bluuebunny/crossref_metadata_2025 huggingface dataset:
Multifunctional commercial buildings in steel and composite construction
Authors: Stroetmann Richard Maria , Hüttig Lukas
Published: February 2021

A relatively high vacancy rate of office buildings can be found in Germany and in many other Euro- pean countries. The building of the future should be planned in a way that the consequences of social and sociological changes within its life cycle can be incorporated with low monetary re- sources to avoid the vacancy of the property and to achieve a higher profitability. For this, it is necessary to allow for the suitability for different uses, which is variability, in addition to the flexi- bility for the same use. Steel and composite construction provides advantages over conventional reinforced concrete construction because, besides large spans and fewer columns, a reduction of building materials can be achieved. In the following, results of the FOSTA AIF research projects P881 and P1118 are presented. Contents are the definition of design parameters and the structur- al design of multi-storey buildings for establishing multifunctionality.
Bending Moment Diagram as Shape: Bicontentio Bridge and Bicontentio Sinus Footbridge in San Sebastián (Spain)
Authors: Guisasola Mario
Published: February 2021

Two Bicontentio bridges have been built in the Martutene quarter in San Sebastián (Spain). They have replaced two previous bridges over the Urumea river with insufficient hydraulic clearance. Both bridges are an application of a pre-designed parametric bridge developed by ANTA.

The characteristics of the Bicontentio bridge prototype include forms that mimic bending moment diagrams, hidden abutments, neutral colors, and it integrates the natural terrain with the support structures. To achieve a more slender appearance, the cross-sections along the length of the bridge prototypes are very variable.
Product Configuration – Performance Improvements of Design Work
Authors: Gerth Robert , Smiding Erik , Jensen Patrik , Simonsson Peter
Published: February 2021

The design process in construction has seldom been a target for industrialization, as it is assumed to be creative, ad-hoc, and iterative. However, digitalization has opened the door for the integration of design automation into construction through the use of product configurators. Configurators enable the specification of project-specific features from a pre-developed product platform. The case study demonstrates how configurator implementation affects the design process of a noise barrier and project performance. When the configurator is used, the specification process becomes simplified, systematized, and includes fewer iterations. Supporting software ensures information flow, reducing lead-time and production costs. Furthermore, configurator use increased the flexibility to respond to a client’s topographical adherence requirements, as well as the blueprint quality and buildability. This case study shows that the design of civil engineering products can be industrialized through the configuration of product platforms.
iPM: The Evolution of Project Management
Authors: Jurgens Chris
Published: February 2021

During the 1950's, project management evolved as a distinct discipline from the engineering and defense industries. Modern projects however are larger, more complex and subject to tighter productivity constraints (time, cost and quality) than ever before.

Modern projects often fail due to their inability to manage complexities and/or poor communication networks. It would thus appear that the current project management methods are not able to reliably deliver such projects. Innovative alternatives need to be researched.

This paper presents a guideline to integrate the latest project management methods, brute processing power and human ingenuity to add maximum value. It thereby hopes to lessen the task-loading of project managers and engineers, whilst improving project delivery.
BIM Application in China Corporate United Pavilion Design
Authors: Zheng Zhang , Li Li
Published: February 2021

World Expo 2015 is hosting from May 1 to October 31 in Milan, Italy. "Feeding the Planet, Energy for Life" is the core theme of Expo Milano 2015. This common thread runs through all the events organized both within and outside the official Exhibition Site.

China Corporate United Pavilion(CCUP) , with "Chinese Seeds" concept, interprets the dream of Chinese companies that putting efforts for conservation of natural resources and food security. The concept is arised from the breaking ground by a sprouting seeds. The life comes from the green heart, and gradually turns into a spiral DNA chain tracing an upward path. The geometric shape of building is simple and clean with a internal ramp gently brings visitors upwards to the roof garden. To build up a gentle and natural environment, the heart of the pavilion is wrapped by a tree-shape column system which allow nature light come in and cast shadows naturally. Since the pavilion is a temporary construction for six months, aesthetically lightweight and breathable membrane is being used. All these materials will be transported back to China and re-used after Expo Milano.

