bluuebunny/crossref_metadata_2025 huggingface dataset:
Role of cement content in specifications for concrete durability: cement type influences
Authors: Dhir R. K. , McCarthy M. J. , Zhou S. , Tittle P. A. J.
Published: November 2009

In this paper, which describes part of a major investigation, the role of cement content in specifications for concrete durability is examined. The main cements considered were (a) Portland cement (PC; CEM I), (b) PC/30% PFA (CEM II/B-V) and (c) PC/50% GGBS (CEM III/A), while other BS EN 197-1 cements were tested selectively. Concretes of fixed w/c ratio (w/(PC + addition) ratio), but with cement contents varying around the minimum values given in standards were evaluated. The workability of concrete with low cement and water contents was controlled with a superplasticiser and the fines content was maintained by the use of ground limestone as a filler. Tests were carried out to examine these effects on the fresh, engineering, permeation and durability properties of concrete. The results show that at fixed w/c ratio, reduction in cement content by up to 22% had no adverse effect on most concrete properties and, if anything, gave some improvement. The various cement types and combinations tested had little effect on the trends observed. Overall, it was concluded that, in addition to minimum strength class and maximum w/c ratio (and in some cases cover depth), specifying minimum cement content for concrete durability was not necessary.
Fundamental tests of reinforced concrete columns subjected to seismic loading
Authors: Sinha S. , Roy L.
Published: November 2009

Past experimental research studies on the strength and ductility capacity of structures showed that the ductility capacity is strongly affected by loading condition. For repeated loading such as earthquake motion, the design based on the strength and ductility factor alone is not always reasonable, and the energy absorption capacity of structures is a better index for evaluating seismic safety. This study quantitatively investigates the energy absorption capacity of reinforced concrete (RC) column subassemblies. Five RC columns were tested under four types of repeated loading. Once the energy absorption capacity is calculated, the structural safety under strong earthquake motion may be judged by the comparison between the energy imparted to the structure by earthquakes and the energy absorption capacity of the structure.
Neural network modelling of creep in masonry
Authors: Reda Taha M. M. , Noureldin A. , El-Sheimy N. , Shrive N. G.
Published: November 2009

Stresses and deformations in concrete and masonry structures can be significantly altered due to creep. However, accurate prediction of creep is difficult due to its dependency on a large number of parameters (e.g. section geometry, relative humidity, stress level, age of loading). This paper introduces a new method based on artificial intelligence to model creep of masonry. Feedforward artificial neural networks (ANN) are investigated as a modelling technique for predicting creep. Experimental data for creep of structural masonry are used to develop the networks. Changes in network architecture are examined to produce prediction models. Fifteen networks are developed and analysed statistically. Creep models with accuracy in the range ± 15% are attainable using ANN.
A remote monitoring system for stadia dynamics
Authors: Reynolds P. , Pavic A. , Ibrahim Z.
Published: November 2009

This paper describes a remote monitoring system that has been developed to acquire large quantities of high-quality in-service vibration data to be used in the development of enhanced guidance for stadia dynamics. The system measures structural accelerations, video of crowd activities and other environmental data. The system is controllable via a broadband internet connection and the data can also be downloaded remotely. It was installed at Valley Parade, Bradford for a period of more than 12 months during which time data were acquired from 20 football and nine rugby matches. A cursory examination of these data has shown that the crowd affects the natural frequencies and damping of the structure and that the changes depend on the configuration of the crowd (seated, standing, etc.). It is anticipated that the data acquired on this and other structures will ultimately be used to understand better the nature of crowd–structure dynamic interaction and the dynamic forces produced by crowds.
Lateral torsion-flexure buckling of corrugated web steel girders
Authors: Sayed-Ahmed E. Y.
Published: November 2009

Resistance to lateral torsion-flexure buckling of steel I-girders with plane webs is a very important design requirement. Codes of practice allow designers to use the critical moment of a simply supported beam subject to a constant moment and relate it to the critical moment of any other loading case via an ‘equivalent moment factor’. On the other hand, the compression flange outstand-to-thickness ratio which controls the flange local buckling is another important design parameter. According to most codes of practice this ratio, together with web-to-thickness ratio, defines the I-section class and compactness. Recently, plate girders with corrugated steel webs have been used in different structural applications and bridges. The girder's flanges provide the flexural capacity with no contribution from its corrugated web which provides the girder's shear capacity. Lateral torsion-flexure buckling and local flange buckling of corrugated web girders still need to be investigated. A numerical analysis based on the finite-element technique was performed on these girders. The critical moment causing lateral instability was numerically determined. The finite-element model results were used to investigate the applicability of the critical moment design equations, currently used for a girder with a plane web, to corrugated web girders. The validity of the equivalent moment factor concept to corrugated web girders was also examined. The numerical model was then used to scrutinise the local buckling behaviour of the compression flange for girders with corrugated webs. The applicability of the currently used limiting values for flange outstand-to-thickness ratio which define the section class to corrugated web girders was also examined.
Revised code provisions for long-term deflection calculations
Authors: Beeby A. W. , Scott R. H. , Jones A. E. K.
Published: November 2009

