Engineering Commons^™

A Study On Hydraulic Conductivity Of Fine Oil Sand Tailings, Mingyue Liu

Electronic Thesis and Dissertation Repository

In oil sand waste tailings pond, the gravity segregation takes place, where coarse particles settle relatively more quickly than fine particles, and a stable suspension, known as the mature fine tailings (MFT), is formed. Compression of MFT appears to be very slow, and MFT remains suspended in tailings pond for decades due to the low permeability. Large volumes of MFT continually accumulate in tailings ponds, and therefore MFT storage requires a large containment pond, which generates environmental concerns and leads to MFT management challenges. Hydraulic conductivity is one of the most important properties of MFT because it controls consolidation behaviors. …

Static And Dynamic Properties Of Controlled Low-Strength Materials Incorporating Treated Oil Sands Waste, Ahmed Mneina

Electronic Thesis and Dissertation Repository

Controlled Low-Strength Materials (CLSM) is a self-compacted self-leveling cementitious material with compressive strength of 8.3 MPa or less. It is used as an alternative of soil backfill materials in geotechnical and infrastructure applications. This study investigates the effects of incorporating treated oil sand wastes (TOSW) as a partial replacement of sand or fly ash on fresh and hardened properties of CLSM. In addition, the environmental impact of the proposed new mixtures was evaluated. The results show that CLSM mixtures incorporating TOSW had satisfied the limits and requirements of ACI committee 229 for CLSM with no environmental hazards. The incorporation of …

Liquefaction Susceptibility Analysis Of Fraser River Sand In Miniature Cone Penetration Tests And Cyclic Direct Simple Shear Tests, Stephen Jones

Electronic Thesis and Dissertation Repository

The cone penetration test (CPT) and, its geophone-equipped form, the seismic cone penetration test (SCPT) are increasingly used site investigation techniques to determine in-situ geotechnical properties of soil profiles as well as liquefaction susceptibility in seismically active locations. The use of experimental techniques, most notably miniature cone penetration testing (MCPT), can be used to recreate these in-situ tests in a controlled laboratory setting.

In this study, MCPT tests are completed using Fraser River sand to determine cone tip and sleeve frictional resistances as well as shear wave velocity measurements and are validated using in-situ SCPT tests and existing soil classification …

Liquefaction Assessment Of Carbonate-Silica Silty Sands Using Energy, State Parameter And Shear Wave Velocity, Naemeh Naghavi

Electronic Thesis and Dissertation Repository

The liquefaction behaviour and dynamic properties of reconstituted natural carbonate-silica silty sand samples were investigated in a series of monotonic and cyclic triaxial tests. The critical state parameters of the mixtures with different levels of fines were obtained through monotonic triaxial compression tests. Bender element tests were performed at the consolidation stage to characterize soil’s initial state and small strain properties. The results demonstrated that soil contraction capacity, liquefaction potential and undrained brittleness increase by increasing the state parameter. A general correlation between shear wave velocity and state parameter was established. The susceptibility and triggering of liquefaction under cyclic loading …

Comparative Investigation Of Bored And Continuous Flight Auger Piles With Consideration Of Green Concrete, Mahmoud Kassem

Electronic Thesis and Dissertation Repository

Bored and continuous flight auger (CFA) piles are two widely used cast in place reinforced concrete pile types that are constructed employing different techniques, which affect their performance and capacity. However, both are classified as non-displacement piles and are designed accordingly using the same method. Therefore, the objective of this work is to comparatively investigate the axial and lateral performance of bored and CFA piles installed in sand. In addition, the potential of constructing sustainable piles utilizing green concrete mixture that incorporates treated oil sand waste (TOSW) was investigated. Fresh and hardened properties along with durability performance of CFA concrete …

Electrokinetic Consolidation Of Oil Sands Tailings: An Experimental And Numerical Study, Yu Guo

Electronic Thesis and Dissertation Repository

The management of fine oil sands tailings, known as mature fine tailings (MFT), is a major challenge for the oil industry in the Northern Alberta, Canada. Dewatering and consolidation of MFT are slow and time consuming due to high water content and low permeability of MFT. The electrokinetic (EK) dewatering treatment has shown to be effective on oil sands tailings based on the results of previous researches. Therefore, this thesis is focusing on experimental and numerical studies of EK dewatering of oil sands tailings. The thesis includes three parts, i.e., EK dewatering of oil sands tailings and kaolinite slurry, EK …

