studies about the efficiency of possible anti-vibration devices, appropriate considerations have been adopted and those are working very properly so far.
Rehabilitation of Deteriorated Timber Piles with Fiber Reinforced Polymer Composites
Authors: Menkulasi Fatmir , Baghi Hadi , Hall David , Farzana Nahid
Published: February 2021

Louisiana has a large inventory of timber bridges in service. The timber piles in these bridges are succumbing to the effects of biological degradation that initiates in the wet-dry zones. Replacing these deteriorated piles is a costly process and in-situ repair of the piles with fiber reinforced polymers (FRP) is an economic alternative. An experimental program was conducted to evaluate the capacity of FRP strengthened deteriorated timber piles under axial loads with different lengths and depths of deterioration zone. A total of 11 monotonic tests were conducted. The investigated repair technique increases the capacity of damaged piles by 98% to 383% and enhances the capacity of undamaged piles by 3% to 22%. All failure modes were observed in the wooden portion of the pile outside the repaired region. Strain gage measurements indicate that the FRP shell is mobilized more when the annular void is smaller.
Seismic Performance of Cross Laminated Timber (CLT) Platform Building by Incremental Dynamic Analysis
Authors: Shahnewaz Md , Tannert Thomas , Alam Shahria M. , Popovski Marjan
Published: February 2021

The present study performed Incremental Dynamic Analysis on a case study Cross-laminated timber (CLT) platform building. The building was designed for the seismic modification factors of Rd=2.0 and Ro=1.5 for the soil Class C in Vancouver, BC, Canada. A 2D non-linear finite element model was developed in OpenSees. CLT panels were modelled as orthotropic elastic shell elements and the connections were modelled as non-linear springs that account for both uplift and shear deformation. The connections and wall parameters for hysteresis models were calibrated from test results. The seismic performance of the building was evaluated using the 22 bi-axial ground motions. The seismic demand was recorded in terms of inter-storey drift ratio. The results indicated that the case study CLT platform building has a sufficient factor of safety against collapse (Collapse Margin Ratio of 3.1) under a Maximum Credible Earthquake.
A monolithic approach for modeling viscoelastic materials in civil engineering
Authors: Kraus Michael A. , Niederwald Michael , Siebert Geralt
Published: February 2021

This paper presents a methodology called ‘GUSTL’ [1], which is designed to efficiently estimate the parameters of a Prony-series representation of linear-viscoelastic material behaviour using measured data of the complex modulus 𝑬∗(𝑓) obtained in a dynamic mechanical thermal analysis. ‘GUSTL’ is based on the idea of solving an inverse problem, established as a physically motivated system of linear equations, by a nonnegative least-squares procedure. The whole methodology is validated against sample data from an epoxy-coated carbon reinforcement grid for concrete structures.
Full Live Load Test of a Cable-Stayed Bridge
Authors: Trowland Morgan T. , Robazza Brook R.
Published: February 2021

In March 2016, the cable-stayed Atal Setu Bridge, newly completed in northern India, was load tested with 42 trucks representing the full design live load of 854 tonnes. Load tests are routine in India and their objective is to assure the owner that the bridge had been built to the required quality. Test trucks were positioned in four phases; after each phase, the elevations of 26 control points on each side of the bridge, as well as coordinates of four control points on each pylon, were surveyed to track deflections. The survey results were corrected for thermal movements using a reference set of hourly survey results from the preceding five days. Surveyed deflections were compared to analytical predictions and a go/no-go decision was made for the next phase of trucks. All trucks were successfully positioned and at 24 hours after load removal, 97% of the deflection was recovered, satisfying the 85% limit of the Indian Roads Congress code.
Modelling of structures and joints for performance-based design
Authors: Ozola Lilita
Published: February 2021

In this article some particular case studies of using innovative solutions regarding structures and joints are presented with the purpose of pointing out those solutions which are used in construction, but which have lead to sad consequences due to their failure or being prone to failure due to their high sensitivity to overloading or to changes in loading arrangements between the connected members. The subject under revision is hard loaded Warren trusses made of I- profiles including end-plate joints with bolts in tensioned chords. The solution when using Warren trusses with support diagonals loaded in tension and made of glue laminated timber comes under criticism regarding the specifics of anisotropic wood material. The design models examined are presented in order to disclose the redistribution of internal forces after the detailing of joints.

