bluuebunny/crossref_metadata_2025 huggingface dataset:
Framework of Bridge Design Method under Multi-Hazard and Its Application to Super-Span Multi-Pylon Cable-Stayed Bridges
Authors: Chen Airong , Tian Yu , Ma Rujin
Published: March 2016

In common practice of bridge design, each hazard is considered and inspected individually. In recent years, more and more bridge collapse accidents expose defects in current bridge design methodology. Researches about comprehensive demand for all hazard scenarios, including simultaneous and/or cascaded hazards events, are of great significance. Reasonable bridge design method should include all possible hazard scenarios in an integrated manner in order to mitigate the structural risk under multi-hazard in the life-cycle and achieve structural performance that satisfies owner and societal expectations. This paper presents an innovative performance, risk, life-cycle based framework for bridge design method emphasized on multi-hazard consideration. The proposed formulation divides the whole bridge design process into six steps, namely preliminary design, hazard analysis, performance design, risk assessment, hazard mitigation measure design, life-cycle cost analysis. The ultimate objective of the bridge design process according to the proposed design method is a design scheme that has minimum life-cycle cost on condition that it meets specified performance standards and risk criteria. The proposed framework is illustrated through an application example of two super-span multi-pylon cable- stayed bridges, which are alternatives for Qiongzhou Strait Bridge design scheme. The feasibility of the proposed design method is verified among its application, in which one design scheme with satisfactory safety, functionality and relatively lower total cost is recommended.
Renewable Energy Storage Megastructures
Authors: Jurgens Christiaan
Published: March 2016

Renewable energy is seen as a source of clean, safe and sustainable energy. Many renewable energy sources however have a common Achilles’ heel, namely intermittent energy supply.

This paper confirms the global need for energy storage. The Super Flywheel Concept, a renewable energy storage megastructure, is then put forth as a possible solution to the challenge. Flywheel storage was specifically chosen as it is seen to be safe, environmentally clean, low maintenance and scalable.

By evaluating the conceptual design, construction materials, buildability and energy storage capacity of the Super Flywheel, the concept was ultimately deemed to be feasible.

Though not one of the key objectives, it was also determined that a similar concept may be used for the electrification of rural African villages…
Structural Engineers as Creative Leaders – from Stadia to Pavilions
Authors: Leach Jon , Webster Thomas , Nicolin Rossella
Published: March 2016

Structural engineers are in a unique position to influence creativity in design. Using modern technology and computational analysis we are able to work efficiently with complex geometry and performance-based structural analysis. Good design should be a synergy of creative aesthetic forms and engineering judgement and experience, and the design methods we are now able to harness can help to inspire structural engineers to be a key part of a collaborative architectural design process.
Bridging to the Bicentenary: Collaboratively Educating Engineers and Architects
Authors: Mistur Mark , Letchford Chris , Stein Michael
Published: March 2016

Rensselaer Polytechnic Institute (RPI) has been educating civil engineers for almost 200 years and over the last fifteen a unique collaborative program has developed between the Department of Civil & Environmental Engineering, the School of Architecture and prominent structural engineers. Funded by the Bedford Endowment, the program pairs architecture and structural engineering students over their senior semesters in a range of courses designed to improve mutual understanding, develop awareness of design motivations and aesthetics in the engineers and structural forces and forms in the architects. Led by a leading structural engineer from practice on a three year appointment, the Bedford Professor teaches both a seminar and a studio class and leads a ten day travelling workshop at the end of each academic year that exposes engineering and architecture students to best practice examples of collaboration in the design of the built environment.
E-Learning, The future of Structural Engineering Education?
Authors: Lozano Galant Jose Antonio , Briseghella Bruno , Zordan Tobia , Turmo José
Published: March 2016

In last years, the traditional blackboard teaching has been supplemented by visual aids like slide projectors and videos. The phenomenal growth of the Internet has brought in new teaching media, such as E-learning. Online courses and multimedia material over the Internet open the educational experience up to distant students without schedule restrictions, making E-learning an attractive option especially for professionals. Nevertheless, the overwhelming amount of material currently available might complicate the offer selection. Furthermore, internet globalization makes that quality levels of these materials might differ significantly. Aware of these problems, IABSE created the E-Learning board to address conveniently the online learning in structural engineering. Recently, the Association has created a new platform that aims to become a leader in quality online education. As a way to promote the use of this platform, the E-learning board proposes a debate focused on how the future of structural engineering education is linked with the different kinds of E-learning in both academia and industry training.
Preliminary Design of the New Bridge for the St Lawrence River
Authors: Carter Matthew , Potapova Lana , Balmer Doug , Jensen Poul , Svanberg Kasper
Published: March 2016