It is well established that tension stiffening, the contribution of the concrete in tension to the stiffness of a reinforced concrete member, is a significant parameter in deflection calculations and this is recognised by design codes such as BS 8110 and Eurocode 2. These codes make provision for tension stiffening effects and also distinguish between short- and long-term behaviour. What is not known, however, is how rapidly tension stiffening decays with time or how significant this rate of decay might be for deflection calculations. This paper reviews the current approaches to tension stiffening in BS 8110 and Eurocode 2 and then summarises a major experimental investigation which was undertaken to explore time dependent aspects. Revisions to BS 8110 and Eurocode 2 are proposed as a result of this work. Further refinements for modelling tension stiffening effects in reinforced concrete members are also described.
Human-induced swaying forces on flexible structures
Authors: Yao S. , Wright J. , Yu C.-H. , Pavic A. , Reynolds P.
Published: November 2009

This paper addresses the effect of a stationary human subject swaying side to side on a flexible structure that can move perceptibly. Similar tests have not been conducted before, so a unique test rig is described and the test methodology explained. The test rig was developed at The University of Manchester to permit a person to sway on an idealised single-degree-of-freedom system with variable natural frequency and mass. We present a set of results that show the effect of the flexibility of the structure on the levels of force and response that can potentially be generated by swaying humans. The acceleration and displacement responses show significant peaks when the swaying frequency is in the region of half the natural frequency and of the natural frequency itself, which indicates that the first and second harmonics of human-induced forcing functions are exciting resonant response. It has also been found that the force level drops at or near to resonance, which is somewhat analogous to the force ‘drop-out’ encountered near resonance in shaker-based modal testing. This result indicates the potential for significant human–structure interaction in the sway direction when the sway motion of the structure is perceptible.
Flat slab design: past, present and future
Authors: Jones A. E. K. , Morrison J.
Published: November 2009

This paper looks at the various methods of flat slab design as prepared in a consultant's office, while also marking the hundredth anniversary of the first published account of the construction of a flat slab. It examines the practicalities of the recommendations available in BS 8110 and indicates areas where further research is required. Current analysis methods are compared for accuracy and ease of use, and reference is made to how these methods have evolved. This development of flat slab design and analysis methods will continue; views on this future trend are presented.
A state-of-the-art office in Brentwood, Essex
Authors: Hughes A. , Warburton P.
Published: November 2009

A new building for British Telecommunications (BT) at Brentwood was designed to reflect and adapt to organisational change. Concern for the environment was a major part of the building services brief. Consideration for the user was expressed as a requirement to reduce the level of occupant complaint below the norm in BT buildings. The length of the air conditioning season has been greatly reduced by maximising the openable window season. The mixed mode concept influenced the planning and structure of the building in many ways, notably the ceiling height, helping daylight to penetrate, and the double skin. Confirmation that the building has satisfied the brief is contained in the views of the occupants. After two years of occupation BT was happy to allow Arup to undertake a post-occupancy survey under licence to Building Use Studies (BUS). The building is in the top 98% of comfort performance and shows an increase in productivity of 7%.
The strength of steel end-plated connections
Authors: Kamtekar A. G.
Published: November 2009

A yield line approach that uses straight yield lines only is developed to assess the strength of four ‘standard’ end-plated beam-to-column connections. The proposed procedure can be used to analyse the full range of moment connections, including wind moment connections. The strength of the connection can be predicted using relatively simple formulae. The strength predictions are found to agree well with available experimental results. A simple procedure is suggested for designing such connections to provide both adequate strength and adequate ductility. It is used to analyse some standard connection designs contained in a publication by the Steel Construction Institute (the Green Book). The designs in the Green Book appear to be very conservative. Applying the procedure proposed herein to these designs leads to a significant reduction in the end plate thickness though it may require the bolt size to be increased in some cases.
Strength and durability of concrete with ash aggregate
Authors: Basheer P. A. M. , Bai Y.
Published: November 2009