Channel Form And Processes In A Formerly Glaciated Terrain, Nathaniel Bergman

Electronic Thesis and Dissertation Repository

Despite that many places around the world in general, and North America in particular, were glaciated during the last ice age, relatively little is known about rivers that evolved over these landscapes once they deglaciated. These rivers are commonly categorized as alluvial with a glacial legacy, and often described as plain gravel-bed or sand-bed rivers. Alternatively, they are considered to be bedrock rivers when the glacial deposits were eroded and underlying rock was exposed. However, ignoring the glacial history of these rivers is scientifically wrong and they should be termed "semi-alluvial". This work shows that classification is important, not only …

Foundation Effects Of Trees Under Wind Loads, Padmavathi Venkata Sagi

Electronic Thesis and Dissertation Repository

Winching tests were conducted on a mature 24-year-old Norway spruce tree. The tree was instrumented with strain gauges along the root structure and tilt sensors along the tree stem and was winched to failure. Tracked tree-root system response to failure load and the material properties of the tree-root-soil system were used to examine the applicability of simple engineering principles to tree stability analysis. Tree stability was studied using the principles of Winkler foundation model for the first time. In order to study the very complex windthrow phenomenon, a novel experimental technique was used. Tree saplings with complete structural root systems …

Time-Dependent Behaviour Of Micro-Tunneling Construction In Queenston Shale, Hayder Mohammed Salim Al-Maamori

Electronic Thesis and Dissertation Repository

The Queenston shale among other shales from southern Ontario exhibits time-dependent deformation behaviour. This behaviour is manifested in the form of volume increase which can cause damages to the hosted underground structures. The time-dependent deformation of rocks can cause cracks in the springline of tunnels, wall inward movement, roof spalling and floor heave, which requires costly remedial measures. The expansion of the existing infrastructures in southern Ontario requires construction techniques, such as micro-tunneling to build new tunnels and pipelines under the existing structures with minimal impact to these structures and to the environment. However, adopting this technique in swelling rocks, …

Electrokinetics And Vacuum Combined Dewatering Of Oil Sand Tailings, Rui Zhang

Electronic Thesis and Dissertation Repository

One of the challenges faced by the oil sand industry is the dewatering of mature fine oil sands tailings (MFT) due to the low permeability. Vacuum pressure or electrokinetic (EK) dewatering is effective to meet this objective. This research was focused on the experimental study and analytical modelling to explore the influence of combined vacuum and EK treatment on MFT. In this study, systematical experiments on MFT recovered from the northern Alberta were carried out. At first, the characterization and EK cell tests were conducted to measure the basic properties and the coefficient of electroosmotic permeability (ke) of MFT. Secondly, …

Evaluation Of Fatigue Response Of A Carbonate Clay Till Beneath Wind Turbine Foundation, Jordan A. Kiss

Electronic Thesis and Dissertation Repository

This thesis describes full-scale field monitoring and analysis of an onshore shallow wind turbine foundation and an associated laboratory testing program. The aim of the study was to investigate the soil-structure interaction under coupled cyclic vertical-horizontal-moment loading. This involved simulating the soil element behavior in controlled laboratory tests, evaluating the accumulated cyclic soil damage and correlating this with the observed wind and turbine responses. The results form an important part of the ‘wind-chain’, providing information for optimizing the performance of wind turbines, extending their operational lifespans and potentially for development of structural health monitoring systems. The field monitoring systems for …

Seismic Vulnerability Of Buried Energy Pipelines In Northern Canada, Behrang Dadfar

Electronic Thesis and Dissertation Repository

Permafrost in Canada’s North covers the terrain either continuously or discontinuously. Geological hazards associated with the presence of permafrost are serious barriers against development of the northern hydrocarbon resources. In recent decades, negative effects of geohazards such as frost heave, thaw settlement, slope instability on the safety of northern pipelines are widely studied; however, those of the seismic events are not. During earthquakes, buried pipelines may suffer damage from the induced transient ground deformations (TGD) and/or permanent ground deformations (PGD). While the former is caused by seismic wave propagation, the latter can result from liquefaction, faulting and landslides. This thesis …

