The following are summaries of papers published in other parts of ICE Proceedings during 2003 that readers of Structures and Buildings may find of interest. You can get copies of individual papers emailed or posted to you for £5 or faxed to you for £2 a per page from the ICE library (telephone +44 (0) 20 7665 2251; fax +44 (0) 20 7976 7610; e-mail library@ice.org.uk). In all cases you need to complete a copy request form which can be downloaded from the ICE website at www.ice.org.uk. Summaries of all papers in ICE journals are also freely available and fully searchable at the ‘journals on-line’ section of the ICE website at www.ice.org.uk.
Gateshead Millennium Bridge, UK: fabrication, assembly and erection
K. Butterworth, D. Carr and P. Kassabian
Proceedings of the Institution of Civil Engineers—Bridge Engineering, 2003, 156, March, 11–19
On 20 November 2000 the Gateshead Millennium Bridge was lifted into place, in one, over the UK's River Tyne. The spectacular nature of the bridge design—the world's first vertically rotating bridge—and the audacity of the erection scheme attracted large crowds and significant publicity. The bridge currently takes its place as part of the regeneration of the Gateshead Quayside. This paper describes the fabrication and erection of the bridge structure by Watson Steel.
Weathering steel bridges
C. N. Dolling and R. M. Hudson
Proceedings of the Institution of Civil Engineers—Bridge Engineering, 2003, 156, 39–44
Weathering steel is a high-strength, low-alloy steel that in suitable environments forms an adherent protective rust ‘patina’, to inhibit further corrosion. The corrosion rate is so low that bridges fabricated from unpainted weathering steel can achieve a 120-year design life with only nominal maintenance. Hence a well-detailed weathering steel bridge in an appropriate environment can provide an attractive, very low maintenance, economic solution in many locations. This paper highlights the benefits of weathering steel bridges, describes the limitations, and comments on both the material availability and the appearance of such bridges. It also provides advice on a range of issues including design and detailing, fabrication and installation, inspection and maintenance and remedial measures, should corrosion rates exceed those anticipated at the design stage.
Dynamics of the Hungerford Millennium footbridges, UK
M. S. Fletcher and J. S. Parker
Proceedings of the Institution of Civil Engineers—Bridge Engineering, 2003, 156, June, 57–62
Hungerford Bridge Millennium Project in London, UK—a complex seven-span multi-cable-stayed structure—was under construction at the time of the oscillations of the nearby Bankside Millennium Footbridge. The design criteria and methods of calculation used to assess oscillation and displacement are described. The results of physical testing of the bridge by mechanically induced vibration and by a walkover test are compared to the calculated values. The calculations predicted performance in service with adequate accuracy. Measurement of structural damping during the physical tests indicated that it was lower than expected.
Analyses of a composite bowstring truss with tension stiffening
R. P. Johnson
Proceedings of the Institution of Civil Engineers—Bridge Engineering, 2003, 156, June, 63–70
Several methods of elastic global analysis of the deck structure of a composite bowstring truss bridge were explored, to find how best to represent tension stiffening of the concrete without iterative calculation, and to check the design of the shear connection. Strut-and-tie models for the behaviour in in-plane shear were found to be unsuitable. The recommended method is based on the model for tension stiffening given in Eurocode 4: Part 2, and represents the deck slab as a Vierendeel truss. Results are compared with those from ‘uncracked’ and ‘fully cracked’ models.
Section model tests on human–structure lock-in
A. McRobie, G. Morgenthal, J. Lasenby and M. Ringer
Proceedings of the Institution of Civil Engineers—Bridge Engineering, 2003, 156, 71–79
In June/July 2000, shortly after the opening of the London Millennium Bridge, experiments were undertaken on a full-scale section model built to represent a footbridge swaying under pedestrian action. The processes of human–structure interaction and the phenomenon of phase synchronisation were investigated. Various instabilities were observed using 3D motion capture equipment, and lateral forces were inferred from the dynamic response of the rig. Implications for footbridge design are discussed. Of particular concern is the possibility of vertical synchrony. In lieu of detailed experimental data, it is recommended that the existing footbridge stock be surveyed with respect to a dimensionless group, analogous to the Scruton number of wind engineering, for each mode (horizontal, vertical, torsional or general). A graph of an equivalent mass per unit area against frequency could be of use to designers in assessing new designs against the performance of existing structures.