A previous investigation to replace natural sand in concrete with furnace bottom ash (FBA) from a coal-fired thermal power plant in Northern Ireland, UK indicated that the water demand of fresh concrete decreases with the increase of the FBA content. Therefore, in the current study the water content was decreased for concretes containing FBA for a given slump and a constant cement content of 382 kg/m3. The natural sand was replaced with the FBA at 0, 30, 50, 70 and 100% by mass and three slump ranges, 0–10, 10–30 and 30–60 mm, were considered. The water content of the mixes was determined by carrying out trials. The effect of FBA on water demand, density, compressive strength, pull-off tensile strength, abrasion resistance, drying shrinkage, air permeability, sorptivity, carbonation, chloride diffusion and salt scaling resistance of concretes containing FBA was studied. The results indicated that the water demand of fresh concrete decreases with an increase of FBA content while it has no significant effect on density, compressive strength, pull-off tensile strength or abrasion resistance. The air permeability, sorptivity and drying shrinkage increases beyond 30% FBA content, but the resistance to chloride ingress and salt scaling improves. The depth of carbonation also increases with an increase in the FBA content beyond the 30% replacement level. Overall, FBA content up to 30% as fine aggregate can be incorporated in structural concrete with mostly beneficial effects to various properties of concrete, provided the cement content is kept constant and the water content corresponds to that for low-slump concrete mixes.
Estimation of ultimate stress in external FRP tendons
Authors: Du J. S. , Au F. T. K.
Published: November 2009

In a prestressed concrete beam with external tendons, the tendon stress depends on the member deformation, and it cannot be determined from section analysis alone as in the bonded case. Previous work has been mainly on the ultimate stress in unbonded steel tendons, with little on unbonded fibre-reinforced polymer (FRP) tendons. To account for the relative slip between the unbonded tendon and concrete, the ratio of the equivalent plastic hinge length to the neutral axis depth is analysed using available test results. It is found that this ratio for unbonded partially prestressed concrete (UPPC) beams with external FRP tendons can also be treated as a constant as for those with unbonded steel tendons. A simple method for evaluation of the ultimate stress in either steel or FRP external tendons is therefore proposed. After suitable modifications, the equations currently adopted by various design codes can still be used to predict the ultimate stress in external FRP tendons of UPPC beams.
Stress limits for aramid fibres
Authors: Giannopoulos I. P. , Burgoyne C. J.
Published: November 2009

Aramid fibres should have many structural applications: they should be used as tendons in prestressed concrete, as stay cables in bridges and as ropes in marine industry owing to their good tensile properties, low weight and lack of corrosion. However, uncertainty about their ability to carry significant loads for a long period of time has meant that engineers have been reluctant to adopt them. Two new techniques (stepped isothermal method and stepped isostress method) are now available that allow accelerated testing to be carried out at low stress levels, in such a way that the long-term creep and creep rupture properties can be determined without having to extrapolate more than one decade on a log-time scale. Such tests have now been carried out on two slightly different aramid fibres: Kevlar 49 and Technora. The paper shows how this information can be used to predict the safe operating stresses for these fibres when under sustained load, which is precisely the sort of application for which they are most economically suited. The effects of yarn variability are considered, as are the effects of different temperatures and varying loads. The aim is to be able to predict the behaviour of aramid fibres when subject to load durations of 100 years or more, without having to provide excess material because of a lack of applicable test data.
Adhesive bonding in steel beams strengthened with CFRP
Authors: Deng J. , Lee M. M. K.
Published: November 2009

The strengthening of metallic beams with a bonded carbon-fibre-reinforced polymer (CFRP) plate has found many applications in bridge and building structures in recent years. The structural behaviour of the adhesive bonding in this technique is the most distinct element to be considered. In this paper, previous analytical, experimental and numerical studies under static and fatigue loadings by the present authors are reviewed. An S–N curve based on the peak interfacial stresses is proposed to predict the fatigue life to crack initiation of the retrofitted beams. An equation to predict the fatigue life during the crack propagation has also been developed. Finally, the geometric effects of the spew fillet and of the taper at the plate end of the retrofitted beam are discussed. In the conclusion, design recommendations for steel beams strengthened by bonded CFRP plates are detailed based on the findings obtained from the studies presented.
Deep embedment of FRP for concrete shear strengthening
Authors: Valerio P. , Ibell T. J. , Darby A. P.
Published: November 2009

