bluuebunny/crossref_metadata_2025 huggingface dataset:
Abordaje oportuno para incrementar atenciones preventivas en embarazadas en tiempos de Covid
Authors: Baquerizo Suárez Pedro Javier , Moreira Cedeño Leydi Diana , Baquerizo Suárez Cecilia Andrea
Published: February 2021

Ante el panorama de la actual pandemia de Covid-19, en países en los cuales la salud materna sigue siendo una preocupación de las políticas públicas y agendas nacionales, la preparación y el apoyo de respuesta es clave a fin de evitar un incremento de las muertes maternas. Recientemente y hasta la fecha, se conoce que las mujeres embarazadas presentan un mayor riesgo de enfermarse gravemente y morir a consecuencia del Covid-19, asimismo, un mayor riesgo de presentar otras complicaciones. Las atenciones preventivas que se puedan brindar a las embarazadas para protegerlas del Covid-19, puede evitar el contagio y la propagación de la enfermedad, además de sus complicaciones. El objetivo del presente estudio consiste en plasmar algunas generalidades acerca del manejo adecuado de la embarazada que permita aumentar las atenciones preventivas durante esta Pandemia. El modelo de investigación es una revisión de tipo documental bibliográfico. Se encontró que las embarazadas deben adoptar las mismas medidas preventivas que el resto de la población para evitar el contagio. Las pacientes deben ser clasificadas en tres grupos: embarazos de bajo riesgo, de alto riesgo y embarazadas con Covid-19 positivo, esto con la finalidad de adecuarlas tanto las medidas como los equipos de protección personal y disminuir la infectabilidad, seguir las recomendaciones epidemiológicas y asegurar el bienestar de la madre y el feto. En conclusión, todas las regiones del mundo han elaborado, con base a los conocimientos sobre la infección actual basados en la evidencia disponible, buenas prácticas y recomendaciones de la OMS y expertos, de diferentes manuales, guías y recomendaciones, con la finalidad de brindar la mejor atención a la embarazada durante esta pandemia. Es fundamental que estas guías se mantengan en constante actualización conforme a las novedades que surjan en esta materia.
Innovative Expansion Joint Replacement for Burlington Bay Skyway
Authors: Ostrowski Joseph , Sidky Sherif , Lai David
Published: February 2021

The innovative expansion joint replacement design for the Burlington Bay Skyway Northbound Structure in Hamilton, Ontario resulted in substantial economic and social benefits. The existing modular expansion joints were distressed and at the end of their service lives. Joint replacement was complicated by several constraints, including high traffic volumes, limited detour options, a restriction against full closures of the bridge, a moratorium by the client agency on splicing modular joint assemblies, and the limited available load capacity of the structure. The bridge articulation was modified and the existing breather joints were mobilized to reduce movement at 16 modular expansion joints. This allowed these joints to be successfully replaced with an innovative prefabricated module expansion joint assembly incorporating a single strip seal. The design minimized traffic closures and disturbance to the public, while also realizing substantial cost savings.
Lead Rubber Bearings for Seismic Isolation of Structures in Cold Climates - New Developments
Authors: Mendez-Galindo Carlos , Moor Gianni , Rassy Samy
Published: February 2021

Nowadays, even in areas that have not been well known for the application of seismic protective measures, there is a growing tendency to design highway bridges, especially curved ones, to withstand strong seismic demands. This paper describes the challenge faced in the seismic isolation using LRBs of a curved highway viaduct where low temperatures must be considered in the design. Specifically, the LRBs must be able to withstand temperatures as low as -30 °C for up to 72 hours, while displaying only minor variations in their effective stiffness. This extreme condition required the development of a new rubber mixture, and the optimization of the general design of the isolators. Since the relevant specifications such as AASHTO Guide Specifications for Seismic Isolation Design and EN 15129: Anti-Seismic Devices contain only limited test data relating to low- temperature performance, extensive full-scale low-temperature dynamic testing was carried out.
Seismic Performance and Failure Mechanism Study of Double Deck Bridges by Pushover Analysis
Authors: Zhang Jie , Yi Jiang , Li Jianzhong
Published: February 2021

Double deck bridges are increasingly adopted to alleviate the overcrowded traffic in China. However, its seismic performance is more complicated and less well-studied, comparing with ordinary standard bridges. In this paper, pushover analysis is employed to investigate influence of structural parameters on the seismic performance of double deck bridges. Analysis results show that a relative small column reinforcement ratio is feasible for double deck bridges, as cap beams and joints are likely to damage if the column reinforcement ratio is too high. The failure mode of double deck bridges can be categorized into two types according to the height of upper column and columns. One type is that plastic hinges appear in both upper and lower columns, and the other type is that plastic hinge just appear in the upper or lower column. Cap beams with relative large cross section dimension are favourable, as the strong beam-weak column mechanism is achieved.
Performance Indicators for assessing RAMS SHEEP performance
Authors: Høj Niels Peter , Stipanovič Irina , Klanker Giel
Published: February 2021

