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This paper presents the effectiveness of seven ground motion scaling methods and two spectral matching methods to achieve compatibility with the Canadian National Building Code (CNBC) 2005 uniform hazard spectrum for Montreal to perform nonlinear seismic analysis. Databases of 30 historical records and 30 Eastern North America simulated records have been selected to compute the reference mean seismic demand and its dispersion. The characteristics and destructive capacity of ground motions have been studied using a large number of indices computed from ( i) the records themselves, ( ii) a series of single degree of freedom structures, as well as ( iii) a four-story steel frame. Record scaling methods to the target spectrum using ( i) spectral intensity, ( ii) reducing the mean square error, ( iii) and minimizing dispersion as well as time domain spectral matching generated coherent seismic demand and dispersion in agreement with the reference values. Spectral matching to a specified elastic design spectrum does not reduce the dispersion of the nonlinear response. Therefore close spectral matching cannot be used to reduce the number of records to minimize the resources allocated in seismic safety assessment. At least seven records, as recommended in current CNBC and FEMA (2012) guidelines to compute an average response, should be used to characterize the nonlinear behaviour of structural systems. [ABSTRACT FROM AUTHOR]

The usage of recycled asphalt shingles (RAS) in hot mix asphalt (HMA) pavements provides many benefits as long as they are properly engineered into the various HMA mixes. Contractors, consultants, and Departments of Transportation have evaluated the performance of these various materials, although they are still only used in a limited number of areas. Alternatively, recycled asphalt pavement (RAP) is recognized as a high value recycled material and is actually the most recycled material in North America. In Ontario, RAP is successfully used in most HMA. Related studies on HMA containing RAS and RAP are limited in Canada although recently studies and field trials on effectively using RAS in HMA in Ontario have been completed by the Centre of Pavement and Transportation Technology (CPATT) at University of Waterloo in partnership with Miller Paving Ltd and the Ontario Centre of Excellence. This paper presents key findings from a comprehensive laboratory investigation and analysis of six asphalt mixes with RAS and RAP in Ontario through dynamic modulus, resilient modulus, thermal stress restrained specimen, and flexural fatigue testing. Using RAS alone or combining with RAP makes the asphalt stiffer at high and low temperatures respectively. Lowering the low temperature performance grade of the asphalt binder by 6 °C and incorporating 3% RAS or less with RAP in HMA mix design can result in meeting the appropriate specification. While field testing of RAS pavements demonstrated that surface friction properties are in good condition in various environmental and loading conditions, the laboratory test results and field performances indicate that RAS can be a useful additive to asphalt mixes in Ontario hot mix pavement through reasonable mix design. [ABSTRACT FROM AUTHOR]

In this paper, the seismic performance of 1970s regular R/C bridge is investigated in terms of ductility demand, considering site-specific time histories and the amplification effect of soil with heterogeneous stratigraphy. The five seismic site classes of the 2005 National Building Code of Canada were used in this study and seismic site analyses were performed on soil columns representing real stratigraphies of typical Quebec City soil profiles. A total of 24 linear modal dynamic analyses and 24 nonlinear time-history analyses were performed using historical earthquakes representative of Eastern Canada. It was found that the bridge model shows yielding at the base of the columns for site classes C, D, and E. For site classes D and E the 2005 NBCC amplification factors were found to underestimate the amplification effect on the bridge's response. These results also show that the energy dissipation is a better indicator of damages than the permanent displacement. [ABSTRACT FROM AUTHOR]

To improve construction productivity and performance, it must be measured. The Construction Sector Council (CSC) has started a Labour Productivity and Project Performance Benchmarking Program for the infrastructure sector of the construction industry in Canada. Metrics were developed for project cost, time, safety, and quality performance; labour productivity; rework; project conditions; and management practices related to health and safety. Data from 19 projects located in different regions of Canada were collected and analyzed. Based on the results and on industry feedback, additional metrics for practices related to project planning, materials management, and construction supervisory skills development were developed. This paper describes the development of the program. Lessons learned during the development and implementation of the benchmarking and metrics program are summarized and steps to establish a sustainable program are identified. It is concluded that a successful program is feasible and has the potential to have broad impact. [ABSTRACT FROM AUTHOR]