Due to its complex design, BIM technology is being introduced to CCUP design process. Developer, design team, and construction team, all participants collaborate to put their effort to deliver a satisfied work. This paper is introducing the BIM application in CCUP design, and analyzing the challenge the BIM design is facing to. At last, the author give the outlook of BIM trend in China.
Analysis of the Productivity of the Process of Concreting in Federal District: Characterization and Proposal of Improvements
Authors: da Silva Araújo Suélio , Sato Simões Rudi , Rodrigues Filho Halley , Uribe Palácio Cristian David , Marques Carvalho Michele Teresa
Published: February 2021

This paper presents an analysis of the concreting service held in the Distrito Federal from data collected in the survey, by the union of construction industry (Sinduscon-DF), on the concreting indicators between 2010 and 2011. Emphasis on process management and market satisfaction, the main problems are raised, analyzed the root causes and provided potential solutions in order to improve the provision of that service. This work is justified by the absence of detailed knowledge about the relationship of this activity with improved productivity and quality of processes and enterprise.
Retrofit of Heritage Structures: Sustaining Environment and Culture
Authors: Sarkisian Mark , Mathias Neville , Keileh Jeffrey , Zhang Joanna , Lyrenmann John
Published: February 2021

Retrofitting and reusing existing structures instead of demolishing and rebuilding them is an environmentally sensitive way to deal with aging building stock. The carbon footprint of the former action can be shown to be significantly smaller than that of the latter. When the buildings in question have historic significance, there is the added question of sustaining cultural heritage. Retrofit approaches in seismically active California, USA, are presented and two examples of heritage building renovations that adopted very different seismic retrofit strategies are presented.
Non-invasive interventions on three concrete structures of high cultural and aesthetic value
Authors: Brühwiler Eugen
Published: February 2021

This contribution reports on the restoration of three concrete structures of high cultural and aesthetic values located in Switzerland. The three case studies highlight the importance of understanding cultural values of engineering structures and concrete architecture in particular, in view of interventions to satisfy demands of modern use. Non-invasive interventions for re- establishing durability and for structural strengthening were developed and realized. In all cases, UHPFRC (Ultra-High Performance Fiber-Reinforced Cement-based composite material) has been applied. It is shown how non-invasive and thus low cost interventions can be performed on “old” concrete structures with adequate respect of cultural and aesthetic values in order to improve them in view of a second service duration.
Tendering Based on Life Cycle Cost and Life Cycle Analysis
Authors: Köylüoğlu Özgür
Published: February 2021

Construction projects have high social and environmental costs by nature. A tendering procedure including estimation of the environmental life cycle cost in awarding a contract can facilitate best engineering solutions along with least damage to the environment. Basing the award criteria to the life cycle cost (LCC) and life cycle analysis (LCA) can be made by calculating the total CO2e emissions of a project, then pricing and including this cost in the tender price. As application of sustainability principles is crucial at the design stage, it is proposed to include cost of CO2 in the BOT projects and public residential projects where there is a developer-contractor responsible from the design as well as the construction of the facility, so an effort will be made to reduce bid price, hence CO2 price and emission. In this study, effect of CO2 price level on different types of projects are investigated to understand applicability of the procedure for public projects.
Increased innovation through change in early design procedures
Authors: Larsson Johan , Jansson Gustav , Olofsson Thomas , Simonsson Peter
Published: February 2021

Increasing industrial productivity and innovation is essential to meet needs to reduce lead times and costs. However, diffusion of systemic innovations in project-based industries (PBIs), such as the infrastructure sector, has proven difficult. The Swedish Transport Administration (STA) has unique opportunity to influence the degree of innovation in the sector, due to its strong position as the largest public client of infrastructure in Sweden. Therefore, the aims of an ongoing study reported here are to identify and evaluate challenges and requirements affecting the diffusion of innovation related to this key client. This is being done by examining relevant aspects of construction infrastructure projects executed via the pre-defined design procedure currently applied by STA. The results reveal that the procedure hampers diffusion since certain activities must be performed early, is applied indiscriminately to all types of projects, and hinders inter- organizational collaboration.
Thinking critically about structural engineering through role-playing games
Authors: Huynh Tracy , Payá-Zaforteza Ignacio
Published: February 2021

Education plays a major role in the development of a sustainable environment. Therefore, structural engineering education should pay considerable attention to the technical aspects, but it should also try to build a more sensitive general public and engineering profession that values sensible and exceptional designs.

This paper presents two experiences developed at Princeton University (US) and at the Universitat Politècnica de València (Spain) aimed to build critical thinking. In these experiences, the students analysed critically the suitability of two bridges (the Streicker Bridge by C. Menn and HNT, and the Assut de l’Or Bridge by S. Calatrava) based on the ideas of Structural Art. To do so, a debate was held with one group of students supporting a specific bridge design, a second one arguing against it and a third one playing the role of the judges to determine the final verdict. The paper provides the details of the organization of the debates as well as evidences of the success of the approach.
Using Sustainability as a Driver for Change in Denmark’s Construction Industry
Authors: Horswill Duncan , Nielsen Timo
Published: February 2021

The main aim of this research is to compare two structural systems – PC (precast concrete) and CLT (cross laminated timber) with respect to commercial viability and environmental credibility. The findings from this work are then set against two environmental ambitions of Copenhagen that are intrinsically linked to the construction industry in Denmark.

To be the first city in the world to be carbon neutral by the year 2025.

To build 6.8 million sqm of new buildings by the year 2025.