This study is aimed at avoiding the risks in structural design and failures of structures.
Cloud Accelerated Performance Based Seismic Design
Authors: Chok Kermin , Tomek Pavel , Clifton Trent
Published: February 2021

Non-linear Time History Analysis (NLTHA) is a key enabler of Performance Based Seismic Design (PBSD). Arup Los Angeles office typically performs these simulations in LS-Dyna solver. In order to respond to the demands of concurrent design projects, the authors have adopted a cloud centric approach to accelerate our workflows and to enable the use of non-linear time history analysis as a design tool as opposed to a verification tool. This paper will present our custom workflow which enable a dramatic compression of the time required for these analysis. The workflow generates LS- Dyna models in parametric fashion via Rhino- Grasshopper. Since a single design iteration of analysis can result in 48 to 110 models from a range of ground motions and input parameters these models are typically executed on a compute cluster with a large number of compute cores. The resulting number of analyses generates a large amount of data (8-16TB) which we post process leveraging “Big Data” approaches typically used by other industries (financial or retail firms).
Calli Extradosed Bridge: Fast track project for an extradosed bridge in seismic area
Authors: Ozkul Ozgur , Ozel C. Noyan , Yayim Cagri , Combescure Etienne , Buchin-Roulie Vanessa , Fabray Nicolas , Erdogan Julien
Published: February 2021

Calli Bridge, in Antalya city center, is the first extradosed bridge in Turkey. This 180m long bridge is composed of an 80m main span and two side spans of 50m. The concrete deck is a twin pi-section of 2.5m in depth and 15m wide, making the bridge 30m wide. The extradosed PT cables are composed of 2 sets of 4 cables 31HDE15 per pi-section that will go through 3 pylons of 7m height, using Freyssinet saddles and cohestrand technology. For the first time worldwide, a 1,960MPa ultimate tensile strength strand is used, which has a direct impact on pylon’s dimensions. As Antalya is located in high seismic hazard zone, a base isolation using LRB has been proposed. Thanks to this innovative concept for Calli Bridge of combining extradosed cables with base isolation and high strength strands, a cost effective solution has been reached. With the control of the overall supply chain of specific equipments, conception and construction were managed in only 7 months.
Comparing Seismic and Tsunami Load Demands on Reinforced Concrete and Concrete Filled Steel Tube Bridges
Authors: Stephens Max T. , Winter Andrew , Motley Michael R. , Lehman Dawn E.
Published: February 2021

In recent years, earthquakes and subsequent tsunami impacts on coastal communities have resulted in significant loss of life and damage to infrastructure. The impact of the ground shaking and tsunami damage was exacerbated by the failure of the transportation infrastructure, which delayed emergency services and had significant long-term impacts on local economies. These events have prompted an increased interest in updating structural design codes for bridge structures and informing retrofit strategies for the existing bridge infrastructure. One of the primary challenges for researchers is to differentiate between damage sustained during an earthquake and damage sustained during an ensuing tsunami. State-of-the-art numerical modeling procedures exist for both seismic analysis and damage prediction of structural systems as well as high-fidelity tsunami force prediction on large-scale structures, but these models are typically quite disparate in nature and require some coupling mechanism for multihazard analysis. In this work, the open-source structural analysis software OpenSees was used in-tandem with the open-source computation fluid dynamics software OpenFOAM to predict the damage susceptibility of reinforced concrete (RC) and concrete filled steel tube (CFST) bridges subjected to seismic and tsunami loading scenarios. For the seismic hazard analysis, a suite of near-field ground motions was scaled to predict the representative response of the two structures to a maximum considered seismic event (MCE). In parallel, a series of tsunami loading scenarios, including bore-type tsunami impact and rising steady-state flows, were developed using OpenFOAM models; these loading scenarios were applied to the structural models in OpenSees to evaluate the performance of the structures for a tsunami-only loading scenario to allow for a direct comparison of the seismic and tsunami demands and response. Preliminary results highlight the severity of the tsunami hazard, as both structures adequately resisted the MCE seismic hazard, but demonstrated a high collapse potential for all tsunami loading scenarios.
Seismic Retrofitting of Existing Structures – Common Strategies and Case Studies
Authors: Mendez-Galindo Carlos , Moor Gianni , Baillés Borja
Published: February 2021

The design of critical structures to withstand the effects of earthquakes continues to gain importance all over the world. Most recently, several countries in Latin America have started to implement advanced seismic protection systems. The main objective of these systems is always the people’s safety. However, the integrity of the structures and their serviceability immediately after an earthquake play an important role in the speed of the emergency response, particularly bridges, hospitals and schools. Additionally, the cost associated with repair or reconstruction of damaged structures is likely to be small compared to the economic impact caused by disruption of serviceability after an earthquake and during the long reconstruction phase.

Seismic isolation systems provide an alternative to conventional earthquake resistance design such as strengthening of structural elements (columns or beams), and have the potential for significantly reducing seismic risk without compromising safety, reliability, and economy of structures. As an alternative to seismic isolation, energy dissipation becomes essential in terms of seismic protection. The use of effective devices able to dissipate high amounts of energy ensures that other structural elements do not undergo excessive demands that could cause significant damage.

