Fires in mine tunnels and other underground space are a serious hazard, that can, if left unchecked, result in significant economic loss and human tragedy. In the UK, methods such as water deluge, foam application, and various types of handheld extinguishers have been used, but statistics show no improvement in the incidence of fire. Water mist has the potential to be an effective fire suppression system for tunnel spaces. Typical water mist systems utilise small droplets of around 100 micron that have a low terminal velocity and a high surface to volume ratio. This leads to behaviour distinct from that of traditional sprinklers. Various mechanisms of action have been identified: removal of heat; oxygen depletion; fuel cooling; attenuation of radiation; and disruption of air flow. The relative importance of each is case dependent. Current research has focussed almost exclusively on enclosures with minimal or no ventilation, and no data relevant to the application of mist in tunnels exists. In this thesis, a series of Computational Fluid Dynamics (CFD) simulations, based on published experimental data, are used to indirectly validate a CFD model of a hypothetical water mist system applied to a real tunnel fire, and to improve the understanding of how water mist performs in a strongly ventilated space. The water mist is represented by a Lagrangian-based particle-tracking model. This model is fully coupled to the continuous phase, accounting for transfer of momentum, heat, and mass. A 16m3 unventilated enclosure is used first to validate a pool fire model based on 0.3m square pools of methanol (27 kW) and hexane (115 kW). The behaviour of a thermal plume in a tunnel with forced ventilation is then validated, initially using a fixed volumetric heat source of 7.5kW in a small-scale tunnel, and then on a full-scale 3m square cross-section tunnel with a 3m diesel pool using the pool fire model. The water mist model is validated with the enclosure fire, and a sensitivity study assesses the effect of droplet diameter, spray velocity and angle, and water flow rate on the performance of the system. Finally water mist is applied to the tunnel fire At low ventilation, oxygen depletion and air-flow disruption are significant, whereas at high ventilation the only effect of the mist is to remove heat and reduce temperature.

In recent years, the rapid development of new information technologies has significantly impacted on the product development process as strategic means to gain competitive advantage in a global market. In the engineering domain, powerful computer-based tools such as Computer Aided Design systems enable engineers to perform various design tasks and realise product concepts in the early phase of the product development process. However, the increasing complexity of modern products as well as the globalization of product development further necessitate distributed and collaborative design environments. This is where different computer systems and dispersed specialists in similar or different disciplines need to collaboratively be involved in shared design activities. Therefore, the integration and communication of engineering information are two of the most key technical factors in ensuring successful collaboration. The current application of information technology in supporting collaboration during the design process is limited to either a document-based or a common format-based exchange level. These methods provide relatively simple forms of collaboration compared with desired distributed and collaborative design environments that can deliver more effective ways of collaboration. The work detailed in this research investigates the advantages of using modern distributed information technologies alongside a suitable framework and a product model to support multi-disciplinary collaborative design. The work also involves exploring other important issues related to real-time collaborative design environments. These are design transaction management, access control, communication, and version management. The research work employs modern technology and distributed computing to enhance the processes of collaborative building design. The research proposes a framework and a product model to extend the functionalities of stand-alone and single-user design systems to facilitate synchronous collaborative design where distributed designers can work concurrently on a centralised shared model and carry out all necessary communication and data exchanges electronically. The implemented framework proposes a data transaction management approach that ensures efficient concurrent access to the model data and maintains data consistency. The framework also employs software agents to automatically access and operate on the information exchanged among the collaborators. The proposed product model in this work extends an adopted model to support access right control and version management. The work is implemented in an experimental software as a client-server model. .Net technology is used for implementing the framework and the product model and virtual reality technology is used to allow for intuitive interaction with the system. The research concludes that the utilisation of the modern distributed technologies can effectively induce change in the design process toward a more collaborative and concurrent design. As demonstrated within this work, these technologies with a suitable system design can meet the main requirements of a real-time collaborative building design system.

