Electro-osmosis is one of the five electrokinetic phenomena that may occur in soils, and the phenomenon of principal interest to this thesis. It may be defined as the movement of the pore fluid in a fine-grained soil caused by the application of a DC electrical potential difference across the soil mass. One of the main reasons that electro-osmosis has not received a more widespread application in the field of geotechnical engineering is due to the difficulty of successfully applying the electrical potential field to the soil mass. This thesis addresses the technique of using a carbon filled polymeric electrokinetic geosynthetics (EKG) to apply the electrical potential field and induce electro-osmosis in a soil mass. The thesis reviews the historical development of geosynthetics and the different techniques available for making them electrically conductive are discussed. A new type of EKG band drain is introduced and its construction, durability and connection technology are presented. The application of electro-osmosis, through the use of the EKG band drain, to the functions of soft soil consolidation, cohesive fill to reinforced soil structures and the volume control of shrinking and swelling susceptible soils are considered. Design methods are developed for these functions and are applied to two full-scale field trials in the application areas of electroosmotically enhanced reinforced cohesive soil and electro-osmotic volume control of an embankment, and a smaller scale field trial of electro-osmotic consolidation of soft soil. The results of these field trials have been analysed with respect to the design methods developed and confirm their validity for future use. Soil acceptability criterion have been developed to allow the applicability of electro-osmosis, to a soil to be evaluated based upon conventional and electro-osmosis specific soil mechanics laboratory tests. Potential future applications for electro-osmosis and EKGs are suggested.

This research is aimed to develop a series of design guidelines and relevant prediction tools for the incorporation of natural ventilation in atrium spaces as a passive cooling strategy. Focused on the geometrical and thermal characteristics of atrium buildings, four issues related to this purpose are investigated in this work including thermal comfort, wind-induced ventilation, buoyancy-induced ventilation and combined buoyancy and wind driven ventilation: In order to identify when passive cooling strategies are needed for atrium spaces, a new thermal comfort assessment method which enables the treatment of the solar radiation and non-uniform environment is developed using M.ATLAB as the data exchange platform. It is found that high mean radiant temperature (MRT) can be a more significant factor contributing to the thermal discomfort of the space when the internal occupants' level is irradiated by the sun rays. It is also shown that the air temperature at the occupants' level is mostly affected by the temperatures of the surfaces at lower levels and the temperatures at the roof level and the upper areas generally have little influence on the air temperature at the occupants' level. The study of wind-induced ventilation is concerned with the airflow through roof openings since the atrium is' often placed in the centre of a building and· as a result the openings at lower levels are not available. In this way the air movement in the space is actually driven by the recirculation rather than the direct main flow from the wind. Three. possible flow patterns, and related controlling forces for each flow pattern are defined first, based on which the impacts of the design parameters on the ventilation performance are investigated by CFD techniques and design guidelines are developed accordingly. The effects of the location of heat source and the control of the neutral level when bidirectional flow occurs are studied for buoyancy-driven natural ventilation of atrium spaces. The tendency of the heat source efficiency with the variation of. its location is examined and the optimised location for the heat source is suggested, based on which the guidelines for the selection of materials for the atrium internal surfaces are made. A series of new' algorithms are also developed for the prediction of neutral level when bi-directional flows occur and validated with CFD simulations. The investigation of the combined ventilation focuses on the condition where wind forces and buoyancy forces partly assist each other and partly oppose each other, and it is found that the phenomenon of solution multiplicity still exists for this condition and different solutions may have different ventilation performance depending on the initial conditions.