Bridge management strategies need to specify maintenance actions, which are required in order to keep a desired performance level. This paper presents the structure and basic ideas for the development of a guideline incorporating different aspects of bridge performance goals, which may vary according to technical, environmental, economic and social factors. Furthermore it discusses the need for agencies to measure bridge performance against objectives on structure and network level. The paper is based on activities in the COST Action TU 1406, which aims to bring together both research and practicing community in order to accelerate the establishment of a European guideline for bridge management.
A proposal for classification of key performance indicators for road bridges
Authors: Limongelli Maria Pin , Orcesi Andre
Published: February 2021

Because of the competing demands for scarce resources (funds, manpower, etc) national road owners are required to monitor the condition and performance of infrastructure elements through an effective inspection and assessment regime as part of an overall asset management strategy. COST Action TU1406 aims to bring together research and practicing communities in order to establish a European guideline in this issue. In this context, this paper proposes a framework to classify research-based performance indicators related to highway bridge life-cycle analyses according to a parameter readiness level (PRL). Such a method examines program concepts, technology requirements, and demonstrated capabilities to rate the level of maturity of different categories of indicators. This approach is illustrated with some examples.
Recommendations for proof load testing of reinforced concrete slab bridges
Authors: Lantsoght Eva , van der Veen Cor , Hordijk Dick , de Boer Ane
Published: February 2021

Proof loading of existing bridges is an option to study the capacity when crucial information about the structure is lacking. To define the loading criteria for proof load testing, a review of the literature has been made, finite element models of existing viaducts have been made, and on these viaducts, proof loading tests have been carried out. These bridges were heavily instrumented, to learn as much as possible about the structural behaviour during proof loading. Additional laboratory experiments have been used to develop controlled loading protocols, and to identify which stop criteria can be used for which case. As a result of the analysis and experiments, recommendations are given for proof loading of bridges with respect to the required maximum load and the stop criteria. These recommendations have resulted in a guideline for proof loading of existing reinforced concrete slab bridges for The Netherlands.
Rosedale Overhead: Functional Upgrades, Structural Rehabilitation and Seismic Retrofit
Authors: O'Hagan Sean , Holmes Keith , Saiedi Reza , Khan Saqib , Hamersley Bruce
Published: February 2021

The Rosedale Overhead is a 77m long two-lane crossing of BC’s Highway 9 over a busy railway track. Built in 1956, the current improvements include widening, new barriers, seismic retrofit and structural rehabilitation, including full concrete deck replacement. The initial design considered retaining and over-coating the existing girders. However, the final design was the outright replacement of the existing girders, with the new girders configured as continuous spans. This concept was preferred because of the lower costs, a savings partly attributed to the reduced number of girder lines from eight to five and bearings by more than half. A reliable seismic load path was established by infilling the bents either side of the rail tracks and locking the bridge ends with new semi-integral abutments. All other bents were left un-retrofitted with low-friction PTFE bearings to reduce lateral bent demands and avoid foundationupgrades.
Fire Resistance Performance of Prefabricated Composite Floor System Infilled with Phase Change Material
Authors: Park Min Jae , Ju Young K. , Min Jeong Ki , Yoon Sung Won
Published: February 2021

In South Korea, the most common floor system installed on steel frames have been deck slab system. Disadvantage of this system is increasing construction duration due to concrete curing and additional fireproofing protection works. As fireproofing protection installed by people handwork had low quality and material wastes, floor systems that had fire resistance performance and easily applied to steel frames started being developed. Prefabricated Composite Floor System was also developed to apply to steel structures without fireproofing protection and features of this system were largely influenced by Phase Change Material filled inside the system. Phase Change Material could be differently made by additives and some materials were developed to enhance the fire resistance performance of systems by changing additives. In this research, the fire resistance performance of Prefabricated Composite Floor system with infilled different Phase Change Material was evaluated and predicted by using finite element analysis program ABAQUS/CAE 6.10-1. In addition, the effect of wire meshes and the type of PCM were investigated by using temperature distributions and displacements during 2 hours fire test modelled at finite element program.
The effect of constraining measures for road traffic on highway bridges
Authors: Nowak Marcel , Fischer Oliver
Published: February 2021

The current German guideline for reassessment of existing road bridges (Nachrechnungsrichtlinie) allows for constraining measures for road traffic in order to reduce the load impact on bridge structures. However, quantification of this reduction is specified only for selected cases in the guideline. This paper presents results from analysis of the effect of different constraining measures for unidirectional road traffic, such as no passing of motor trucks, minimum inter- vehicular distance regulation, and modification of traffic routing, on the resulting structural demands for selected highway bridges. The results are compared to the reference case of normal, unconstrained traffic to demonstrate the effectivity of different constraining measures. Findings from this analysis can serve as base for calibration of modified load models for bridge reassessment when enforcing the respective constraining measures for road traffic.‌‌‌
Harnessing Results of Nonlinear Dynamic Soil Structure Interaction Analysis in Reinforcement Design of an Underground Rail Station
Authors: Tomek Pavel , Chok Kermin , McKenna Colm , Freudenberger Frank
Published: February 2021