The New Bridge for the St. Lawrence Corridor Project is a 3 billion dollar urban highway project which is being procured through public private partnership. The centrepiece of the project is a 3km crossing of the St Lawrence River which forms a vital link between the city of Montreal and the Brossard shore. The design includes a cable-stayed main span over the St Lawrence Seaway with elevated approaches on either si de. The approach bridge substructure is a unique "W-pier" supporting three separate box girders. The design has been developed through a number of stages to arrive at a solution which is architecturally elegant as weil as being durable and buildable. This paper will describe the preliminary design of the bridge, explaining the evolution of the design in different stages and demonstrating how technical requirements and architectural vision were combined in the design.
The New JTI Headquarters in Geneva - an Iconic Shape in the Swiss Landscape
Authors: Baker William , Binci Massimiliano , Guscetti Gabriele , Lelli Lorenzo , Marsh Stuart
Published: March 2016

The new JTI Headquarters constitute a novel architectural landmark in Geneva. The nine-storey building stands on a triangular shaped parcel; it is characterized by three main tubes creating an open environment on the ground floor which boasts a public pedestrian passage. The facade trusses create an impressive 60-meter-span cantilever on the north-east side. On the south-west side, the building also lifts off the ground in a bridge-like fashion spanning over 80 meters. The main frame is composed of three-dimensional steel trusses supporting light-weight composite slabs without intermediate supports. Specific procedures, namely, controlled unpropping, jacking and temporary tie-down of the structure, allowed for safe cladding installation and control of building deformations. Advanced natural fire analysis led to a consistent reduction of fireproofing measures of the steel floor framing.
The Rendsburg High Bridge across the Kiel Canal
Authors: Bartzsch Matthias , Geissler Karsten
Published: March 2016

The Rendsburg High Bridge – a railway viaduct across the Kiel canal – is a more than 100 year old technical monument. Nevertheless, it is used under full traffic load – as a bottleneck for the traffic to Scandinavia. The bridge, a riveted steel construction, is currently being extensively retrofitted. The measures comprise, beside the renewal of the corrosion protection and the repair of defects, a strengthening for today’s railway traffic loads. Thus, the bridge can be preserved for the long run

– also an important contribution to the building culture.
Bridge over the Vistula River in Kamień, Poland
Authors: Yeoward Andrew , Jarominiak Wojciech , Igielski Adam
Published: March 2016

The article describes the design and construction of a newly built road bridge over the Vistula River in Kamień in south-east Poland. Key features of design and construction of the iconic, over 1km long structure are presented. Construction commenced in September 2012 and was completed in May 2015.
Characteristics of wind pressures on a rectangular tall building in the time domain
Authors: Zhuang Xiang , Dong Xin , Zheng Yimin , Zhao Xin
Published: March 2016

The characteristics of wind pressures on a rectangular tall building, especially on the side face, were researched through a wind tunnel test. Firstly, the mean and fluctuating pressures on each face were presented. When the flow is normal to the short edge, larger pressure gradient was detected on the side face with the greatest suctions located near the leading edge. Then these suctions transformed into positive pressures near the trailing edge. Secondly, the span-wise correlations of wind pressures on the side face were presented in terms of cross-correlation coefficients. The correlation curves attenuate fast on the wider side face, while the attenuation was less obvious when the narrower face is alongwind. Lastly, the non-Gaussian regions were identified by the third and the forth order statistical moments of wind pressure time histories,. For the narrow side face, the non-Gaussian region was near the leading edge where the flow separation occurs. However, the non-Gaussian region was discovered close to the trailing edge where flow reattachment occurs for the wider side face.
A New Steel Damper and Its Applications in Long Span Bridges
Authors: Shen Xing , Ye Aijun
Published: March 2016

To resist seismic impact, fixed supports were often installed between the girder and piers (or towers) in transverse direction of long span bridges. As a result, the sub-structures and fixed bearings had to be designed extraordinarily strong to resist the design earthquake. However, when larger earthquake occurred, the bearings and sub-structures were still vulnerable. Friction Pendulum Sliding Bearing (FPSB) could be used in bridges to reduce seismic forces of piers and foundations. But the dissipation energy capacity of FPSB was poor when the vertical dead load was so small that the installation of FPSB on these piers often resulted in unacceptable transverse seismic displacement between the girder and piers (or towers). This made FPSB not suitable to be used on piers or towers of cable-supported bridges and side piers of other long span bridges. A new seismic system combining bridge Transverse Steel Damper (TSD) with sliding bearings is proposed in the paper. TSD consists of two parts: the upper part and lower part, which are connected to the girder and piers, respectively. The dissipation energy elements, triangular plates, are welded on the steel plate of the lower part. The steel hemispheres are placed on the vertex of each triangular plate to guarantee clear force transferring path. The steel hemispheres can slide on the Polytetrafluoroethylene (PTFE) slides, which are attached on the surface of steel blocks of the upper part. This connection structure can make TSD adapt to the bridge longitudinal movement between the girder and piers (or towers). Pseudo static test of TSD specimen proved its good synchronicity, excellent energy dissipation and displacement capacity. Test results also revealed that hysteretic characteristics of TSD could be simulated by equivalent bilinear model. Furthermore, three long span bridge cases by using TSD seismic system, i.e. two cable-supported bridges and one steel arch bridge, are presented in the paper. The TSD seismic system could be used in longitudinal or transverse direction between towers and the girder, or transverse direction between side piers and the girder. The performance of TSD seismic system in three cases demonstrated that TSD seismic system could effectively reduce seismic forces of sub-structures and control transverse displacement between the girder and piers top within acceptable level. Meanwhile, TSD seismic system will be an excellent solution to improve seismic performance of long span bridges, especially in transverse direction.
Concept for the Future Development of Eurocode 3 Design of Steel Structures
Authors: Kuhlmann Ulrike , Zizza Antonio
Published: March 2016

