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Shrewsbury, United Kingdom

Crawford J.W.,University of Sydney | Deacon L.,Mouchel | Deacon L.,Cranfield University | Grinev D.,University of Southampton | And 4 more authors.
Journal of the Royal Society Interface | Year: 2012

Soils are complex ecosystems and the pore-scale physical structure regulates key processes that support terrestrial life. These include maintaining an appropriate mixture of air and water in soil, nutrient cycling and carbon sequestration. There is evidence that this structure is not random, although the organizing mechanism is not known. Using X-ray microtomography and controlled microcosms, we provide evidence that organization of pore-scale structure arises spontaneously out of the interaction between microbial activity, particle aggregation and resource flows in soil. A simple computational model shows that these interactions give rise to self-organization involving both physical particles and microbes that gives soil unique material properties. The consequence of self-organization for the functioning of soil is determined using lattice Boltzmann simulation of fluid flow through the observed structures, and predicts that the resultant micro-structural changes can significantly increase hydraulic conductivity. Manipulation of the diversity of the microbial community reveals a link between the measured change in micro-porosity and the ratio of fungal to bacterial biomass. We suggest that this behaviour may play an important role in the way that soil responds to management and climatic change, but that this capacity for self-organization has limits. © 2011 The Royal Society. Source


Canning L.,Mouchel
Advanced Composites in Construction 2011, ACIC 2011 - Proceedings of the 5th International Conference | Year: 2011

Minsterley Bridge is a 101 year old Grade II Listed structure carrying the main access road into Minsterley Village in Shropshire over the Minsterley Brook. The 10m span reinforced concrete arch bridge is an early example of the Hennebique system and was originally designed by Louis Gustave Mouchel. The original structure had an assessed capacity of 7.5 Tonnes assessment live load (ALL) in accordance with BD211. No weight restriction to the bridge was in place as it provides critical access to the village. Regular monitoring of the structure was therefore undertaken until it could be strengthened. A number of strengthening/construction options for the structure had been considered in the past, although none had sufficiently met the requirements of all stakeholders. However, a novel strengthening proposal comprising a composite concrete saddle and CFRP strengthening to the soffit successfully met the requirements of the stakeholders and enabled the structure to be strengthened to full HA loading at minimum cost and disruption. The strengthening system comprised a thin in-situ concrete saddle acting compositely with the existing arch barrel with bespoke shear connectors, together with CFRP fabric and pultruded plates bonded to the arch intrados. Other associated repair/refurbishment works included passive cathodic protection, concrete repairs, highway and drainage works. This paper describes how the use of CFRP strengthening as part of a package of strengthening works enabled a historic structure to be given a new lease of life whilst meeting the technical requirements of modern traffic loading. Source


McClymont K.,University of Exeter | Keedwell E.,University of Exeter | Savic D.,University of Exeter | Randall-Smith M.,Mouchel
Journal of Hydroinformatics | Year: 2013

The optimisation of water distribution networks (WDNs) by evolutionary algorithms has gained much coverage in the literature since it was first proposed in the early 1990s. Despite being well studied, the problem and objectives continue to evolve as demands on water companies change. Motivated by the increased focus on reducing the risk of discolouration, this study examines a three objective version of the WDN design problem which takes into account cost, head excess and discolouration risk. Using this formulation, this paper presents a method for producing optimised network designs aimed at reducing discolouration risk in the network design phase and thus reducing the associated long-term maintenance and operational burdens of the system. This paper discusses the use of a discolouration risk model and, using this model, the optimisation of network design, specifically pipe diameters, to produce a range of high quality self-cleaning networks. The network designs are optimised using the Markov-chain hyper-heuristic (MCHH), a new multi-objective online selective hyper-heuristic. The MCHH is incorporated in to the known NSGA-II and SPEA2 and supplied with a range of heuristics tailored for use on the WDN design problem. The results demonstrate an improvement in performance obtained over the original algorithms. © IWA Publishing 2013. Source


Backus J.,Mouchel | McPolin D.,Queens University of Belfast
Journal of Materials in Civil Engineering | Year: 2016

Carbonation and chloride ingress are the two main causes of corrosion in reinforced concrete structures. An investigation to monitor the ingress of chlorides and the effect of carbonation on chloride ingression during an accelerated 12 month cyclic wetting and drying exposure regime that simulates conditions in which multiple mode transport mechanisms are active was conducted on ground granulated blast furnace slag (GGBS) concrete. The penetration of chloride and carbon dioxide was evaluated using water and acid soluble chloride profiles and phenolphthalein indicator, respectively. The results indicated that when chloride and carbon dioxide ingress concomitantly the effects can be adverse. Carbonation has a detrimental effect on the binding capacity of the concrete, increasing the concentration of free (water soluble) chlorides. This contributed to greater concentration and greater penetration of chlorides and thus an increased corrosion risk. © 2016 American Society of Civil Engineers. Source


Bishop P.,Mouchel
Tunnels and Tunnelling International | Year: 2015

Peter Bishop, technical director for tunnels engineering at Mouchel raises the issue of providing for the needs of those with reduced mobility during a road tunnel evacualtion. The term ?reduced mobility' refers many individuals and groups who might experience difficulty in evacuating a tunnel to a place of safety during an emergency. The United Nations published a Convention on the Rights Of Persons with Disabilities, which all members signed up in 2006. It called for reasonable accommodation by modifying existing infrastructure without imposing a disproportionate cost, for the first time alluding to the notion that disability provision should be considered when designing new infrastructure. Access on an equal basis to the physical environment of transportation by the elimination of obstacles and barriers to accessibility must be included to the buildings, roads, public transport, and other indoor and outdoor facilities. Source

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