This paper presents some of the recent applications of seismic retrofitting in Mexico and Venezuela. These two countries are in active seismic areas that have experienced strong earthquakes. The development of the engineering expertise in the region, together with the availability of affordable and effective systems have encourage the use of advance seismic protection technologies, such as elastomeric isolators, as well as viscous dampers. The study cases presented in this paper serve as evidence of the increasing interest of designers, contractors and owners for safer and efficient structures, which above all ensure the safety of the population, and mitigate structural damage.
Numerical Study on 1200m-span Railway Cable-stayed Bridges with Four Different Girder Sections
Authors: Chen Guorong , Dai Gonglian , Liang Jinbao , Yang Linghao , Yue Zhe , Liu Wenshuo
Published: February 2021

The longest railway cable-stayed bridge, Hutong Bridge, with a 1092m main span, is going to be finished construction in 2019. It is no doubt that a railway cable-stayed bridge with main span over 1200m will come into being in the near future. This paper, basing on the design method of Hutong Bridge, extends a numerical study on cable-stayed bridges with 1204m main span. The numerical models adopt four different girder sections which are truss girder, orthotropic truss girder, box truss girder and box girder, aiming to find out the most suitable girder for the bridge. The advantages and disadvantages of these four kinds of sections will be valued by the effects on the pylons and piers, the stiffness of the girders, the effects on the railway and manufacturing cost. In conclusion, the mechanical characters of the box truss girder is better than other three sections and the cost of it ranks the third among these sections.
Going Digital: Increase Performance and Productivity Using A Common Data Environment
Authors: Tanase Lee D.
Published: February 2021

Interoperable design, modeling and analysis are keys to the success of today’s bridge projects. The next generation of bridge modeling software requires that it be purpose-built for bridge designers and contractors who need to create, construct, maintain, and document a wide variety of bridge information throughout the lifecycle of the asset.

Building and exchanging information in a common data environment using information-rich 3D model increases data quality, collaboration, constructability and operational aspects including asset management. Reduction in the project’s overall costs for the entire ecosystem are important for all stakeholders and the availability of intelligent 3D models are a key component in providing accelerated project delivery and information mobility.

How much is too much information and to what is our goal? Can we shorten the construction schedule? Are we designing for construction and can we meet the expectations of the travelling public during construction with the proposed design? A true data model addresses these questions and progresses the integrity of our engineering profession. This is when vision meets reality.

The purpose of this presentation will be to provide an overview of how technology can provide cost savings with the ability to interoperate with all stakeholders during design, construction and beyond on bridge projects of all sizes.
Life-cycle cost analysis of concrete structures reinforced with stainless steel reinforcing bars
Authors: Van Niejenhuis Colin , Walbridge Scott , Hansson Carolyn
Published: February 2021

The durability of reinforced concrete highway bridges is significantly affected by heavy road salt applications that are prevalent in parts of Canada and regions of the world with cold winter climates. Over time, chlorides migrate through the concrete to the reinforcing steel (rebar), resulting in corrosion and eventual loss of structural performance due to concrete spalling and loss of bond between the rebar and concrete. This causes significant reductions the service life of the structure. To address this issue, recent efforts have been undertaken to evaluate the use of corrosion resistant alternatives to traditional reinforcing steel, including stainless steel rebar. Along with assessing the increased durability that can be achieved, cost comparisons have been performed to identify conditions under which the increased cost associated with stainless steel rebar is warranted. In this paper, the results of recent analytical studies performed on the benefits of stainless steel rebar use will be presented. A significant gap identified in the literature has been the limited extent to which the effect of cracks in the concrete has been considered in assessing the corrosion performance of the rebar. In the current study, a probabilistic model for predicting the service life of reinforced concrete elements exposed to chlorides by Hartt (2012) has been modified to consider the effect of cracks on the diffusion coefficient, using a simplified approach proposed by Lu et al. (2011). In this paper, the modified model is described and used to demonstrate the effects of surface chloride concentration and the presence of cracks on rebar performance. This performance is characterized using a “critical cost ratio” below which it is economically appropriate, from a life-cycle cost perspective, to use stainless steel rather than black steel rebar.
Concrete Structure Assessment using ACI 562: History and Possible Next Steps
Authors: Bartlett F. Michael
Published: February 2021