The presented paper shows an extract of recent work regarding the revision of EN 1993 on European and national level including selected scientific and technical issues and a summary of the activities executed within the European Standardization committee CEN/TC250/SC3 “Design of Steel Structures“ under the chair of Prof. Dr.-Ing. Ulrike Kuhlmann. A concept for revision has especially been developed in view of the further developing of Eurocode in the frame of Mandate M/515.
The New Lifting Bridge in Bordeaux, France - Mechanism Design Code Constraints and Freedoms
Authors: Skelton Paul , Griesing Keith
Published: March 2016

While the design creates a visual lightness, the 2720 ton, 117m vertical lift span of the Jacques Chaban-Delmas Bridge in Bordeaux France is designed to carry four lanes of traffic, two sweeping pedestrian and bicycle paths and two light rail tracks. The unique design build process successfully drove a fierce competition resulting in several dramatic designs. This paper will focus on some of the innovative techniques that would not be permitted by North American design standards.
Barriers to global adoption of Eurocode 3 and 4
Authors: Hicks Stephen , Uy Brian , Kang Won-Hee
Published: March 2016

In 2010 the structural Eurocodes replaced the equivalent national standards in all EU member states. As a result of this, many other countries around the world that have historical connections with the UK are now adopting the Eurocodes as their national standards. For steel construction, adoption is proving challenging in these countries. This paper describes the different approaches that are being used in the Asia-Pacific region.
Visual Project Organization
Authors: Seitz Peter
Published: March 2016

Highly complex projects concerning large, demanding, construction tasks require planning teams that are continuously growing bigger. For a project to be successful it is important that the core information is re- ceived by every party working on the project. Comprehensive project manuals or project descriptions can- not constantly be read by them due to the limited amount of time they have. This article shows methods on how to support the most important information on the project by publicizing graphs showing the optimal flow of information within the project team.
Report of an Unexpected Vortex-Induced Vibration in an Actual Suspension Bridge
Authors: Hwang You Chan , Kim Sun Joong , Kim Ho Kyung
Published: March 2016

An unexpected vibration was observed on the Yi Sun-sin Bridge on October 26th, 2014. Since the bridge was subjected to a single mode vibration in limited amplitude for one and half hours, it was regarded as a vortex-induced vibration (VIV). Since the bridge was aerodynamically well designed for the VIV as well as flutter instability, the cause of the vibration was investigated via a series of two-dimensional wind tunnel tests. The one-side lanes were closed to traffics and the epoxy- coated wearing surface was being replaced at the time of the VIV. Since the primary source was estimated as the temporal screens applied on the bridge railings for maintaining curing temperature of the replaced wearing surface, wind tunnel tests were carried out for the section model of the deck section with and without the screens. This paper presents the screen effects on VIV of the investigated bridge and the illustration of the observed vibration based on in-depth investigation with a series of two-dimensional wind tunnel.
A procedure for prioritizing seismic risk reduction of load bearing masonry structures
Authors: De La Harpe Charlie H. W. , Wium Jan A.
Published: March 2016

Densely populated areas are subjected to significant risk if buildings are not designed for potential seismic events. This paper presents an approach for prioritizing the allocation of funds for seismic risk reduction of unreinforced masonry apartment facilities. The outcome would enable public authorities to decide where available funds should first be allocated for seismic risk reduction of such facilities.

The approach includes not only the structural capacity of the building, but the availability of emergency services, recovering potential of the community, and other factors. These were identified through discussions with local authority officials, through evaluation of previous studies on disaster risk management, and through examination of structural design code requirements.

The proposed model uses principle factors with weights identified from literature. Sub factors are defined and weighted with input from industry sources. Indicators identified from various sources are used as basis to score sub factors in an evaluation.
Structural Fire Assessment of Concrete Filled Steel Hollow Sections
Authors: Negrisoli Giorgio , Stefanaki Kalliope , O'Connor Mark
Published: March 2016

Concrete filled hollow steel (CHS) members offer a number of benefits and are often used in tall buildings and other industrial structures. In this case the behaviour of the concrete filled hollow section is investigated as a component of a restrained diagrid truss system at the fire limit state.