Smart card fare collection systems for public transit produce a huge quantity of data on a daily basis. The ability to follow the use of a single card throughout the months gives the opportunity of measuring the loyalty of the individual to the service. Then, operators can have quantitative knowledge of the loyalty in their network. However, it is also important to know what are the factors that influence the survival of the users. This paper presents the application of a discrete time hazard model to 5 years of data of a medium-size transit authority in Canada. The concept of the hazard model relates to the fact that the probability to continue the use of a smart card by user i, at time t, is conditional to the probability of not cancelling the card before the time period. Hence, its use is appropriate in this case. Results for the regular adult fare show that loyalty is positively influenced by residential density and by the transit share in the area. A younger population will also be retained longer in the system. However, a high unemployment rate has a negative impact on survival. A high share of transit and walk trips is also affecting the loyalty, suggesting that the retention is reduced when there are more mode choices available to the commuter. [ABSTRACT FROM AUTHOR]

Pervious concrete pavement offers sustainable solutions to urban growth challenges by providing a stormwater management alternative and benefits to the ecosystem and community. Maintenance may not always be required but is likely needed in general to maintain adequate performance of pervious concrete. A Canada wide study has been initiated to evaluate the performance of pervious concrete pavement in the Canadian freeze-thaw climate. This paper presents the results to date related to the work that has been performed in evaluating maintenance methods at five field sites across Canada. In general, the results indicate that it is essential to agitate the debris in the voids to remove and clear as much material as possible. The maintenance methods that have been evaluated are the following: sweeping using a broom or street sweeper; rinsing the surface with a garden hose or large hose; vacuuming; and power washing. [ABSTRACT FROM AUTHOR]

In this study, the equation for the punching shear strength prescribed in the Canadian code is evaluated based on a database of experimental results. This paper also includes a discussion of the effect of several parameters on the punching shear strength in the Canadian and European codes. The experimental work presented includes testing of ten full-scale two-way slabs with different reinforcement ratios to examine the effect of reinforcement ratio on punching shear capacity. A simplified practical punching shear equation is also proposed based on statistical analysis of experimental results from the database. Statistical regression analysis is conducted on 190 test data available in the literature to evaluate the influence of reinforcement ratio on punching shear strength. The proposed equation accounts for the effect of slab depth using fracture mechanics concepts. The analytical study showed that the reinforcement ratio has a strong influence on punching shear strength. The proposed equation could be an alternative to the current punching shear equation used by Canadian Standards Association CSA-A23.3-04 design code. [ABSTRACT FROM AUTHOR]

This paper presents an assessment of the seismic performance of a ductile concrete core wall used as a seismic force resisting system for a 12-storey concrete office building in Montréal, designed according to the 2005 National building code of Canada (NBCC) and the 2004 Canadian Standards Association standard A23.3. The core wall consists of a cantilever wall system in one direction and a coupled wall system in the orthogonal direction. The building is analyzed in the nonlinear regime. The main conclusion from this work is that the capacity design shear envelope for the studied wall structure largely underestimates that predicted, primarily in the cantilever wall direction, and this in turn significantly increases the risk of shear failure. This issue is essentially due to (i) an underestimation by the new NBCC spectral response acceleration of the higher mode responses of a reinforced concrete wall structure whose seismic response is dominated by higher modes; and (ii) a deficiency in the capacity design method in estimating the wall shear demand on such walls, even when their behavior is lightly inelastic. [ABSTRACT FROM AUTHOR]