The shear capacity of existing concrete structures is often unable to meet current standards requirements. This may be attributable to increased load requirements, inadequate shear provisions in the original design, deterioration of materials or an increased demand in shear capacity owing to flexural strengthening. There are various approaches to the repair and strengthening of existing concrete structures in shear using fibre-reinforced polymer (FRP), involving the use of plates or fabrics externally bonded to the web, prestressed straps wrapped around the beam or the use of bars mounted near the surfaces of the web. However, when only the top or bottom faces of the concrete member are accessible, as in the case of bridge beams made contiguous within a deck or for corbels, a different approach is proposed, called the deep embedment technique: vertical holes are drilled into concrete upwards from the soffit in the shear zones, high-viscosity epoxy resin is injected and then FRP or steel bars are embedded into place. In this paper, the results of a series of tests on unstrengthened and strengthened small-scale and large-scale reinforced concrete and prestressed concrete specimens with and without stirrups are presented. The proposed technique is shown to be feasible, successful and potentially more effective than other shear strengthening approaches. A simple model derived from the truss analogy is shown to be able to predict the capacity of the strengthened beams and can therefore be used as a design tool for the scheme.
Study of CFS-strengthened RC beams with shear key
Authors: Yi Seong-Tae
Published: November 2009

It is sometimes known that when the bonding strength of reinforced concrete (RC) flexural members strengthened with fibre sheet composites is sufficient, debonding failure does not occur until the sheet fails. However, many researches have reported that debonding failure occurs frequently before the fracturing of the sheet itself at early loading stages, even though the bonding length is sufficient. On the grounds of practicality, it is very important to prevent debonding at the ends of the soffit plate using mechanical anchors and to eliminate the possibility of debonding failure. This study was carried out to evaluate the effectiveness of shear keys and U strips on the flexural behavior of RC beams. The ply numbers of carbon fibre composite sheet (CFS), location of the shear key, and existence or non-existence of the U strip were selected as the main test variables. The test results showed that the behaviour of a beam having shear keys near the supports, non-existent U strip, and one-ply CFS along the overall length and the other ply along the centre half-length showed the most apparent improvement compared to the other beams.
Medway Tunnel—construction
Authors: Court D. J.
Published: November 2009

The Medway Tunnel project in north Kent comprises a link road approximately 1500 m long, 720 m of which is in tunnel under the River Medway, from the site of the old Royal Naval Dockyard in Chatham across to the Hoo peninsula in Rochester. Construction splits naturally into eight discrete sections by virtue of the construction methods employed and this paper expands on these various methods with special emphasis on the construction of the immersed tube tunnel element. The contract commenced in 1992, and at the end of the contract in 1996, the client received a project completed to time and cost and as defined in his scope of works.
Geotechnical engineering for the Medway tunnel and approaches
Authors: Leiper Q. , Roberts T. , Russell D.
Published: November 2009

The design and construction of the Medway immersed tube tunnel and approach structures required a thorough investigation of the site and a detailed understanding of the geology and geotechnical behaviour of the soils. The paper describes the ground investigation and discusses how the design accommodated the ground conditions to allow the tunnel and approach structures to be safely and efficiently constructed. Two main geotechnical challenges are described; the approach embankments and the casting basin in which the immersed tube tunnel sections were constructed. Part of the approach embankment was constructed over very soft soils. The construction made use of vertical drains, stage construction and preloading to ensure that the embankment was constructed economically within the available programme. The immersed tube tunnel sections were constructed in a casting basin next to the river. The design of the casting basin required careful consideration of the stability of the temporary slopes and the dewatering system had to deal with large quantities of water without causing significant settlement of some sensitive nearby structures. These two areas are discussed and details of the construction and performance are provided.
The detailed design of the Medway Tunnel project
Authors: Mainwaring G. D. , Weeks C. R. , Brandsen C.
Published: November 2009

Immersed tube tunnels may be considered to be particularly suited to a design-and-construct form of contract, in that there is considerable influence on the permanent structure by the temporary works required for the float-out and immersion of the tunnel elements. The scope of the reference design produced by the engineer for the Medway Tunnel project, which allowed tenders to be sought, afforded flexibility for the tenderers in their options for constructing the immersed tunnel, the cut-and-cover tunnels, and their approaches. This paper discusses the designs carried out by Mott MacDonald for the various forms of construction employed on the project by the contractor. These works include the cut-and-cover tunnels which were constructed using permanent diaphragm walls or with cast-in-place concrete within a temporary combi-pile wall arrangement, the piled slabs and gravity structures which were employed on the open approaches, the innovative sand-placing method used for the embankment built on very soft ground, and the immersed tunnel itself. The paper also addresses the coordination required in the design-and-construct process between the designer and contractor, and also between the civil and mechanical and electrical works. Finally, the paper discusses some of the technical complications encountered during the construction of the project, and how the design-and-construct form of contract was beneficial in achieving a rapid and satisfactory solution.
The basis for Dublin's transportation policy beyond 2000
Authors: Rogers M.
Published: November 2009