Firstly, a FE solid model was developed and used to investigate the thermo-mechanical interaction of the composite member under fire loads. The results were used to develop a simplified representation of the member which could be included within a global model of a diagrid truss system and analysed under many different scenarios.

The purpose of this paper is to discuss the innovative methodology used, and the results obtained within the detailed analyses to study the inherent capacity of the diagrid structure with no additional passive fire protection.
Tools for Measuring a City’s Resilience in a Fire Following Earthquake Scenario
Authors: Elhami Khorasani Negar , Gernay Thomas , Garlock Maria
Published: March 2016

The paper provides a framework to evaluate the response of buildings in a community subject to fire following earthquake. First, a model is developed to determine the probability of ignition in buildings of a community due to an earthquake. Second, fragility functions are developed for buildings subject to fire, to quantify the structural damage and the expected losses. The ignition model, combined with the fragility functions, can be implemented in a GIS based risk management platform to evaluate economical losses in a region from fire following an earthquake.
A Toolkit for Structures Asset Management
Authors: Hickey Ray , Mikhaylov Sergey , Hesketh Oriana , Tachtsi Lila , Berry Steve
Published: March 2016

Maintaining infrastructure is challenging for asset owners, who make complex decisions on investment planning and prioritisation of maintenance spending. The use of tools to analyse data provides a repeatable and auditable evidence base to support decision making. The Structures Asset Management Planning Toolkit allows asset owners to carry out lifecycle planning, works prioritisation and calculates asset value to meet financial reporting obligations. The toolkit is one of the few tools that performs calculations at component level: taking into account external factors (environment, traffic levels, etc.), as well as the condition of other components within a structure to estimate the rate of deterioration. The toolkit includes over 300 deterioration profiles, is widely used in the UK and considered the de-facto standard.
A local, data-based approach for SHM-based point ranking of bridges
Authors: Andersen Jacob , Alcover Isaac
Published: March 2016

The present paper presents a conceptual approach to combine, via a point ranking method, monitoring data with data arising from visual inspections, in order to maximize the outcome of information used to operate and maintain bridges. Firstly, an overview over current approaches for interpreting monitoring data is given as well as an overview over Operation and Maintenance (O&M) strategies. Then, two examples are shown to illustrate how monitoring data can be used for predicting remaining life of key bridge components such as welded joints or movable joints. Finally, a conceptual approach is outlined describing how monitoring information in terms of the estimated remaining lives can be combined with inspection data via Point Ranking methods to enhance inspection and maintenance planning and budgeting, hence contributing to bridge the gap between Structural Health Monitoring (SHM), visual inspections and bridge management (O&M) strategies.
Traffic Load Effect Forecasting for Bridges
Authors: Leahy Cathal , Obrien Eugene , O'Connor Alan
Published: March 2016

Traffic flows, as well as truck weights, increase with time. This must be taken into account in order to accurately assess traffic loading on bridges. The Eurocode Load Model 1 is used for the design of new bridges but a scaled down version of the model can be used for the assessment of existing bridges. This scaling is usually done by applying α–factors to the load model. The effect of traffic growth on these α–factors is assessed in this paper. Weigh-in-motion data from the Netherlands is used as the basis for traffic models which simulate year-on-year growth of both traffic flow and truck weights. A time-varying generalised extreme value distribution is then used to calculate the characteristic load effects and determine the α–factors. The effect of different traffic growth rates on these α–factors is then examined. It is found that an increase in truck weights has the most influence on the α–factors but that increased flow also has a significant effect.
Limit analysis for civil engineering structures
Authors: Arquier Mathieu , Cespedes Xavier
Published: March 2016

The analysis of ultimate limit state (ULS) of a structure requires a stability study until failure. This mechanical behaviour is complex to compute with standard tools. Cracking, damage, elastic-plastic law, etc., are phenomena which often lead to numerical problem of convergence and interpretation of results. It is therefore often advised to use codes instead (Eurocodes, AASHTO, etc.), but this solution comes at the expense of accurate analysis of the physical behaviour of failure. An alternate solution is limit analysis, which combines two parallel and complementary methods. Used on a finite element mesh for rigid-plastic calculations, these two methods lead to a full determination of the physical failure: mechanism, stresses distribution and safety factor. Strains presents a software program using limit analysis for steel beam connections nodes, taking into account such phenomena as contact, separation, friction, welding, plasticity and pre-stressed bolts.
Rehabilitation of transportation infrastructures: the potential of new materials
Authors: Nabaei Sina , Nendaz Sébastien
Published: March 2016