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The aim of the thesis is to reduce the occurrence of errors in construction documents by developing a theoretical model to capture the dynamics of processes that define the relationship between the factors causing errors in construction documents. The research justified a mixed-mode research approach and the use of system dynamics as the modelling tool. Different types of errors in construction documents were identified that can be classified as follows, starting with the most serious: the erroneous; omissions; failure to conform to design parameters; failure to follow procedures; coordination problems; failure to address operability and constructability issues; and finally, the difficulty of biddability. Also factors affecting the occurrence of errors in construction documents were identified and classified. The classification was based on individual and includes project management, designer, client, and project characters. Using System Dynamics modelling tools each factor has been concluded, with experts’ validated causal analysis diagrams that explain the highly dynamic relationship between the factors and the element(s) having a direct influence on the occurrence of errors in construction documents, using prior theoretical knowledge extracted from the literature, case-study projects and interviews. The developed model simulated the occurrence and behaviour of errors while producing construction documents. The focus of the model is based on an understanding of the internal mechanism of the occurrence of these errors, to avoid placing blame in favour of finding the true, long-term solution to a problem. Measuring the model's behaviour and using sensitivity tests for the correctly solved errors revealed two types of behaviour: one where the model shows reasonable behaviour up to a certain drop in the value of the factors, and the second where the model is under full control of the value of the factors when this value drops below 10%. Among the most sensitive factors were the designer’s previous experience, the designer’s education, the experience of the designer with similar projects, and the factor of the designer’s reputation. These findings were validated and supported by case study projects. The model can be used as a valuable tool in communicating the impact of complex structures on the behaviour of errors in construction documents, and has created opportunities for expanding the study of project dynamics in several potentially valuable directions. This research points to ways of improving performance through improved understanding of the occurrence and structure of errors in construction documents.

This research investigated the thermal environmental performance of atria in the tropics, with special reference to Malaysia. The main design problems that affect the thermal and energy performance in existing Malaysian atria are overlighting and overheating due to the direct application of western top-lit atrium roof form. As such, 'this research proposed the side-lit atrium form which aimed at controlling direct sunlight as a way to improve thermal and energy performance of atria in the tropics. Based on the proposed conceptual atrium form, this research examined quantitatively some of the low energy design features and ventilation strategies that can possibly contribute to a better indoor thermal environmental performance of atria in the tropics. The ultimate aim of this research is to propose design principles and guidelines for new low-energy atria in the tropics The combined research methods are as follows: developing a conceptual low energy atrium form based on the vernacular design features to be used for computer modelling studies; carrying out field measurement and monitoring on an existing atrium building which provides validation data for dynamic thermal simulation program TAS; modelling exercise on the same monitored building using dynamic thermal modelling to develop confidence in correctly modelling thermal stratification within the multi-level atrium; employing dynamic thermal modelling to model representative atrium .forms (i.e. both side-lit and top-lit model) and examine quantitatively the effects of some of the key design parameters (i.e. wall-to-roof void area, roof overhangs, and internal solar blinds) on the thermal comfort and energy performance in atria due to both full natural ventilation and pressurised ventilation; and utilising computational fluid dynamics (CFD) to complement the dynamic thermal simulation results, and to investigate quantitatively the thermal and ventilation performance within the atrium well in response to the changes of design parameters (i.e. varying the inlet to outlet opening area ratio and outlet's arrangement). The research findings supported the research proposition and demonstrated the effectiveness of the side-lit form as a way to improve the thermal and energy performance with regard to users' thermal comfort in atria in the tropics. The main,findings from both dynamic thermal simulation and computational fluid dynamics (CFD) are as follows: full natural ventilation strategy is not viable for Malaysian atria; both sufficiently high wall-to-roof void area and extending high-level internal solar blinds can greatly improve the atrium's thermal performance particularly on occupied levels; sufficiently wide roof overhangs above the clerestory areas of the side-lit atrium form generally improves the thermal and energy performance within the central atrium throughout the yea~; reasonably comfortable thermal environment on occupied levels of a low-rise atrium can be achieved by only supplying cooler air at low-level with sufficient ventilation rate; sufficiently higher inlet to outlet opening area ratio can improve the thermal performance on the occupied levels; and with equal inlet and outlet opening area, changing the outlet's arrangement (i.e. location and arrangement) would not significantly affect the atrium's thermal performance.

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