This paper briefly summarizes the development of the structural safety provisions of ACI 562-16 “Code Requirements for Assessment, Repair, and Rehabilitation of Existing Concrete Structures”. An initial proposal to specify factored load combinations that depend on the desired Reliability Level of the element being assessed was not implemented. Instead, for cases where the required structural element dimensions, reinforcement locations and material properties are measured by the evaluator, the specified strength reduction factors are identical to those specified for Analytical Strength Evaluation in Chapter 27 of ACI 318-14. In all other cases, the strength reduction factors for assessment are identical to those specified for design in Chapter 21 of ACI 318-14. The reliability indices associated with these proposals are quantified and critically reviewed, and possible new directions for a future edition of ACI 562 are considered. The currently specified strength reduction factors yield higher reliability indices for tied or spirally reinforced columns than they do for beams subjected to bending, which is appropriate. The use of the assessment strength reduction factors yields a specified rating load that is markedly greater for columns than for beams with respect to the original design value, however: the associated 50-year probabilities of failure increase by a factor of roughly 25 for beams and by a factor of roughly 4300 for columns with spiral reinforcement. A preliminary procedure for building assessment is presented where the resistance factor is selected instead of the factored load combination to achieve a desired target reliability index. This simplifies the assessment as the structural analysis would be conducted using a single set of factored load combinations and the impact of different consequences of failure could be reflected in the resistance factor selected.
IZMIT Bay Suspension Bridge – Advanced Post tensioning system
Authors: Inoue Manabu , Yanagihara Masahiro , Durmaz Müslüm , Kara Aydin , Bellikan Erol , Pedersen Flemming Michael , Löhning Thomas
Published: February 2021

This paper introduces the advanced post-tensioning system adopted in the anchorage for IZMIT Bay Suspension bridge (now named “Osman Gasi Bridge”) in Turkey. The system is based on unbonded tendon instead of the conventional grout solution. The reliable long-term durability is provided by the dehumidification system and the condition inside a tube is continuously monitored. In addition, “strand-by-strand” method gives the possibility to replace strands in the feature. The method has been verified by a mock-up test. Major steps of strand replacement are also described in this paper together with some notable key issues.
Cable Erection of Triple Pylons (multi-span) Suspension bridge, New Millennium Bridge
Authors: Yang Kyuyoung , Kim Jungin , Choi Jinhyuk , Park Taekwun , Kim Jaehong
Published: February 2021

The triple pylons suspension bridge in Korea, New Millennium Bridge, has triple pylons and multi- span. For the erection of main cables with 21 strands and 2,667 wires, the Prefabricated Parallel Wire Strand (PPWS) method has been adapted, and the cable erection work will be conducted from June to August in 2017. The paper describes the installation and design of catwalk and pylon saddle and erection of main cable of New Millennium Bridge.
Innovative Technology of Yavuz Sultan Selim Bridge Design and Construction
Authors: Paik Hansol , Kwak Sungtae , Park Wonjeong
Published: February 2021

This study dealt with innovative technologies developed for the structural design and construction of a new hybrid cable bridge named Yavuz Sultan Selim Bridge. It is a cable-stayed suspension bridge under the combined road and rail loading which is located in the northern side of the Bosphorus strait. It was proposed at an initial stage as a conventional suspension bridge type with truss double deck which has the sufficient rigidity to ensure its stability in an extreme environment and serviceability in a railway operation status. However, a new bridge in the Bosphorus strait was required to be aesthetically harmonized with existing two suspension bridges. For this reason, a hybrid bridge type in a high rigidity composing of a cable arrangement with orthogonal single box was developed for achieving good aesthetic view and serviceability in rail operation status. The techniques reported in this paper were focused on a hybrid system for the high-rigidity suspension bridge, a pendulum bearing for an additional rigidity and a newly developed fatigue test criteria for stiffening cable and damper designs. In addition, a plan of temporary struts and a Tower top beam(TTB) installation, special measures to resist against wind effects during the construction and for deck closures were enunciated in the paper.
Atal Bridge: Efficient Delivery of Construction Engineering Services Using Information Communication Technology
Authors: Trowland Morgan T. , Robazza Brook R.
Published: February 2021

India has massively increased investment in transportation infrastructure over the last decade, including the deployment of advanced technologies such as cable-stayed bridges. To relieve a domestic skills shortage, the services of foreign civil engineering consultants are often engaged, especially on technologically advanced projects. This paper presents a case study of the cable-stayed Atal Setu Bridge, a new link to the state of Jammu & Kashmir; recounting the diverse ways that foreign consultants assisted in the construction phase; and how newly available communication technologies made this process more efficient, even in an area with poor communication infrastructure. The geometry control during the complex erection sequence is described, including the methods of communication employed in this process. These communication channels assisted the transfer of both ‘hard’ technical knowledge and ‘soft’ organizational skills which are essential to civil engineering projects.
Finite element investigation of the compressive membrane action effect on concrete slabs
Authors: Genikomsou Aikaterini , Polak Maria Anna
Published: February 2021

