bluuebunny/crossref_metadata_2025 huggingface dataset:
How will 'Digital Technology' change Asset Management in the railways?
Authors: Doherty Andy
Published: February 2021

The development of digital technology is increasing ever exponentially. Large Infrastructure organisations like railways but also water, electricity, etc have struggled to keep up with and utilise this new digital technology effectively. This due to many factors; the size and burden of the existing asset base, limited funding, and perhaps just as importantly knowledge and competence. The later is not just about growing a new knowledge in our workforce but also understanding that opportunities (and risks) that digital technologies can bring.

The massive opportunity is to utilise this technology explosion to transform Asset Management in large infrastructure organisations to bring the cost base down, and utilise whole life managment in ways we have not yet achieved. This together with the completely new way of working and increased functionality and capability is creating a compelling business case. Indeed the business case is more than just good asset management, as these new technologies provide increased functionality to the primary objectives of the railway such as increased capacity, performance, and asset reliability whilst lowering costs.

Having described this, many would say we have all been on the journey for some years. But if we honestly ask ourselves we would have to admit that the first systems we railways started using in the late 1990s have already been replaced, or we are on radically upgraded versions. This because the data structures, the amount of data, the functionalities we need to process and access the data, turning data into useful information and most importantly knowledge are still emerging.

This is perhaps obvious to us all, but some much is changing in multiple directions if is difficult to see the whole picture to utilise these primary capabilities to enable a step change in our Asset Management processes. I believe it is helpful to separate and look at the individual processes.

In this presentation I will explain Network Rail’s vision and strategy to develop and radically improve the railway we provide in services to our Customers and in its Asset Management. I will then go on to show examples of the ongoing RD &T work and our first steps on the journey.
Risk and Resilience of Civil Infrastructure Systems under Extreme Events
Authors: Akiyama Mitsuyoshi
Published: February 2021

Recent large earthquakes in Japan including the 2011 Great East Japan earthquake and the 2016 Kumamoto earthquake caused not only damage and collapse of structures due to strong ground motions, but also washout of structures due to the subsequent giant tsunami and huge landslide. It is expected that the damage and the economic loss resulting from the anticipated Nankai Trough earthquake would be larger than those resulting from these two recent large earthquakes. Although the quantifications of risk and resilience associated with damage to structures and civil infrastructure systems under extreme events is still an important research topic in the structural engineering community, research studies on risk reduction and resilience enhancement in terms of structural control, restoration of structures and post-disaster debris management must be also developed. These research topics and studies are the main topic of this paper.
A pro-active concept in asset management supported by the quantified Value of Structural Health Monitoring
Authors: Sousa Helder , Slobbe Artur , Courage Wim
Published: February 2021

Over the past century, European countries have developed mature and extensive transportation infrastructure networks, in which bridges play a vital role. Their design is increasingly influenced by life-cycle multi-objective performance criteria, which comprise economic, environmental and social factors. Hence, the emphasis has shifted from new build to maintenance and rehabilitation.

Such scenario gradually imposes improving/developing concepts towards an efficient utilization of the existing infrastructure networks. Moreover, since the beginning of the 21st century, a significant effort has been made on the assessment of the structural performance of key assets by integrating advanced physical and probabilistic models and benefiting from available monitoring data.

In this context, a pro-active Structural Health Monitoring (SHM) concept is introduced, which has two components, mainly (i) a damage identification tool and (ii) a monetary quantification tool for assessment of its benefit. This work is supported by a case study – the Lezíria Bridge -, one of the most comprehensive case studies documented in the literature. A pedagogical example is presented for illustration and retain the key message about the utility of the proposed tool.
A review on experimental flexural cracking in FRP reinforced concrete members
Authors: Barris Cristina , Zubillaga Paula , Torres Lluis
Published: February 2021

This paper aims to assess the relationship among crack width and several influencing parameters of Fibre Reinforced Polymer (FRP) Reinforced Concrete (RC) flexural members. A database with the results of 133 concrete specimens reinforced with different types of FRP bars available in the literature has been collected and analysed. A bond coefficientkb has been adjusted for the maximum crack width of all specimens by using ACI-440 and ISIS Canada design guidelines in the service range, obtaining a mean bond coefficient of 1.11 and 0.72, respectively. The effect of the surface treatment and modulus of elasticity of the FRP rebar, and then· ratio on the bond coefficient have been studied, obtaining no significant influence of the studied parameters due to the high scatter of results.
A review on wall-to-timber floor anchorages in URM buildings
Authors: Solarino Fabio , Oliveira Daniel V. , Giresini Linda
Published: February 2021

Out of plane failure of unreinforced masonry walls is considered one of the most vulnerable seismic hazards in medium and high earthquake-prone regions. Efficient structural connections enable global equilibrated mechanisms, ensuring the “box-behavior”. Timber floors are widely used as horizontal diaphragm in historical constructions, and their connection to the boundary walls is crucial to facilitate internal force redistribution and to restrain out of plane walls. Wall-to-floor anchorages are typical in existing historical buildings, and innovative solutions are proposed nowadays by engineers as strengthening devices. Unfortunately, they are often too invasive or unsustainable solutions, applied without reliable seismic design and evaluation through valid models.