Underground structures located in highly active seismic regions can experience significant earthquake demands. Non-Linear Dynamic Soil Structure Interaction (NLDSSI) analysis using multiple earthquake records is becoming more prevalent method of assessment of those demands and is included in Design Criteria of many American transportation agencies. This paper will explain the advantages and challenges of NLDSSI compared to traditional seismic design methods of underground structures and an example of application on an underground station located in Los Angeles. To deal with the amount of data generated by NLDSSI the design team developed a semi- automated post-processing tool for reinforcement design using LS-Dyna model results, MySQL database, post-processing and custom visualization in Rhinoceros 3D and Grasshopper.‌
Design and Erection of the Arrah-Chhapra Bridge
Authors: Robazza Brook R. , Trowland Morgan T. , Sohal Gurpreet S. , Jeakle David L.
Published: February 2021

The Arrah-Chhapra Bridge represents an evolution of bridge technology and construction processes in the Indian State of Bihar. The bridge will be an important link in the 117m-person state; increasing the road transportation capacity over the Ganges River by 66%. The original plan called for 36 approach spans that were to be erected span-by-span as precast box girder segments, whereas the 16 navigation spans were to be cast-in-place with variable depths of up to 8m. To reduce the construction schedule, while also creating a flexible construction sequence, McElhanney Consulting Services Ltd. engineers proposed an alternative extradosed system that permitted free- cantilevering segments of only 3.4m deep; enabling multiple spans to be erected simultaneously and rapidly. Through detailed construction stage analysis, rigorous geometry control, and exhaustive efforts in the riverbed, the new bridge is entering its final stages of construction.
Static and Dynamic Study of a 700 m Long Catenary Bridge
Authors: Szabó Gergely , Pálossy Miklós , Mátyássy László
Published: February 2021

Catenary pedestrian bridges are spreading all over the world with larger and larger span lengths. These engineering structures are extremely slender; therefore the wind effects seem to be the boundary to the span length maximization. There is apparently a strong need to increase the span length of such bridges, which makes it important to assess the feasibility of super-long spans. In this paper a pedestrian catenary bridge is investigated. The crossing would be built in an adventure park between two hills. The span of the main catenary cables would be 700 m, nearly twice as much as the longest bridge of its kind. The feasibility study comprises static and dynamic calculation of the structure. Catenary structures are geometrical nonlinear in nature, which requires third-order theory to follow. A program was written to conveniently model the structural behaviour. Nonlinear static calculation was used to determine the stiffness properties of the completed bridge, from which the tangential stiffness matrix could be compiled. The dynamic calculations were performed based on modal analysis via the extracted dynamic mode shapes and natural frequencies. The bridge structure was assessed with special attention on the wind effects; buffeting and coupled flutter phenomena were considered the most relevant wind related oscillation cases to deal with. Buffeting was handled by generated artificial wind loading in the time domain. The critical flutter wind velocity was determined based on a complex eigenvalue as well as time domain analysis. A parametric study was carried out in order to find the optimal wind- cable spatial geometry for the best buffeting and flutter performance.
US 60 Smithland Bridge – Navigation Modeling
Authors: Hunley Tony , Perkins Taylor , Kuntz Chris , Hyner Matthew
Published: February 2021

As part of the bridge type study for this major bridge replacement project over the Cumberland River, an innovative approach to addressing the needs of the navigation industry and expediting the new bridge span arrangement and Coast Guard approval process was used. Realistic 3-D virtual environment navigation modelling was utilized to quickly come to a decision on the necessary span length of the bridge, which would not have been foreseen during the bridge span arrangement/type study phase. The Seamen’s Church Institute’s world-class navigation simulation facility was utilized to leverage multiple pier placement locations and the expertise of experienced barge captains to evaluate various bridge span arrangement options. Significant project re-design time and costs were saved while achieving early concurrence on the required navigation clearances by the US Coast Guard. The new bridge features a 213.4m main span.
Enhanced strut-and-tie model for reinforced concrete pile caps
Authors: Mathern Alexandre , Chantelot Gautier , Svahn Per-Ola , Kettil Per , Rempling Rasmus , Engström Björn
Published: February 2021