Numerical Modelling Of Wind Turbine Foundations Subjected To Combined Loading, Venkatesh Madhukar Deshpande

Electronic Thesis and Dissertation Repository

With the growing wind industry in Canada, it has become important to optimize wind turbine foundation design. Wind turbine foundations are subjected to combinations of vertical, horizontal and moment loads due to vertical self-weight of the structure and soil surcharge. Additionally, there are significant lateral loads and overturning moments attributed to varying wind forces acting at considerable tower heights above the ground level. In this thesis, the undrained bearing capacity response of circular & octagonal foundations subjected to combined loading is calculated using finite element analyses. Previous works have mostly focused on circular foundations. An octagonal foundation of the style …

Application Of Treated Oil Sands Drill Cuttings Waste In Micropiles Construction, Moustafa Ahmed Raafat Mohamed Aboutabikh

Electronic Thesis and Dissertation Repository

A micropile is constructed by drilling a hole, placing a steel reinforcing element, grouting it using neat cement. However, cement production consumes energy and generates carbon dioxide. Implementing waste materials in construction applications represents a sustainable solution for many waste management problems. On the other hand, oil sands drill cuttings waste represents one of the most difficult challenges for the oil sands mining sector. Reducing the amount oil sands drill cutting waste sent to landfill offers one of the best solutions for waste management. This thesis presents an innovative solution for application of treated oil sands waste (TOSW) in grout …

Slope Stability Enhancement Of An Upstream Tailings Dam: Laboratory Testing And Numerical Modelling, Yazeed A. Alsharedah

Electronic Thesis and Dissertation Repository

Mine tailings are the byproduct of mining activities, which need to be disposed of once the ore is extracted. They can be disposed of in either dry or wet forms. The latter is most common with the tailings being disposed of in the form of slurry inside retention structures. The retention structure may be a natural, manmade, or built dam, which is the case in most of nowadays mining locations. In this thesis, improving the stability of an upstream tailings dam using soil additives is investigated. The experimental phase of this study involved laboratory tests conducted to characterize mine tailings …

Investigation Of Hybrid Foundation System For Offshore Wind Turbine, Ahmed Mohamed Reda Abdelkader

Electronic Thesis and Dissertation Repository

Green energy resources are essential to meet the growing energy demands in the near future while reducing the effects of global warming. Offshore wind energy is one of the main efficient renewable energy sources which drive the ever increasing expansion of offshore wind farms globally. Wind energy technologies are improving making energy production more affordable, which helped Denmark, for example, to produce about 25% of its energy. One of the main challenges for offshore wind projects is the cost of foundation construction, which represents about 40% of the total cost. The investigated hybrid foundation system has the potential to reduce …

Behaviour Of Helical Pile Connectors For New Foundations, Muhammad Ahmad Muhammad Diab

Electronic Thesis and Dissertation Repository

Despite the wide application of the connections between slender pile types, which end with a mono steel bar at the ground level (e.g. helical piles and micro piles), and new reinforced concrete foundations with limited width (e.g. RC grade beams) in the piling industry in North America, neither a clear understanding of the connections' behaviour nor a specific design criteria for their implementation is presented.

The main goal of this research was to clearly understand the behaviour of these connections and their failure mechanism under monotonic and cyclic loadings. The research methodology involved conducting experimental tests on 33 full-scale pile-foundation …

Fundamentals Of Electro-Flotation And Electrophoresis And Applications In Oil Sand Tailings Management, Raquibul Alam

Electronic Thesis and Dissertation Repository

This thesis addresses two challenges facing the management of mature fine tailings (MFT) from oil sand processing. The first challenge is the high concentration of residual bitumen in tailings ponds, which poses a hazard to aquatic biota and impact to the environment. A laboratory scale study is carried out to assess the suitability of electro-flotation (EF) for removal of bitumen from oil sand tailings slurry. The results of the study confirm that EF is effective to reduce bitumen contents of tailings slurry. At a current density 150 A/m², the bitumen concentration is reduced from 106.8 mg/L to less …