This paper presents a literature review on the traditional and innovative wall-to-timber floor anchors used in unreinforced masonry buildings taking into account experimental works, analytical and numerical studies.
A Sustainable Timber Footbridge Complementing an Historic and Sensitive Environment
Authors: Edwards Liam , Heaney Stephen , Harris Tony , Beade Pereda Héctor
Published: February 2021

This paper discusses the design of a bespoke glulam footbridge on a highly sensitive and challenging site. The bridge was designed by WSP and Knight Architects on behalf of Monmouthshire County Council. The 60m long crossing will provide a safer pedestrian crossing of the River Usk between Llanfoist and Abergavenny. The location presents a myriad of conflicting constraints including flooding, heritage, aesthetics, H&S, and environmental designations. The three-span bridge comprises half-through configuration supported on the abutments at either end and an intermediate pier located in a ‘dry’ shingle bar within the river channel. The primary beams comprise glulam construction and are protected with external architectural timber cladding on each elevation. This paper will focus on the rationale which formed the basis of the design, reviewing key design details as well as addressing the main challenges of the design.
An Overview on H2020 Project “ReSHEALience”
Authors: Ferrara Liberato , Bamonte Patrick , Suesta Falcó Cristina , Animato Francesco , Pascale Carmine , Tretjakov Aleksej , Camacho Torregrosa Esteban , Deegan Peter , Sideri Stamatina , Gastaldo Brac Enrico Maria , Serna Pedro , Mechtcherine Viktor , Cruz Alonso Maria , Peled Alva , Borg Ruben Paul
Published: February 2021

In the framework of H2020, the European Commission recently funded the project ReSHEALience (www.uhdc.eu). The main idea behind the project is that the long-term behaviour of structures under extremely aggressive exposure conditions can highly benefit from the use of high performance materials, in the framework of durability-based design approaches. The project consortium, coordinated by Politecnico di Milano, features 14 partners from 8 different countries, including 6 academic/research institutions and 8 industrial partners, covering the whole value chain from producers of concrete constituents to construction companies to stake-holders and end-users. The main goals of the project are the development (a) of an Ultra High Durability Concrete (UHDC) and (b) a Durability Assessment-based Design (DAD) methodology to improve structure durability and predict long-term performance under Extremely Aggressive Exposures (EAE). The project will tailor the composition of UHDC, by upgrading the UHPC/UHPFRC concept through the incorporation of tailored nanoscale constituents.
"Autopista Urbana Siervo de la Nación" - Flyover at México City Lake Zone: The importance of design to achieve a sustainable infrastructure during ist life-cycle
Authors: Campos e Matos António , Barbosa José Luís , Durão Mário , Leite Ricardo
Published: February 2021

The “Autopista Urbana Siervo de la Nación” (AUSN) Highway, is located at Mexico City, and is currently under construction. The highway, with a length of 14.5Km and 4 lanes divided in 2 carriageways (A4 type cross section), intends to target the milestone of a fast and safe road axis. The available right-of-way to built the new infrastructure presents several restrictive constrains that led to the construction of a flyover throughout approx. 90% of the AUSN total length.

The unique geotechnical scenario that characterizes the Valle de México’s lake zone, with the well- known regional settlement phenomena, along with the peculiar features that define the seismic action within the “lacustres” areas of the city, associated with high structural response amplification, lead to complex structural solutions and demanding calculations, particularly concerning the foundation´s design, optimizing the structure behaviour and minimizing the global costs during all the infrastructure’s life cycle.
Behaviour of RC structures strengthened with prestressed CFRP laminates: a numerical study
Authors: Sena-Cruz José , Correia Luís , França Paulo
Published: February 2021

The externally bonded reinforcement (EBR) technique is one of the most widely used strategies for the flexural strengthening of reinforced concrete (RC) with fibre reinforced polymer (FRP) materials. The EBR technique offers several structural advantages when the FRP material is prestressed. The development of high shear stresses at the ends of the prestressed FRP material can cause premature FRP peeling-off failure. This premature failure can be delayed or even avoided with the use of special end-anchorage systems, like the mechanical anchorage (MA) system and the gradient anchorage (GA) system. This paper presents an experimental and a numerical study on RC slabs strengthened in flexure with prestressed carbon FRP (CFRP) laminate strips, namely: (i) one reference slab; (ii) one slab strengthened with non- prestressed externally bonded CFRP (EB-CFRP) laminate; (iii, iv) and two slabs strengthened with prestressed EB-CFRP laminates using the MA and GA systems. The performance of these simulations was compared with results of the slabs experimentally tested up to failure. Subsequently, these models were used on a parametric study that intended to investigate the influence of different parameters affecting the behaviour of the slabs strengthened with prestressed EB-CFRP laminates.
Bending test of a composite steel-timber beam jointed by bolts
Authors: Fujita Masanori , Ohtaki Mayo , Iwata Mamoru
Published: February 2021