Strut-and-tie models provide a simple and rational way to design discontinuity regions in reinforced concrete structures. However, when it comes to three-dimensional concrete elements such as pile caps, enhancements are needed to ensure a reliable and not overly conservative design. This paper presents an enhanced strut-and-tie model adapted to the analysis and design of reinforced concrete pile caps. The model is based on consistent geometries of three-dimensional nodal zones and struts and integrates a strength criterion for confined bottle-shaped struts. An iterative process is used in order to optimize the position of the members by refining the dimensions of the nodal zones. The model is validated by experimental results from tests on four- pile caps reported in the literature, showing effective predictions of their ultimate capacities. This enhanced strut-and-tie model can lead to safe and less conservative design of pile caps.
Surrogate Modelling For Fatigue Damage of Wind-Turbine Blades Using Polynomial Chaos Expansions And Non-Negative Matrix Factorization
Authors: Mylonas Charilaos , Abdallah Imad , Chatzi Eleni
Published: February 2021

A computational approach for the estimation of fatigue degradation of composite wind turbine blades by means of time domain aero-servo-elastic simulations is proposed. Wind turbine blades are subjected throughout their lifetime to highly stochastic loading. Fatigue damage of the composite reinforcement of the wind turbine blades has been identified early on in the wind turbine design practice as a factor driving design. A simple fatigue accumulation model is utilized for the spar cap reinforcement of a wind-turbine blade. Non-Negative Matrix Factorization (NMF) for the damage accumulation random field is used for dimensionality reduction. An approximate computationally efficient model, relying on Polynomial Chaos Expansion (PCE) of the damage state with respect to probabilistically modelled mean wind and turbulence intensity is derived. The framework is exemplified in a case-study of a 1.5MW wind turbine.
Concrete towers out of semi-precast elements - erection of a prototype tower section
Authors: Fischer Ilja , Schönweger Maria Charlotte , Kollegger Johann
Published: February 2021

The further the transition from fossil to renewable energy generation is advancing the more wind turbines are build. Cites on-land with high wind speeds get more and more exploited, therefore cites with moderate and low wind speeds are getting more often in the focus for a wind turbine erection. At such cites, turbines need bigger rotors and higher towers in order to generate economical energy. That is why new construction methods for higher towers are of interested. Therefore, a new tower erection procedure was invented. The method is characterized by the use of standard and plain double wall elements, which are available all over the world. These elements are assembled to load bearing segments. The segments are stacked over each other as long as they are hollow and the hollow core of the double walls is filled with concrete, whereby all joints are reinforced therefore a monolithic and continuously reinforced tower structures is gained. Such a tower can be erected fast, while providing a structural resistance similar to a cast-in-place structure. The method was already tested in the erection of a prototype tower section where it demonstrated its practical feasibility.
The Gamechanger: How BIM for Bridges triumphs over the competition and revolutionizes design workflows.
Authors: Alestra Michael
Published: February 2021

Pennoni realized that times are changing in the bridge design industry. With the advent of new technologies, the firm sought a more efficient workflow than the traditional 2D design process. Uncertainties within this time worn approach had engineers performing redundant tasks, reworking tedious calculations and spending time updating plan sheets when unanticipated design changes occurred. This resulted in less competitive project proposals and inflated project budgets. After careful planning, it was decided that a BIM approach would be used on new bridge design projects. This approach develops a design model early in the concept and proposal phase â€“ with the added benefit that the same model can evolve with the project as it is advanced through TS&L and subsequent milestone submissions. Developing 3D design models early on has allowed engineers and designers to visualize the entire design. Pennoni engineers are also able to better identify problems during design, instead of being uncovered later in construction, where costs from unforeseen delays can escalate. This approach has resulted in streamlined preliminary designs and higher quality visualizations and proposals, resulting in more project wins. Post award, the efficient use of the same models has reduced project man-hours and improved project budgets. Additionally, the BIM process also acts as secondary quality control â€“ helping to minimize errors and increase overall level of quality in the project deliverables. Discussion will include the benefits of using the 3D design models to develop the 2D plan sheets, developing a refined structural analysis, generating accurate quantities and the ability to produce stunning visualizations which are used in client outreach and public planning events.
Dehumidification – An Effective Strategy for Preserving the Cables of Suspension Bridges
Authors: Beabes Shane R. , Colford Barry R. , Bulmer Mark J.
Published: February 2021

The majority of suspension bridge cables consist of thousands of high-strength galvanized steel wires typically around 5mm in diameter. The wires are compacted into a near-circular shape then traditionally protected by externally applied red lead or zinc paste, galvanized wrapping wire, and paint. As evidenced by cable inspections, water inevitably intrudes into the interstices of the cable causing atmospheric corrosion, hydrogen-induced stress corrosion cracking and broken wires.