Geothermal heat pumps (GSHPs), or direct expansion (OX) ground source heat pumps, are a highly efficient renewable energy technology, which uses the earth, groundwater or surface water as a heat source when operating in heating mode or as a heat sink when operating in a cooling mode. It is receiving increasing interest because of its potential to reduce primary energy consumption and thus reduce emissions of GHGs. The main concept of this technology is that it utilises the lower temperature of the ground (approximately <32°C), which remains relatively stable throughout the year, to provide space heating, cooling and domestic hot water inside the building area. The main goal of this study is to stimulate the uptake of the GSHPs. Recent attempts to stimulate alternative energy sources for heating and cooling of buildings has emphasised the utilisation of the ambient energy from ground source and other renewable energy sources. The purpose of this study, however, is to examine the means of reduction of energy consumption in buildings, identify GSHPs as an environmental friendly technology able to provide efficient utilisation of energy in the buildings sector, promote using GSHPs applications as an optimum means of heating and cooling, and to present typical applications and recent advances of GSHPs. The study highlighted the potential energy saving that could be achieved through the use of ground energy sources. It also focuses on the optimisation and improvement of the operation conditions of the heat cycle and performance of the GSHP. It is concluded that GSHP, combined with the ground heat exchanger in foundation piles and the seasonal thermal energy storage from solar thermal collectors, is extendable to more comprehensive applications.

The main purpose of this programme of research was to establish characteristic water levels to which new and existing properties of masonry construction can be protected against flooding. Typical flood protection systems often rely on the structural strength of the building and in doing so generate significant lateral loadings. Current guidance appears to be based on the results of a single experimental study and no calculation technique is currently available to determine suitable characteristic levels. The research aim was addressed by conducting a series of experimental tests at model scale and by developing a theoretical analysis. Model scale masonry wall panels were successfully tested in a geotechnical centrifuge and were subject to hydraulic loading or uniform wind loading. Wind loading was considered to allow validation of the experimental procedure to results in the literature. Wall panels were constructed from both brick and block units and the effect of different mortar strengths, openings, vertical loadings and cavity construction were assessed. The experimental procedure showed very good repeatability in terms of ultimate load and generally a yield line type failure mode was observed. A theoretical analysis based on yield line analysis was developed using spreadsheet software and verified using the results from the experimental programme. The analysis gave a good approximation of the experimental ultimate loads, but the optimised failure mode was not always consistent with that observed in the tests. A parametric study was completed to assess the effect of varying parameters not considered in the experimental study and in addition a typical domestic property was modelled to assess its resistance against flood loading. The characteristic water level for the weakest wall of the property was found to exceed the value given in the guidance, of 0.6 m, by 38 % and signified the importance of completing the correct modelling procedure.

Realising the benefits of implementing Building Information Modelling (BIM) tools and processes on projects worldwide, the architecture, engineering and construction (AEC) industry is rapidly moving towards BIM adoption. This calls for higher levels of interoperability amongst existing design and analysis tools used by various project team members. An approach to achieving higher levels of BIM maturity and interoperability is to adopt open, non-proprietary data exchange standards such as the Industry Foundation Classes (IFC). Efforts are currently underway to establish IFC-compliance in analysis tools. Establishing interoperability between architectural BIM models and energy analysis tools has been a challenging effort. With the industry chasing renewable energy targets for existing and new building stock, it becomes imperative to incorporate analysis tools for renewable energy systems (RES) in this effort. A plethora of tools are used by the project team to assess the performance of various RES in existing buildings or in post-design stages of new buildings. A holistic RES simulation tool is required that can assess various RES and their impact on the building’s energy consumption, carbon emissions and operational costs. Developing this tool’s interoperability with architectural BIM models would lead to higher adoption. The aim of this thesis is to develop a methodology to support renewable energy simulation by using architectural BIM models based on open data exchange standards thereby enhancing their interoperability. The research process involved a literature review of the existing RES analysis methods and approaches of developing IFC-compliant analysis tools. A methodology was developed that involved a standardised conceptual framework that can be used to establish compliance in RES analysis tools with open-data exchange schemas. The conceptual framework was implemented in a solar PV simulation model by means of a prototype. The prototype was validated against existing PV analysis tools and presented to industry experts to gain their feedback. It was concluded that the tool supported RES assessment of buildings in early design stages and could be widely adopted as a BIM tool by the AEC industry.

