A number of methods have been proposed that utilize the time domain transformations of the frequency dependent impedance functions to perform time-history analysis of structures accounting for soil-structure interaction (SSI). Though these methods have been available in literature for a number of years, this study is the first to rigorously examine the limitations and advantages of these methods in comparison to one another. These methods contain certain stability issues that required investigating which lead to the formation of an analysis procedure that assesses a transform method’s stability. The general applicability of these methods was demonstrated by utilizing them to model increasingly sophisticated reference problems. Additionally the suitability of these methods to being incorporated into hybrid simulations of nonlinear inelastic structures considering soil-structure interaction was confirmed. The modelling of a nonlinear structure considering soil-structure interaction is an improvement over the most common modelling strategies that model solely linear-elastic behaviour.

A suite of NLFEA programs, VecTor, has been developed at the University of Toronto. However, this software still requires the development of other functions to execute some types of analyses. One of the required functions is the consideration of transient creep strain in the heat transfer analysis. Moreover, there is a strong need to develop a general graphics-based post-processor applicable to VecTor programs. The first objective of this thesis is to develop a function considering the effect of the transient creep strain, because it can have significant influence on the behaviour of concrete under elevated temperatures. The second purpose of this thesis is to construct the new analysis visualization features compatible with entire suite of VecTor programs. As the result, the modified post-processor, JANUS, has had its abilities expanded significantly.

Midsize cities face a number of sustainability challenges, particularly in terms of transportation and land use, however only a small subset of the literature has addressed these issues. Examination of the literature reveals two reasons for this: there is no consensus on a definition of midsize cities used for transportation research purposes, and there is very little empirical understanding of midsize city characteristics. This thesis addresses both of these issues. In order to establish the bigger picture, an empirical classification of Canadian cities is completed and used as a tool to analyze the travel behaviour characteristics of Canadian midsize cities. This work is followed by two detailed case studies of midsize Canadian cities – the City of Kamloops, British Columbia, and the Town of Milton, Ontario. The case studies employ both qualitative and quantitative research methods to explore the context around travel behaviour in each community.

Epoxy-coated reinforcement was developed in the 1970s and became the primary corrosion protection technique in North America. Throughout the years, ECR has exhibited mixed results, with some regions and jurisdictions reporting good corrosion protection while others reported poor field performance of ECR. It has been established that epoxy coating can lose its adhesion in a wet environment thus providing poor corrosion protection of reinforcing steel. However, limited research has been done on the influence of concrete pore solution on adhesion of epoxy coating to reinforcing steel. This research investigates the effect of high alkali conditions on performance of ECR bars. Based on the test results, it was found that the rate of disbondment increases as the hydroxyl ion concentration increases and presence of high temperature accelerates the disbondment process.

Epoxy-coated reinforcement was developed in the 1970s and became the primary corrosion protection technique in North America. Throughout the years, ECR has exhibited mixed results, with some regions and jurisdictions reporting good corrosion protection while others reported poor field performance of ECR. It has been established that epoxy coating can lose its adhesion in a wet environment thus providing poor corrosion protection of reinforcing steel. However, limited research has been done on the influence of concrete pore solution on adhesion of epoxy coating to reinforcing steel. This research investigates the effect of high alkali conditions on performance of ECR bars. Based on the test results, it was found that the rate of disbondment increases as the hydroxyl ion concentration increases and presence of high temperature accelerates the disbondment process.

Midsize cities face a number of sustainability challenges, particularly in terms of transportation and land use, however only a small subset of the literature has addressed these issues. Examination of the literature reveals two reasons for this: there is no consensus on a definition of midsize cities used for transportation research purposes, and there is very little empirical understanding of midsize city characteristics. This thesis addresses both of these issues. In order to establish the bigger picture, an empirical classification of Canadian cities is completed and used as a tool to analyze the travel behaviour characteristics of Canadian midsize cities. This work is followed by two detailed case studies of midsize Canadian cities – the City of Kamloops, British Columbia, and the Town of Milton, Ontario. The case studies employ both qualitative and quantitative research methods to explore the context around travel behaviour in each community.

Rapid delivery of backfill to support underground openings attracted many mines to adopt paste backfilling methods. As a precaution to prevent liquefaction and to improve the mechanical performance of backfills, a small portion of a binder is added to the paste to form the cemented paste backfill (CPB). Recently, adding sand to mine tailings (MT) in CPB mixes has attracted attention since it enhances the flow and mechanical characteristics of the pastefill. This thesis investigates the effects of adding sand to CPB on the undrained mechanical behavior of the mixture (CPBS) under monotonic and cyclic loads. Liquefaction investigations took place at the earliest practically possible age. Beyond this age, the present research focused on characterizing the evolution of stiffness and obtaining the values of the stiffness parameters that could be useful for designing and modeling backfilling systems. The liquefaction investigation involved monotonic compression and extension triaxial tests. Neither flow nor temporary liquefaction was observed for all cemented and uncemented specimens under monotonic compression, while temporary liquefaction was observed for all specimens under monotonic extension. The addition of binder and sand to MT was found to slightly strengthen the pastefill in compression while weakening it in extension. Under cyclic loading, the addition of sand negatively impacted the cyclic resistance. However, binder was found to be more effective in the presence of sand. All specimens exhibited a cyclic mobility type of response. The evolution of effective stiffness parameters for two CPB-sand mixtures was monitored in a non-destructive triaxial test for five days. Self-desiccation was found to not be influential on the development of early age stiffness. Moreover, a framework is suggested to predict the undrained stiffness at degrees of saturation representative of the field. The credibility of the proposed test in providing stiffness parameters at representative strain levels of the field was verified.