Since its first application on the Akashi-Kaikyo Bridge in Japan, cable dehumidification has emerged as an effective method of protecting cables from the damaging effects of water. This paper will discuss the types of suspension cables, traditional cable protection systems, typical findings from internal cable inspections, and the history and effectiveness of dehumidification as a technique for protecting the main cables of suspension bridges.
On the use minor and non-destructive methods for the safety evaluation of an historic RC bridge: the Bôco Bridge
Authors: Sánchez-Aparicio Luis Javie , Bautista-De Castro Álvaro , Ramos Luís F. , Sena-Cruz José
Published: February 2021

Currently in use, the Bôco Reinforced Concrete (RC) Bridge, built in the early of 20th century, is one of the oldest RC bridges in Portugal. Its initial structural system, erected following the Hennebique system, was retrofitted in the 1960s to support heavy traffic, increasing the section of its structural components. However, the low quality of implemented retrofitting solution has promoted the presence of pathological processes, mainly concrete spalling and steel corrosion. In this context, the present paper shows the first results obtained during the second experimental campaign carried out on the bridge. This campaign comprised the use of several minor and non-destructive methods (laser scanning, operational modal analysis, and laboratory material characterization and mechanical tests), with the aim of improving the knowledge of the bridge and create an accurate numerical simulation (by means of Finite Element Model) to evaluate the safety level of this bridge. Results derived from this campaign, show a bridge with high load capacity, verifying the Ultimate Limit State.
Building-Integrated Photovoltaic – Standardization and Testing
Authors: Rehde Franziska , Weller Bernhard
Published: February 2021

Opaque building surfaces offer large-area spaces for generating energy. Today, sustainable façade systems contribute to producing high-performance buildings that are economical and energy- efficient. Furthermore, PV which are integrated in the building skin as building integrated photovoltaic (BIPV) produce energy. They play an important and leading role in achieving the future goals of emission free energy consumption. Several requirements of national building laws and regulations have to be considered since PV modules are integrated into the façade as building products. In order to realize a BIPV project properly, detailed knowledge of building codes is required. Therefore, the EU research project “Construct PV” aims for a common and Europe-wide applicability of BIPV. This paper presents the legal situation of building codes in Europe and selected national regulations, which will establish a basis for future BIPV design in achieving the goals of an emission-free source of renewable energy.
Testing of coiled spring pins as shear connectors
Authors: Hällmark Robert , Collin Peter , Möller Mikael
Published: February 2021

A few decades ago, steel-concrete composite bridges were quite rare structures, whereas steel girder bridges with non-composite concrete decks were rather common. For the latter type of structure, composite action can be obtained long after the bridges were constructed by post installation of shear connectors. Most installation procedures involve reconstruction of pavement and concrete deck, which will result in traffic disturbance. There are however some types of shear connectors that can be installed from underneath, connecting the top flanges to the concrete deck, without affecting the upper surface. This means that the bridge can be strengthened during traffic. One type of such a shear connector is the coiled spring pin, which is an interference fit connector. This paper presents the results from push-out tests conducted in order to find the static capacity and the load-slip behaviour of coiled spring pins used as shear connectors.
Dynamic Analyses of Ship Impact to the New Bridge over Storstrømmen
Authors: Andersen Jacob Egede , Talic Edita , Kock Henrik Bredah , Iqbal Muhammad Rizwa
Published: February 2021

Ship impacts to bridges are relatively rare and therefore treated as accidental loads. Due to the low probability of occurrence, it is logical to allow some degree of plastic behaviour of the impinged structure, since the alternative, a completely elastic response, may lead to disproportionally large material usage.

This paper presents the principle of, and results from, numerical analyses conducted for the illustrative design of the new bridge over Storstrømmen in Denmark. This is an approximately 4km long bridge consisting of 80m viaduct spans and two navigations spans of 160m in a single-pylon cable-stayed configuration. The girder is a continuous, post-tensioned concrete box girder carrying two railway tracks, two road lanes and a combined pedestrian/bicycle path.

Since ship impact is a transient event, the numerical analyses conducted consist of dynamic analyses in the form of time-series that include relevant non-linearities of the ship, soil and bridge bearings. Hereby a realistic picture of the bridge response during, and after, impact is obtained allowing the comparison between pre-defined failure modes and the bridge response.

In addition, the time-series produced are used to calibrate a linear model for train safety/runability calculations in conjunction with ship impact to define design criteria's for maximum bridge accelerations levels at ship impact, in order to prevent trains from overturning.

The runability model itself have be tested against the Danish Great Belt West Bridge, a comparable railway concrete girder bridge, in order to justify that the model gives correct acceleration levels for the train/structure interaction and subsequently acceleration levels at ship impact.