In Switzerland, a considerable number of transportation infrastructure rehabilitation projects are expected till 2020. In this new context of mobility, rehabilitation projects have become increasingly complex under various constraints, such as the traffic maintenance under reconstruction and the rapid facility delivery with the minimum cost. This paper brings insights from our practice on how new technologies such as the Ultra-High Performance Fiber Reinforced Concrete (UHPFRC) and the fiber composite sandwich decks could be leveraged for the best satisfaction of these macro constraints. The assessment is based on two criteria of the facility delivery time and the traffic control under reconstruction. The application of UHPFRC is discussed both as a waterproofing layer integrated to the pavement layout and also as a promising reinforcement technology for concrete deck rehabilitation. A project is also reviewed highlighting a fiber composite sandwich deck as a replacement solution enhancing a rapid facility delivery.
Strengthening the Chillon viaducts deck slabs with reinforced UHPFRC
Authors: Brühwiler Eugen , Bastien-Masse Maléna , Mühlberg Hartmut , Houriet Bernard , Fleury Blaise , Cuennet Stéphane , Schär Philippe , Boudry Frédéric , Maurer Marco
Published: March 2016

Located in Switzerland, Chillon viaducts are two parallel highway posttensioned concrete bridges built in the late 1960s. The concrete of the deck slabs of these bridges shows signs of early stages of the alkali-aggregate reaction (AAR), which will induce, in time, a decrease of the concrete strength. To insure structural safety for future traffic demands, it was decided to strengthen the slab by adding a layer of 40 mm of an Ultra High Performance Fiber Reinforced cement-based Composite (UHPFRC) material, reinforced with steel rebars. Strain-hardening UHPFRC, with its low permeability, is used as a waterproofing layer protecting the slabs from the water to reduce the rate of AAR. UHPFRC has excellent mechanical properties and also acts as an external tensile reinforcement for the slab, increasing its bending and shear resistance and extending the fatigue life. To investigate this increase in structural resistance, an analytical calculation is done using models previously developed based on extensive experimental campaigns. Finally, the choice of UHPFRC for strengthening was also the most efficient in terms of intervention duration and cost.
Feasibility of an Intelligent Bridge Integrated with the Smart Monitoring System
Authors: Miyamoto Ayaho , Motoshita Minoru
Published: March 2016

This paper introduces an approach to the realization of an ICT-based bridge remote monitoring system which enables real-time monitoring and control for unexpected heavy loads such as big earthquake and strong typhoon. In this paper, the integrated bridge remote monitoring system called the “Intelligent Bridge” consists of a stand-alone monitoring system (SMS) and a web-based internet monitoring system (IMS) for bridge maintenance but also its application to intelligent bridge system as an intelligent structure. For the purpose of verifying its validity to actual bridge structure, an attempt is made to study the possibility of controlling the actual structural performance by adjusting the cable forces on a 2-span continuous cable-stayed bridge model. The experimental results demonstrate that the implemented monitoring system supplies detailed and accurate information about bridge behavior for further evaluation and diagnosis, and it also opens up prospects for future application of web-based remote system to actual in-service bridges under field conditions.
Monitoring of a Large Railway Arch Bridge
Authors: Geier Roman , Mack Thomas , Petraschek Thomas
Published: March 2016

During the partially reconstruction of the Pyhrn railroad line from the Austrian Federal Railways between Linz and Selzthal instead of the old Steyrtalbridge from 1905 a new arch bridge over an storage reservoir was built in 2014. The new bridge is built in reinforced concrete with a length of about 180m. The design of the structure was determined by the rail-track-interaction as it was essential to avoid using rail expansion joints as expensive and maintenance-intensive components. For this reason, extensive measurements should provide information on the structural behavior and are compared with the assumptions and results of the structural analysis. In addition to measurements during an initial loading test the structural behaviour over the seasonal cycle should be determined by measurements. The installed monitoring system stores data since November 2014.
Improved safety verification of existing bridges using monitored data
Authors: Treacy Mark , Brühwiler Eugen
Published: March 2016

Conventional safety verification of existing bridges generally incorporates a combination of visual inspections and structural analysis based on a specified traffic load model, which can be significantly different to the local site traffic. In addition, assumptions regarding the mechanical properties of the various construction materials are generally obtained from codes or test data, which are also subject to much uncertainty. Monitoring of the structural behaviour of bridge elements now offers a viable compliment or even alternative to analytical calculations. This paper presents real case study bridges, where data from monitoring has been explicitly used to better understand the action effect behaviour and to verify the structural safety. A number of novel data treatment techniques are introduced for evaluation of extreme and fatigue damaging effects.
A modified bang-bang control for MR damper and experimental validation using RTHS
Authors: Li Xin , Lu Xilin , Cui Ye , Dyke Shirley
Published: March 2016