Monotonic And Cyclic Performance Of Spun-Cast Ductile Iron Helical Tapered Piles, Ahmed Fahmy

Electronic Thesis and Dissertation Repository

The performance of a novel piling system is investigated, which involves a spun-cast ductile iron (SCDI) tapered shaft fitted with a lower helical plate. It combines the efficiency of the tapered section, the competitive cost, effectiveness and durability of spun cast ductile iron with a rough surface and the construction advantages of helical piles. The system is installed using a fast, low vibration and reduced noise process. Seven instrumented piles including five SCDI tapered and two steel straight pipes were installed in sand using mechanical torque. The piles were subjected to cyclic and monotonic compression, uplift and lateral load tests. …

Helical Pile Installation Torque And Capacity Correlations, Jared Louis Harnish

Electronic Thesis and Dissertation Repository

Large diameter helical piles are being utilized increasingly to support large compressive and tensile loads. Both the magnitude of the required installation torque and the pile capacity can be directly attributed to the soil shearing resistance developed over the embedded area of the pile including the shaft and helical plates. Hence, the pile capacity can be correlated to the installation torque. Such correlations are widely used in helical pile industry as a means for quality control/quality assurance. However, the reliability of capacity-torque correlations for predicting the large diameter helical piles is adversely affected by the inaccurate measurement of the installation …

Static And Dynamic Response Of Silty Toyoura Sand With Pva Fibre And Cement Additives, Colin J.R. Schmidt

Electronic Thesis and Dissertation Repository

After the Great East Japan Earthquake of 2011, nearly 24 million tons of disaster debris such as concrete products, natural and polymeric fibres, and tsunami deposits remained on the coast of Japan. Much of this debris was recycled and repurposed in engineering projects such as embankments, park restoration, and agricultural field restoration around Tokyo Bay, one of the hardest hit regions of the country. Such a major disaster developed a need for the stabilization of the liquefaction susceptible regions of the reclaimed Tokyo Bay coastline. This thesis specifically focuses on the stabilization against liquefaction of Toyoura sand with the typical …

Miniature Cone Penetration Test On Loose Sand, Sepideh Damavandinejad Monfared

Electronic Thesis and Dissertation Repository

Considering the difficulties associated with preparing loose sand samples in large calibration chambers and wide area of research on the behavior of loose sands, miniature calibration chamber experiments are used to perform cone penetration tests on soils in different states. A miniature cone calibration chamber has been designed and developed in this study. Nineteen tests have been performed on Ottawa sand and the results are compared to the available data in the literature. The accuracy of the results is validated by comparing the results with the suggested rate for the cone resistance in sands in literature. More specifically, results are …

Performance Of Micropiled Raft In Sand And Clay-Centrifuge And Numerical Studies, Ahmed M. Alnuaim

Electronic Thesis and Dissertation Repository

A micropile is a small diameter “cast-in-place” pile, which was initially used to repair deficient foundations. The overall performance of a micropiled raft (MPR) foundation system is similar to a piled raft foundation where the load is transmitted through both the raft and the micropiles. This thesis explores using micropiled rafts (MPR) as a new highly efficient foundation system that combines the advantages of the piled raft system and the efficient installation of micropiles and associated ground improvement. Currently, there is no guidance available regarding the performance of MPR foundations. Therefore, the main objectives of this research are to evaluate …

Static And Seismic Performance Of Geosynthetics-Strengthened Pile Foundations, Ahmed M. Taha

Electronic Thesis and Dissertation Repository

Geosynthetic reinforcement in earth structures has been used extensively over the last two decades. Extensive research has been carried out to investigate solutions to enhance the lateral stability of pile foundations. This research is motivated by the need to install piles in sites characterized by soft subsurface soil conditions, and often times, in seismic active areas. This research work explores an innovative use of geosynthetics to enhance the lateral performance of pile foundations. The static and seismic soil-structure-interaction behaviors of geosynthetics-reinforced pile foundation systems were evaluated using a series of reduced scale physical model tests performed on a shaking table …