The current design codes for punching shear resistance of flat slabs are based on empirical formulations derived from test results of isolated slab-column connections, where the compressive membrane action was ignored. Testing continuous slab systems is very uneconomical and in most cases not possible. In this paper, finite element analyses (FEA) are performed to investigate the structural performance of continuous slabs. A previously tested and analysed isolated slab with larger in-plane dimensions and different boundary conditions is considered. The FEA results indicate that the shear capacity of the continuous slab is much higher compared to the capacity of the isolated slab. The numerical models are used to examine the effect of low reinforcement ratio in the response of the continuous slabs. Finally, a comparison between analytical results and code provisions indicates the conservatism of the design codes.
Intelligent Future Building Skins –
Authors: Aßmus Elisabeth , Weller Bernhard , Haskell Jake , Sengewald Timo
Published: February 2021

Algae growth on building facades would usually be a cause for frustration among the majority of building owners. But what if microalgae were cultivated intentionally on facades as a future building concept for energy or domestic warm water supply? A team of German scientists and technicians consisting of ADCO Technik GmbH, ARUP Deutschland GmbH, Frener & Reifer GmbH, SSC Strategic Science Consult GmbH and Technische Universität Dresden is developing flat panel bioreactors made of glass for building skins. This paper presents the construction of a photobioreactor prototype. It describes the design approach including the structural design and flow simulations. The mechanical, physical and chemical loads are characterized and experimental studies on adhesive materials are presented.
Timber bridges – Load carrying behaviour according to climate changes
Authors: Franke Steffen , Franke Bettina , Schiere Marcus , Müller Andreas
Published: February 2021

Timber road bridges have been built worldwide for centuries. The high performance of wood as structural material is approved. However the influence of moisture induced stresses in cross sections according to the varied ambient climate are still questioned. Results observed in the long term monitoring of six timber bridges provide first guidelines for practitioners. Further on, first numerical simulations are carried out for the assessment of the long term behaviour of timber bridges over the life cycle. The numerical simulations include the moisture diffusion transport in wood as well as the resulting stress strain behaviour of the timber member. The research results provide new guidelines for the planning engineers, the definition of an active or passive zone of the cross sections, and provide a differentiation of the service class over the cross section.
Pretensioned, Rocking Bridge Columns for Accelerated Construction and Enhanced Seismic Performance
Authors: Thonstad Travis , Mantawy Islam M. , Eberhard Marc O. , Stanton John , Sanders David H.
Published: February 2021

A new precast bridge bent system has been developed that accelerates on-site construction activities, minimizes residual displacements even after large seismic events and reduces post- earthquake damage. The connections are the key to the system’s seismic performance. They were tested under quasi-static conditions and found to perform exceptionally well with nearly zero strength degradation and little concrete damage, even after being loaded cyclically up to drift ratios of 10%. The restoring properties of the system were evaluated through multi-shaking table tests conducted on a quarter-scale, two-span bridge specimen. The maximum residual drift ratio during testing was 0.4%, even after excursions to drift ratios exceeding 13%. This paper describes the new system, compares its performance to that of more conventional cast-in-place construction, and describes key aspects of its design philosophy.
Seismic Performance of Perforated Steel Plate Shear Walls Designed According to Canadian Seismic Provisions
Authors: Barua Kallol , Bhowmick Anjan
Published: February 2021

Perforated Steel Plate Shear Wall (P-SPSW) is a relatively new lateral load resisting system. Research on P-SPSW is in the initial stage, and to the best of these researchers’ knowledge, no seismic performance of code designed P-SPSWs has been studied yet. The main objective of this study is to evaluate the seismic performance of code designed P-SPSWs. Three multi-storeys (4-,

8-, and 12-storey) P-SPSWs were designed according to the seismic provisions of NBCC 2010 and CAN/CSA S16-14. Nonlinear time history (NTH) analysis was conducted using detailed finite element (FE) modeling techniques for a series of ground motion records which were compatible with Vancouver response spectrum. All the perforated shear walls exhibited excellent seismic behavior including high stiffness, stable ductility, good energy dissipation capability and also current code equation provides a good estimation of the shear strength of the perforated plate when the infill plate is fully yielded. The applicability of the modified strip model (MSM) was also evaluated in this research for unstiffened P-SPSW. It was observed that the modified strip model captures the inelastic behavior of multi-storey unstiffened P-SPSWs with adequate accuracy. The ultimate strength was predicted well, and the initial stiffness was slightly underestimated.
The Shenzhong Link – A synthesis of architectural and structural design
Authors: Forsberg Torben , Ove Jensen Poul
Published: February 2021

