Halcrow Group Limited is a multinational engineering consultancy company, based in the United Kingdom.Halcrow is one of the UK's largest consultancies, with origins stretching back to 1868. The UK-based consultancy specialises in the provision of planning, design and management services for infrastructure development worldwide. With interests in transportation, water, maritime and property, the company is undertaking commissions in over 70 countries from a network of more than 90 offices. Wikipedia.
Amatya B.L.,Halcrow Group Ltd. |
Soga K.,University of Cambridge |
Bourne-Webb P.J.,Skanska |
Amis T.,Geothermal International |
Laloui L.,Ecole Polytechnique Federale de Lausanne
Geotechnique | Year: 2012
Energy piles are an effective and economic means of using geothermal energy resources for heating and cooling buildings, contributing to legislative requirements for renewable energy in new construction. While such piles have been used for around 25 years with no apparent detrimental effect, there is limited understanding of their thermo-mechanical behaviour. This paper synthesises the results from three published field studies and illustrates some of the engineering behaviour of such piles during heating and cooling. Simplified load transfer mechanisms for a single pile subjected to pure thermal loadings (i.e. without mechanical load) and combined thermomechanical loadings have been developed and are used to interpret the field data with regard to change in axial stress and shaft friction during heating and cooling. The effect of end restraint and ground conditions on the thermo-mechanical response of energy piles is discussed. Values of change in axial stress and mobilised shaft friction due to thermal effects that may be useful in the design of energy piles are presented.
Frampton A.P.R.,Halcrow Group Ltd.
Journal of Coastal Research | Year: 2010
Beach management guidance has previously tended to focus on beach management for coastal-defence purposes and has only given passing consideration to the amenity value of beaches. This paper, based upon a desk-study review of available beach management plans and published research, examines some of the issues of concern in providing beach management for amenity purposes and identifies techniques and methods used to achieve this. In examining these issues, examples of the relationship between how beaches are managed for the purposes of both amenity and coastal defence are provided to demonstrate how beach amenity forms an integral part of holistic beach management. Amenity is identified as a perception of beach users of a location's elements that provide a positive, enjoyable benefit. The findings presented in this paper identify a number of issues that affect the amenity provided by beaches. These can be broadly grouped as those involving direct interaction with the physical/natural environment, such as beach character and beach maintenance, and those involved with managing beach use, such as beach safety, zoning, and the provision of facilities, services, and access. Linking all of the issues of beach management for amenity purposes is the need to convey information to beach users in a clear and effective way such that it is easily understood. This is primarily via signage at the beach, but it also involves using public awareness and education campaigns and providing information via the Internet. However, it is also acknowledged that issues at the beach will vary from location to location both within a country and between countries. Therefore, when considering the management of beach amenity, it is important to first understand what the perceived amenity of a beach is through such mechanisms as beach-user surveys and video monitoring. © 2010 the Coastal Education & Research Foundation (CERF).
Pontee N.I.,Halcrow Group Ltd.
Proceedings of the Institution of Civil Engineers: Maritime Engineering | Year: 2011
This paper clarifies the term 'coastal squeeze' and explains the other causes for coastal habitat loss in addition to sea level rise and the presence of sea defences. A case study from north-west England is then presented based on an analysis of historical Ordnance Survey maps. This high-level analysis shows that coastal narrowing has occurred on undefended as well as defended profiles. This is consistent with there being a number of other factors responsible for changes in the width of the coastal zone in addition to sea level rise and the presence of defences. In cell 11 other contributory factors such as changes in the positions of offshore banks and channels, the alongshore sediment supply and the wind-wave climate are likely to have resulted in greater losses of habitat than coastal squeeze. It is concluded that previous assessments of coastal squeeze are likely to have overestimated the extent of coastal squeeze and therefore the requirement for compensatory habitat.
Ingham J.,Halcrow Group Ltd.
Proceedings of the Institution of Civil Engineers: Forensic Engineering | Year: 2012
Delayed ettringite formation (DEF) is a relatively rare but potentially severe form of internal sulphate attack of concrete. In the worst cases it has caused loss of serviceability of the affected concrete structure. DEF was first identified as a problem in heat-cured concrete during the 1980s and in recent years has also been found to occur in in situ concrete structures. Once established, it can cause expansion and cracking, which weaken concrete members and accelerate deterioration by other mechanisms such as reinforcement corrosion. This briefing explains how DEF occurs and how it is diagnosed and discusses how it can be prevented and managed in concrete structures.
Bates P.D.,University of Bristol |
Horritt M.S.,Halcrow Group Ltd. |
Fewtrell T.J.,University of Bristol
Journal of Hydrology | Year: 2010
This paper describes the development of a new set of equations derived from 1D shallow water theory for use in 2D storage cell inundation models where flows in the x and y Cartesian directions are decoupled. The new equation set is designed to be solved explicitly at very low computational cost, and is here tested against a suite of four test cases of increasing complexity. In each case the predicted water depths compare favourably to analytical solutions or to simulation results from the diffusive storage cell code of Hunter et al. (2005). For the most complex test involving the fine spatial resolution simulation of flow in a topographically complex urban area the Root Mean Squared Difference between the new formulation and the model of Hunter et al. is ~1cm. However, unlike diffusive storage cell codes where the stable time step scales with (1/Δx)2, the new equation set developed here represents shallow water wave propagation and so the stability is controlled by the Courant-Freidrichs-Lewy condition such that the stable time step instead scales with 1/Δx. This allows use of a stable time step that is 1-3 orders of magnitude greater for typical cell sizes than that possible with diffusive storage cell models and results in commensurate reductions in model run times. For the tests reported in this paper the maximum speed up achieved over a diffusive storage cell model was 1120×, although the actual value seen will depend on model resolution and water surface gradient. Solutions using the new equation set are shown to be grid-independent for the conditions considered and to have an intuitively correct sensitivity to friction, however small instabilities and increased errors on predicted depth were noted when Manning's n=0.01. The new equations are likely to find widespread application in many types of flood inundation modelling and should provide a useful additional tool, alongside more established model formulations, for a variety of flood risk management studies. © 2010 Elsevier B.V.