This paper examines the conclusions of the 1995 Dublin Transport Initiative Final Report and asks whether the themes/options that performed best in the multi-criteria analysis (MCA) undertaken within the report subsequently formed a substantial part of the chosen core strategy of transport projects. The author states that the link between the MCA and the chosen strategy is diminished as a result of a lack of rationality in the decision-making process leading to the formation of the strategy. In particular, the paper highlights the post-MCA exclusion of the two best performing themes, heavy rail and extensive road development, together with the failure to separate out two of the major public transport options, light rail and bus, into separate themes to allow their relative evaluation. The author demonstrates that the core strategy is given a level of performance by the Dublin Transport Initiative (DTI) that is inconsistent with the actual performance of its constituent themes in the MCA. The direct comparison of light rail and heavy rail using cost–benefit analysis also leaves a number of questions unanswered, with the two being viewed as mutually exclusive rather than complementary to each other. The lack of alternative solutions put forward during the public consultation phase also gives rise for concern. The 1999 DTI update continues to emphasize the importance of light rail, with limited reference to the examination of the heavy rail option. Given the present economic prosperity, and the delay in the actual implementation of a light rail system, an opportunity still exists to explore in detail which option or combination of options would constitute the most appropriate rail-based public transport system for Dublin.
The use of permeable materials for backfilling trenches
Authors: Alobaidi I. M. , Ghataora G. S. , Billam J. , Coombs R.
Published: November 2009

The use of cementitious permeable backfill materials containing pulverized fuel ash based aggregates for trenches was investigated by means of laboratory tests and a field trial. Single-sized Lytag and Aardelite aggregates were used in this investigation. Laboratory measurements included unconfined compressive strength, 10% values, flowability, permeability and freeze–thaw resistance. These results were compared with those of foamed concrete. It was found that the flowability of Lytag and Aardelite depended in part on the spherical shape of the particles and therefore low water–cement ratio was required to achieve a workable mix which does not need compaction. Aardelite mix showed high potential for backfilling trenches because during pilot testing it performed as well as Lytag and it was much cheaper than the latter aggregate. However, more work is needed to develop a mix design. A field trial was conducted on a Lytag mix and its performance was compared with that of granular type 1 backfill. The trench backfill materials complied with the Highways Authorities and Utilities Committee specification and required no compaction. Field trial showed that Lytag backfill performed better than type 1 granular sub-base in terms of having lesser long-term settlement. A cost estimate of the backfill materials suggested that the Aardelite backfill is similar to granular based sub-base. In the long term it may be cheaper, as it may require little or no maintenance.
The use of lime-treated British clays in pavement construction. Part 2: The effect of mellowing on the stabilization process
Authors: Holt C. C. , Freer-Hewish R. J. , Ghataora G. S.
Published: November 2009

The USA field experiences in the 1960s with lime treatment of marginal materials for pavement layers resulted in the introduction of a ‘mellowing’ period of between 24 and 72 hours, after mixing and prior to final compaction. This period facilitates reaction between the soil and the lime so that pulverization criteria and compact-ability can be achieved. As a result of these early experiences, the ‘mellowing’ period has become an integral part of specifications for lime-treatment processes used globally but it has been based on limited scientific justification. Under the Department of Transport (DoT) Specification for Highway Works (1991 and 1993 amendments) a ‘mellowing’ period of between 24 and 72 hours is mandatory. This period of mellowing is also recommended in volume 4 of the Design Manual for Roads and Bridges HA/74/95. 1 Part 1 of this paper, 2 also presented in Transport, discussed results of a research programme that investigated the effect of mellowing on the modification process of four British soils (Mercia Mudstone, Oxford Clay, Lower Lias and London Clay) treated with quicklime. This second paper presents the findings of the second phase of this research, which investigated the effect of mellowing on the stabilization process of the same four soils discussed in Part 1. Both papers suggest a need to improve the design methods for lime treatment of clays in the international procedures. 3
Rails around London—in search of the railway M25
Authors: Elliff C.
Published: November 2009

The transport infrastructure of London and the south-east of England is suffering increasing congestion as traffic levels rise, year by year. The traditional response of constructing new roads no longer appears sustainable, and solutions must be found elsewhere. Rail transport is now accepted as the optimum environmentally friendly means of moving large volumes of passengers and freight, and several schemes have been proposed either to enhance existing routes, or to create new ones. This paper outlines the author's vision for a new circumferential railway, around the western side of London, to provide main-line railway links to Heathrow and Gatwick airports, and a freight bypass for Channel Tunnel traffic. Entitled the Grand Junction Link, it would effectively become the ‘railway M25’.
CrossRail: Introduction
Authors: Heath D. L.
Published: November 2009

Donald Heath was the Project Director during the latter stages of the design phase. His introduction to this suite of papers outlines the key features of CrossRail, and the content of the seven papers, which range from the historical background, through design procurement to options on the way forward to construction.
CrossRail: Scope, background and feasibility
Authors: Fergusson J. C.
Published: November 2009