The aim of this paper is to challenge the use of PC in the light of Copenhagen’s environmental ambitions and of the availability of CLT. In this way, we hope to promote the role of engineers not just as technical problem solvers but as valuable contributors to contemporary social and political discourse.
Development and implementation of a new steel bridge edge beam for a cost-efficient replacement
Authors: Veganzones José Javier , Ramos Sangrós Diego , Sundquist Håkan , Nilsson Ulf
Published: February 2021

Bridge edge beam replacements in Sweden imply high life-cycle measure costs during the bridge’s life span. Moreover, the long duration of roadworks with a partial or full closure of the bridge causes significant user costs. The Swedish Transport Administration presented new edge beam solutions that could be better for the society in terms of cost. The purpose of this paper is to present the development and implementation processes of a new steel edge beam in a bridge project and evaluate its cost-efficiency. The design and planning phase is described addressing the challenges encountered and explaining the execution of the works. A life-cycle cost analysis is performed to compare with the standard concrete integrated edge beam. The steel edge beam results in a cost-efficient alternative for an edge beam replacement because of the lower life-cycle costs due to a faster execution of works and good working conditions.
Design Challenges of the Horotiu Paa Bridge – Maximising Structural Efficiency and Economy
Authors: Edwards Liam
Published: February 2021

The Horotiu Paa Bridge, also known as the Karapiro Gully Bridge is the largest weathering steel bridge in New Zealand. Construction of the bridge was recently completed in November 2015. The bridge is part of the Cambridge section of the Waikato Expressway in New Zealand. The Waikato Expressway is one of the seven state highways, named the Roads of National Significance, identified by the government as essential to New Zealand’s economic prosperity. The bridge spans over the Karapiro Gully with a total length of 200m, consisting of four 50m long equal spans and is 24m wide, servicing 4 lanes of traffic.

This paper discusses the design development, key design aspects, innovations and technical challenges for the design of the Horotiu Paa Bridge.
Interventions on existing buildings in ‘aggregates’: lessons learnt from some Italian collapses
Authors: Palmisano Fabrizio , Perilli Pasquale
Published: February 2021

The Italian historical city centres are often composed of the so-called building ‘aggregates’. According to the Italian standards, a building aggregate consists of a set of adjacent buildings that is the result of an articulated and not unitary genesis due to multiple factors (e.g. different construction and modification ages, materials, uses, owners). Some recent collapses have clearly shown that there are many factors that can influence the structural behaviour of an aggregate even if the intervention is limited to a part of a building. These cases have highlighted that the design approach to this kind of interventions is not as obvious and simple as shown in the present Italian standards. This article, analysing two recent aggregate collapses, aims to highlight the main aspects that have to be considered during the design and the site supervision of interventions in historical building aggregates.
Italy Tower Collapse in São José do Rio Preto - São Paulo - Brazil
Authors: Rebouças Stucchi Fernando
Published: February 2021

This paper discusses the collapse of Italy Tower, a 16-storey building, that fall down 10 years after construction, with 10 floors upside down in a lateral street.

The designed structure and the structure as built were verified and a possible and probable cause was identified.
Deterioration of connections and failure of light-weight façade envelopes due to sequence of seismic and wind actions
Authors: Dakov Dimitar , Belev Borislav , Penelov Chavdar
Published: February 2021

Insulated sandwich panel walls are typically screw-connected to their supporting substructure and therefore enforced to follow the displacements of the primary structure imposed by wind and seismic actions. The paper presents an investigation of the façade envelope of a warehouse building which was slightly damaged by a recent earthquake and underwent partial failure during a wind storm a few years later. Of particular concern are the corner zones of tall single-storey buildings with stiffness irregularity in plan where the interstorey drifts produced by relatively weak earthquakes could trigger deterioration of the panel fastenings and increase their vulnerability to subsequent wind suction effects. When concealed (hidden) fastenings are used the designer should take measures either to reduce the shear and tension demands on the fastenings or to increase their capacity, e.g. through application of load distributing plates.
Forensic investigation of early age Alkali-Aggregate Reaction damaged concrete elements: causes and lessons
Authors: Brühwiler Eugen
Published: February 2021

Precast L-shaped reinforced concrete of the platforms of a railway station showed excessive damage after only 8 years of service. Damage led to important deformation (outward bending towards the railway clearance outline) of these elements to such an extent that they had to be urgently replaced because of safety reasons. Forensic investigation revealed Alkali-Aggregate Reaction (AAR) to be the cause for the damage.