In March 2016 COWI with Dissing+Weitling architecture won the international competition for a fixed link between Shenzhen on the east side and Zhongshan on the west side of the Pearl River Estuary near Guangzhou in China. The Shenzhong Link is 24km long and includes 7km immersed tunnel, 4km cable supported bridges, 12km approach bridges and an artificial island. The link will serve the transit traffic of a 2 x 4 lane expressway and local traffic to a terminal building on the artificial island. Engineers and architects jointly developed the bridge structures, artificial island and tunnel with the overall objective to achieve an iconic, yet harmonious and elegant link from one end to the other. The award of the 1st price of the competition was followed by these words of the Client’s: "The design philosophy of the concept is advanced. The overall design of the link is magnificent, elegant and concise. The design of main bridges, the approach bridges and the artificial island is integrated, the holistic impression and iconic landmark of the link is prominent, the whole link is in harmony with the surrounding environment, the Y-shaped pier shaft of approach bridges give a very strong sense of rhythm." The teamwork of engineers and architects is supposed to be exceptionally successful. This paper describes the innovative bridge concepts of the fixed link, their justification in terms of structural strength, durability, economy and architecture, and how they were developed. The basic demands of strength, stability and durability actually go well hand-in-hand with elegant and slender bridge structures, that are yet inexpensive. The engineers and architects worked in close collaboration from the very beginning of the competition, pro’s and con’s of different design options were discussed by the team, and by joint efforts, the concepts were changed or modified into their final shape.
Conceptual Design, Detailed Design, and Construction of the Terwillegar Park Stressed Ribbon Footbridge
Authors: Ellis Reed , MacLaggan David , Savard Carl , Reske Jason
Published: February 2021

In January 2013, the City of Edmonton called for proposals for a new 300 m footbridge across the North Saskatchewan River in Edmonton, Alberta, Canada. Consultants were challenged to develop concepts that were innovative, fit the context of the deep natural river valley, and meet strict budgetary and schedule requirements. In October 2016, the longest and first multi-span stressed ribbon bridge in Canada was opened to the public. The Terwillegar Park Footbridge was designed by Stantec Consulting Ltd for the City of Edmonton and forms a key link in the river valley park system in that city. Stressed ribbon bridges can be described as precast concrete structures that are erected segmentally on cables and post-tensioned to achieve a continuous, slender, prestressed concrete structure. In this paper, the conceptual and preliminary design process of the Terwillegar Park Footbridge is described and challenges encountered in the design and construction of this elegant and innovative structure are shared.
Construction of the Terwillegar Park Stressed-Ribbon Footbridge
Authors: Paulsen Michael , Shields Nikola
Published: February 2021

The recently completed Terwillegar Park Footbridge is a new stressed ribbon bridge located in Edmonton’s river valley. The bridge is 262 m in length and is one of the longest stress-ribbon bridges in the world. This bridge type comprises a thin deck, supported on highly stressed bearing strands, and post-tensioned to achieve the necessary stiffness and desired geometric shape.

Associated Engineering, working as an erection engineer for Graham Infrastructure developed methodology to construct this bridge, described in this paper. One innovative accelerated construction method used was the creation of the ‘messenger’ loop system that facilitated bearing strand and precast panel installation. Furthermore, the construction erection team was required to provide geometric set-out during construction and involved modelling, monitoring and reporting of the bridge during construction.
Performance assessment of embedded distributed optical fiber sensors in reinforced concrete structures
Authors: Barrias António , Casas Joan R. , Villalba Sergi
Published: February 2021

In this paper, an experiment where distributed optical fiber sensors (DOFS) were implemented in two small concrete beams subjected to a three-point load test is outlined. Here, an optical backscatter reflectometry based DOFS is implemented simultaneously embedded in the concrete (glued to the steel rebar) and attached to the outer surface of the concrete after its hardening. For comparison purposes, three electrical strain gauges are also used in the rebar. The main objectives with this experiment, is to analyze the feasibility of installation of DOFS directly on the rebar element of a reinforced concrete beam and compare the measured strain at rebar and surface of the concrete.
Distributed Deflection Measurement of Reinforced Concrete Elements Using Fibre Optic Sensors
Authors: Brault Andre Rober , Nurmi Sara , Hoult Neil A.
Published: February 2021

The construction of new infrastructure required to meet the demands of a growing global population has substantial negative impacts on the environment. Structural engineers can help reduce these negative impacts through efficient material use in reinforced concrete (RC) design, as steel and concrete production accounts for a significant portion of global greenhouse gas emissions. In RC design, stiffness and support condition assumptions often lead to large discrepancies between design models and true behaviour. Critical insight would be captured if the deflected shape of RC beams could be practically measured. A method of measuring the deflected shape of RC beams using distributed fibre optic sensors (FOS) is presented. Six RC beams were tested in three-point bending. The FOS results were evaluated against displacement transducers and were found to capture deflected shapes accurately until loading exceeded 50% of the beams’ ultimate capacities.
The Existing Champlain Bridge - Overview of Issues – The Owner’s Perspective
Authors: Carlin Glen P.
Published: February 2021

Montreal’s Champlain Bridge was the first large scale use of prestressed concrete in Canada. A lack of understanding of corrosive effects from the long term use of de-icing salts has, over the decades, led to severe corrosion of the concrete girders. A poor drainage system and water infiltration through the pre-stressing anchors contributed to accelerating deterioration. A decision to replace the bridge was taken in 2011 only 49 years after its opening.

