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Open Access
1d compression creep behaviour of kaolinite and bentonite clay
(2011) Varatharajan, Sivarajan; Wong, Ronald C. K.
Creep mechanisms and factors influencing the creep in clay soils are not yet well understood due to the complex structure of clay matrix. An experimental program was conducted to investigate the parameters affecting the creep behaviour. One-dimensional single stage, stepwise and overloaded-unloaded compression creep tests were conducted using standard oedometer apparatus on kaolinite and bentonite clay samples. Single and radial drainage conditions with different pore fluids were considered. Required creep stress levels were achieved using instantaneous loading increments. Effects of stress level, stress history, pore fluid chemistry, fabric structure, drainage condition and mineral compositions of clay on creep behaviour were studied based on the experimental results. Drainage condition exhibited insignificant influence on creep. Creep mechanisms were explained as a combined effect of sliding of clay particles at their contacts and deformation of particle itself. Compression of micro pores during the creep is negligible. Developed model successfully describes the creep behaviour interims of viscosity.
Open Access
A Comparison of irrigation upstream automatic controllers
(1991) Schaalje, Michael A.; Manz, David H.
Open Access
A comparison of the sample survey and open house methods of public consultation for transportation issues in the City of Edmonton
(2004) Mackay, Malcolm; Hunt, John Douglas
Open Access
A computer tool for managing logistics in construction industry
(2011) Almohsen, Abdulmohsen; Ruwanpura, Janaka
Open Access
A computer-aided mixture proportioning system for durable concrete
(2002) Nazir, Mohamed Nizar Mohamed; Day, Robert L.
Open Access
A contribution to risk-based inspection and maintenance planning for deteriorating pipelines and pressure vessels
(2017) Haladuick, Shane; Dann, Markus R; Maes, Marc; Achari, Gopal; Egberts, Philip; Huang, Qindan
Engineering systems are subject to deterioration processes, such as corrosion and fatigue, which reduce the resistance to failure. If failure occurs, it can have large social, economic, and environmental consequences. To mitigate this risk, regular inspections and maintenance are performed. To minimize the overall cost of operating the system, it is important to optimize the inspection and maintenance plan. Lifecycle risk-based inspection and maintenance planning, which involves determining the expected total cost of operating a system over its lifecycle, is the most established method of determining the optimal inspection and maintenance plan. However, lifecycle risk-based inspection and maintenance planning for complex engineering systems with many components requires a detailed analysis that can be computationally demanding; therefore, simplifications and assumptions are commonly used in the literature. The objective of this dissertation is to expand the state of knowledge in risk-based inspection and maintenance planning for pipelines and pressure vessels, removing many common assumptions and simplifications. Some aspects of the research specifically target pipelines or pressure vessels, while others are generic to any engineering system. Specifically regarding pressure vessels, a simple methodology is presented to determine the optimal maintenance time for a pressure vessel with an unexpectedly severe defect. This methodology is then expanded to account for the dependent failure events in pressure vessels with multiple defects and failure modes. For pipelines, a risk-based maintenance methodology is developed to decide whether it is better to continuously repair defects in a pipeline or to replace entire pipeline sections. This methodology also examines the impact of an uncertain lifecycle on risk-based maintenance planning. For general engineering systems, the use of heuristic algorithms in improving the computational efficiency of solving risk-based inspection and maintenance optimization problems is examined. Finally, a methodology is developed to perform risk-based inspection planning for the next inspection type, without requiring a lifecycle analysis. This study aids system operators in determining the optimal inspection and maintenance plan. It also provides methodology to perform risk-based inspection and maintenance planning in a computationally efficient or simpler manner, to make the techniques more practically applicable.
Open Access
A Coupling connection for precast column bases
(1986) Tsoi, Helena M., 1948-; Loov, Robert E.
Open Access
A Decision Support System for Efficient Utilization of Overdesign as a Fast Tracking Technique in Modular Steel Pipe Racks
(2012-12-12) Khoramshahi, Fereshteh; Ruwanpura, Janaka
Abstract To effectively address today’s aggressive schedule demands in the oil and gas industry, engineering and construction activities are usually overlapped to some extent to attain schedule compression. Overdesign is one of the techniques used in a project’s engineering phase to reduce the information dependency between activities, which results in overlapping. When there is insufficient design information, designers usually adopt more conservative assumptions in their designs than would normally be the case. This overdesign means successor activities can start and progress well ahead of and long before accurate details can be determined. Although this helps to reduce the overall schedule, it is not a risk-free process on its own. One of the major concerns in overdesign is the lack of design optimization, which will be directly translated to extra costs and increased materials wastage. Likewise, the assumptions made might not be conservative enough, necessitating rework. A review of the overdesign literature pointed to a lack of explicit research about overdesign as a schedule compression technique. This research study was designed in a way to address some of the gaps in the current overdesign literature. The purpose of the research presented in this thesis was to develop a decision support system for choosing the best opportunities to apply overdesign in oil and gas projects that provide the greatest schedule compression for the least incremental cost. The scope of the research is limited to the modular steel pipe racks. A mixed methods approach was taken to conduct this research. The purpose of the qualitative part was to build the overdesign conceptual framework, which further formed the basis for formulating the overdesign time-cost trade-off problem. This helped model the overdesign problem using stochastic decision tree principles. The entire process laid the foundation for developing the decision support system. The quantitative part of the research involved gathering real project information, which was used to relate the degree of conservativeness of the assumptions in overdesign to the probability of rework associated with any overdesign decision. This research provides contributions in four distinct categories: theoretical, literature, methodological and finally industry contribution.