In view of establishing the responsibilities in this costly case, a major question was whether the contractor mandated for the fabrication of the elements could have been sufficiently knowledgeable of the AAR phenomenon at the time of execution of the construction works. Also, the role of standards and in general the notion of “state-of-knowledge” of the profession were important issues.
How to deal with Structures affected by Delayed Ettringite Formation
Authors: Godart Bruno
Published: February 2021

The expansive sulphate internal reaction of concrete due to Delayed Ettringite Formation (DEF) can damage concrete structures severely. DEF is defined as the formation of ettringite in a concrete after setting, and without any external sulphate supply, but with water supply. This phenomenon occurs in concretes exposed to frequent humidity or contact to water, and subjected to a relatively high thermal treatment (> 65°C) or having reached high temperatures during casting. This reaction may cause large structural disorders due to unexpected deformations and additional stresses in concrete and reinforcement, and the problem is therefore to know how to deal with such structures affected by DEF. The prediction of future deterioration, the appraisal methodology and the assessment of the efficiency of remedial operations are crucial points for existing affected structures whose serviceability and structural safety may constitute a serious concern.
Estimation of the influence of climate change on snow load on structures
Authors: Croce Pietro , Formichi Paolo , Landi Filippo , Marsili Francesca
Published: February 2021

The aim of the present study is to set up a general procedure to predict future trends in snow loading on structures, taking into account the impacts of climate change according different emissions’ scenarios, modelled at a global scale. The procedure is validated against high quality data series collected for at least 50 years at weather stations in Italy, well representative of the Mediterranean climatic features. In a second phase of the study, the procedure will be extended to all European climatic regions in view of the next revision of Eurocodes.
Vehicle Safety Assessment on Bridge Deck under Cross wind
Authors: Kim Se-Jin , Kim Ho-Kyung
Published: February 2021

Vehicle accidents on a bridge deck under cross wind have been reported in the past decades. This is one of bridge design issues, especially for sea-crossing bridges. Prior to determining any measure such as the use of windscreen, the safety of running vehicle should be assessed with a systematic procedure.

The purpose of this study is developing an assessment procedure of vehicle safety under cross wind with consideration of the wind direction, the shape of bridge deck, and the type of vehicle. The stochastic approach is applied for the long-term wind data. The procedure consists of three steps: 1) estimation of cumulative distribution function of wind data, 2) estimation of critical wind speeds, and 3) estimation of the number of days for traffic control. The proposed procedure is applied to an example bridge and several factors affecting the vehicle safety are discussed.
Global and seismic analysis of Chacao Bridge
Authors: Nessa Kristin , Kaasa Lars Halvor , Hole Kornelius Drange , Jakobsen Svein Erik , Mhamed Aymen Cheikh
Published: February 2021

The Chacao Bridge is an asymmetric two-main-span suspension bridge crossing the 2.5 kilometer wide Chacao Channel in Southern Chile.

The bridge has main spans of 1155 m and 1055 m and a total length of 2754 m. The three concrete pylons have different heights and the Central Pylon (inverted Y-shape) is tuned to balance uneven forces in the two main spans.

The bridge site has especially harsh environmental conditions with strong winds, strong currents, and most notably, high seismicity, adding challenges to the bridge design.

In the process of detail design, a comprehensive set of global analyses have been conducted. This paper identifies some of the different sets of analyses and special challenges faced in the analysis procedures.
Seismic retrofit for the truss bridges of the Seto-Ohashi Bridges
Authors: Fukunaga Susumu , Nishitani Masahiro , Kawato Chihiro , Toyama Naoki
Published: February 2021

In original seismic design of the Seto-Ohashi Bridges, an inland near-field earthquake was not considered. And there is concern that large-scale earthquakes would occur in the near future. Therefore seismic retrofit for truss bridges of the Seto-Ohashi Bridges has started. In the seismic retrofit design for the truss bridges, it was decided that seismic response of overall bridge was reduced firstly and the truss members were strengthened by additional stiffeners secondly. The stiffeners were attached to the truss members by bolting, because it was difficult to ensure quality of field welding. As inner surface of the closed box-section truss members has no coating, drilling bolt holes in the members was thought to increase the probability of corrosion of the members. Therefore it was decided to apply airtightness measures for the inside of the closed box-section members after their drying.
Application of the Equivalent Static Analysis procedure for the seismic design of buildings with added viscous dampers
Authors: Palermo Michele , Dib Antoine , Silvestri Stefano , Gasparini Giada , Trombetti Tomaso
Published: February 2021

Most of the actual seismic design procedures for structures equipped with viscous dampers requires the development of non-linear time-history analyses, which, even though of quite common use among the researchers, still represent a challenge for professional engineers. The paper describes a simple Equivalent Static Analysis procedure for the seismic design of building structures equipped with added viscous damper. The procedure, which is based on the fundamentals of the dynamics of multi-storey frame structures with added viscous dampers, is aimed at estimating the maximum forces in the viscous dampers as well as the peak internal actions in the structural members. The simplified procedure is applied for the design of a 3-storey reference steel frame analysed by other researchers.
An innovative seismic protection system for existing buildings: External Dissipative Towers
Authors: Dezi Luigino , Gara Fabrizio , Gioiella Laura , Balducci Alessandro
Published: February 2021