Proposals for an east–west railway linking existing railways across central London have been examined on many occasions over the last 100 years, culminating in the present CrossRail scheme, recommended by the Central London Rail Study in 1989. 1 CrossRail, linking counties east and west of London with the City and the West End, will be operated by suburban trains up to twelve cars in length carrying a quarter of a million passengers a day. Twin tunnels will be built beneath central London from west of Paddington to Bethnal Green with five new subsurface stations at key locations. Outside of London, trains will run mainly on existing lines to Reading, Aylesbury and Shenfield with new and extended platforms where required. This first paper outlines the scope of the project, the historical background, initial engineering feasibility work and preparation for the Parliamentary Private Bill.
CrossRail: Planning and design of the central London section
Authors: Taylor D. J. , Fergusson J. C.
Published: November 2009

Provision of around £1 billion of new infrastructure for the central London tunnels and stations has required significant investment in procurement of both the design and information to support that design. This paper outlines the procurement and management of the design process, including a description of the central area infrastructure and the relevant supporting technical work.
The use of weigh-in-motion data in pavement design
Authors: Hakim B. Al , Collop A. C. , Thom N. H.
Published: November 2009

This paper investigates the use of weigh-in-motion (WIM) data in the context of UK pavement design procedures. The effects of different power laws on the production of vehicle wear factors (VWFs), design traffic and subsequent pavement thickness design are investigated using two sources of WIM data. With the exception of one site, the average VWFs obtained are lower than those currently used in UK pavement design procedures, although the variability is quite high. Typically, the minimum pavement design traffic prediction was obtained using a fourth power law. Using current UK pavement design procedures for a range of materials, the effect of different exponents can make a difference of up to 50 mm to the pavement design, depending on the expected traffic level. The various errors associated with WIM measurements and the effects of these errors on the production of VWFs and subsequent pavement thickness design are investigated. Three effects have been identified, these being those due to calibration error, random sensor error and dynamic loading. It is found that, using a fourth power law, the effect of sensor/dynamic and calibration errors is to overpredict the traffic by typically 15–20% which is likely to result in a 5–15 mm overdesign of pavement thickness for typical flexible pavement structures.
Determining the performance of quieter road surfaces
Authors: Phillips S.
Published: November 2009

Type approval for proprietary thin asphaltic surfacings has recently been introduced in the UK through the Highway Authorities Products Approval Scheme (HAPAS). This scheme includes a noise test that gives a noise classification that can be used for comparing different surfacings. The data generated can also be used to predict traffic noise levels. The assessment of noise is currently carried out using the Statistical Pass-By (SPB) test method. This method has proved to be a suitable interim procedure for type approval purposes but it is currently limited by the stringent site requirements of the standard and by the influence of factors related to the traffic stream and weather conditions. Supplementary test methods are under development that will overcome the site selection difficulties and research has been concluded that will help to take account of influential factors. This paper reviews the progress made in developing suitable test procedures for road surface noise evaluation. It also describes some of the equipment developed in the UK for use in both research and routine assessment of road surface noise.
Prediction of groundborne vibration from vibrating rollers
Authors: Crabb G. I. , Hiller D. M.
Published: November 2009

The increasing size and power of modern construction plant and its potential to cause damage or disturbance, coupled with a growing requirement for assessment of environmental impacts of construction works, have led to a need for reliable ground vibration prediction. While there is a growing need to minimise the adverse effects of construction works, over-conservative restrictions on vibration may lead to significant and unnecessary cost increases. A programme of research has been undertaken to provide data and advice by which objections to schemes may be judged and a means of assessing the environmental impact of vibration from construction works. This paper focuses on one aspect of this research: ground vibration caused by vibrating rollers. A literature review revealed little published work relating to vibration from vibratory compaction. Extensive data were therefore acquired from construction sites including a range of roller types, topographies, fill types and soil types. In addition, a controlled trial of vibration from a range of vibrating rollers operated on a specially constructed test bed was undertaken. An empirical model was developed, based on readily available information, to predict the peak particle velocity at distances of up to 100 m from the source. The predictor was derived largely from the controlled trial data and has been validated by fitting to the data from construction sites.
Development of an alternative design for the West Rail viaducts
Authors: Cooper J. H. , Harrison M. F.
Published: November 2009