Today, the most vulnerable girders are instrumented and the owner, The Jacques Cartier and Champlain Bridges Incorporated, has installed steel trusses beneath the exterior concrete girders as a risk management strategy.
The Existing Champlain Bridge – Instrumentation, Monitoring and Load Tests
Authors: Tinawi René , Lavigne Dominic , Crépeau Louis , Sobhani Ehsan
Published: February 2021

This paper describes the instrumentation and monitoring of the 50 spans of the Champlain Bridge in Montreal using optical sensors at mid-span for recording flexural strains on the exterior post tensioned girders. These girders were subjected to structural degradation due to corrosion of the strands. Presently over 320 optical sensors are installed on the bridge to record data on a continuous basis at 50Hz. Such data contains invaluable information for monitoring the bridge response and condition after each monthly Load Test. In addition, the daily dynamic traffic loading is analysed to detect any sign of degradation in the post tensioned girders.
The Third Bosporus Bridge - Its longitudinal and transversal behaviour
Authors: De Ville Vincent , Duchêne Yves
Published: February 2021

The Third Bosporus Bridge is a highly rigid suspended bridge with a main span length of 1’408 m and a total length of 2’260 m located at the north of Istanbul near the Black Sea.

The cable system is a combination between stiffening cables (stay system) and classical suspension. The towers are 320 m high. The steel deck, on the main span, is 5.50 m high and 58.50 m wide with 4 road lanes in each direction, 2 railway tracks and 2 sidewalks.

Of course, for such huge spans, the wind loads and seismic hazard are very important, but with the addition of two railway tracks, the effects of the large and combined loads have to be examined in detail.

For railway traffic, it was very important to check that the vertical displacements were limited. But this hybrid suspension induces non negligible longitudinal displacements leading to a large distension of several stay cables. Then, if classically, the support scheme is important in the vertical and transversal directions, for this bridge, the longitudinal direction had also to be examined in detail.

Different solutions have been studied for the transversal and longitudinal supports. Pendular bearings have been chosen for the longitudinal direction. The paper will explain the interest of the different support schemes.
Assessment of efficiency of intensity measures for performance- based travelling fire design
Authors: Teslim-Balogun Adeyanju , Málaga-Chuquitaype Christian , Stafford Peter J.
Published: February 2021

Current fire design methods assume a uniform temperature distribution in building compartments, which is unrealistic for large compartments. In contrast, travelling fire models account for the non-uniform distribution of temperatures in large compartments. However, an adequate fire intensity measure (IM) is important to properly define the severity of the fire, especially within the context of a performance-based design. This paper presents an assessment of IM as related to various engineering demand parameters (EDP) in order to establish the most efficient IM for performance-based travelling fire design. Non-linear analyses were carried out on generalised steel frame models to determine their structural response. Regression analysis was also carried out and it was observed that the length of fire was the most efficient IM in the range of EDPs considered. The results will be useful in the performance-based fire design of steel structures.
Punching shear behaviour of edge column connections in continuous flat slabs
Authors: Einpaul Jürgen , Vollum Robert , Ramos António
Published: February 2021

This paper deals with the behaviour of reinforced concrete flat slabs around their connections to edge columns. Using a non-linear finite element model with shell elements and simple assumptions regarding flexural and shear response, this study investigates the magnitude of unbalanced moments transferred between the slab and the column as well as the distribution of shear forces in the slab around the connection. The influence of distribution of reinforcement between hogging (around the columns) and sagging (in the mid-span) areas as well as in the directions parallel and perpendicular to the slab edge are analysed. The behaviour of continuous slabs is compared to that of typical test specimens. It is shown that the distribution of shear stresses in test specimens may be significantly less uniform which can lead to lower punching capacities in the tests than in actual continuous slabs.
Seismic Performance of Columns with Grouted Couplers in Idaho Bridges
Authors: Ebrahimpour Arya , Earles Barbara
Published: February 2021