Investigation Of Hollow Bar Micropiles In Cohesive Soil, Osama F. El Hadi Drbe

Electronic Thesis and Dissertation Repository

Micropiles are used in various applications, including low capacity micropile networks, underpinning and seismic retrofitting of existing foundations and high capacity foundations for new structures. They facilitate fast installation with a high degree of ground improvement. The current Federal Highway Administration (FHWA) design guidelines designate hollow bar micropiles as Type B micropiles, even though their construction technique is different than typical Type B, which results in overly conservative design. In addition, the current practice for construction of hollow bar micropiles is limited to drilling bit/hollow bar diameter ratio of 2.5 or less. In this thesis, full-scale load tests were conducted …

Cyclic And Post-Cyclic Response Of Silt And Sandy Silt Soils, Ali El Takch

Electronic Thesis and Dissertation Repository

A series of cyclic and monotonic constant-volume ring shear tests were carried out to determine the cyclic and post-cyclic response of silts and sandy silts with 25% and 50% sand. The elastic soil behavior at very small shear strain (γ < 10^-4%) was investigated through shear wave velocity (Vs) measurements using bender elements at vertical stresses ranging from 50 to 300 kPa, while strain-controlled constant volume cyclic ring shear tests were conducted to establish shear modulus (G) and damping ratio (D) at larger shear strain amplitudes (γ > 0.01%). Liquefaction and strain-softening occurred at excess pore water pressure ratios (r_{u …}

Hydrogeological And Thermal Sustainability Of Geothermal Borehole Heat Exchangers, S. Emad Dehkordi

Electronic Thesis and Dissertation Repository

Assessment of the current approach taken by guidelines and design methods of vertical closed loop heat exchangers shows that often groundwater flow is either disregarded or is not methodically incorporated. The state of scientific research in this arena reveals that overlooking the groundwater flow in the design procedure may not always be a correct assumption. The significance of advective heat transport compared to conduction is defined by the groundwater flux or Darcy velocity which heavily depends on the hydraulic conductivity of the ground, followed by the hydraulic gradient which has a relatively limited range. A sensitivity analysis on ground and …

Static And Seismic Soil Culvert Interaction, Osama Salem A. Abuhajar

Electronic Thesis and Dissertation Repository

Failures of box culverts under static and earthquake loads can cause significant economic loss. Therefore, it is important to investigate the soil-culvert interaction of box culverts to understand their responses to such loads. The response of buried box culverts is a complex soil-structure interaction problem, where the relative stiffness between the soil and the structure is a critical factor. Soil arching is an important aspect of the soil-culvert interaction problem, and results in the redistribution of free-field stresses due to the presence of buried structures and leads to an increase or decrease in the loading around box culverts.

A series …

Change In Pore Size Distribution Of Compacted Soil Layers And Its Effect On Solute Breakthrough Curves, Sara Karimi

Electronic Thesis and Dissertation Repository

It is often useful to predict contaminant migration from waste containment systems, such as landfills, as part of the assessment of the overall impact of such systems on the receptor environment. In many instances, material properties, for example, those of the liner, are assumed to be constant. This study was conducted to evaluate the accuracy of considering constant material and transport parameters in the modelling of sodium and chloride breakthrough curves through a compacted soil layer using the commercial software, Pollute v.7. Experiments were conducted with three different mixtures of glass beads and varying amounts of kaolinite (30, 40 and …

Monotonic And Cyclic Behaviour Of Steel Fibre-Reinforced And Frp-Steel Fibre-Reinforced Helical Pulldown Micropiles, Mahmoud Meckkey M. El Sharnouby

Electronic Thesis and Dissertation Repository

Helical piles are a deep foundation system that can be used to support pipelines, telecommunication and transmission towers, and low- and medium-rise buildings. Advantages of helical piles include: short installation time with minimal noise and vibration levels; can be installed with ease in limited accessibility site; and onsite quality control by measurement of installation torque.

The main objective of the current research is to assess the performance of steel fibre-reinforced helical pulldown micropiles (RHPM), and fibre-reinforced polymer-steel fibre- reinforced pulldown micropiles (FRP-RHPM) under axial and lateral monotonic and cyclic loading conditions.

The research methodology involved conducting full scale field testing …