Based upon the investigations made also risk analysis have been carried out, in order to show the overall risk complies with railway authorities and Eurocode requirements.
Three-Dimensional Non-Linear Analyses of Special Reinforced Concrete Moment Frames
Authors: Phillippi Donald J. , Liuzza Gabrielle
Published: February 2021

The design of special reinforced concrete moment frames (SMFs) requires the consideration of both strength and stiffness. SMFs are proportioned and detailed to allow for extensive inelastic deformations, but most frames are designed using elastic (or modified elastic) two-dimensional models. Two concepts not included in design are the increased lateral stiffness of axially loaded compressive columns (and by contrast, the loss of stiffness of columns in tension) and the increased displacement of leeward columns due to concrete beam elongations. In this paper, shear-force distribution between columns and corresponding beam elongations will be presented using three-dimensional non-linear finite element analyses (3DFEAs). Analyses include load-to- displacement results and associated changes in beam stiffnesses from the 3D-FEA and compare those results to two-dimensional finite element analyses.
Design Challenges Related to Providing Lateral Load Resistance to Existing Buildings in Accordance with Current Building Codes
Authors: Duntemann John F. , Sfura Jon F. , Hesam Pedram
Published: February 2021

The evaluation and retrofit of existing buildings using current Building Codes can present a variety of challenges to structural engineers. There is a substantial inventory of buildings throughout the United States that predate modern Codes in regards to wind and seismic demands. The state-of- engineering practice has also evolved considerably since the time these buildings were constructed. This paper examines the existing deficiencies, the analysis of these deficiencies, and the proposed retrofit solutions for a precast reinforced concrete warehouse constructed in the mid-1950’s. The building has been subjected to multiple design-level wind events during its service life, including Hurricane Katrina in 2005, and exhibited satisfactory performance. The ASCE 7-10 and 2012 IBC Building Code were the applicable standards at the time of our analysis in 2016. The Southern Building Code was the applicable building code prior to the adoption of the IBC Code. The seismic demands based on the current standards were determined to be up to ten times greater than the wind demands, which raised some compelling questions regarding the applicability of the current ASCE 7 and IBC seismic provisions in a geographical area where the design lateral loading has been historically controlled by wind. It was also observed that the connectivity between the lateral load resistant elements and structural diaphragm was poor to non-existent, which required creative solutions to connect the structural elements in a manner that produced a reliable lateral load path.
Securing visual quality and architectural intent while aiming for an affordable tender design - the procurement of the Mersey Gateway Crossing
Authors: Halaczek Bartlomiej , Knight Martin
Published: February 2021

Since its announcement in 2005, the Mersey Gateway Crossing Project between Runcorn and Widnes is getting close to its completion. The 9.5km long bypass corridor project, featuring a 1000m long three pylon cable stay bridge, becomes a precedent on a procurement route that allowed its client, Halton Borough Council, to maintain a high quality design intent while controlling the budget of a project, which was under increasing pressure as regards affordability, due to economic downturn. With the help of infrastructure specialist Knight Architects the client managed to outline areas of greater flexibility and key design requirements. The resulting descriptive Design and Access Statement, was a key reference document in the subsequent Competitive Dialogue. Using the Mersey Gateway as an example, the paper will explore how the choice of the right procurement route enables to realise a major infrastructure project of high functional and architectural quality, while allowing the client to remain in control of both budget and design, significantly improving its chances to be supported by the public.
Cross-Sections of long Composite Bridges – Performance based Design
Authors: Reintjes Karl-Heinz
Published: February 2021

Steel-concrete composite bridges play an important role in building motorway bridges of small and of long spans. The paper puts the focus on large span bridges of the construction type deck bridge. Today, four different cross-sections are built regularly. These four cross-section types are investigated and the adequate area of use is proposed considering life cycle performance. Possibilities of further development are discussed.
A Baseline Study of a Major Viaduct in Toronto, Canada, for Strategic Planning for the Superstructure
Authors: Lam Wilson , Li Edward
Published: February 2021

The F.G. Gardiner Expressway (Gardiner) is a major transportation artery in the City of Toronto, Ontario, Canada and has an “Elevated” section, a 6 km long viaduct structure of over 500 spans. The City constructed the viaduct in segments between 1955 to 1964, and since then the viaduct has undergone over 100 rehabilitation projects to keep it continuously operating. Recent plans for the “Elevated” section involved a complete realignment and replacement of a 2-km long section at its east end, and a superstructure replacement for the remaining 400 spans as the bulk of the substructure will remain. This has posed questions concerning the disparity of life expectancy and maintenance efforts of the existing substructures, and those of the new superstructure, and the correctness of this method of rehabilitation. This paper is a case study to describe an approach to assess and recommend an overall strategy in addressing this challenging question.
Prestress Loss Monitoring Using Long-Gauge Fiber Optic Sensors
Authors: Abdel-Jaber Hiba , Glisic Branko
Published: February 2021

Prestressed concrete is an important building material due to its economy and superior performance compared to reinforced concrete. Given the current attention to infrastructure monitoring and condition assessment, creating methods for monitoring prestressed concrete specifically is increasingly important. Assessment of prestress losses in the field, an important parameter in prestressed concrete, is required in order to ensure safety, and allow designers to better understand the evolution of losses particularly as they pertain to new concrete mixes. This paper presents a method for the monitoring prestress losses using strain measurements collected from sensors embedded in the concrete. The method is applied to measurements from Streicker Bridge, a prestressed concrete bridge on the Princeton University campus. The method shows promising results and can be used for monitoring more complex beam-like structures.
The Existing Champlain Bridge - Assessment of Structural Deficiencies
Authors: Griezic Andrew , de la Puente Alejandro , de Gaspé Lizotte Jean , Lasheras Gustavo , Demers Francois
Published: February 2021

