<p>This thesis describes the development of a technique to build small-scale shear wall building models using a suitable concrete mortar. Tests were conducted to study the behaviour of such models under lateral load. The analysis of the problem was done by treating the model as a thin-walled cantilever beam based on Vlasov's thin-walled beam theory. The test and analytical results are compared to investigate the validity of this approach.</p> / Master of Engineering (ME)

<p>A geographical information system has been creatively utilized to assist in the study and better understanding of the spatial variation and distribution of certain processes in water resources and coastal engineering. Hydroinformatics is the contemporary term that best describes the interactive knowledge-based non-expert decision support systems (DSSs) developed in this study in the form of GIS-based algorithms.</p> <p>The spatial distribution of the annual orographic rainfall on the island of Crete (Greece) was modelled by using the multiple linear regression (MLR) method. The MLR models, developed and applied through the GIS interface, provided better estimates/predictions of rainfall at un-gauged locations than the conventional spatial interpolation techniques. This, in turn, resulted in more realistic spatial distribution of rainfall. A new DSS was developed that was applied to the island of Crete and Switzerland to asses rain gauge worth within an established network. This system provided the tools needed to reduce the number of gauges, if necessary, in an existing network, which means eliminating redundant gauges while maintaining an efficient network. Another tool was also developed to provide a ranking system that is based on performance evaluation of a number of spatial interpolation techniques in large and small rain gauge networks. Recommending the usage of certain techniques over others for a certain set-up of gauges and their records should improve the gridded precipitation input to distributed hydrological models. The same procedure may be followed for any other spatial variable (hydrological, meteorological, etc). Switzerland and the municipality of Hamilton-Wentworth (Ontario, Canada) were used as test cases for system evaluation.</p> <p>A new GIS module was developed to estimate reference evapotranspiration based on the Penman-Monteith and Class A Pan Evaporation methods and using the station- and grid-based approaches. Although the combination of the grid-based approach and the Penman-Monteith method is recommended, the collection of significant amount of meteorological data from a relatively dense meteorological network is required for better results.</p> <p>GIS was also used to facilitate the estimation of irrigation water requirements for different scales. Zooming in from large-scale (in the island of Crete) with limited number of meteorological stations to smaller scales with more "representative" stations provided support for the usage of the grid-based approach for calculating irrigation requirements.</p> <p>For coastal engineering, a GIS pre-processor was developed for pollutant transport modelling in coastal areas. It provides accurate input to the models in the form of user-specified well-descritized bathymetry and shoreline, which are also used for post-processing purposes (i.e. graphical display). In addition to saving time in generating input files, this GIS pre-processor provides higher spatial accuracy, since all themes are geographically-referenced, which eliminates the possibility of overlapping or misplacing. It also shows great flexibility in generating grids of different cell sizes, interpolation techniques, and spatial extent. Transferability of the project between users and terminals makes it more accessible and convenient.</p> / Doctor of Philosophy (PhD)

<p>This thesis involves the consideration of the reinforced concrete beam as a composite beam with incomplete interaction. The flexual carrying capacity of the remaining uncracked portion, and the distribution of shear stress throughout the depth of a cracked beam are studied analytically.</p> / Master of Engineering (ME)

<p>The existing gap between minimum reinforcing requirements specified in the current Canadian masonry design standard (CSA S304.1 2004) and the provision for unreinforced masonry limits engineers to use the same minimum requirements for regions with low or moderate seismic demands. As a result, this restricts the use of reinforced masonry construction as a cost-efficient building system in regions with moderate seismic risks. In this research program, the performance of partially grouted reinforced masonry (PG-RM) shear walls, having larger reinforcement spacing than specified as minimum seismic requirements, has been evaluated to help in future efforts to offer some relief from the code's limitation.</p> <p>As the first phase of this research study, a computationally efficient numerical tool (finite element model) capable of predicting the pre- and post-peak response of PG-RM shear walls under in-plane loading was developed. The performance of the numerical model was evaluated by simulating available shear wall tests from other studies as well as the shear wall tests done as part of experimental program of this work. In general, acceptable accuracy was observed in numerically predicting both the pre- and post-peak behaviour of the shear wall specimens and the model was shown to be a reliable tool for further studies.</p> <p>The experimental program was intended to document the effects of reinforcement spacing and aspect ratio on the response of PG-RM shear wall under cyclic reversed loading. Direct small scale modelling using half-scale model concrete masonry units was chosen for the experiments. Two stages of testing were conducted. The first stage was designed to investigate the performance of masonry wallettes (panels) under the action of diagonal compression loading. Various patterns of grouting and reinforcing were studied by testing nine diagonal compression specimens. The second stage of the experimental research focused on the response of PG-RM shear walls under constant axial load and fully reversed cyclic lateral loading. The test matrix consisted of five masonry shear walls with nearly the same reinforcement ratios. The walls included three aspect ratios and three reinforcement spacings. Visual observations, loading, displacements, and crack pattern were recorded throughout the tests.</p> <p>The developed numerical model was used to expand the scope of the study to include the effects of level of axial load and amounts of horizontal and vertical reinforcement on the behaviour of PG-RM shear walls. In addition, the effect of reinforcing two cells at the ends of a PG-RM shear wall was also simulated. Close agreement was observed between the shear resistance estimated based on the Canadian masonry design standard (CSA 2004) and the experimental results of the PG-RM shear walls dominated by the shear failure mode. However, it was shown that the seismic load reduction factor, R value, suggested by CSA (2004) underestimates the energy dissipation ability of PG-RM shear walls despite the shear dominated behaviour observed for the test walls.</p> <p>The finding of this research study indicates a relatively ductile behaviour with satisfactory energy dissipation capability for PG-RM shear walls. This emphasises potential application of this type of wall as a more cost-efficient alternative in the future of masonry construction.</p> / Doctor of Philosophy (PhD)