In light of global environment issues, the authors proposed a building system comprising steel and timber structure (Hereafter referred to as CSTS), which consist of rolled-H section steel and timber. The CSTS is assumed to adapt for mid-rise story building steel structures. It is a design method of the CSTS that uses the concept of a damage-controlled structure characterized by using buckling-restrained braces as a seismic response control member. It is assumed to use materials such as a cross laminated timber(CLT) for floor structure of the CSTS. The hysteresis model of the CSTS is established based on the available experimental data. Assuming practicality, bending test of the composite steel-timber beam members jointed by bolts is conducted. Behaviour of the composite steel-timber beam members affected by different intervals of bolted joints is evaluated.
BIM Practical Application - New bugesera international airport (Rwanda)
Authors: Soares Joel , Marques Hugo , Oliveira João , Araújo Alberto
Published: February 2021

The increasing complexity of buildings is expressed through different aspects. Requirements such as complex architectural shapes and highly demanding environmental performance require better and more sophisticated engineering solutions.

The challenging deadlines and budget control demand optimized and automated solutions that adapt perfectly to each project and to the evolution between design stages. These and other aspects generate a proliferation of information and make the life cycle of the project progressively more complex and difficult to control. In this scenario it is imperative for the design team to make use of the most advanced tools available and adapt the design processes to exceed current expectations and prepare future market demands.

GEG has already fully embraced the BIM methodology, in order to respond to these challenges on the projects it is involved.

This article intends to present a specific project - the New Bugesera International Airport of Kigali in Rwanda - as an example of implementation of these processes. Through this example such aspects as the strategies, the difficulties, the advantages, and the tools used to overcome the different challenges are presented. The possibility of showing on site construction, as this is a fast track design build project that is already under construction, introduces additional difficulties but also increases the interest to present this case.
Bridge failures analysis as a risk mitigating tool
Authors: Syrkov Anton , Høj Niels Peter
Published: February 2021

The research background as a database of bridge failures was created by author at the place of main work in 2006 - 2015 for improving design. Since 2015, an initiative to collect and analyse data on failures and collapses of bridges was continued by Working Commission 1 of IABSE, since 2017 - by the Target Group 1.5. For further study, the information concerning highway and pedestrian bridges collapsed over last 52 years was selected. The consequences for human life and health were defined at the rate of fatalities and injured persons. Also the types of crucial human errors or other force majeure, hazards and causes were analysed. The tendency of failures number increasing correlating with operating life cycle period was revealed. The ways of future TG1.5 research activity development are outlined aiming to the relevant risks mitigation. Some proposals for the risk management measures are presented.
Brisa's Journey on Asset Management System Modelling
Authors: de Oliveira Carlos Biscaia
Published: February 2021

In 2016, Brisa decided to challenge the way decisions over physical assets planning and maintenance operations were being made. The main goal was to develop a new model for Brisa’s Asset Management System, aligned with IAM culture, PAS 55 mindset and ISO 55 000:2014 framework, enabling to maximize the asset’s performance, without losing sight of risk reduction and cost optimization.

An assessment of Brisa’s current maturity status, regarding its asset management culture and practices, was made, identifying hints to draw the main long-term goals. Drivers to the transformation plan were identified and the roadmap of implementation outlined, approaching both strategical and operational perspectives.

This document focus on the transformational journey endeavored from AM Processes re-design to IT systems architecture strategy, identifying gaps and exploring opportunities to improve Brisa’s Asset Management processes and related support systems.
Cementitious adhesives for NSM carbon laminate strengthening system with treated surfaces
Authors: Firouz Reza Mohammadi , Pereira Eduardo B. , Barros Joaquim A. O.
Published: February 2021

One of the main concerns of using structural composites as an effective technique for strengthening and rapid restoration of concrete structures is the behaviour of these systems in fire condition. Epoxy resins are currently used to bond structural composites to concrete substrate, but the vulnerability of their properties to high temperatures can compromise the strengthening effectiveness of these systems. Hence, finding an alternative adhesive is of a great importance. Recent studies presented promising results with the use of cement based materials as adhesives due to their good ability for transferring stresses and compatibility to the substrate. This study explores the adoption of a pre-treatment procedure for carbon fibre laminates for increasing the bond strength according to the near surface mounted (NSM) strengthening technique. Pull-out tests results confirmed the effectiveness of the proposed approach for enhancing the bond strength.
Continuous Monitoring System of Metro Lines to Assess Long-term Behaviour of Massive Train Wheels.
Authors: Pistone Elisabetta , Töll Hanno , Hauser Thomas
Published: February 2021

This paper presents the results of a continuous monitoring system placed on the Metro line in Vienna, Austria, aimed at assessing the long-term behaviour of massive train wheels. Until today, conventional resilient wheels are used on Viennese metro trains. However, it is planned to substitute this type of wheels with massive wheels.