The 50 approach spans of the Champlain Bridge each consist of seven precast post-tensioned girders. Deterioration of the PT tendons is observed in the girders at multiple locations, raising concerns about the integrity of the remaining tendons. Due to the uncertainties involved in determining the number of tendons that have become ineffective due to corrosion, multiple inputs are used in a comprehensive assessment program to determine the condition of the girders and establish the load carrying capacity of the Bridge. The assessment allows the corporation managing the bridge to plan rehabilitation and strengthening programs to ensure user safety and that will ensure the structure remains open to traffic. The comprehensive assessment program includes visual inspections, exploratory openings, monthly load tests and daily monitoring. The program represents a proactive and preventative approach using multiple inputs identify critical deficiencies and address them through a comprehensive rehabilitation program.
Discrete modeling of reinforced and prestressed concrete beams under shear loads
Authors: Wan-Wendner Lin , Vorel Jan , Strauss Alfred , Cusatis Gianluca , Wan-Wendner Roman
Published: February 2021

Conventional finite element software and associated numerical models are usually used to analyze the mechanical behavior of structural scale concrete beams. However, they lack the ability of accounting for concrete heterogeneity or including concrete aging and deterioration effects. This paper introduces the advanced techniques to model the behavior of reinforced and prestressed concrete beams under shear loads utilizing a discrete particle model incorporating effects from creep, shrinkage and prestress loss. Five-meter long concrete beams with full reinforcement and different prestress levels were tested under shear loads. Material tests of the concrete, including unconfined compression, uniaxial tests to measure modulus of elasticity, and splitting tests, were carried out on the day of shear testing. Concrete creep and shrinkage measurements were also conducted to study their effect on prestress loss and consequently shear response. The model constructs the beam with concrete as discrete particles and the steel rebars/tendons as beam elements. The concrete behavior is defined by constitutive laws with its material properties calibrated based on standard experimental tests. The behavior of reinforced rebars and prestressing tendons follow the elasto-plastic law of typical steel with known Young’s modulus and yielding strength. The rebar beam elements and solid concrete elements interact with each other using penalty constraints. Before the shear load is applied, creep and shrinkage losses of concrete are evaluated, of which the parameters were calibrated based on the experimental measurements. The results of the predictive shear simulations for the reinforced and prestressed beams resemble those of the tested specimens including but not limited to the force-displacement curves, the failure types, and the crack patterns. These analysis-and-modeling techniques hold great significance to innovations in structures.
Development, testing and construction of the hybrid FRP composite – concrete road bridge
Authors: Siwowski Tomasz W. , Rajchel Mateusz , Kaleta Damian
Published: February 2021

Fibre reinforced polymer (FRP) composites have become an integral part of the construction industry because of their versatility, high strength-to-weight ratio, enhanced durability, resistance to fatigue and corrosion, accelerated construction and lower maintenance and life-cycle costs. However, all-composite structural bridge systems have specific shortcomings such as high initial costs, low stiffness and the existence of brittle failure modes. To make the best use of materials and to overcome the above shortcomings, combinations of FRP and conventional materials have recently been investigated. The innovative hybrid idea of a “FRP composite – concrete” structural system for bridges is proposed. The objective of this paper is the description of the new bridge system itself and the presentation of research results related to its development, as well as a demonstrative bridge construction.
Static and dynamic performance of an orthotropic-deck pultruded fibre-reinforced polymer footbridge
Authors: Caprani Colin , Satasivam Sindu , Ahmadi Ehsan , Ngan Jun Wei , Zhang Shaohua , Bai Yu
Published: February 2021

Pultruded glass fibre reinforced polymer (GFRP) is a strong, light, and durable material that is very well suited to modular structural forms. The replacement of aged and deteriorated small footbridges is an ideal use for such structures. However, GFRP has low stiffness; this and the typical low mass of GFRP structures, mean that they can be susceptible to human-induced vibration. Further, the vibration design rules for footbridges have evolved over the years from experience with steel and concrete structural forms. Consequently there is a need to investigate the suitability of GFRP footbridges and the applicability of current design rules. A team at Monash University has recently constructed a 9 m long orthotropic deck pultruded bonded GFRP footbridge to investigate these issues. Extensive material testing and full-scale structure testing has been carried out to establish the overall structural behaviour accurately. This paper explains the design and construction of the footbridge, and reports the results of the static performance assessments. Bond performance, shear lag, and deck-beam composite action are all examined under uniform load and four-point bending tests. This paper also reports the results of extensive experimental modal testing and numerical modelling of the structure. Further, a novel sequence of human walking trials has been performed to assess the vibration performance under real loading conditions. The modelling of human-induced vibration and the response of the structure is also considered in this work. The results will assist in developing improved guidelines for the design and construction of such structures.
Experimental and Numerical Investigations on the Shear Capacity of Existing Prestressed Concrete Bridges
Authors: Fischer Oliver , Schramm Nicholas , Gehrlein Sebastian
Published: February 2021