Magneto-rheological (MR) damper, an effective semi-active control device has been used for response reduction of structures in civil engineering. This paper presents a modified bang-bang control algorithm for an earthquake excited structure using MR damper. This controller was developed based on linear quadratic Gaussian (LQG) controller and Kalman filter. The performance of the proposed controller was evaluated by comparing with four controllers for the control of a three story structure with one MR damper on the first floor. These four controllers are (1) clipped optimal controller; (2) decentralized Bang-Bang Controller; (3) passive control with a constant 0 volts; (4) passive control with a constant 3 volts. Real-time hybrid simulation (RTHS) tests were given to illustrate the application and effectiveness of the proposed modified bang-bang control strategy. Overall, the proposed controller is quite competitive as compared with above controllers in terms of reduction in the maximum inter-story drifts, displacements, absolute accelerations, and control forces.
Control Strategies for Active Vibration Control via Twin Rotor Damper
Authors: Bäumer Richard , Starossek Uwe
Published: March 2016

The twin rotor damper (TRD) is an active mass damper. It comprises a pair of eccentric masses that rotate about parallel axes. In a preferred mode of operation, the continuous rotation mode, the two masses rotate with constant angular velocity in opposite directions. The resultant of the induced centrifugal forces is a directed harmonic force that can be used for damping. In previous theoretical work, a control algorithm for the continuous rotation mode was developed. However, when the vibration amplitudes become small, this control algorithm does not lead to the desired constant motion of the rotors. The TRD can even re-excite the motion of the system instead of damping it. Various approaches can be used for preventing these undesired effects. For instance, a second identical TRD unit can be added. When the vibration amplitudes are large, both units work in unison and damp the motion. When the vibration amplitudes become small, a phasing is introduced between the two units so that the control forces of both units more and more neutralize each other. Control strategies implementing this and an alternative approach have been developed and proven experimentally.
Accelerated Bridge Construction using Ceramic Concrete Slabs
Authors: Tassew Samson , Lubell Adam
Published: March 2016

Recent adoption of Accelerated Bridge Construction approaches have typically focussed on intensive pre- fabrication of reinforced concrete components using traditional construction materials and techniques, later joining the components in place after erection. To further optimize this construction approach, there exists a strong need to use alternative construction materials that can both simplify and enhance the efficiency of the pre-fabrication and joining processes. Phosphate cement binders used in ceramic concrete have long been recognized for their rapid strength gain, excellent dimensional stability and superior ability to chemically bond across construction cold joints compared to concretes produced with Ordinary Portland Cement binders. To this aim, laboratory studies were completed to examine the feasibility of utilizing ceramic concretes produced with phosphate cement binders for full- and partial-depth precast bridge deck slab applications. Six slab strips were fabricated and tested with similar overall dimensions but which varied according to their layered slab composition and the fabrication techniques. Specimens had cross-section dimensions of 200 x 150 mm high and were tested in 4-point bending over a span of 1800 mm. Compressive strengths of the ceramic concrete ranged from 23 to 43 MPa. Reinforcement included conventional deformed steel bars and, in some cases, glass textile fabrics near the tension face intended to better control surface cracking. The primary interest in the test program was to study the stiffness, strength and cracking behaviour of the slab strips. The results demonstrated that specimens cast in layers with intentional inter-layer cold joints had similar performance to those cast monolithically, but splitting cracks were observed along interfaces between fiber-reinforced and non-fiber reinforced concrete layers at higher shear stresses due to the reinforcement configuration and the multi-layer casting. Further study of the structural response of the slabs was completed using a developed analytical model that directly incorporated the mechanical properties of the material obtained through testing. The cross-section response and full-member flexural response predicted by the model were in good agreement with the test specimen results for the parameters studied. Overall, the tests confirm the viability of the proposed prefabricated ceramic concrete slabs for use as part of an Accelerated Bridge Construction system.
Early-Age Compressive and Tensile Strength Gain of a Locally Developed UHPC
Authors: Manning Mark P. , Giesler Andrew J. , Weldon Brad D. , Jáuregui David V. , Newtson Craig M.
Published: March 2016

Ultra-high performance concrete (UHPC) mixture proportions have been developed consisting of materials local to the state of New Mexico, USA. Researchers and precasters have been working together to implement the locally developed UHPC in a precast facility and establish economic and efficient mixing, casting, and curing procedures for production of prestressed structural members. This study investigates the development of two mechanical properties within the curing period: compressive strength and flexural tensile strength. The introduction of steam curing and high strength steel fibers is used to develop ultimate compressive strength in excess of 138 MPa and increased flexural tensile capacity. Specimens were tested at regular intervals in compression and four-point flexure to investigate early age strength gain, providing evidence to support earlier strand release and facilitate a more efficient precast process to ensure economic use of UHPC.
Effect of Surface Preparation and Curing Method on Bond Strength between UHPC and Normal Strength Concrete
Authors: Hong Sung-Gul , Kang Sung-Hoon
Published: March 2016