<p>This thesis presents a comprehensive approach to numerical modelling of the nonlinear behaviour of structural masonry. Masonry is a heterogenous material, which displays orthotropic symmetry. The anisotropy effects are described here by incorporating a set of distribution functions specifying the directional dependence of material properties.</p> <p>In the first part, a macroscopic failure criterion for structural masonry is proposed. This criterion is derived within the framework of the critical plane approach. First, a general discussion is provided examining the performance of this framework within the context of both classical linear and nonlinear criteria. Subsequently, a bi-linear form of failure criterion for strucutral masonry is proposed. Extensive numerical study is performed examining the behaviour in biaxial compression-tension and compression-compression regimes for different orientations of the sample relative to the loading direction. The results are compared with the available experimental data.</p> <p>In the next part, the results of a 3D seismic analysis of the masonry walls of a power substation building - typical of those constructed in the elastic range, assuming orthotropic material properties, and the admissibility of the stress field is assessed based on the proposed failure criterion. A numerical study is performed examining the effect of different reinforcement strategies.</p> <p>The focus of the last part of this thesis is on the description of progressive failure in structural masonry. A continuum formulation is developed here which is applicable to a representative volume comprised of a large number of units interspersed by mortar joints. The framework defining the conditions at failure when employing the critical plane approach is extended to model the inelastic deformation process. This is accomplised by incorporating a multi-laminate approach in which the average response is derived from sliding/separation characteristics along a set of randomly distributed planes. The localized deformation is descrived by considering a structured medium comprising the intact masonry intercepted by a distinct macrocrack. Extensive numerical simulations are performed examining the response of brickwork in compression/tension regimes at different orientations of the bed joints relative to the loading direction. A boundary-value problem which involves an inelastic finite element analysis of a bearing masonry wall subjected to in-plane loading is also studied.</p> / Doctor of Philosophy (PhD)

Master of Engineering (ME)

<p>Traffic engineers rely heavily upon the fundamental relationships between the variables speed, flow and capacity which characterize the traffic stream. Accurate knowledge of the operational behaviour of roadway traffic inevitably enhances the reliability of planning and design. Because of the importance of basic relationships to traffic engineering, this study was undertaken. The study involves investigating the important relations between speed, flow and capacity currently existent for uninterrupted flow on multilane highways in Ontario. The results are compared with information established by both the Highway Capacity Manual (HCM) and Polytechnic Institute of New York (PINY). Comparisons are made of 5-minute and 15-minute hourly flow rates, and calculated truck equivalents with those currently recommended. In addition, the impact of adverse weather conditions on fundamental speed-flow relationships and how occupancy (density) relates to speed and flow were investigated.</p> <p>Results of the study indicate that there is a significant difference between relations presently in use and those existing on roadway facilities. In particular, capacity was found to be in excess of 2000 passenger cars per hour and speeds were noted as being higher than established values.</p> / Master of Engineering (ME)

<p>A research program into the investigation of the behaviour of double chord HSS Warren trusses is presented. The experimental results of eleven tests on five different types are reported; these include two Back-to-Back trusses, two Standard trusses and a Bolted type. One of the Back-to-Back trusses employed stiffening plates to reinforce gapped connections while the other had web members fully overlapped. The two Standard trusses had different eccentricities depending on whether the ends of the web members were square cut or angle cut. Gusset plates and tie plates were used to stiffen the connections for the Bolted truss. Retreats after reparations were undertaken in the event of a localized joint or member failure so that maximum information could be obtained from the program.</p> <p>An analytical model has been developed and incorporated into an existing plane frame program for analysis of the double chord HSS trusses. Three types of yield mechanisms that are accounted for are plastic hinge formation at the end of a member, member failure due to plastic limit load and yielding of the spring for modelling a connection.</p> <p>The experimental and analytical results are then compared thus confirming the validity of the analytical model. Finally, conclusions and recommendations are outlined for the analysis, design and feasibility of double chord Warren trusses with hollow structural sections.</p> / Master of Engineering (ME)