The Kowloon–Canton Railway Corporation (KCRC) West Rail Phase I project consists of a new 30·5 km long railway in the North West New Territories of Hong Kong. Of the overall route, approximately 13·4 km is elevated on viaduct and station structures. In accordance with the Hong Kong Noise Control Ordinance, the Environmental Protection Department of Hong Kong imposed stringent controls on the noise levels caused by trains running on these viaducts. The conforming design for the viaducts was prepared by KCRC's appointed detailed design consultants. The joint venture contractor, Maeda–Chun Wo Joint Venture, wished to submit a most competitive bid for the viaduct contracts. Robert Benaim and Associates investigated options for an alternative design with the objective of finding a more economic design solution. It would be essential to submit with the tender an authoritative report that analysed the noise and vibration performance of any proposed alternative, and compared this on an equal basis with the performance of the conforming design. The process by which the alternative viaduct design was developed is outlined in this paper.
Rebuilding the Welsh Highland Railway
Authors: Savage A.
Published: November 2009

North Wales has been famous as the centre of narrow gauge railways, and the most famous of those lines was the Ffestiniog Railway (FR). The FR was involved in another, lesser known, line, originally called the North Wales Narrow Gauge Railways, which was later extended to join the Ffestiniog line at Porthmadog, when it was renamed the Welsh Highland Railway (WHR). The WHR, opened in 1923, was not a success, and closed after only thirteen years. Fifty years later the FR set out to rebuild the line, this time with adequate capital, and extend it to Caernarfon, its natural destination. The paper looks at the history of the line, at the engineering challenges that arise from restoring a railway that was originally built to a very low budget, and that lay derelict for over sixty years, and how those challenges are being overcome.
Environmentally sustainable transport: concept, goal and strategy—the OECD's EST Project
Authors: Caïd N. , Crist P. , Gilbert R. , Wiederkehr P.
Published: November 2009

Moving people and freight in an environmentally sustainable manner will be one of the biggest challenges of the 21st century. A new, target-oriented approach is needed that places environment and health at the top of the policy agenda for transport and related sectors, at international, national, and local levels. The OECD recently completed a five-year initiative with the development of Guidelines for Environmentally Sustainable Transport (EST) and concluded that there exists a new way towards a sustainable transport future. Unlike conventional approaches to transport policy, EST uses a backcasting approach. This involves defining what is meant by environmentally sustainable transport, developing a vision, and then working out how to realise it. It also implies an assessment of the economic and social implications of EST. Environmentally sustainable transport doesn't mean less transport than we have today, but it certainly means different transport using technological advances and 'smarter’ transport through innovative mobility management, integrated mobility services and freight logistics. This paper summarises the main results of the project based on the case studies from twelve OECD countries. It also includes a series of Guidelines for policy-making endorsed by OECD Environment Ministers in 2001. The EST Guidelines have been elaborated to assist governments at all levels in the development and implementation of strategies towards EST. Their effective implementation requires strategies that accommodate the particular geographic and socio-economic conditions of countries or regions and involve all parties concerned.
Recycling in transport infrastructure
Authors: Reid J. M.
Published: November 2009

Key factors in the Government's agenda for sustainable construction are to increase the amount of recycling and use of alternative materials. In practice, a number of issues can limit the extent of these activities. If the objectives of sustainable construction are to be realised, these issues must be positively addressed. This paper looks at recycling in the renewal of transport infrastructure, defined as the earthworks, drainage and pavements for roads, railways, airports and canals, but many of the issues are also relevant to other sectors of construction. Issues perceived as obstacles to recycling include lack of specifications, concerns about reliability and quality control, the application of the waste management regulations, potential pollution of the environment, increased risk, adversarial conditions of contract, balancing supply and demand, planning restrictions and the economics of recycling. In many cases these obstacles are more apparent than real, and perhaps the greatest problem is lack of awareness. Guidance and a number of case studies are presented in a document produced by TRL Limited, entitled Recycling in transport infrastructure. Further action is required to resolve some issues, in particular those connected with the waste management regulations, and these are discussed in the paper. Solutions are proposed, including the establishment of a National Industrial Forum to resolve issues involving the environmental protection agencies, industry, infrastructure owners and operators, and government.
Watford match day parking scheme
Authors: Thomas A.
Published: November 2009

A match day parking scheme was implemented in west Watford in October 2000 in response to calls from residents that action be taken to address the growing parking problems associated with matches (both football and rugby) played at Vicarage Road Stadium. Much of the area surrounding the stadium consists of terraced housing where space for parking is limited. It was felt that supporters ignored the needs of residents, often parking across driveways, and had no regard for safety. Residents complained that they were not able to leave their homes by car during a match because there would be nowhere for them to park on their return. The aim of the scheme was, and continues to be, to put the interests of residents first while providing limited parking opportunities for soccer and rugby fans visiting Vicarage Road Stadium on match days. In the summer of 2001 a review was carried out to gauge satisfaction levels among local residents affected by the scheme, and to hear views regarding potential changes and improvements. On the whole, the results of the survey showed that local residents were happy with the scheme, with many residents not wanting changes at all. Some residents on surrounding streets wished to be included in the scheme, having observed the benefits.
Evaluation of a mechanism for urban road maintenance by level of service
Authors: de Solminihac H. , Lobo E. , Jiménez N. , Altamira A.
Published: November 2009

