SummarySlope failures related to pore-water dissipation, stress relaxation and desiccation cracks are major problems occurring in our ageing road network. Consequently, the remediation works necessary to correct these problems are known to cause congestion and delays that, in turn, cause financial loss. In order to decrease the recurrent time of maintenance work, Mouchel is running a pilot test using fibres mixed and compacted with natural soil to remediate a small failure occurred in an embankment south of the M25. Research in micro-reinforced soils is still in its infancy and, although laboratory research has shown that the addition of micro-reinforcement improves the strength properties of the composite material significantly, very little is known about their behaviour in situ, or of the effects of the field techniques currently in use to mix and compact the fibres, on their performance. This project, suported by Mouchel and the Highways Agency, is to study the effects of the field techniques in the performance of the composite material, originated from the mixture of clays with polymer tape fibres.The research will focus on the effects of compacting heavily overconsolidated peds (lumps) of clay on the fibre orientation and distribution within the embankment. A few samples of the in-situ compacted material, porvided by Mouchel, and samples prepared in the laboratory, will be dissected, and the results used as a basis to understand the orientation and distribution of fibres. Swelling and triaxial tests will be carried out on large diameter samples; the results will be used to understand and provide good quality data of the mechanical properties of the compacted reinforced and non-reinforced soil. The test results, together with the pilot study run by Mouchel, will provide the data to analyse the performance of the new material and their use in the maintenance of existing slopes along the highway network in UK. The outcome is expected to provide a better understanding of the effects of discrete fibre reinforcement on heavily overconsolidated clays and the effects of in-situ mixing and compaction techniques in the response of the composite soil. This will allow effective guidance in the construction and/or remediation of slope failures and widespread the use of this type of reinforcement as an effective way to reduce maintenance works on embankments. Improvement of soil characteristics using micro-reinforcement can also lead to a more sustainable way of using otherwise unsuitable soils instead of disposing of them

Selective hyperheuristics are a set of optimisation techniques that effectively optimise the search algorithm during an optimisation run by selecting combinations of lower level heuristic operations (e.g. mutation, crossover & replication). They operate at the level above metaheuristics (e.g. evolutionary algorithms) and are thus able to react to changes in the search space by modifying the heuristics that are applied to the search problem. Traditional selective hyperheuristics consider single heuristics and heuristic pair performance when determining the heuristic to select next. This project will develop new methods known as a sequence analysis based hyperheuristics (SEQAH) and will investigate the use of sequence analysis techniques, taken from other computational domains such as bioinformatics and natural-language processing, to determine heuristic selection. SEQAH methods will record the search process as a sequence of pairs of heuristic application and performance, and will process this information to inform the selection of the next heuristic to apply in the optimisation. This will allow the technique to automatically select the best heuristics to apply for a given problem - effectively tuning the algorithm to new optimisation problem types, regardless of the underlying application area. By selecting from a set of heuristics, the SEQAH techniques can combine ordinary heuristic operations (e.g. mutation and crossover) with more problem-specific heuristics such as human-designed 'rules-of-thumb' into one coherent algorithm that is able to generate near-optimal solutions in less computational time. The developed techniques will be tested on problems from the literature and a suite of real-world problems in water distribution optimisation including the design, rehabilitation and operation of large-scale water systems. The optimisation of these systems has the potential to offer improved services in terms of reliability and water quality and to reduce the future cost and environmental impact of providing clean, safe drinking water to homes across the country. The SEQAH technique also has the potential to extend beyond the water industry and should be applicable to any number of optimisation problems in many application areas due to its ability to adapt to new problem spaces online.

The research applies philosophical ideas about expertise-in-context to improving practice in construction companies thus providing economic, social and cultural benefits. Construction is a rich environment displaying the use of expertise-in-context at a variety of levels in very intense and unique situations. The research will explore the therapeutic or diagnostic role of philosophy and its usefulness to practice, through the loosening of preconceptions and the exposure of unexamined assumptions and consequences based on a conception of knowledge as a process of activity (individual or social) rather than an abstract commodity that can be accumulated. \n\nThree construction companies, Mouchel, Pettifer Construction, and Rider Levett Bucknall, have agreed to be involved. The project will involve small group workshops with practitioners on site in these companies analysing the philosophical dilemmas in their work in order to sensitise them to the benefits of clear thinking in context so that they can revise their practice and company processes thus providing economic benefit. \n\nThere are three stages. The first stage will use a series of stories, embodying philosophical dilemmas, from the construction industry in order to develop language and concepts of expertise-in-practice with participants. For example, the concept of waste has a context dependent meaning so there may be confusion over whether buffer time between activities and adornment on a building should be so described. These skills will be used in the second stage involving small group discussion taking individual's actual experiences of practice and helping them to expose faulty and inadequate assumptions about knowledge and to identify organisational contradictions in structure and processes. The third stage will involve a number of participants taking this activity themselves into their organisations, and an exploration of how more rigorous thinking can be embedded in company structure and processes in a long term sustainable way.\n\nIndividuals involved will understand and value their skills more clearly recognising their expertise-in-context including diagnosing limitations to their knowledge and work context which they will be able to communicate to a wider public. This will provide immediate benefit to the individuals and company, however, also demonstrating a better image of the industry to attract new entrants. The activity will raise the cultural awareness of construction practitioners towards philosophy and the resultant publicity from the project will broadcast this generally across the industry. At the same time, the project will challenge philosophy to provide an articulation which can be appreciated in non academic environments. In the long term, this will enable staff to change company structures and processes so they are aligned with improvements in practice, and to assist colleagues in therapeutic and diagnostic thinking thereby creating a critical mass of staff for effective change. These processes facilitate sustainable evolutionary change from within.\n