Portland-limestone cements (PLC) have been used in practice for a considerable period of time in several countries. In 2008, the CSA A3000 cements committee approved the addition of a new class of cement with up to 15% interground limestone. The CSA A23.1 concrete committee also approved the use of PLC in concrete in 2009. However, to date, due to uncertainty about the performance of Portland-limestone cements in sulfate environments, their use has not been allowed in sulfate exposures. In this study, the sulfate resistance of five different Portland-limestone cements and their combinations with various amounts of supplementary cementitious materials (SCMs) were examined. Besides the standard tests performed at 23 °C, a modified version of the ASTM C1012 test was developed in this study (adopted in 2010 as CSA A3004-B) and used to investigate the possibility of thaumasite form of sulfate attack at 5 °C. It was found for tests conducted at 23 °C that while 100% cement mixes deteriorated in sulfate exposure due to conventional sulfate attack, partially replacing the Portland cements and Portland-limestone cements with 30% or 50% slag was effective in making the mixes highly sulfate-resistant. In sulfate exposure at 5 °C, all of the 100% cement mortar bars failed the test and had completely disintegrated due to the formation of thaumasite. Partially replacing cement with 30% slag was effective in controlling the deterioration at 5 °C only for Portland cements and not Portland-limestone cements. However, all the combinations of the cements with 50% slag were resistant to the thaumasite form of sulfate attack. In a parallel study, the hydration of Portland-limestone cements and the relationship between strength and porosity of mortar samples were examined. The results of hydration studies revealed that the limestone portion of Portland-limestone cements reacts with the alumina phases and produces carboaluminates, which contributes to the strength. As the limestone content of the cement increased, the shift in the optimum level of SCM providing maximum strength and minimum porosity was attributed to the availability of more alumina, which allowed more limestone to participate in the hydration reactions, forming additional carboaluminate hydrates.

This thesis presents the development and validation of a high ductility seismic resistant steel brace connector called the Yielding Brace System (YBS) that improves the earthquake performance of steel braced frame buildings. The connector is comprised of two steel castings which dissipate seismic energy through flexural yielding of specially designed triangular yielding fingers. In this body of work, the need for such a system is presented along with a summary of previously developed steel castings for enhanced earthquake performance of building structures. The development of the YBS concept is then discussed in detail and equations are developed to predict the elastic and plastic response of a YBS connector based on the geometry of the yielding fingers. The low-cycle fatigue life of the cast steel material used for the yielding elements of the YBS is characterized based on the results of several cyclic, small-scale yielding fingers tests and a low-cycle fatigue life prediction model is derived. Following this, the design of a prototype connector for the second storey brace of a fictitious six storey sample building located in Los Angeles is presented. This design is conducted using the low-cycle fatigue prediction model, the response prediction equations and non-linear finite element analysis. Results of four full-scale prototype tests are then presented. Two of the tests are axial tests of the device alone, while the other two are full-scale braced frame tests. Finally, the design of a 12-storey sample building is presented. This building design is then evaluated via non-linear time-history analysis using the FEMA P-695 methodology. The results from these analyses are then discussed and compared to a similar study conducted on the same building designed with buckling restrained braces. This work shows that the Yielding Brace System is a highly ductile, seismic resistant brace that can be used as an alternative to the buckling restrained brace with the potential to provide a stiffer structure with increased ductility.

Large-scale earthmoving activities make up a costly and air-polluting aspect of many construction projects and mining operations, which depend entirely on the use of heavy construction equipment. The long-term jobsites and manufacturing nature of the mining sector has encouraged the application of automated controlling systems, more specifically GPS, to control the earthmoving fleet. Computer vision-based methods are another potential tool to provide real-time information at low-cost and to reduce human error in surface earthmoving sites as relatively clear views can be selected and the equipment offer recognizable targets. Vision-based methods have some advantages over positioning devices as they are not intrusive, provide detailed data about the behaviour of each piece of equipment, and offer reliable documentation for future reviews. This dissertation explains the development of a vision-based system, named server-customer interaction planner (SCIT), to recognize and estimate earth material loading cycles. The SCIT system consists of three main modules: object recognition, tracking, and action recognition. Different object recognition and tracking algorithms were evaluated and modified, and then the ideal methods were used to develop the object recognition and tracking modules. A novel hybrid tracking framework was developed for the SCIT system to track dump trucks in the challenging views found in the loading zones. The object recognition and tracking engines provide spatiotemporal data about the equipment which are then analyzed by the action recognition module to estimate loading cycles. The entire framework was evaluated using videos taken under varying conditions. The results highlight the promising performance of the SCIT system with the hybrid tracking engine, thereby validating the possibility of its practical application.