<p>This thesis studies the effects that nonproportional damping has on the vibrational characteristics of two and three level systems. In additions, error levels in response prediction are estimated for two simplified time history procedures and a response spectrum technique. It is shown that nonproportional damping creates significant changes in the damped frequency, damping ratio and mode shape of each mode of vibration of the system relative to those found for a similar system exhibiting proportional damping. The study of the prediction of the maximum system response to seismic basic motions demonstrates that there exist three regions where different dynamic analysis procedures should be used. A physically uncoupled analysis should be used for large mass ratios. A complex modal analysis should be used if the mass ratio is of an intermediate value. Diagrams are supplied which allow one to readily determine which of the three methods is the most appropriate for a design.</p> / Doctor of Philosophy (PhD)

<p>A large number of low and medium-rise buildings have steel moment resisting frames as the primary lateral load resisting system. During the past few decades, much confidence has been placed on this type of structural system for resisting seismic loads. However, after recent earthquakes (e.g. Northridge, California, in 1994, and Kobe, Japan, in 1995) the confidence in this system was reduced as a result of various types of damage that moment resisting steel frames suffered. This resulted in a recognition of the need to evaluate the performance criteria on which current provisions are based. While there have not been any major casualties dueu to earthquakes in Canada during the past few decades, in fact there is an actual seismic hazard which affects significant regions of the country, for example, the cities of Victoria, Vancouver, Quebec City, Montreal, and Ottawa. The design peak ground motions in such regions are moderate in comparison with those in California or Japan, however the uncertainties associated with estimating the expected ground motions are such that twice or three times the seismic design level motions are likely to occur. The main objectives of this research study are: (i) to evaluate the seismic level of protection afforded to steel moment resisting frame building structures designed in accordance with the current Canadian provisions (i.e. NBCC (1995) and CAN/CSA-S16. 1-94), and (ii) to investigate the effect of the different design philosophies and seismic hazard design levels on the inelastic dynamic response of multi-storey steel frame structures. Six storey office buildings located in regions of high, intermediate, and low seismic hazard, and a ten storey office building located in a region of intermediate seismic hazard are designed in accordance with the current Canadian provisions using three design philosophies, namely strong-column weak-beam (SCWB), weak-column strong-beam (WCSB), and strong-column weak-panel zone (SCWP). The scope of the research program includes: (a) modelling of the structural elements; (b) nonlinear push over static analyses/inelastic dynamic analyses, and (c) evaluation of the damage potential associated with each design. In the study analytical models are modified and incorporated into the PC-ANSR computer program in order to perform the inelastic dynamic analyses of the frames. The inelastic models take into account the spreading of inelastic deformations in beam-column elements, connection flexibility and panel zone deformations. A cyclic model for the panel zone element is developed and introduced into PC-ANSR. The performance of the frames is evaluated both statically using monotonically increasing lateral load (nonlinear push over static analyses), and dynamically by subjecting the inelastic model to an ensemble of actual strong ground motion records (time-history analyses). The main ensemble of time-histories used in the study consists of twelve earthquake ground motion records selected on the basis of Newmark-Hall design spectra amplification factors. An additional ensemble of time-histories (twelve records) is selected based on the uniform hazard spectrum for Vancouver which describes the new seismic hazard information given by the Geological Survey of Canada. The additional ensemble is used to investigate the implication of the new seismic hazard information on the performance of the six storey frames in the intermediate seismic hazard region. The results of the inelastic dynamic analyses are presented in terms of statistical measures of the maximum response parameters determined during the time-history analyses. Also, the results of the nonlinear push over analyses are presented and compared with those of the dynamic analyses. The performance expectations of the frames are evaluated in order to assess both the overall level of protection provided to the frames and the preferred design philosophy. It is concluded from the analyses that in high and intermediate seismic hazard regions, a well-designed and detailed ductile moment resisting frame (i.e. SCWB or SCWP) can withstand ground motions of twice the design level with a very little likelihood of collapse, while an ill-conditioned designed frame (i.e. WCSB) may develop a collapse mechanism even at the design level excitation. In regions of low seismic hazard activity, the three frame design types perform satisfactorily, and can withstand twice the design level excitations with only a moderate amount of damage.</p> / Doctor of Philosophy (PhD)