Real strength of high-performance concrete bridge deck slabs
S. E. Taylor, G. I. B. Rankin and D. J. Cleland
Proceedings of the Institution of Civil Engineers—Bridge Engineering, 2003, 156, June, 81–90
Deterioration of bridge deck slabs due to corrosion of reinforcement has become increasingly evident over the past 40 years and continues to be the cause of costly repair programmes. Detailing to reduce the risk of corrosion is simpler if the percentage of reinforcement is low. It is now recognised that laterally restrained slabs exhibit strengths far in excess of those predicted by most design codes. This increase in strength can be attributed to arching or compressive membrane action (CMA), and by recognising it in design, lower percentages of reinforcement can be specified. CMA has been incorporated into a small number of design standards. However, problems still exist in translating the arching theory into slabs in practice. The problem is in the assessment of the degree of external lateral restraint inherent in slab structures. This paper presents the results of tests on eight one-third-scale bridge deck edge panel models with target compressive strengths of 100 N/mm2. The test programme aimed at realistically modelling the restraint conditions intrinsic in the edge panel of a real bridge deck slab. A method for assessing the real restraint in such a slab was incorporated into an existing arching theory by using an effective slab width concept. The procedure showed good correlation with the test results and with other results reported in the literature.
Seismic response analysis of long-span steel arch bridges
A. S. Nazmy
Proceedings of the Institution of Civil Engineers—Bridge Engineering, 2003, 156, June, 91–97
The non-linear seismic behaviour of tied, half-tied, and deck-type long-span steel arch bridges is investigated using two-and three-dimensional analytical models. A non-linear time-history analysis, which includes all possible sources of geometric non-linearity, was performed on all models studied. The seismic response of the two-dimensional and three-dimensional models of each bridge type was compared, and the effect of the vertical component of ground excitation was evaluated. Furthermore, the response to synchronous and non-synchronous ground excitation was computed and compared for each bridge type. The study emphasises the importance of performing three-dimensional analysis for all arch bridge types in capturing the effect of coupling among vertical, lateral, and torsional motions. It concludes that the vertical component of ground motion has limited effect on the bridge response, especially for the half-tied and deck-type steel arch bridges, and that non-synchronous ground excitation could increase the member forces considerably, except for tied arch bridges.
Experimentally-based assessment of masonry arch bridges
P. J. Fanning and T. E. Boothby
Proceedings of the Institution of Civil Engineers—Bridge Engineering, 2003, 156, September, 109–116
This paper presents a summary of a continuing research programme intended for the development of generally applicable assessment procedures for masonry arch bridges, for which the assumptions and assessment results can be justified by experimental observations. The research is being undertaken in three phases. Phase I consists of experimental testing of bridges under service loads for the purpose of observation of bridge behaviour. A further purpose of the experimental programme is to provide data for the validation of three-dimensional non-linear finite-element models. In Phase II, three-dimensional non-linear finite-element models capable of capturing the principal features of the bridge response, based on a prescribed procedure and using standardised values of strength and stiffness, were developed. In Phase III the application of a two-dimensional model for the assessment of stone masonry bridges was considered. The assessment method used is based on a prescribed procedure using standardised values of strength and stiffness, which can be implemented in any general structural analysis programme. This phase also included a comparison of the proposed assessment method with other methods in common use.
Dynamic measurements on bridges: design, rehabilitation and monitoring
Á. Cunha, E. Caetano, R. Calçada, G. De Roeck and B. Peeters
Proceedings of the Institution of Civil Engineers—Bridge Engineering, 2003, 156, September, 135–148
This paper aims to stress the relevant role that the experimental assessment of the dynamics of bridges can play during the phases of conception and design, construction, reception, rehabilitation and monitoring (temporary and long-term). The importance of the experimental approach in these phases is essentially derived from experience gained from involvement in dynamic tests on several bridges: the Jindo (South Korea), Infante D. Henrique, Vasco da Gama, Luiz I (Portugal) and Z-24 (Switzerland) bridges.