Since 2016 three train sets were therefore equipped with massive wheels and let circulate in the underground railway network under trial runs. Nine measuring systems were installed within the metro network in the form of monitoring stations to continuously record data during these train passages. Selected indicators are permanently measured, post-processed and transmitted in real time to a web-interface accessible. On the basis of approximately 2,000 daily recorded trains, statistical analysis has been performed, thus providing information on train condition and on the impact of massive wheels.
Corrosion risk assessment for structures using BS EN ISO 9223 (2012) and BS EN ISO 9224 (2012)
Authors: Gedge Graham , Walport Emily , Frydman Bruna
Published: February 2021

Corrosion in service environments limits the durability of many metals. Historically, assessment of that risk adopted a qualitative approach based on generic descriptors such as rural, urban, industrial or coastal environments. These terms are ill-defined and open to interpretation. BS EN ISO 9223 (2012) provides three methods to evaluate risk for several different metals including structural steel and zinc. Two of the methods are quantitative whilst the third remains qualitative. The qualitative method is the most commonly used in engineering because the quantitative methods require data collection over a minimum period of 12 months. This paper provides a methodology to improve risk assessment by use of the quantitative method in BS EN ISO 9223 (2012) to estimate the first-year corrosion rate using historic data sets. Long-term corrosion loss estimation uses the equations in BS EN ISO 9224 (2012).
Crack Spacing Model for FRP Reinforced Concrete Beams based on Stress-Transfer Approach
Authors: Kaklauskas Gintaris , Ng P. L. , Sokolov Aleksandr
Published: February 2021

The present study develops a mean crack spacing model for fibre-reinforced polymer (FRP) reinforced concrete (FRP-RC) beams. The proposed model is based on stress-transfer approach and compatibility of mean strain in the FRP reinforcing bars, in order to predict the mean spacing of primary cracks in the stabilised cracking stage upon flexure. Typical concrete block element between adjacent cracks is demarcated into the debonding zone, the effective zone, and the central zone. The interactions between concrete and FRP reinforcement is reflected in the model by taking into account the stress-transfer, and the mean reinforcement strain along the concrete block element is evaluated from the principle of compatibility. Multiple FRP-RC beams specimens reported in the literature are analysed using the proposed model. The predicted mean crack spacing results agree closely with the experimental results, with root-mean-square error of approximately 10%. Hence, the developed mean crack spacing model is of satisfactory accuracy.
Deep Learning Based Active Monitoring for Anti-collision between Vessels and Bridges
Authors: Chen Limu , Xia Ye , Pan Dexiong , Wang Chengbin
Published: February 2021

Deep-learning based navigational object detection is discussed with respect to active monitoring system for anti-collision between vessel and bridge. Motion based object detection method widely used in existing anti-collision monitoring systems is incompetent in dealing with complicated and changeable waterway for its limitations in accuracy, robustness and efficiency. The video surveillance system proposed contains six modules, including image acquisition, detection, tracking, prediction, risk evaluation and decision-making, and the detection module is discussed in detail. A vessel-exclusive dataset with tons of image samples is established for neural network training and a SSD (Single Shot MultiBox Detector) based object detection model with both universality and pertinence is generated attributing to tactics of sample filtering, data augmentation and large-scale optimization, which make it capable of stable and intelligent vessel detection. Comparison results with conventional methods indicate that the proposed deep-learning method shows remarkable advantages in robustness, accuracy, efficiency and intelligence. In-situ test is carried out at Songpu Bridge in Shanghai, and the results illustrate that the method is qualified for long-term monitoring and providing information support for further analysis and decision making.
Define Urban Limit Conditions by Applying Performance Goals
Authors: Basaglia Alberto , Spacone Enrico , Brando Giuseppe , Gonzalez Aleksander , Aprile Alessandra
Published: February 2021