This paper deals with an innovative system for seismic protection of existing buildings, especially strategic ones, patented as “Dissipative Towers”. This protection system is based on the structural coupling of the building with new steel truss towers constructed externally and then rigidly connected to the building floors by means of steel elements; the towers are erected over a rigid

r.c. thick base plate that is restrained to the foundation cap with a spherical hinge located in central position. The towers are equipped with dissipative devices located between the two plates, at the angles; the effectiveness of the dampers is enhanced by the use of articulated quadrangles which amplify the vertical displacements of the devices. The effectiveness of the system can be very high and it is usually designed to satisfy the Immediate Occupancy Limit State even for high intensity earthquakes. In this paper this innovative system is described referring to the retrofit of two existing school buildings in Italy, both characterized by a reinforced concrete frame structure. The seismic rehabilitation is obtained by suitably positioning external dissipative towers and eliminating expansion joints. The towers allow a high level of seismic protection at the Save Life Limit State, with a significant reduction of horizontal displacements and accelerations. The seismic protection is achieved with a moderate economic impact due to the elimination of indirect costs related to the arrangement of internal spaces, interruption and/or relocation of activities.
The wind microclimate optimisation of large-scale re-developments
Authors: Hankin David , Aurelius Leighton , Cammelli Stefano
Published: February 2021

One of the key challenges facing the large-scale re-development process of existing commercial areas into mixed-use zones is to ensure a site-wide layout that not only serves the purposes of the scheme being developed, but also provides comfortable wind microclimate conditions for all users. In order to ensure that pedestrian comfort is suitable and meets best-industry practice targets, it is recommended that at the early stages of master-planning, the site-wide wind comfort is thoroughly examined via boundary layer wind tunnel testing. This approach is examined via a case study conducted on the re-development of a large-scale education zone in South London into a mixed-use zone whereby a series of basic massing schemes were examined to determine the “macro” scale wind climate across the entire site and subsequently re-examined at a more “micro” level to resolve any wind issues via the introduction of purposely developed mitigation measures.
Peak factor estimating methods of non-Gaussian wind pressures on a rectangular high-rise building
Authors: Zhuang Xiang , Dong Xin , Zheng Yimin , Zhao Xin
Published: February 2021

A wind tunnel test was conducted on a rectangular high-rise building. Firstly, based on the third and the fourth order statistical moments of wind pressure time histories, the non-Gaussian regions were identified. Results show that on the windward face, the non-Gaussian region was near the edge and the corner areas. For the narrower side face, the non-Gaussian region was near the leading edge. However, the non-Gaussian region was discovered close to the trailing edge where the flow reattachment occurred for the wider side face. Then, by parametric analysis and fluctuating wind pressure spectrum fitting, a simplified method for peak factor estimating was derived on the basis of the moment-based Hermite method and the Revised Hermite Model, named Three-parameter Hermite Model. Lastly, the accuracy and efficiency of moment-based Hermite method, Revised Hermite Model and Three-parameter Hermite Model were tested by the instantaneous extreme value and the histogram of wind pressure histories. Results show that compared with the peak factors of the instantaneous extreme values, peak factors calculated by the moment-based Hermite method were overestimated. While the peak factors of Revised Hermite Model and Three-parameter Hermite Model show a smaller error. The PDFs of Three- parameter Hermite Model are in good agreement with the ones of Revised Hermite Model, which show a better fit to the histogram of wind pressure histories.
Modelling of self-excited wind forces on long span bridges using State-space models
Authors: Xu Yuwang , Øiseth Ole , Moan Torgeir
Published: February 2021

Frequency domain methods, neglecting nonlinear characteristics, can in some cases inaccurately predict the response of long span cable-supported bridges. Time domain methods are commonly applied when nonlinearities need to be considered because it is challenging to include these in frequency domain analysis. In this paper it is shown how a rational function fitted to aerodynamic derivatives can be converted to a state space model to transform the frequency-dependent aerodynamic forces to the time domain. A user element has been implemented in the software ABAQUS in order to include the self-excited forces in the dynamic analysis. The element has been developed as a one node element that is included in the nodes along a bridge deck. The flutter stability limit of the Hardanger Bridge has been calculated in a comprehensive case study to illustrate the performance of the presented methodology.
Large-scale replacement project of Hanshin Expressway
Authors: Kono Yasushi
Published: February 2021