Systematic re-analyses of prestressed concrete bridges in Germany show, that only some 5% can fulfil all requirements given by current design standards whereas more than 60% of the bridges ex- hibit relevant or severe deficits. Hereby, the majority of the deficiencies are related to insufficient shear capacity. In order to more realistically assess the actual shear capacity, several research pro- jects have been launched comprising numerical and theoretical investigations as well as extensive experimental testing. The present paper will firstly illustrate typical deficiencies of existing con- crete bridges and will then discuss current research activities on the shear capacity. In doing so, experiments using an innovative laboratory setup will be described allowing a realistic testing of concrete beams at a reduced length utilizing the substructure technique. Finally, full-scale experi- ments on a prestressed 7-span continuous road bridge will be presented and discussed.
Botín Art Center in Santander, Spain
Authors: Lorenzo José Maria , Sanchez Jose Luis
Published: February 2021

Botín Art Center is a remarkable work of Engineering and Architecture design in the north of Spain, in the beautiful front seaside of Santander bay.

This multipurpose building, signed by Renzo Piano, will be open to the public in 2017.

The building is a real challenge from a structural point of view. Minimizing the number of supports on the ground floor and flying over the sea, the structure is designed in order to accommodate all the architectural requirements.

Botín Art Center is composed by two building with a common underground basement and elevated footbridge connections. The West Building is conceived as a Gallery Exhibition Center with external dimensions of 80,0m*30,0m. The East Building is a multipurpose building of 48,0m*27,5m, with Educational areas and a Auditorium for conferences or music concerts.
Shaking Table Test on a Super Long-span Cable-stayed Bridge Subjected to Spatially Varying Ground Motions
Authors: Xie Wen , Sun Limin , Xia Ye
Published: February 2021

A 1/70 scaled model of a trial designed super long-span cable-stayed bridge with a central span of 1,400 m, including group piles foundation and site soil modelled by utilizing laminar shear box, was designed, constructed and tested using a multiple shaking tables array system at Tongji University. The influences of different traveling wave velocity on the seismic response of the scale model with different structural systems, such as floating structural system, elastically constrained structural system and energy dissipation supporting pier structural system, were investigated under spatially varying ground excitations with considering traveling wave effects in the longitudinal direction. And the influence mechanism of input wavers with various traveling wave velocity on the seismic response of different structural systems are further clarified under non- uniform excitations in the longitudinal direction. The experimental results show that pile-soil- structure interaction (PSSI) has significant effect on the seismic responses of the towers and piers for three structural systems under non-uniform excitations; the seismic responses of different structural systems of the cable-stayed bridge scaled model is sensitive to the traveling wave velocity of earthquake waves, which suggests that traveling wave effects should be considered in the seismic design of the super long span cable-stayed bridges. This kind of shaking table test can help to improve understanding on dynamic performance, and is very useful for seismic design and analysis for a super long span cable-stayed bridges excited spatially varying earthquakes, especially for a super long span cable-stayed bridges considering with PSSI.
Seismic Retrofit of the McIlraith Bridge
Authors: O'Connell Ryan , Ajrab Jack
Published: February 2021

The McIlraith Bridge is a 202 m long six-span variable depth steel plate girder structure located in Ottawa, Ontario, with in-span joints in each girder at the second span from each end separating the structure into three segments. The seismic evaluation and retrofit design was completed to the newly adopted CSA S6-14 and based on the Seismic Performance Category of the structure, Performance Based Design was required. To decrease the demand on the substructure elements and increase the durability of the structure, seismic isolation bearings and flexible link slabs were selected as the preferred seismic retrofit scheme. Time History Analysis was performed to verify the results of the Elastic Dynamic Analysis.
Uncertainty of Visual Inspection on the Reliability Analysis of Timber Elements
Authors: Sousa Hélder S. , Ribeiro Sérgio , Matos José C. , Branco Jorge M. , Lourenço Paulo B.
Published: February 2021

In this work, the uncertainty related to the process of visual inspection of timber elements as a method to define different strength classes is quantified. For that aim, visual inspection was made to different chestnut timber elements at local and global scales. The inspection was made by sixteen different inspectors, with low experience, and by an expert for benchmark analysis. The uncertainty of the visual inspection process was measured by the analysis of these independent observations obtained under the same conditions of measurement, resulting in the quantification of the experimental standard deviation to characterize the variability of the observed values and of the experimental standard deviation of the mean to characterize the uncertainty of the process. A reliability analysis was also made using random samples including the uncertainty from the visual inspection process, obtaining reduction factors for a specific case study.