A growing interest concerning the seismic risk assessment at urban scale has been observed. In Italy, recent earthquakes highlighted the vulnerability of the built environment causing severe damage and a high number of casualties. In addition, historical city centres are part of the cultural heritage and their preservation is deemed necessary. For these reasons, understanding how to assess urban systems behaviour is crucial. A major step in this direction is the definition of the Emergency Limit Condition (ELC), by the Civil Protection Department. More recently, a theoretical framework with four additional urban limit conditions has been proposed. This paper tries to take a step forward in this direction by assigning specific performance goals to defined urban limit conditions. These goals are linked to different level of damage and functionality loss of buildings and infrastructures and the possible short-to-long term effects on the population and economy.
Deformation and Cracking Behaviour of Concrete Beams Reinforced with Glass Fibre-Reinforced Polymer Bars
Authors: Kaklauskas Gintaris , Timinskas Edgaras , Ng P. L. , Sokolov Aleksandr
Published: February 2021

This paper reports the experimental and numerical studies of concrete beams reinforced with glass fibre-reinforced polymer (GFRP) reinforcing bars with and without the addition of steel fibres. GFRP- reinforced concrete beam specimens of equivalent geometry were produced and tested under symmetrical two-point loading configuration. Deformation and cracking behaviour were monitored during the test, and the curvature was determined from the measured deformation response over the pure bending zone. In view of the lower stiffness of GFRP bars compared to conventional steel bars, the effectiveness of adding steel fibres to increase the flexural stiffness is investigated. Experimental results show that the steel fibres could reduce the average crack width and deflections of the beam, and could lead to a more ductile failure mode. The beam specimen was numerically analysed by employing the nonlinear finite element programme ATENA, and the analytical results are in good agreement with the experimental results.
Design of freeform gridshell structures – Simplifying the parametric workflow
Authors: Dyvik Steinar Hillersøy , Luczkowski Marcin , Mork John Haddal , Rønnquist Anders Nils , Manum Bendik
Published: February 2021

Freeform structures can provide both aesthetically interesting and material efficient solutions but are considered a demanding task for both structural design, manufacturing and architectural design. A free form surface is therefore rationalized into something more buildable like the gridshell. However, a digital design process with freeform geometry can be a complex and confusing task. By defining a gridshell asnodes(joints) andelements(members), we can set up a parametric workflow that handles the complexity in design and analysis. Optimization and rationalization of shape, topology, and cross-section are studied real-time, giving the designer confidence and design- freedom. This paper explains a parametric workflow for designing freeform gridshells. Through the design and construction of a timber gridshell pavilion with 3D printed nylon nodes, we discovered important elements of the parametric design process of freeform gridshells.
Determining the Best Pareto-solution in a Multi-Objective Approach for Model Updating
Authors: Infantes María , Naranjo-Pérez Javier , Sáez Andrés , Jiménez-Alonso Javier F.
Published: February 2021

Using a multi-objective optimization algorithm avoid the use of weighting factors to balance the different residuals in a finite element model updating procedure under the maximum likelihood method. By using this approach, the fittest model is not unique and a set of solutions that form a curve, so-called Pareto optimal front, is obtained. Within this paper, first a review of the state of the art on the criteria used to determine the most adequate model among all the solutions of the Pareto front is presented. Subsequently, a case study of a real footbridge is considered. A finite element model of the footbridge is updated based on its experimental modal parameters. The Non- Dominated Sorting Genetic Algorithm is used to obtain the Pareto front. Since all the solutions in the Pareto front are non-dominated, the selection of the best candidate requires a reasonable criterion. Herein, different procedures to select the best updated model are discussed.
Development of cement-based mortars for 3D printing through wet extrusion
Authors: Zahabizadeh Behzad , Cunha Vítor M. C. F. , Pereira João , Gonçalves Cláudia
Published: February 2021

The construction sector is connoted as an extremely traditional business sector since long ago. However, due to the increase of the global competiveness, there is a demand on the development of new building materials and construction methods that can bring added value to the companies. The 3D concrete printing is a novel construction approach within digital construction that can offer a higher degree of optimization and flexibility for producing either structures or structural elements with complex geometries. One of the main challenges in the 3D concrete printing using wet extrusion is balancing properly the rheological and mechanical properties of the printable mixtures. In this study, several mixtures were developed and their capability for being used in 3D printing was assessed and discussed based on their rheological properties. The compressive strength of the matrices that could be properly printed are also presented.
Displacements Needed for collapse in Masonry Arches
Authors: Antuña Joaquín , Hernando José Ignacio , Magdalena Fernando , Aznar Antonio
Published: February 2021

The forces acting on buildings hardly change throughout their useful life. Even in the case of change of use, the variation is not usually important in comparison with the building’s own weight, especially in masonry constructions. Although the forces are unchanged, except in the case of earthquake, buildings of this type have often suffered different kinds of collapses. Collapse is not due to increased tensions and breakages of material, but is caused by unacceptable increases of displacement in supports. To assess the safety of an existing construction, study of the equilibrium conditions can give us an idea of the trajectories of forces and the level of tensions. Nevertheless, assessing building safety makes it necessary to know the magnitude of the displacements necessary for collapse to occur.
Duplex stainless steel in infrastructure: applications, challenges and opportunities
Authors: Baddoo Nancy
Published: February 2021