Synchronised pedestrian excitation of footbridges
T. M. Roberts
Proceedings of the Institution of Civil Engineers—Bridge Engineering, 2003, 156, December, 155–160
A simple theory, based on the governing differential equations of motion, has been developed for predicting the critical number of pedestrians likely to induce synchronised lateral excitation of footbridges. Detailed prescription of the lateral forces, produced by pedestrians synchronising their motion in response to lateral accelerations of the bridge, is not required. The theoretical prediction is compared, and shows close agreement, with the results of full-scale tests on the London Millennium Footbridge.
An integral composite bridge of high skew
B. Bell
Proceedings of the Institution of Civil Engineers—Bridge Engineering, 2003, 156, December, 191–198
At Killsharvan, west of Julianstown, Co. Meath, the new M1 between Dublin and Belfast crosses the River Nanny. Although only about 6 m wide in the summer, the river floods the adjacent fields during the winter. With the advent of the embankment carrying the new dual two-lane (future three-lane) motorway, the river has been widened, trained between sheet piled walls 20 m apart. Owing to the 48 degrees of skew and the 2·5 m allowance for footpaths each side, the span of the bridge is 40 m. A three-span multi-cell in-situ concrete bridge formed part of the contract awarded to Siac-O'Rourke Joint Venture. The central span was arch-shaped, 2·5 m deep at the sides and 1·25 m deep at the centre. The river was expected to flood to the underside of the ‘arch’ at its sides. As part of a value engineering proposal, an alternative integral bridge was offered by the contractor, of composite construction. The paper describes the features of the bridge, some of them unusual.
Gateshead Millennium Bridge—an eye-opener for engineering
J. Johnson and P. Curran
Proceedings of the Institution of Civil Engineers—Civil Engineering, 2003, 156, February, 16–24
The Gateshead Millennium Bridge over the River Tyne in north-east England is an unique tilting bridge for pedestrians and cyclists. Opened by the Queen in May 2002, the inspirational 105 m span structure subsequently became the first bridge to win the Royal Institute of British Architect's 2002 Stirling Prize for ‘building of the year’. This paper provides an overview of what has become known as the ‘blinking eye’ bridge and of the processes adopted to achieve and deliver it—not least the spectacular superstructure installation.
Downland gridshell—an innovation in timber design
R. Harris, O. Kelly and M. Dickson
Proceedings of the Institution of Civil Engineers—Civil Engineering, 2003, 156, February, 26–33
Innovations in timber construction are relatively rare these days. However, a modest utility building at an open-air museum in Sussex has attracted worldwide attention for the novel featrues of its double-layer timber gridshell roof. Apart from being the first such structure in Britain, it was the first built with ‘optimised’ green oak, the first designed in accordance with the new timber Eurocode and the first to use a new patented node joint system. It sets a new benchmark for lightweight sustainable, cost-effective construction.
Automated construction in Japan
M. Taylor, S. Wamuziri and I. Smith
Proceedings of the Institution of Civil Engineers—Civil Engineering, 2003, 156, February, 34–41
Over the last 20 years the concept of automating construction and civil engineering operations has become a reality within Japan, resulting in improvements in site safety, efficiency and productivity. Examples renewed in this paper include concrete finishing, material handling, earthworks and integrated construction automation systems. However, the paper concluded that construction environments need to be much more structured and controlled before construction robots can really start to take over.
Briefing: A new focus for structural integrity
M. Burdekin
Proceedings of the Institution of Civil Engineers—Civil Engineering, 2003, 156, May, 58
Structural integrity engineering has been vital to the offshore, nuclear and aircraft industries for many years but has only recently debuted in general engineering. Mike Burdekin of UMIST reports on the background and role of a new UK forum designed to increase understanding.
Briefing: Permanent formwork—an unknown risk
P. Markham
Proceedings of the Institution of Civil Engineers—Civil Engineering, 2003, 156, May, 59
Profiled steel permanent formwork is commonly used in composite slab construction. However, according to Paul Markham, design engineer with a major contractor, a buck-passing approach to procurement means a major accident is waiting to happen.
