Engineering Commons^™

Thermal And Mechanical Studies Of Thin Spray-On Liner (Tsl) For Concrete Tunnel Linings, Taesang Ahn

Electronic Thesis and Dissertation Repository

The thesis presents a summary of Thin Spray-On Liner (TSL) effects on concrete. Three aspects, fire insulation, adhesion strength on concrete surface and load carrying capacity (i.e. flexural strength) on segmental concrete liners, are presented. Small-scale to full-scale laboratory tests were conducted using ASTM standards or devised methods. The TSL effects on three aspects were then compared with the results for uncoated concrete specimens. Numerical analyses using TEMP/W for the thermal response of TSL and a FE program, ABAQUS for the mechanical response of TSL were respectively carried out and compared with the measured results. Additionally, numerical analyses in respect …

Seismic Microzonation Of Great Toronto Area And Influence Of Building Resonances On Measured Soil Responses, Dimitar Genchev Mihaylov

Electronic Thesis and Dissertation Repository

A pilot seismic microzonation of the Greater Toronto Area (GTA) is used to establish the conditions and limitations of geophysical methods for site response investigations in city conditions. Maps of fundamental soil resonant frequencies, amplifications at these frequencies and interpolated average shear wave velocity of top 30 m of soil profile (VS- 30) used in soil classification were compared to the maps of drift thickness and surficial geology for the GTA. The non-applicability of the interpolated VS-30 map for site classification between measured test points is indicated. It is also shown that the soil response cannot be estimated properly using …

Investigation Of Hybrid Monopile-Footing Foundation Systems Subjected To Combined Loading, Mohamed El-Marassi

Electronic Thesis and Dissertation Repository

Laterally loaded structures such as wind turbines, offshore platforms, earth retaining structures, bridge abutments and many other structures impose complex loading regimes on the supporting foundations. These foundations are typically subjected to combinations of vertical, horizontal and moment loadings resulting from the vertical self-weight of the foundation system, superstructure, soil fill and surface surcharge, in addition to significant lateral loads and moments due to soil pressures, wind loads, waves and currents. In the case of shallow foundations, the weight and dimensions must be sufficient to resist tilting and sliding, whilst at the same time preventing failure of the subsoil and …

Geotechnique, Physico-Chemical Behaviour And A New Erosion Model For Mine Tailings Under Environmental Loading, Rozalina S. Dimitrova

Electronic Thesis and Dissertation Repository

Comprehensive geotechnical characterisation of mine tailings is required for the design, construction and safe operation of mine waste management facilities against the large number of potential failure risks. It is important that the characterization is carried out under the stress range and drainage conditions relevant to those encountered in the field.

The present research utilized mine tailings samples from a copper/nickel base-metal mine. Kaolinite and bentonite clays were added to the mine tailings in order to study the effect of clay percentage and clay mineralogy on the behaviour of saturated tailings/clay systems with varying composition. Slurries with moderate or high …

Vibration Isolation Using In-Filled Geofoam Trench Barriers, Ashref Mohamed A. Alzawi

Electronic Thesis and Dissertation Repository

A significant amount of numerical and experimental research has been conducted to study the vibration isolation by wave barriers considering open trenches, in-filled concrete or bentonite trenches, sheet-pile walls, and rows of piles. A few studies have investigated the use of expanded polystyrene (EPS) geofoam material as wave barriers, which indicated that in-filled geofoam trenches can be used as effective wave barriers. However, no engineering design method is available to date for the design of such type of wave barriers. This dissertation presents comprehensive experimental and numerical investigations on the use of in-filled geofoam trench barriers to scatter machine foundations …

Dynamic And Static Performance Of Large-Capacity Helical Piles In Cohesive Soils, Mohamed A. Elkasabgy

Electronic Thesis and Dissertation Repository

Large-capacity helical piles can provide immense construction and performance advantages over the conventional concrete and steel piles. Nowadays, there is significant interest in using large-capacity helical piles to support foundations that would be subjected to both dynamic and static loading.

The main objectives of this thesis are to: investigate the dynamic response and impedances of large-capacity helical piles; develop an analysis methodology for their dynamic response; and investigate their static axial compression and lateral behaviour, considering installation effects on their dynamic and static performances. The thesis presents the first full-scale vertical and horizontal dynamic field testing program executed on large-capacity …

Evaluation Of Wind-Induced Resuspension On The Performance Of A Mine Tailings Storage Facility, Laxmi Kant Kachhwal

Electronic Thesis and Dissertation Repository

Proper management of sulphide rich reactive mine tailings is a growing concern for mining industries. Oxidation of tailings can release acids and toxic metals into the surroundings, which can potentially pollute the ecosystem. Confining tailings under shallow water covers is one of the most successfully applied technologies for long-term storage. The water has lower solubility and diffusivity of oxygen than air and can significantly reduce the influx of oxygen to the bed tailings. However, wind-induced waves and currents in the water can resuspend bed tailings and ultimately result in oxidation.

Extensive field investigations were carried out to evaluate the performance …

The Behaviour Of Cement Stabilized Clay At High Water Contents, Saeed Sasanian

Electronic Thesis and Dissertation Repository

Artificial cementation of soft clays has been used for several years for different ground improvement projects. Although considerable work has been done to develop advanced machinery and techniques for the implementation of artificial cementation, less knowledge is available on the mechanisms involving the formation of the artificial structure and the resulting mechanical behaviour. The primary objectives of the present work were to investigate the formation of microstructure in artificially cemented material with Portland cement, find the relationships between cementitious bonding and clay mineralogy, and create constitutive frameworks for predicting the mechanical behaviour of cement-treated clays.

Qualitative and quantitative microstructural characterisation …