The Hanshin Expressway was first opened more than 50 years ago in 1962. It has subsequently grown into a network that boasts an operating distance of 259 km and daily traffic of approximately 700,000 units. However, damage has manifested in the expressway because of aging of core structures. To avoid future catastrophic failures due to these damages and road closures associated with them, overall structural replacements (large-scale replacements) are planned. These replacements are planned for 6 segments of the expressway that are not expected to be improved in the future through repair and maintenance.
Monitoring structural behavior of reinforced concrete walls with openings using digital image correlation
Authors: Sabau Cristian , Popescu Cosmin , Sas Gabriel , Blanksvärd Thomas , Täljsten Björn
Published: February 2021

Several measuring techniques based on digital image correlation (DIC) are nowadays used in many fields. DIC measurements can facilitate documentation of crack patterns on specimens subject to loading, valuable information, which would otherwise be hard to obtain, especially in the case of reinforced concrete elements. This can not only give a better insight into the failure mechanism of the element, but also evaluate cracking as measure of serviceability.

This article discusses existing serviceability limits and failure modes of reinforced concrete walls in buildings in light of results obtained using DIC on two half-scale reinforced concrete walls with openings tested to failure. Results suggest that cracks induced by a load level equivalent to 70% of ultimate load bearing capacity, do not exceed limits indicated in relevant guidelines.

The failure mode of two way walls with openings was found to be similar to that of two way slabs also with openings, however differences were identified in the development of the failure mechanism. Finally, two strengthening strategies of reinforced concrete walls are discussed.
New Durable Bond Anchorage for Strengthening with Prestressed Near Surface Mounted CFRP
Authors: Vorwagner Alois , Burtscher Stefan , Lachinger Stefan
Published: February 2021

The condition of transport infrastructure is deteriorating over time due to different influences (e.g. traffic impact, corrosion, and fatigue). This forces new sustainable and efficient strengthening methods, which faces future demands. Prestressed near surface mounted (PNSM) is a strengthening method which enables new and powerful possibilities. A carbon fibre reinforced polymer (CFRP)-strip is stressed and bonded to the structure within the concrete cover region. The devices are removed, and permanent anchorage is established by epoxy resin only. The result is a smooth surface of the strengthened structure without any corrosive parts remaining on the object. This opens new and efficient ways for strengthening, by increase of serviceability, durability and activation of dead load.

The efficient application of PNSM-strips is nowadays possible due to the (i) recently available prestressing unit, (ii) reuse of costly devices, (iii) short time for installation and (iv) simple and efficient application methods. Full scale tests of beams and slabs show functionality of this method which opens following opportunities: activation of dead load, durable system (no steel, lower crack width), efficient use of the CFRP-material, reduction of deflections, low intervention on the structure and improved life cycle behaviour.

The crucial point is the application of the pressing force without any steel parts remaining. All the processes have to operate within the concrete cover of max. 3 cm, so a special prestressing device and permanent bond anchorage were developed. The strips are applied in 2 steps. In step 1 the strip is prestressed and bonded in a groove to the structure, in step 2 the anchorages are removed and the permanent bond anchorage is implemented. In this paper experiments and investigation of the permanent bond anchorage are presented.
Monitoring and Inspection of a Fiber Reinforced Polymer (FRP) Road Bridge
Authors: Gabler Markus , Pelke Eberhard , Knippers Jan
Published: February 2021

The Friedberg Bridge in Germany was the first FRP - steel composite road bridge in Europe when it was opened to traffic in 2008. The bridge has a span of 27 m and a total width of 5 m. It had been designed for full vehicle live load as per EN 1991 with the then applicable NA for Germany. An extensive senor network had been installed to investigate the structural behavior of the bridge when subjected to daily temperature cycles and live loads. The bridge has also been visually inspected over the first years of use.

This contribution will present the sensor readings during load tests and daily temperature cycles. The results allow for assessment of the load bearing behavior of the FRP deck and adhesive interface of the deck to the steel girders as well as long-term effects. This can be used for calibration of a detailed FEA model of the bridge, which can be used for future design tasks of FRP bridges. For example, the analysis shows that the contribution of the surfacing layer as well as the parapets is non-negligible for proper modeling of the structural behavior.

The load testing was supplemented by visual inspections, which didn’t showed any visible damage to the adhesive layer nor the FRP deck.
Influence Evaluation of Scratch, Coating Method and Spray Method by Combined Cycle Test of Metal Spray Plate
Authors: Hattori Masafumi , Furuya Yoshiyasu , Hirose Takeshi
Published: February 2021

Metal spray is beginning to come into use as a means of extending the life of steel bridges by preventing corrosion. A combined cycle test parameterizing the type of spray metal, scratch depth, surface preparation grade and the spray method was carried out to evaluate the effect of scratch caused during construction, the effect of the coating methods of the sprayed metal surface and the effect of spray methods. The test showed that the spray method, scratch depth and coating method affect durability, that coating on the spray metal surface can have adverse effects on durability and that even simple touch-up coating can be highly effective as a repair method.
Sustainability in action – Expansion joint renewal with focus on retention and re-use
Authors: Spuler Thomas , Hoffmann Simon , Savioz Pascal
Published: February 2021