Hungerford Bridge millennium project—London
J. Parker, G. Hardwick, M. Carroll, N. Nicholls and D. Sandercock
Proceedings of the Institution of Civil Engineers—Civil Engineering, 2003, 156, May, 70–77
The £50 million Hungerford Bridge millennium project in London provides two stunning new cable-stayed footbridges across the Thames, one on each side of Charing Cross railway bridge. Effectively it recreates Brunel's 1846 suspension footbridge to Hungerford market, the piers of which remain in the railway bridge structure. Heightened fears over unexploded bombs in the river bed led to a major redesign just after work started but a switch to the NEC contract helped ensure a smooth completion.
Electrification of US opening rail bridges
R. Wilson
Proceedings of the Institution of Civil Engineers—Civil Engineering, 2003, 156, May, 86–93
Electrification of the final stretch of the busiest passenger railway in the USA required substantial modification to five existing opening bridges—some nearly 100 years old—to accommodate 25 kV overhead power lines. This paper reports on the development and installation of an innovative, moving catenary system, believed to be the first of its kind in the world, which has breathed new life into an ageing infrastructure.
Briefing: Tall buildings: when will the research begin?
S. Alexander
Proceedings of the Institution of Civil Engineers—Civil Engineering, 2003, 156, August, 102
The terrorist attacks in New York nearly two years ago raised some serious concerns about the safety of tall buildings. Given that high-rise is firmly on the sustainable development agenda, Stuart Alexander of WSP laments the lack of any UK research into how to make such buildings safer.
Briefing: Composite decking—a design responsibility
G. Couchman
Proceedings of the Institution of Civil Engineers—Civil Engineering, 2003, 156, August, 103
Using profiled decking for composite slab construction is perfectly safe provided engineers ensure they have properly thought through their design. Graham Couchman of the Steel Construction Institute also says designers should take care when delegating responsibility for what is an integral part of their work
Crowd-related failure of bridges
B. Wolmuth and J. Surtees
Proceedings of the Institution of Civil Engineers—Civil Engineering, 2003, 156, August, 116–123
Over the past 180 years there has been a significant number of crowd-related bridge collapses around the world. Barring natural disasters or human conflict, they have involved greater loss of life than any other form of structural failure. This paper reviews crowd-related bridge collapses over the years, providing details of geographic and chronological distribution, form of structure, primary materials, imposed loading, crowd behaviour and the extenet of injuries. It concludes that those responsible for bridge design and maintenance must ensure that design details are robust, structures are properly maintained, and crowds are effectively managed.
Halley—at the edge of ice-station design
D. Blake
Proceedings of the Institution of Civil Engineers—Civil Engineering, 2003, 156, November, 168–174
Halley, the 50-year-old Antartic survey station where the hole in the ozone layer was discovered, is by necessity in one of the most inhospitable parts of the earth. Its resident staff are exposed to temperatures down to −55 degrees celsius and winds up to 150 km/h. Everything they build eventually gets embedded in a moving ice shelf. As such, the first four stations were abandoned after ten years or so. The current station, Halley 5, is radically different from the previous designs in that it uses a mix of jackable and ski-mounted structures. However, there is still room for improvement, particularly in regard to energy use, and Halley 6—already on the drawing board—is likely to be a further major step forward in sustainable ice-station design.
Highway bridges and environment—sustainable perspectives
K. Steele, G. Cole, G. Parke, B. Clarke and J. Harding
Proceedings of the Institution of Civil Engineers—Civil Engineering, 2003, 156, November, 176–182
Civil engineering infrastructure is generally maintained in accordance with safety, economic and technical issues. But what of the environmental impact of such activitie? Regular maintenance can have a significant environmental impact—particularly in the case of bridges, where closure can result in traffic jams and lengthy detours. Higher cost but lower maintenance components and transfer of structures to lower-grade sites are possible answers which, until now, have been difficult to assess. This paper reports on a life-cycle assessmetn method developed to factor environmental impact into bridge maintenance strategy. Though developed for bridges, it has potential application throughout the facilities management sector.