Duplex stainless steels have unique properties which can be exploited in a wide variety of applications in the construction industry. The high strength of duplex stainless steel (30% higher than the widely used carbon steel grade S355) leads to specific applications in weight sensitive structures, for example structural members on the topsides of offshore platforms and bridge girders. These applications are usually situated in corrosive environments where durability, combined with long service life, are important and maintenance closures are very costly. Structural applications of duplex stainless steel in the energy and transportation sectors are reviewed. Based on an assessment of the complete supply chain (encompassing design, procurement and fabrication), obstacles to the wider use of structural duplex stainless steel are identified with some recommendations about how they may be overcome. The future burden caused by the use of materials that are not inherently durable in the service environment has led to a growing appreciation that the use of more durable materials in infrastructure applications is the key to maximum availability and low life cycle cost. A huge programme of infrastructure development is needed to meet future demand in both developed and developing economies, which includes the construction of airports, bridges, railways, roads, tunnels and power plants. New opportunities for duplex stainless steel in the creation of resilient, cost-efficient and fit-for purpose energy and transport networks are discussed.
Dynamic identification and collapse assessment of Rubbianello Bridge
Authors: Ragni Laura , Scozzese Fabrizio , Gara Fabrizio , Tubaldi Enrico
Published: February 2021

This paper investigates the causes of failure of Rubbianello Bridge, a multi-span masonry arch bridge located in Central Italy, which suffered the collapse of two of the seven spans due to foundation scour during a very severe flood in December 2013 and the collapse of two more spans during another major flood event in 2016. An accurate nonlinear 3D model of the bridge is developed. The elastic properties of the model are calibrated based on both material tests and an experimental campaign carried out for the dynamic identification (in terms of vibration frequencies and modal shapes) via operational modal analysis of the remaining part of the bridge. A numerical simulation of the scour hole progression is performed in order to identify the collapse mechanism of the bridge under the first major flood and estimate the level of scour that caused the bridge failure.
Effect of bond in the development length of CFRP pretensioned beams
Authors: Toumpanaki Eleni , Lees Janet M. , Terrasi Giovanni P.
Published: February 2021

Carbon Fibre Reinforced Polymer (CFRP) tendons present an alternative material that can mitigate steel corrosion problems in concrete bridges. The use of CFRP prestress tendons can result in more durable prestressed concrete structures. However, the potential matrix plasticisation of CFRP tendons in humid environments and their inherent lack of ductility need to be considered in the design process. A tension stiffening analysis is undertaken to study the effect of variations in bond strength parameters on the cracking behaviour, deformability and structural performance of CFRP prestressed beams. The bond strength scenarios under consideration reflect either low or high bond conditions. The former could be associated with epoxy plasticisation and bond degradation due to moisture ingress at a crack location. A low bond performance results in a smaller number of cracks and higher deflections at failure compared with high bond tendons.
Effects of Median Strip Connecting Twin Bridges on Dynamic Performance
Authors: Wu Haoyan , Xia Ye , Yi Xin , Sun Pingkuan
Published: February 2021

The median strip connecting twin bridges has effects on the rigidity and dynamic characteristics of the bridges, but the effects are usually ignored, resulting in unexpected dynamic performance or even structural resonance. In this paper, the mechanism of median strips as a connection role between twin bridges is analyzed. Finite element models of the twin bridges and median strip are developed to analysis the effects on the overall system. Experimental study of typical twin bridges with a median strip was conducted to explore the relationship between the median strip and the vibration. Based on these analyses, recommendations related to overall structural performance are made to ensure a safe and rational design for twin bridges with median strip especially on dynamic performance in the future.
Evaluating Existing Structures due to Adjacent Construction
Authors: Halpern Jenna R. , Feuerborn Jr. James W. , Balsamo Luciana , McCoy Jessica , Wu Jason
Published: February 2021

In dense urban environments like New York City, structures are constantly erected on lot lines and abutting existing, often historic, structures. Renovations and new construction adjacent to older lot line structures are especially challenging and risky. The need for protecting adjacent properties during construction operations is hence necessary. Instrumental to this effort are structural evaluations and monitoring of the structures adjacent to construction sites. This paper will discuss the strict requirements for structural evaluation and specific assessment techniques for buildings adjacent to construction sites in New York City and internationally.
Experimental validation of the FE model for dynamic analysis of a composite railway viaduct's deck slab
Authors: Malveiro Joel , Sousa Carlos , Calçada Rui , Ribeiro Diogo
Published: February 2021