A bridge’s expansion joints will almost certainly have to be replaced several times during the course of the bridge’s life, often causing great disruption to traffic and significant expense to the owner – impacts which should, of course, be minimised. The choice of expansion joint selected to replace an old joint strongly influences the expense and disruption caused by replacement works, not only for the current replacement project but also for the next one in the future. Therefore, the way in which joint replacement works are to be carried out, and in particular the type of joint to be used, warrants careful consideration by the responsible engineers. This paper presents a range of solutions, covering single gap joints, sliding finger joints and modular joints, which minimise the amount of an existing structure that requires to be broken out when replacing an expansion joint.
Properties of Structural Steels in a Railway Plate Girder Bridge
Authors: Holowaty Janusz , Wichtowski Bernard
Published: February 2021

The results of an examination on structural steels of different grades from a three-span plate girder bridge are presented. The riveted structure consists of six spans of a similar structure but constructed at different periods over the bridge’s service life, with two of the spans estimated to be original and dating from 1873. The structure has degraded at different levels, along with the amount of corrosion. The testing of naturally ageing and normalised specimens enabled the steel degradation and effects of ageing to be assessed. Along with mechanical properties, the weldability of the steels was also assessed.
Strengthening and Reconstruction of the Hugo Treffner Gymnasium building in Tartu, Estonia
Authors: Avellan Kari Christer , Belopotocanova Erika
Published: February 2021

Strengthening and reconstruction of Hugo Treffner Gymnasium building was carried out from 1994 to 1997 in four stages. The mandate of KAREG Consulting Engineers entailed designs of temporary and permanent structures as well as development of a monitoring system and examining the condition of the structure. The foundations on the yard side walls were placed two meter higher than the remaining of foundations of the structure. As a consequence, the above mentioned findings led to forming cracks and brought about the walls of the building to incline. The project involved corner walls and interior walls stabilization, exterior walls strengthening and a new basement area construction. A new reinforced slab was poured, designed using the yield line theory analysis. The use of the selected strengthening options and technique for structural intervention of the walls was found to be a suitable technique to achieve the desired objective.
Experimental behaviour of externally confined concrete columns with inadequate lap spliced rebars under fully reversed cyclic loading
Authors: Chronopoulos Petros , Astreinidis Evangelos , Giokaris Stefanos
Published: February 2021

The seismic performance of RC elements can be significantly impaired by inadequate lap-splicing of their reinforcing bars. In this paper the main findings of an experimental investigation of this influence are presented. Two rehabilitation techniques by means of external confinement of lap- splices are also examined. Cyclic tests on twelve (12) column-like specimens were performed. Four

(4) types of specimens were tested, one (1) with no reinforcement lap-splicing and three (3) with lap-splicing of their longitudinal reinforcement inside their critical regions (plastic hinges). For each type different lap-lengths were used. All specimens had the same geometry and reinforcement detailing. The tests were fully instrumented and monitored. The experimental results of this study are presented hereafter. Conclusions regarding the shear response, the hysteretic energy dissipation and the effectiveness of the strengthening techniques used are made.
Assessment of Bridge Repair Works using Modal Testing Technique
Authors: Kamal Medhat
Published: February 2021

In this research, the ambient vibration method is used as a field dynamic test to evaluate the repair works in bridges. Exciting the bridge, before and after carrying out the repair, using ambient vibration induced by traffic and comparing the results, indicates the changes in the dynamic properties of the bridge leading to a quantitative measure for the quality of the repair. This suggested procedure has been verified experimentally by a direct application to an existing bridge and has been proven to be successful.
A probabilistic approach for handling uncertainty in infrastructure LCA
Authors: Larsson Oskar , Honfi Dániel , Stripple Håkan
Published: February 2021

To demonstrate and support sustainability of large-scale infrastructure projects, life cycle assessment (LCA) has become a common tool used in the evaluation of environmental impact. However, LCA includes a number of phases, which are all associated with uncertainties. Decisions made without regard to these uncertainties may be suboptimal and/or misleading. The current paper discusses some important issues about how to deal with uncertainties in LCA. Two case studies are presented that shows the effect of including uncertainty in various parameters. The results show that a reduction in uncertainty due to manufacturing improvements can increase the reliability of the results significantly. It was also found that the uncertainty assumptions for parameters where data is not available have a large impact on the LCA-results.
Development of Stay Cable Measurement System using Wireless Sensors
Authors: Kwak Younghak , Shin Yoon Bong , Kim In Gyu , Kim Youngjin
Published: February 2021