Open Access
A Decision Support System for Risk Management of Contaminated Sites
(2011) Kluck, Cheryl Lee; Achari, Gopal
Embargo
A Deterministic approach to the design of reinforced concrete beams and slabs
(1972) Price, Patrick St. J.; Ross, Grant A.
Open Access
A Discrete/continuous model for the joint choice of node and shipment size in freight transportation
(1991) Abdelwahab, Walid M.; Sargious, Michel A.
Open Access
A framework for joint implementation: the Rusagas carbon offset project
(2002) Venugopal, Srikanth; Hettiaratchi, J. Patrick A.
Open Access
A framework for team evaluation in a mega-project setting
(2009) Farahmand, Haideh; Jergeas, George
Open Access
A gas generation, migration and extraction model for landfills
(2012) Wang, Chien-Kai Kenneth; Achari, Gopal
A numerical model is developed to simulate the generation, movement, extraction, and surface emission of landfill gas as well as possible air intrusion in a sanitary landfill equipped with an active or a passive gas collection system. The model was validated using results and data published in literature and has been used to study how the efficiency of a gas collection system may be impacted by a number of factors including vacuum pressure, well screen length, intermediate and final covers' thickness and permeability, number of gas collection wells and direction of well placement. The results suggest that a higher gas collection rate can be achieved by using a vertically placed well with a stronger vacuum pressure, a longer well screen, and a thicker and less permeable final cover, while undesirable air intrusion may be minimized by installing a larger number of wells.
Open Access
A Guide for implementation and utilization of pavement management systems
(1988) Enslen, Peter M.; Sargious, Michel A.
Embargo
A High-order triangular finite element for the solution of field problems on orthotropic media
(1971) Harrison, Derrick G.; Ross, Grant A.
Embargo
A Kalman filter-smoother for an inertial survey system of local level type
(1982) Wong, Richard Voon Choong; Schwarz, Klaus-Peter P.
Open Access
A Methodology for Estimating Greenhouse Gas Emissions from Heavy Duty Diesel Trucks Used for Road Transportation in the Construction Sector
(2014-05-23) Amiri, Mona; Sadeghpour, Farnaz
A large growth in the number of Heavy Duty Diesel Vehicles (HDDVs) is one of the main causes that Greenhouse Gas (GHG) emissions from the road transportation experienced a significant increase since 1990. With 97.5% of the total fleet used for delivery being HDDVs, these vehicles play an important role in Canada’s freight transportation. Latest statistics show that 17% of the heavy trucks operate in the construction sector. The objective of this study is to develop a methodology to estimate emissions from a single HDDV used in construction road transportation. The developed methodology showed -14% difference with on-road measurements, which suggests a reasonable accuracy in comparison with similar methods in the literature. This methodology can be used to address increasing GHG emissions from road transportation through implementing behavioural changes such as route planning and load factor management. It can also be also used by the construction suppliers to track and control their share of GHG emissions.
Open Access
A Model for Project Governance in Delivery of Oil and Gas Projects in Alberta
(2015-05-12) Hussain, Tariq; Jergeas, George
“Effective project governance, within corporate governance framework, has become a serious concern for organizations” (Crawford, Cooke-Davies, 2005). Findings of the research revealed various levels of understanding of project governance and a range of governance structures in practice within oil and gas owner organizations in Alberta. The new project governance model recommends oil and gas owners of Alberta reorganize their project governance structures, improve their policies and procedures, develop tools that support project governance, make it mandatory for project personnel to follow governance procedures, improve the governance role of Project Management Office (PMO), do audits for compliance, keep processes updated, and use lessons learned. The results of the focus group survey, conducted to validate the new governance model, revealed an overall agreement from industry professionals. The researcher concludes that the new governance model applied proficiently will help oil and gas owner organizations of Alberta improve governance and oversight.
Open Access
A model for real-time monitoring of pavements for public-private partnership
(2008) Lakkavalli, VenkataKrishna; Cowe Falls, Lynne