The experimental validation of FE numerical models, performed through the comparison between measured and calculated responses, presents an important step in further detailed calculations or simulation of future scenarios. Several parameters to be taken into account in numerical analyses, such as the cut-off frequency, train speed or damping coefficients, might have a preponderant effect in the success of that validation. Therefore, this paper discusses and evaluates the effect of these parameters in the numerical analyses to be carried out on a FE model of the Alcácer do Sal railway viaduct, under the passage of an Alfa Pendular train with a speed equal to 220 km/h. The dynamic behaviour of the deck slab is evaluated, through a methodology that considers train-bridge interaction, taking into account frequency limits equal to 15, 20 and 30 Hz, small variations in the train speed and two different scenarios of damping coefficients.
Finite Element Model Updating of a Grandstand as Basis to Assess its Vibration Serviceability Limit State
Authors: Naranjo-Pérez Javier , Sáez Andrés , Jiménez-Alonso Javier F. , González-Gómez Nicolás , García-Sánchez Felipe
Published: February 2021

The performance of the finite element (FE) model updating technique is validated in this work via the evaluation of the vibration serviceability limit state of a real stadium grandstand. This type of structures can suffer from vibration phenomena due to the dynamic action of spectators. As benchmark structure, grandstand of the University of Malaga stadium is considered. To simulate the action of the spectators, body units were numerically implemented. A preliminary FE model of the grandstand was built and then the updating process was conducted based on the modal parameters experimentally identified. The maximum deck acceleration given for the two different FE models, preliminary and updated, is compared. As result, a relative difference around 19% is obtained. It can be concluded that the updated FE model represents more accurately the structural response of the grandstand.
Fire Tests on the Pre-cast Concrete Sandwich Walls with GFRP Connectors
Authors: Haffke Marcin M. , Pahn Matthias , Thiele Catherina
Published: February 2021

Precast concrete sandwich panels are known for their inherently good thermal, acoustic and structural properties. When using glass fibre reinforced polymeric (GFRP) connectors coupling the concrete layers, excellent thermal properties and high structural stiffness can be achieved. However lack of knowledge on fire resistance of sandwich panels and fire bahavior of GFRP connectors remain an important issue limiting their wider use in the construction. This paper presents results of fire tests performed on real size sandwich walls in terms of fire behavior of the GFRP connectors and its impact on fire resistance of the entire walls. All the three tested sandwich walls met the REI 120-M criteria for load-bearing fire walls. The connectors showed in general good fire resistance and did not contribute to fire spread. The tests delivered important information on structural behaviour of sandwich walls with GFRP connectors loaded with fire and vertical eccentric and impact load.
Forced Time-transient Response Analysis of Acoustic Emission Signals in Bridge Cables Based on Semi-Analytic Finite Element Method
Authors: Wan Keyang , Sun Limin , Yang Yaohua
Published: February 2021

Cable damage is one of the typical diseases of cable supported bridges. Acoustic emission (AE) technique, as a dynamic and non-destructive technique, can be applied to the health monitoring of bridge cables, while the propagation characteristics of AE signals in bridge cables is the key problem. The goal of this paper is to theoretically investigate the time-transient responses of single wire waveguide under excitation. Firstly, a formulation based on semi-analytic finite element (SAFE) method was proposed to calculate the time-transient response in cylindrical waveguides. Next a high tensile strength steel wire with 5mm diameter was used as an example to calculate its displacement responses under narrowband excitation and broadband excitation respectively, with damping effect considered. The results illustrated the propagation characteristics of AE signals in single wire waveguide.
Forensic Engineering: Risks of Performance-Based Engineering for Sustainability or Resilience
Authors: Kardon Joshua B.
Published: February 2021

Professional engineers in the US may be found negligent and therefore liable for damages arising from failure to exercise a level of care, diligence, and skill exercised by other reputable practitioners in similar circumstances. If the professional engineer has accepted the obligation to design for sustainability or resilience, where those terms or performance levels are ill-defined or open to interpretation depending on assumptions or outcomes, the professional engineer may be accepting an extreme or uninsurable risk.

This paper describes the standard of care, which is the measure of a practitioner’s performance as it relates to professional negligence. It examines the relationship between the standard of care and design for sustainability or resilience. The paper addresses 1) a discussion of the sources of the practitioner’s responsibility to design for sustainability or resilience, 2) an explanation of the concept of the standard of care, and 3) the professional liability pitfalls inherent in that design effort. The subject may be unique to professional practice in societies where litigation is used to allocate responsibility for damages, but it may also be universally relevant for practitioners wishing to understand professional responsibilities for such designs.
Framework for the Management of a Large Stock of Earth Retaining Structures
Authors: Amado Joao , Freire Luís , dos Santos Filipe Amarante
Published: February 2021