Acceleration measurement is widely employed in various engineering field, because acceleration sensors generally have low noise and cost effective. Recently, FFT analysis of measured acceleration data is widely used to determine cable tension. This study proposes a stay cable measurement system using acceleration data to determine the cable tension and vibration amplitude. Real vibration amplitude can be estimated with this system by taking the vector summation of the plane (2-axis) displacements measured simultaneously. A small light-weight wireless sensor and cable climbing robot are also proposed to increase the applicability.
An Investigation of Concrete Strength and Ultrasonic Pulse Velocity for an Existing Bridge Group
Authors: Akgül Ferhat
Published: February 2021

Preventive maintenance of civil engineering structures is a highly crucial measure, not only for achieving efficient distribution of limited budgets over existent aging infrastructures but also for maximizing their service lifespans. This paper presents the results of an experimental field study of penetration resistance and ultrasonic pulse velocity test measurements for a pilot bridge group containing 10 bridges located in North-West region of Turkey. Due to maximum energy transmission from the transmitted ultrasonic pulse and the possibility to have access to two faces of the member, direct method is chosen for ultrasonic pulse velocity measurements on middle piers and the girders of the bridges. Decks and the abutments were not tested. The results of concrete strength vs. pulse velocity for the bridges did not show a notable correlation as opposed to typical correlated plots in the literature. However, although the empirical formulas obtained in this study do not follow the typical correlation plots presented in the literature, it seems possible that the formulas obtained in this study may estimate (from pulse velocity) the concrete strength of the middle piers and girders of all reinforced concrete bridges in Turkey built between 1950s and late 1970s.
Study of tension in mooring cables under parametric excitation for submerged floating tunnels
Authors: Cantero Daniel , Rønnquist Anders , Naess Arvid
Published: February 2021

The coastal highway E39 project in Norway is considering the construction a Submerged Floating Tunnel (SFT). Some of the preliminary designs use a mooring system to maintain the structure in the prescribed position. The main environmental load in such a system will be long period swell waves. This low frequency excitation produces a parametrically excited system. Certain situations might lead to parametric resonance or dynamic instability that causes excessive vibrations of the cable and the SFT. However, it is unclear how parametric excitation affects the cable tension of a mooring system. Correct design should avoid excessive forces that might break the line or very small forces that lead to momentarily slack cables. The aim of this paper is to assess the validity of using the stability charts for the design of mooring lines with respect to safe levels of cable forces. This is achieved through the numerical analysis of a cable model using Abaqus. Cable vibrations and cable forces are analysed and compared for a range of amplitudes and frequencies of the support motions. Also the dry and submerged cases are compared, clearly exposing the repercussion of the hydrodynamic effects.
Crossing the Bjørnafjord with a multi-span suspension bridge on floating foundations – Concept Overview
Authors: Veie Johannes , Holtberget Simen Hellgren , Jena Parthasarathi
Published: February 2021

By combining well proven technology from suspension bridge engineering with offshore deep water technology it is found possible to realize a crossing for the 5 km wide and 550 meter deep Bjørnafjord in the western part of Norway. The proposed concept consists of a three span suspension bridge with two rock anchored towers on each side of the fjord, and two floating TLP (Tension Legged Platform) towers midfjord. The two side spans has a length of 1385 meters, the mid span has a length of 1325 meters, and the floaters are anchored at a depth of 550 meters and 450 meters utilizing a combination of suction and gravity anchors or possibly piled anchors. The floaters can be constructed with concrete or steel and two different shapes are looked upon. The superstructure consists of PPWS (Prefabricated Parallel Wire Strands) main cables, hangers and an aero-dynamical box girder. The effect of different configurations of connections and the introduction of a top tie cable to improve global behaviour in the vertical plane are addressed. Major challenges identified are related to ground conditions, environmental loadings, deep sea operations and maintenance and operation.
Crossing the Bjørnafjord with a multi-span suspension bridge on floating foundations – Challenges in design
Authors: Holtberget Simen Hellgren , Veie Johannes , Jena Parthasarathi
Published: February 2021

As part of the ferry free E39 project, along the west coast of Norway, eight fjord crossings will be made. This means new technology has to be developed, as the fjords pose a great challenge related to environmental conditions, ship impact and topography.

This paper gives an overview of the technical challenges foreseen in the design and construction of a multi-span suspension bridge on floating tension legged platform foundations for the crossing of the Bjørnafjord. The crossing is approximately five kilometres wide, and has a depth up to 550 meters. The concept consists of a three-span suspension bridge with two land based towers, and two floaters midfjord.

The suggested solution is multidisciplinary involving structural complexity, aerodynamics and hydrodynamics. Although the bridge components are relatively well understood individually, the interaction between them needs further investigation. In this paper the effects of the components on the whole system are investigated. Different configurations are evaluated, and the interaction between the different components is investigated to understand the effects regarding construction and final design.