Accelerated Bridge Construction (ABC) methods have been limited in moderate-to-high seismic regions because of concerns about the performance of connections. A study was carried out for the Idaho Transportation Department (ITD) on the seismic performance of precast columns with grouted couplers versus the conventional cast-in-place columns. Experimental data provided the necessary input to model the grouted couplers. Using the OpenSees finite element analysis program, selected bridges were subjected to the seismic conditions of the most seismically active location in Idaho. The stresses in both the longitudinal reinforcing bars and the grouted coupler regions are found to be well within acceptable ranges. The largest column drift, using a combination of orthogonal displacements, is about 1.6 percent. Furthermore, grouted couplers may be used to connect precast columns to footings or cap beams for columns with less than 4 percent drift.
Ambient Vibration Testing of the Hawkshaw Bridge
Authors: Araki Yumi , Arjomandi Kaveh , Simpson Robert
Published: February 2021

This paper presents the ambient vibration tests that were conducted on the Hawkshaw Bridge, a three-span cable-stayed bridge located in New Brunswick, Canada. Tri-axial wireless sensors were installed on the bridge girders to capture the bridge acceleration due to the normal traffic condition. Challenges that were faced during the tests and the post-processing of the data are discussed in this paper. The natural vibration frequencies were extracted using Operational Modal Analysis. The vibration frequencies were compared with the finite element analysis results of the original designed bridge and the discrepancies were discussed.
Fatigue Performance Evaluation of Severely Corroded Steel Strands
Authors: Park Yeun Chul , Kim Chul Young , Yoo Seung-min
Published: February 2021

Recently, one of the external tendons in Jung-reung-cheon Viaduct in Seoul was failed after 17 years of service due to severe corrosion in strands. As a part of the in-depth investigation, fatigue tests for the corroded strands were conducted to check the structural safety and serviceability of the defected tendons. Nine corroded strand specimens were collected from the replaced tendons. All corroded strands demonstrated very poor fatigue performance. All the specimens could not satisfy the minimum requirement of two million cycles at the stress range of 190 MPa recommended by Eurocode. Section loss in each specimen was measured at the fractured section and found that there is little correlation between section loss and fatigue life. It may be little fatigue life remaining once corrosion occurred in strands.
Shear Strengthening of Pile Cap Girders Using Carbon Fiber Reinforced Polymer (CFRP) Strips
Authors: Shekarchi William , Jirsa James O. , Ghannoum Wassim
Published: February 2021

Five large-scale reinforced concrete (RC) pile cap girders were tested to investigate the feasibility of strengthening wide-webbed RC members in shear using Carbon Fiber Reinforced Polymer (CFRP) strips that wrapped around the girder and U-wrap strips with CFRP anchors. CFRP strips were applied to uncracked and pre-cracked 813 mm deep by 813 mm wide pile cap girders to determine the shear performance of strengthened members. The test results indicated that the CFRP anchors developed the fracture strength of the CFRP strips even though some anchors were placed in tension zones. The CFRP shear strengthening improved the shear capacity of the pile cap girders by as much as 56%. Strengthening uncracked and pre-cracked specimens resulted in comparable peak shear capacities. However, the pre-existing shear crack caused the average CFRP fracture strain to be lower than in the uncracked girder.
Numerical simulation of long-term creep tests on prestressed beams
Authors: Van Mullem Tim , Reybrouck Nicky , Criel Pieterjan , Taerwe Luc , Caspeele Robby
Published: February 2021

The deformations of concrete elements can increase significantly over time as a result of creep and shrinkage. Different material models, which have been calibrated on large datasets, are available in literature in order to predict this time-dependent behaviour. A cross-sectional calculation tool which employs the age-adjusted effective modulus has been developed to verify the accuracy of six models with respect to creep data available for 24 prestressed beams. These prestressed beams with a span of 8 m were loaded up until 4.5 years in a four point bending configuration. This paper reports on the comparison between the measured and calculated compression strains and deflections. It was observed that the mid-span deflection of the prestressed beams at the end of loading is best prescribed by the model B3 and the Gardner Lockmann 2000 model.
Adaptive Prestressed Structures realized by utilization of Artificial Intelligence Techniques
Authors: Schnellenbach-Held Martina , Steiner Daniel
Published: February 2021

Safety, economy and aesthetics are principal criteria for structural design. Involved contradictions between rising design demands and increasing influences provoke new challenges in the field of engineering and therefor innovative strategies and construction techniques. The conventional passive design principle of prestressed concrete is significantly improved by equipping the structure with appropriate control processes. Adaptive Prestressing is characterized by an active self-adjustment of the construction featuring various potentials. Benefits are verified by previous projects covering self-adjusting prestressed structures. A new implementation approach is based on application of AI-techniques like Fuzzy Logic, expert knowledge and machine learning. By means of experiments on two different prototypes the developed system’s applicability is verified and potential of Adaptive Prestressing is emphasized.