With a view to the development of a life-cycle approach to earth retaining walls, as well as an optimal management of the road assets as a whole, this paper presents a novel framework for the assessment of a large stock of earth retaining structures in a context of limited financial and human resources. In order to adequate the system for the number of structures to be managed a large inventory campaign was previously conducted. These results and how they helped to shape the framework are briefly discussed. Being a proposal for a systematic management of infrastructure assets it was developed according to Business Process Management discipline, namely the Business Process Model and Notation, as specified in the standard ISO/IEC 9510:2013. The developed framework is considered as a management process, with specific intervenient, interrelated activities, specific inputs, and standard outputs.
Geometrical Characterization of Yucatan Churches
Authors: Perez Isis , Vasconcelos Graça , Lourenço Paulo B.
Published: February 2021

This paper presents the methodology used in the geometrical characterization of Yucatan churches. The main aim was to determine the geometrical features of the typical profile that represent with the best accuracy the churches with canon vaults built in the south of Mexico. The methodology was structure in two phases: (1) preliminary studies and definition of the database of the Yucatan churches and (2) statistical studies on the database. After the definition of the key parameters describing the typical profile of one nave Yucatan churches, a statistical analysis was carried out through regression analysis among the different parameters and definition of histograms for the variables. An attempt to describe the key parameters as a function of the span of the churches was also performed. Based on the results obtained, it seems that the Yucatan’s churches were built totally in an intuitive way as they do not present clear numerical relationships between geometrical key parameters.
Guidelines and Recommendations from COST TU 1406
Authors: Wenzel Helmut , Pakrashi Vikram
Published: February 2021

Asset management depends on well-defined rules and standards for general application. Research results often represent the state of science in specific sections of specific cases. Standardization needs a downgrade of scientific work towards generally applicable specifications. This often leads to irritation in the scientific community fearing that their most interesting results are not specifically appreciated. This conflict makes standardization sometimes difficult.

COST action TU1406 is devoted to harmonizing the state of science and technology and to bring all involved disciplines into the process. The results produced are of value for a number of standards on ISO, CEN and National level. This represents another difficulty, namely, to find the right place in any of the organizations and to identify the most suitable technical committee and code.

This contribution reports on the experiences made with various committees and the results achieved. It soon became clear that specific parameters for bridge assessment cannot be standardized because they are too specific for a small sector. The way out is formulating the principles how to define them, to make a framework under which the detail results can be applied, and to define the interfaces to other necessary disciplines.

Sustainability as a headline was found to be suitable and TC59 of ISO was the committee of choice. Frameworks set in ISO55000 (asset management) and ISO31000 (risk management framework) are successfully addressed. A final draft of ISO 21929-2 is to be expected by early 2019.
Influence of shear modulus and drift capacity on non-linear static analysis of masonry buildings
Authors: Beconcini Maria Luisa , Cioni Paolo , Croce Pietro , Formichi Paolo , Landi Filippo , Mochi Caterina
Published: February 2021

In nonlinear static analysis of masonry buildings, the hysteric behaviour of masonry walls is commonly idealized through a bi-linear resistance envelope defined by the lateral stiffness of the wall, the ultimate shear resistance and the ultimate inter-storey drift. Therefore, it becomes fundamental to properly set the modulus of elasticity and shear modulus for masonry as well as to properly evaluate the drift capacity of the walls.

In the paper, the combined influence of shear modulus and drift capacity definition on the assessment of seismic performance of masonry buildings is investigated in details by means of a simplified non-linear pushover type algorithm developed by the authors. In particular, two different definitions are considered for the drift capacity, in terms of ductility and in terms of percentage of the inter-storey height, while for the shear modulus a reasonable set of values is investigated according a database collected combining masonry test results available in the relevant scientific literature with an in situ experimental campaign carried out by the authors.

The results show how the variation in shear modulus can lead to conflicting outcomes for the evaluation of seismic performance of masonry buildings depending on the assumed definition of drift capacity.
Influence of the local bond stress distribution of FRP rebars on the anchorage in concrete
Authors: Caspari Christian , Pahn Matthias
Published: February 2021

Poor durability of building structures leads to high repair costs. The durability of reinforced concrete structures is largely dependent on the corrosion resistance of the reinforcing steel. For applications which are highly endangered by corrosion, fibre-reinforced plastic (FRP) offer a solution. A basic prerequisite for the long-term functionality of a composite material is the bonding of the individual components. The lower modulus of elasticity and the different surface geometry of glass fibre- reinforced plastic (GFRP) reinforcement compared to steel reinforcement lead to a change in the bond stress distribution. This results in different bond splitting effects and load introduction lengths. In this paper, the bond stress distribution over the bond length of steel bars and FRP bars is compared. For this purpose, pull-out tests with short and long bond lengths are investigated. The force transmission from FRP to the concrete is measured by means of a fibre-optic measurement of pull-out tests with long bond lengths and compared with results from the literature.