Engineering Commons^™

Investigation Of Grouted Dowel Connection For Precast Concrete Wall Construction, Douglas J. Provost-Smith

Electronic Thesis and Dissertation Repository

The grouted dowel connection is a simple and cost-effective connection used in many precast concrete structural systems. The required dowel length is currently designed as a regular bar in reinforced concrete, which underestimates the bond strength, thus resulting in excessive connection lengths. Furthermore, precast wall construction continues throughout cold weather, where in-situ heating of the grout used in the grouted dowel connections is usually conducted for short periods of time. Hence, early-age exposure to subfreezing conditions may affect the quality of the grout and subsequently the bond strength of the connection, which can compromise structural integrity.

In this thesis, full-scale …

Development Of Design Loads For Transmission Line Structures Subjected To Downbursts Using Aero-Elastic Testing And Numerical Modeling, Amal Elawady

Electronic Thesis and Dissertation Repository

The failure of transmission line structures due to severe High Intensity Wind (HIW) events is one of the major problems facing the electrical utility companies in various places around the globe including Canada. An extensive research program focusing on this problem started about fifteen years ago at The University of Western Ontario (UWO). In this Thesis, two major milestones are achieved leading to the advancement of the knowledge in this field. The first milestone is conducting, for the first time, a test on an aero-elastic model of a multi-span transmission system under reduced–scale simulated downbursts. The first objective of the …

Behavior Of Fire-Exposed Rc Frames Before And After Jacketing, M. Monir M. Ajan Alhadid

Electronic Thesis and Dissertation Repository

Analysis and design of fire-exposed Reinforced Concrete (RC) frames before and after jacketing with concrete layers are commonly performed using prescriptive methods that rely on the concept of fire rating. These methods were developed based on empirical results on individual RC members subjected to certain fire conditions. In typical fire scenarios, the residual capacity, stiffness and thermal deformations affects not only the local performance of each fire-exposed member, but also the load redistribution and global behavior of the entire frame. In terms of fire safety, the philosophy of the new building codes considers objective-based design as an alternative of the …

Enhancing The Seismic Performance Of Steel Structures Utilizing Superelastic Shape Memory Alloys, Papia Sultana

Electronic Thesis and Dissertation Repository

Although conventional earthquake-resisting structural systems provide the life safety level during earthquakes, they experience significant structural damage when exposed to strong ground shaking that render structural retrofitting as uneconomical. Superelastic shape memory alloys (SMAs) can be used in steel structures to reduce the residual deformations due to their recentering capability, which can facilitate post-seismic retrofitting. The primary aim of this thesis is to enhance the seismic performance of both regular and modular steel structures using an optimum amount of superelastic SMAs material in terms of maximum inter-storey drift, residual drift, and damage scheme.

First, a simplified method based on pushover …

Numerical Studies For Improving Fracture Toughness Resistance Curve Testing Using Single-Edge (Notched) Tension Specimens, Yifan Huang

Electronic Thesis and Dissertation Repository

The fracture toughness resistance curve, i.e. the J-integral resistance curve (J-R curve) or the crack tip opening displacement resistance (CTOD-R) curves, is widely used in the integrity assessment and strain-based design of energy pipelines with respect to planar defects (i.e. cracks). This thesis deals with issues related to the experimental determination of the J(CTOD)-R curves using the newly-developed single-edge (notched) tension (SE(T)) specimens. In the first study, the plastic geometry factor, i.e. the η_pl factor, used to evaluate J in a J-R curve test based on …

Innovating Two-Stage Concrete With Improved Rheological, Mechanical And Durability Properties, Manal F. Najjar

Electronic Thesis and Dissertation Repository

Two-stage concrete (TSC), also known as preplaced aggregate concrete, is a special type of concrete that is produced using a unique procedure which differs from that of conventional concrete. TSC is distinguished by its high coarse aggregate content and exceptional placement technique, whereby aggregates are first pre-placed in the mold then injected with a special grout. The preplacement of aggregates saves substantial energy since only the grout needs mechanical mixing; the grout is self-leveling and needs no vibration and no mechanical compaction. However, TSC applications are still limited despite substantial advancement of modern concrete technology. Therefore, there is a need …

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 …

Analysis And Design Procedure For Liquid-Filled Conical Tanks Under Seismic Loading, Ahmed Musa

Electronic Thesis and Dissertation Repository

Steel conical tanks are widely used for liquid storage in North America and elsewhere. A number of those tanks collapsed in the last decades as a result of instability of the steel shells. Despite being widely used, no specific design procedure is available for conical tanks under dynamic conditions. The research conducted in the current thesis presents a simplified approach for the design of steel conical tanks when subjected to ground excitations in the form of horizontal and vertical excitations.

First, the capacity of steel conical tanks to avoid yielding and buckling of the tank vessel under hydrodynamic pressure resulting …

Steel Compression Members With Partial-Length Reinforcement, Morgan Herrell

Electronic Thesis and Dissertation Repository

Steel wide-flange columns in existing truss bridges may be built-up with flange cover plate reinforcement to increase compressive capacity. This thesis investigates the use of partial-length steel cover plates about column mid-height to improve the weak-axis buckling resistance.

The present research first reviews literature concerning the Euler buckling of members with partial-length reinforcement. Inelastic buckling is simulated by 3-D finite element analysis accounting for cover plate length, cover plate area, bolt hole perforations, yield stresses, residual and locked-in dead load stresses, and initial out-of-straightness. The model is validated by a load test of a full-scale column with bolted reinforcement plates. …

Behaviour Of Reinforced Concrete And Composite Conical Tanks Under Hydrostatic And Seismic Loadings, Ahmed Elansary

Electronic Thesis and Dissertation Repository

Conical liquid storage tanks are widely used to store different liquids and to provide water supply at cities and municipalities. However, no comprehensive guidelines currently exist in the codes of practice for the structural analysis and design of such tanks. The walls of a conical tank can be made of steel, reinforced concrete, or a combination of the two materials in a composite type of construction in which steel and concrete walls are connected using steel studs. The research conducted in this thesis provides a comprehensive understanding of the structural behaviour of reinforced concrete and composite conical tanks under hydrostatic …

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 …