The agency responsible for constructing and maintaining urban roads in Chile has initiated a pilot programme under which responsibility for the maintenance and preservation of urban roads falls within the scope of the private sector, which assumes the commitment to maintain roads in an adequate condition in exchange for a pre-established payment, called urban road maintenance by level of service. The purpose of the research described in this paper was to evaluate the implementation of contracts by level of service. This evaluation was based on comparing total costs (direct and indirect) with the traditional method, considering the savings in operating costs and the impact on users as well as the benefits. Statistical information was considered relating to types of structure, types of road, travel demand, level of road distress, threshold of intervention, construction, maintenance and operating costs, and impacts. Based on the results obtained, it is concluded that it is feasible to apply urban road maintenance contracts by level of service at both a technical and an economic level, and that such contracts should be applied for specific types of road, pavement conditions and types, and contract periods.
Advancement of the annual traffic census in Hong Kong
Authors: Lam W. H. K. , Hung W. T. , Lo H. K. , Lo H. P. , Tong C. O. , Wong S. C. , Yang H.
Published: November 2009

This paper summarises the process, findings and recommendations of a recently completed joint university consultancy project that reviewed the annual traffic census (ATC) in Hong Kong. The results of a survey that assessed the usefulness of the census report are presented, together with an overview of the existing traffic data collection process and traffic detection equipment. Areas for improvement are then identified, including the sampling strategies for the collection of vehicle classification and occupancy data, the procedure for the development of group scaling factors, the method for the selection of core and coverage stations, the approaches to developing growth factors and traffic flow estimation, the presentation method and database structure of the census framework, and the manpower requirements. Based on these identified areas, a new computer program is developed to integrate all of the tasks of the census report and to produce the results in CD-ROM format. Finally, concluding remarks are given together with recommendations for further study.
Decentralisation in developing countries: a model for road administration
Authors: Robinson R. , Stiedl D.
Published: November 2009

Many developing countries are decentralising the administration of their road networks with the aim of improving the delivery of rural transport infrastructure services. A study of decentralisation of road administration in developing countries has been undertaken, including a literature review, and field studies in Nepal, Uganda and Zambia. The evidence from this study suggests that it is proving difficult to realise the expected benefits fully. Problems include a lack of local government powers to exercise political influence, insufficient financial resources, a lack of management capability, and a lack of accountability mechanisms. Limited data also suggest that there is little evidence of existing decentralised systems being particularly responsive to addressing the needs of the rural poor. Different models for administrative decentralisation have been developed through this study. They are described, and recommendations are made for approaches likely to be the most appropriate for rural transport infrastructure administration and management. However, the benefits can be assured only through a long-term investment in establishing effective systems at a local level and building local capacity. There is also a need for the poor to be involved more actively in the planning, financing and implementation process, if poverty alleviation is to be achieved.
Briefing: Highway maintenance drives changes in quality management
Authors: Baylis P. , Hardy R.
Published: November 2009

Traditional quality plans are being replaced by more user-friendly systems. This briefing details an innovative integrated approach to quality management being adopted on the Highways Agency's Area 3 motorway and trunk road network.
Investigation of railway track subgrade. I: In-situ assessment
Authors: Brough M. J. , Ghataora G. S. , Stirling A. B. , Madelin K. B. , Rogers C. D. F. , Chapman D. N.
Published: November 2009

Recent research has shown that there is a discernible relationship between trackbed stiffness and track quality deterioration. Even though correlations between maintenance, track geometry deterioration and subgrade condition have been identified, the trackbed is rarely considered in the design and implementation of maintenance and renewals works proposals. Often track components are maintained or replaced with little regard for subgrade properties and their subsequent effects on continued total asset life. Consequently, a need has arisen for a more consistent, detailed trackbed investigation that can be carried out under the physical working and access restrictions applicable in the UK railway network. Level 1 evaluation refers to the assessment of large track lengths, and is concerned mainly with the initial identification of poor subgrade sites. Level 2 evaluation focuses on the causes of track geometry deterioration at identified poor subgrade sites. This paper presents a critical analysis of test devices for identification and assessment of existing and potential subgrade problems, and of their application in a railways environment. Devices deemed potentially applicable were tested on a site on the existing railway network, and the results are presented in part II of this series of papers.