Briefing: Sustainable development progress—cement and concrete
D. Collins
Proceedings of the Institution of Civil Engineers—Engineering Sustainability, 2003, 156, June, 75–77
This article discusses the recent strategies employed by the cement and concrete construction sectors in their efforts to further sustainable development.
Briefing: Sustainable steel construction: building a better future
M. Sansom
Proceedings of the Institution of Civil Engineers—Engineering Sustainability, 2003, 156, June 81–82
As part of its commitment to sustainable development, the UK Government is encouraging business to develop sectoral sustainability strategies. The steel construction sector has risen to this challenge and, in December 2002, launched its strategy Sustainable steel construction: Building a better future.
Briefing: Lime versus cement: traditional methods for today's buildings
I. Pritchett
Proceedings of the Institution of Civil Engineers—Engineering Sustainability, 2003, 156, June, 83–85
This article provides a brief overview of lime use in traditional buildings and how the benefits identified in conservation work can be applied to sustainable new build projects.
Briefing: Protocols for alternative materials in construction
M. Reid
Proceedings of the Institution of Civil Engineers—Engineering Sustainability, 2003, 156, December. 175–177
A set of protocols has been developed to illustrate how recycled and secondary aggregates can be used in a range of applications in construction. The protocols cover both engineering and environmental aspects and draw on existing specifications, regulations, legislation and guidance documents.
Settlement prevision of piles under vertical load
F. Castelli, E. Motta
Proceedings of the Institution of Civil Engineers—Geotechnical Engineering, 2003, 156, October, 183–191
This paper presents a simplified non-linear method to predict the behaviour of a single pile and/or a pile group under vertical loads. The evaluation of the non-linear settlement is based on an incremental procedure taking into account the decrease of the stiffness parameters with increase of the applied load. The solution, derived first for a single pile, was extended to the case of a pile group, introducing an equivalent pier interacting with the surrounding soil by means of hyperbolic load transfer functions. To take into account group action in the soil–pile interaction, the stiffness of the equivalent pier has been modified and linked to that of the single pile, and a simple expression is also proposed. The numerical results obtained by the proposed method were compared with measurements derived from full-scale load tests on single piles and pile groups, and it has been shown that this procedure can be used successfully for prediction of non-linear pile group settlement. As the method can be easily coded or solved with the aid of a computer spreadsheet, reasonable predictions can be made without expensive and time-consuming analyses.
A new look at rigid concrete pavement design
B. P. Hughes
Proceedings of the Institution of Civil Engineers—Transport, 2003, 156, February, 29–36
The traditional rigid pavement model has long been firmly established as the design basis for both unreinforced and reinforced (jointed and continuous) concrete pavements. It is well proven and has served designers well for many years. However, the efficacy of pavement designs for joint spacing and reinforcement is less certain. The paper therefore compares design procedures for drying shrinkage and thermal effects for pavements with well-established design procedures for other slab structures including ground slabs and examines how pavement design could benefit from this experience and expertise. The comparisons are both useful and informative and provide a number of proposals that could clearly improve design for the long-term performance of concrete pavements, especially continuously reinforced concrete pavements.
A flood failure flowchart for buildings
I. Kelman, R. Spence
Proceedings of the Institution of Civil Engineers—Municipal Engineer, 2003, 156, September, 207–214
This paper identifies the main pathways by which flood-induced pressure differentials may damage residential properties in England. The process looks beyond slow-rise floods and subsequent damage from water contact in order to consider pressures induced by depth differentials, velocity and waves. A Flood Failure Flowchart is presented which provides first-order insight into the main failure modes which should be quantified in detail. Uncertainties remain due to lack of information and weaknesses in the analysis, particularly the reliance on British Standards which are not currently adequate for designing to mitigate all forms of flood damage. British Standards, possibly in the form of a rating system with guidelines, could nonetheless provide an appropriate mechanism for formalising the vulnerabilities which residential buildings experience from flood pressures. The lack of literature in this area suggests that prior recommendations on flood damage reduction did not necessarily have a strong basis overall because they were bounded to exclude flood-induced pressures. This paper is thus only a first step towards systematically identifying and categorising potential failure modes of residences during floods.