In the UK, the sewer system is ageing, poorly monitored and around 300,000 km long. The system is subject to increasing capacity demands because of increased urbanisation, more stringent environmental regulation and the consequences of climate change in the form of more frequent and intense rainfall events. OFWAT, the economic regulator for the water industry, imposes a legal duty on water companies to maintain the structural and operational conditions of their sewer systems and also to progressively reduce flooding incidents from sewers. In 2004 OFWAT identified 5700 sewer flooding incidents and an additional 11600 properties with a 10% annual risk of flooding. In approximately 90% of these cases, flooding was caused by an obstruction in a section of sewer pipe. Consequently, monitoring pipes for obstructions and then rapidly removing them could form an important part of an effective programme to reduce sewer flooding. The aim of this project is to develop novel acoustic technology (sensor and software) to produce a near market prototype that can be used in a live sewer to measure rapidly and objectively in-pipe condition and identify blockages and damage. Sewer monitoring is currently limited to the interpretation of CCTV pictures or the use of LightLine surveys. These methods require a mobile trolley with camera to be inserted and travel up a pipe section acquiring images which are then manually examined and defects/obstructions classified according to the standard Sewer Rehabilitation Manual document. Discussions with sewer operators in the UK indicate that they CCTV survey around 2% of their networks every 5 years. This project will develop an alternative fast method for analysing objectively the condition of a sewer and locating blockages. Recent research at the University of Bradford (EPSRC grant EP/D058589/1) has proved that the area of pipe blockage, extent of cracks, water level and positions of lateral connections can be measured in the laboratory pipes using an acoustic method of inspection. In this way the pipe condition of a sewer could be determined between manholes in the airborne regime. The key element of this acoustic device is a small multi-sensor array and advanced, real-time signal processing algorithm which overcome the effects of ambient noise and reverberation in the manhole environment. The key barriers to transferring this technology to the commercial sector are: (i) construction of an intrinsically safe, robust instrument; (ii) acquisition of sufficient field data to demonstrate clearly to potential users that acoustic sensors can reliably identify defects and obstructions in sewers (iii) demonstration that the acoustic technology can provide data that is compatible with the conventional CCTV methods and can be mapped onto the existing sewer condition classifications and sewer databases used by UK water companies. The data collected in the field will be critical in determining the nature and extent of the industrial funding and commercial interest from potential stakeholders. The investigators are in contact with four commercial organisations who support this work: Richard Long Associates, Mouchel Parkman, Yorkshire Water Services and Thames Water. It is generally agreed that CCTV surveys take between 2 and 4 hours per 100m length for measurement with a similar time for image analysis. This costs between 2 and 40 per linear metre depending on the access constraints. Acoustic measurement potentially reduces the measurement and analysis time to tens of minutes per 100m. Significant efficiencies can be achieved. This would enable operators to survey more of their network more frequently so would allow for better monitoring strategies to be developed, the earlier identification of defects and especially blockages leading to fewer flooding incidents and better planned maintenance.

The proposal aims to develop a practical generalised model for analysing realistically dimensioned and loaded rectangular columns strengthened using FRPs. Strengthening circular concrete columns can be achieved by wrapping with FRP (fibre reinforced polymer). This confines the concrete, and can result in increases in load and strain capacity of over 100%. However, most columns are square or rectangular in cross section. Tests, mainly on small-scale rectangular columns, have shown a lower increase in strength, but still up to 50%. A number of simple empirical models have been developed to predict the increase in strength, based upon these small-scale tests. However, , due to size effect, the limited size of columns used in the tests provide little justification for using these models for the larger size rectangular columns found in practice. Thus, a fundamental investigation is required in order to provide a reliable model of behaviour. In order to establish such a general behavioural model there are three fundamental issues which are not well understood, nor limits defined, and therefore need addressing; size effect, aspect ratio and load eccentricity. Confinement of rectangular columns occurs by generating forces at the corners of the column through strain in the FRP, resulting in an effectively confined cruciform region. When the bond between the FRP and the face of the column breaks down, the FRP is no longer effectively anchored to the sides of the column and, ultimately, must strain from corner-to-corner resulting in lower confinement forces for large columns than for small columns with a small side length. For similar reasons, aspect ratio must also be considered. Additionally, as aspect ratio increases, the effectiveness of confinement is known to reduce. Finally, most columns are loaded eccentrically or have combined bending and axial loads. This results in uneven strain distribution across the section and, therefore unequal confining forces at each corner, resulting in a non-cruciform confined area. The behaviour, considering these three issues, will be ascertained via a series of instrumented and monitored tests on large-scale rectangular columns (for comparison with existing small scale test results), together with qualitative finite element modelling to establish the evolution of the shape of the effectively confined area. This information, together with a suitable bond-stress-slip and concrete failure models, will be used to develop an analytical model for strengthening of rectangular columns based upon the mechanics of the behaviour rather than by fitting experimental results.