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.

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.

This thesis is motivated by the use of full-depth, precast, prestressed concrete panels to facilitate deck replacement of composite bridges. The shear pockets required in using convention shear stud connections, however, can cause durability problems. The objective of this study is to investigate the possibility of eliminating the use of shear studs, and adhesively bond the concrete and steel sections. The feasibility of the developed polyurethane adhesive joint is defined based on the serviceability and ultimate limit states. The joint must have sufficient stiffness that additional deflection due to slip must not be excessive. The adhesive and bond must also have sufficient strength to allow the development of the full plastic capacity of the composite section. The use of the developed adhesive joint in typical composite bridges was found to be feasible. The behaviour under live load was found to be close to a fully composite section.

The self-centering energy dissipative (SCED) brace is an innovative cross-bracing system that eliminates residual building deformations after seismic events and prevents the progressive drifting that other inelastic systems are prone to experience under long-duration ground motions. This research improves upon the design and use of SCED braces through three large-scale experimental studies and an associated numerical building model study. The first experimental study increased the strength capacity of SCED braces and refined the design procedure through the design and testing of a new high-capacity full-scale SCED brace. This brace exhibited full self-centering behaviour and did not show significant degradation of response after multiple earthquake loadings. The second experimental study extended the elongation capacity of SCED braces through the design and testing of a new telescoping SCED (T-SCED) brace that provided self-centering behaviour over a deformation range that was two times the range that was achieved by the original SCED bracing system. It exhibited full self-centering in a single storey full-scale frame that was laterally deformed to 4% of its storey height. The third experimental study confirmed the dynamic behaviour of a multi-storey SCED-frame in different seismic environments and confirmed the ability of computer models of differing complexity to accurately predict the seismic response. To achieve these goals, a three-storey SCED-braced frame was designed, constructed, and tested on a shake table. Lastly, a numerical six-storey SCED-braced building model was constructed. This model used realistic brace properties that were determined using a new software tool that simulates the full detailed mechanics of SCED and T-SCED braces. The building model showed that initial SCED brace stiffness does not have a significant effect on SCED frame behaviour, that T-SCEDs generally perform better than traditional SCEDs, and that the addition of viscous dampers in parallel with SCED braces can significantly reduce drifts and accelerations while only causing a small increase in the base shear.

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.

This thesis is broken into two parts. The first part, Chapters 1 - 7, focuses on work completed performing partial performance assessments in two case studies: the region of Peel in the Greater Toronto Area, and Tláhuac, Mexico. In both, pressure transients were monitored using high-speed sensors. The second part, Chapters 8 - 10, proposes a framework for performance assessments of water transmission and distribution systems, primarily applicable to analysis and operation yet useful in (re)design or additional design work as well. The framework is a synthesis of concepts ranging from fuzzy engineering to psychology and human factors, and will be of particular interest to larger, more sophisticated water utilities who may have a general understanding of their systems but lack specific insights in its operation and operational effectiveness. Careful consideration is given to not only the type of information and possible information fusion, but also details of necessary software and hardware, including possibilities for the system architecture.

The NIST miniature paste prism test was developed to assess sulphate resistance of cements faster than the commonly used ASTM C 1012 test. The goal of this research is to address the current limitations regarding the NIST procedure to determine the optimum testing parameters and to establish appropriate expansion limits. A range of variables including details of specimen design, curing regime, water-to-cementitious materials ratio, and prism length were tested on the materials with a wide range of sulphate performance. The findings of the study demonstrate that even though it can yield results in only three months, the NIST test can provide an erroneous differentiation between certain cementitious materials. Reliability and repeatability of the test results can be improved by using longer specimens and longer curing times. The NIST test can be used as a preliminary screening test, but users need to be aware of its limitations.

This thesis focuses on lead related drinking water quality issues in general and on hydraulic transient induced lead pipe corrosion events in water distribution systems in particular. Corrosion is a complex phenomenon, and particularly in water distribution systems, when its already challenging electro-chemical processes are influenced by numerous other physical and chemical factors. Lead pipe corrosion can itself be influenced by both the hydraulic transients and water chemistry events. To understand the relationship among hydraulic, chemical and material processes, an existing numerical 1-D transient-corrosion model for iron-pipe based systems is modified and extended to apply for systems having lead-pipes connected in series. The coupled hydraulic transient and advection-dispersion-reaction model with improved data handling facilities is applied for analyzing the transient induced lead pipe corrosion behaviors in the system for a range of options and establishes interrelationships among the parameters.

This study demonstrates how the density of a neighbourhood affects its energy demand, metabolism (energy and material flows) and its ability to produce its own energy. Single-family detached houses and row townhouses were each modeled using passive solar housing guidelines with the DesignBuilder building energy simulation software. Energy demand is then modeled within neighbourhoods at two densities based on south facing windows fully un-shaded at 9:00 am, and 12:00 pm solar time on Dec. 21. The neighbourhood metabolisms were then calculated based on location and density. The potential energy supply was evaluated from the spatial characteristics of the neighbourhood (for solar) and the metabolism (municipal solid waste and wastewater flows.) The potential energy demand and supply are then compared for the varying building types and densities to determine the sensitivity of the energy supply and demand relationships.

Fly Ash was tested in relation to its ability to mitigate alkali-silica reaction, its contribution to strength, electrical resistance and heat release with the aim of recommending improvements to fly ash specifications. ASTM C 1567 accelerated mortar bar test results were in agreement with an expansion limit of 0.10 % at 14 days. A non-standard alkali leaching test showed that with high alkali fly ashes as replacement level increases the amount of alkalis leached increases while prism expansions decrease. Measures of pozzolanic activity can be improved by measuring against non-pozzolanic fillers, This requires high replacement levels to reduce statistical variability. Isothermal calorimetry tests showed that high calcium fly ashes can lead to delays in hydration, these delays can be reduced by calcium hydroxide additions. Calcium sulphate additions can also improve hydration.