This study investigates the bond strength of UHPC-to-Normal Strength Concrete (NSC) interface. Bond efficiency between new and old layer is key factors for the performance of composite structures. In this study, old layer is made using UHPC to develop permanent formworks for concrete structures. To investigate the bond strength, cube shaped UHPC-NSC composite specimens are prepared and tested according to the direct-shear and splitting tensile test methods. The test variables are surface conditions and curing methods. The surface conditions include surface roughness and moisture content of UHPC, the curing methods include the curing period, temperature and relative humidity of the specimens. The test results show that the rough and grooved surfaces of UHPC increase the bond strength of the specimens in comparison to the smooth surface of UHPC. The bond strength is also influenced by the curing method of UHPC.
arcoBridge – Low cost FRP Bridges for mainstream applications
Authors: White Simon C. , Price Natalie , Rajamanie Nikesh , Wise Ian , Feltham Ian , Trim Roland
Published: March 2016

Arup are developing arcoBridge, a new modular glass fibre reinforced polymer (GFRP) footbridge designed with a view to accessing the UK rail market. The bridge’s unique modular and post- tensioned design has several advantages over existing steel, concrete and composite designs. Compared to Steel and Concrete, the lightweight bridges require smaller cranes and can be transported to sites with difficult access without costly haul roads. Arup’s initial costs are lower than other GFRP options due to the smaller tooling, QA and workshop size requirements.

The bridge has been designed with a design-for-manufacture philosophy. Working in sympathy with the materials has led to a number of novel design features for a GFRP bridge. These include the incorporation of a post-tensioning system and a patented shear joint design. These features create a stress-state dominated by compression, thus simplifying the design process considerably.

In this paper an overview of the on-going design and testing work is presented, as Arup work towards delivering a 15m span prototype in September 2015. It includes a description of arcoBridge’s novel design features and the laboratory testing that has been performed as validation to date. Further, the paper explains a novel technique, involving full scale factory testing of the first bridge built by each supplier to enable the GFRP structure to be supplied conforming to Eurocode reliability. This is possible even without a published code for this material.
An innovative hybrid GFRP-concrete footbridge structure
Authors: Gonilha José A. , Correia João R. , Branco Fernando , Martins David , Fernandes Lourenço A. , Barros Joaquim , Sena-Cruz José
Published: March 2016

Glass fibre reinforced polymer (GFRP) materials, and GFRP pultruded profiles in particular, have been pointed out as a long-life alternative to traditional structural materials owing to their high strength, low weight, ease of erection, corrosion resistance and low maintenance costs. However, some of the disadvantages inherent to these materials, such as their brittle failure and low elasticity and shear moduli, have limited their widespread use. In addition, these properties seldom allow the full exploitation of the materials’ strength, their design being often governed by deformability limits or instability phenomena.

In order to overcome the aforementioned limitations, several authors have proposed hybrid structural solutions, in which GFRP components are combined with concrete elements, typically used as compression laminas.

This paper presents the development, construction and testing of an innovative hybrid GFRP- concrete footbridge structure, with a length of 11.0 m, comprising two I-shaped GFRP pultruded profiles as main girders and a thin steel fibre reinforced self-compacting concrete (SFRSCC) deck. The use of the SFRSCC material in the compression lamina allowed for the construction of a very thin deck (37.5 mm), owing to its high strength and ductility in tension when compared to traditional concrete, avoiding the introduction of any rebar reinforcement in the deck. This innovative hybrid bridge concept allowed combining the advantages of GFRP structures (in particular maintaining the lightness and durability), while reducing the overall deformability.

The footbridge was characterized experimentally by means of (i) static tests, (ii) modal identification tests, (iii) dynamic tests under pedestrian actions, and (iv) creep tests. The experimental results, in particular those regarding the structural response under pedestrian actions, showed the adequate behaviour of the structure for footbridge applications and demonstrated the feasibility of the structural concept proposed. Additionally, the experimental tests were simulated with current analytical and numerical models, showing that these are adequate tools for the design of hybrid GFRP-concrete structures.
Construction of Humber Bridge A-Frame rocker bearing replacement
Authors: Collins John , Hornby Richard , Smith Daniel , Hill Peter , Webb John
Published: March 2016

Bearings connecting the 1410 m main span deck box to the towers of the Humber were heavily worn. A challenging £4m (US$6.3m) replacement scheme including significant temporary works was implemented. All works to this landmark structure took place with the bridge open to traffic.
Development of the structural system with steel frame and wooden floor-Connection method of steel beam and wooden floor
Authors: Kuratomi Yo , Inada Tatsuo
Published: March 2016