This study developed a conceptual collaborative engagement framework to overcome the challenges and contextual constraints associated with road infrastructure management in Nigeria.

The UK Department of Transport (DoT) has recently encouraged the use of externally post-tensioned structures for bridge construction. This is due to the durability problems encountered with the conventional internally bonded post-tensioned structures. However, due to the lack of bond between the concrete and the external tendons, the ultimate strength of these structures cannot be determined by just performing a sectional analysis at the section of maximum moment. Although several recommendations have been made for the ultimate analysis of these structures, none were considered satisfactory here. Hence the purpose of this investigation is to study the flexural behaviour of these structures of all stages up to collapse, and to propose a practical methodology for estimating their ultimate strength. The study introduces eight non-linear analytical models developed for the prediction of the moment vs. deflection response of simply supported externally post-tensioned beams (with and without deviators located along their spans) up to ultimate. The models employ an iterative procedure that involves the application of loads to the structure in increments up to the collapse condition, where the curvature distribution predicted at each loading sequence is used to estimate the stress increase and variation in eccentricity in the external tendons. Second-order effects due to variation in eccentricity of external tendons and frictional behaviour of tendons at the deviators are both taken into account in these models. The eight models were then verified by comparing the results derived from them with reported experimental data, whereby good correlation was obtained. An extensive parametric study was subsequently conducted using the proposed models applied to the various parameters that influence the ultimate behaviour of externally prestressed structures Finally, the recommendations in the codes of practice for the ultimate design of these structures were also investigated here.

There are many important environmental issues involved in the construction and use of buildings which are either undergoing or require further research. The lack of detailed embodied energy assessments models has been identified and limits possible environmental analysis. This study examines the current state of research into the environmental impact of frame materials, assesses the quality and range of data available, sets up a new framework for evaluation of materials and uses several example structures to assess the environmental impact This has been achieved by, firstly, studying the environment related literature available concerning the frame of the building, separate from other considerations, to provide a clear understanding of the processes involved. Second, data is extracted from the literature and processed to provide a homogenous approach and level field from which frame analysis can take place. Gaps in the available data are identified. Third, the identified gaps are filled using data derived from sources ranging from manufacturers' literature to direct analysis of on site activities. Fourth, a model has been created to assess the environmental impact of the building frame. The factors assessed within the remit of environmental impact are: embodied energy, embodied CO2 and transportation hours. The embodied energy includes the primary energy for all raw materials, transportation, office overheads and contractor operations. These are calculated from the winning of raw materials, through manufacture, to demolition and recycling. Embodied CO2 encompasses the same range of data, but with respect to the CO2 transportation hours estimate the time spend on the road by vehicles involved in the embodied energy and CO2 calculations. Finally data from several buildings has been used, to evaluated the environmental merits of each with respect to each other and to other buildings for which calculations have been performed. Conclusions have been draw and. further work suggested.

No description available.

On- and off-site construction activities during transport infrastructure projectsare major contributors to greenhouse gas (GHG) emissions. The SwedishTransport Administration (STA) has stated the goal of gradually reducing itsemissions from transport infrastructure projects to zero by 2050. However,current life cycle assessment (LCA)-based approaches for estimating GHGemissions are static and location-independent, and thus do not account for thedynamics of construction. Some project-based methods have been proposed,but there is little guidance and insight available to facilitate theirimplementation in real projects during project planning.This thesis aims to explore how CO2 emissions can be reduced during differentstages of the planning process for transport infrastructure. The analysis focuseson emissions during project execution, i.e. on- and off-site constructionactivities including material production, and transportation. An exploratoryresearch approach is used to develop practical CO2 reduction methods thatcould be implemented during the feasibility studies, the design stage, and theprocurement stage of the planning process. These methods and models aredeveloped and demonstrated in case studies. This is a similar to the prototypingmethod in which early drafts of a new system are developed and tested toenable further development into a finalized system. The findings show thatconsiderable CO2 reductions can be achieved if project alternatives areevaluated systematically during the planning process. Although most majordecisions are made during the early stages of the planning process, later stagesshould not be ignored because these offer opportunities to include moredefinitive project data and thereby improve the certainty of the assessments.Future research in this area should look at the entire planning process up to thestart of construction.