The authors propose to replace a reinforced concrete (RC) slab with a cross-laminated timber (CLT) floor panel as a method to increase the use of timber in moderate- or large-scale buildings. The advantages of using CLT floor panels are as follows: 1) the weight of the building is reduced, 2) an environmental value is established, 3) forest resources are effectively utilized, and 4) there is a contribution in solving the global environmental problem. A floor effects the enhancement of flexural stiffness and strength of steel beams; hence, for a robust building structure, the authors must focus on and dynamically solve all structure performance problems. In addition, it is necessary to investigate the method of connection of steel beams and CLT floor panels. Push-out shear tests and pure bending tests were conducted to investigate the structural performance of CLT and composite steel beams. The test results indicated that the CLT and steel composite beam showed good structural performance.
Effectiveness of Techniques for Seismic Strengthening of RC Frame Buildings
Authors: Tsionis Georgios , Apostolska Roberta , Taucer Fabio
Published: March 2016

The techniques for seismic strengthening of reinforced concrete buildings, namely steel braces, masonry infills and shear walls, are reviewed with the aim of assessing their effectiveness for the increase of global strength and stiffness and energy-dissipation capacity, and for providing guidance to designers regarding the most appropriate solution for practical applications. Although the results obtained by extensive experimental testing and numerical analyses of elements and structures present large scatter, they show that the highest performance improvement is provided by shear walls, followed by braces and infills. The review also highlights the issues that remain open in view of the development of design guidelines; the most important are the development of design tools and detailing rules for the connection between new and existing elements.
A repair and retrofitting intervention to improve plastic dissipation and shear strength of Chinese rc bridges
Authors: Lavorato Davide , Santini Silivia , Nuti Camillo , Briseghella Bruno , Xue Junqing
Published: March 2016

In this paper a rapid repair and retrofitting technique for reinforced concrete (rc) Chinese bridges damaged by a strong earthquake, is proposed and tested. This intervention is an upgrade of the one tested with very good results during a previous experimental research on bridges designed according to the old Italian code without proper seismic details. The improvement of the repair operation consists in the use of dissipation systems to substitute the damaged rebar parts at pier base guaranteeing the correct plastic distribution in plastic hinge only. Dissipation systems with different configurations were considered to optimize the intervention. The repaired and retrofitted Italian bridge already studied in the previous research, was designed according to Chinese codes but with insufficient transversal steel reinforcement. Some pier specimens (scale 1:6) of the most stressed pier of this bridge, with and without dissipation systems, were built. A C- FRP wrapping was applied to increase the insufficient shear strength and the ductility in plastic hinge. Cyclic tests were carried out on the scaled specimens at Fuzhou University lab (China) to evaluate the effectiveness of the proposed technique.
Developing a Basis for Design – Embodied Carbon in Structures
Authors: Sarkisian Mark , Horiuchi Christopher , Shook David
Published: March 2016

A basis for design must be established to account for the embodied carbon in a structure. Minimum acceptable goals must be created to encourage a responsible approach to structural design—one that accounts for carbon emissions from groundbreaking through the building’s service life. This should be considered in parallel with carbon emissions resulting from operation of the building and embodied carbon of non-structural components.

An advanced methodology and tool termed the Environmental Analysis Tool™ has been published that evaluates embodied carbon of structural systems in buildings through construction and expected service life. An evaluation of embodied carbon of structural systems in over 200 built structures has revealed trends and correlations among common design parameters such as building height, occupancy type, seismic and wind conditions. Results such as these can be utilized by designers to set design goals, and to form a basis for incentive programs and codification.

Based on the investigation of the above mentioned data set and carbon accounting efforts of built structures, a proposal for embodied carbon limits of new and existing structural systems is proposed.
"China Zun" Tower: Pushing the Limits to Chinese Practice
Authors: Liu Peng , Yu Cheng , Liu Yun Bo , Citerne Dorothee
Published: March 2016

The “China Zun” tower Beijing reaches 528m high and will be the tallest building in Beijing once built. Inspired by an ancient Chinese vessel “Zun”. The plan dimensions reduce gradually from bottom to the waist and then escalate bigger as it approaches to the top to form an aesthetically beautiful and unique geometry. To satisfy the structural requirement for seismic and wind resistance. The structure is a dual system composed of the perimeter mega structure which is made of composite mega columns, mega braces and belt trusses, and the reinforced-concrete core with steel plate embedded walls. Advanced parametric design technology is applied to find the most efficient outer perimeter structure system. The seismic design basically follows a hybrid empirical and performance-based methodology which was verified by the shaking table test and other specimen lab tests.
Wikihouse 4.0: Towards a smart future
Authors: Smith Stuart
Published: March 2016

This paper discusses the advances made on the experimental housing project, Wikihouse 4.0, built at The Building Centre in Store Street, London as part of the London Design Festival in September 2014.

The key themes of the project were to develop a design that could be made freely available online for others to download from which they could print and assemble their own home using readily available materials with only modest professional skills.