Northern communities often have limited resources to resolve petroleum hydrocarbon (PHC) contamination. This project investigated an innovative approach for the management of diesel-contaminated soil in a remote community in Labrador. The soil was first treated in a passively aerated biopile to reduce the concentrations of mobile PHCs. The treated soil was then disposed of in the local landfill. Maximum total petroleum hydrocarbon (TPH) concentrations in soil, concentrations of PHCs with less than 16 carbons in soil, and TPH in leachate decreased during the 1 year field treatment. Microcosms incubated at 7 and 22 °C in the laboratory showed the potential for biodegradation of the PHCs. However, volatilization was likely the predominant PHC removal mechanism in the field. Disposal of treated soil to landfills has the advantage of transforming waste (i.e., soil) into a valued product (i.e., cover for the refuse). The development of risk-based guidelines for the disposal of PHC-contaminated soil into landfills in Canada appears to be needed and is discussed in this paper. Guidelines should be protective of the environment while prevent over-treatment of the soil, which may result in unnecessary spending and environmental impacts. The cost of the system tested was compared to that of treating soil in an off-site facility. [ABSTRACT FROM AUTHOR]

In Canada, the piggery industry is an essential part of the agricultural sector, but the main waste product of this industry, swine slurry, is particularly harmful to the environment. The anaerobic storage conditions and the excessive use of slurry for agricultural fertilization contribute, respectively, to the emission of greenhouse gases and to aquatic pollution. This paper provides a review of these environmental concerns and of the existing mitigation technologies. Water pollution from swine slurry is associated with the nutrients it contains, such as nitrogen and phosphorous, while the main greenhouse gases produced by the piggery industry are methane and nitrous oxide. Available technologies can valorize the slurry through agricultural fertilization, reduce greenhouse gas emissions, by limiting nutrient availability for example, or treat the effluents using solid-liquid separation, flaring or biological processes. Specific attention is paid to biofiltration due to its potential to simultaneously treat these two types of pollution. [ABSTRACT FROM AUTHOR]

The state-of-the-art of sediment source identification is reviewed in this paper. Sediment “fingerprinting” techniques using different “fingerprint” properties were examined. With these techniques, it is possible to identify potential sources of sediment transported in river systems. Such knowledge is useful for implementing sediment control strategies to limit sediment production from upland areas in a watershed as well as for developing guidelines for land use practices to minimize adverse impacts on surface and ground water resources in agricultural watersheds. Examples of sediment source identification techniques that were carried out in agricultural watersheds in different parts of the world were also included in the present review. [ABSTRACT FROM AUTHOR]

Because of changes in functional or security requirements, many new or existing buildings are now required to resist blast loads. New buildings can be designed and constructed to resist defined blast loads. Existing buildings, on the other hand, would have to rely on a risk assessment to determine both its vulnerability to blast effects and the necessary measures to mitigate the unacceptable blast effects. A rapid screening methodology has been developed for conducting a preliminary assessment of buildings against external blast effects. The methodology accounts for the threat, the vulnerability of the building, the consequence of an event and the risk, which is the product of the threat and the consequence. The rapid screening methodology has been applied to several buildings and the results are reasonable. This paper presents the rapid screening methodology and its application to two federal buildings in Canada. [ABSTRACT FROM AUTHOR]

This paper presents a comprehensive review of the new provisions for the design of coupled shear walls in Canadian seismic zones. It follows major revisions that were incorporated in the National Building Code of Canada 2005 (NBCC 2005) and in the Canadian standard Design of concrete structures (CSA A23.3-04), which were due, in particular, to the adoption of a new Canadian map of seismic risk. The present study is intended to address recurring confusions in current practice and the difficulties expressed in the application and interpretation of the new NBCC 2005 and CSA A23.3-04 provisions. A design flowchart is thus proposed as a practical guide, describing, step by step, the required verifications at each stage of coupled shear walls calculation. Finally, to demonstrate the applicability of these new provisions, a numerical example is detailed, following the presented design flowchart. [ABSTRACT FROM AUTHOR]

Single-storey braced steel frame buildings (SSBSFs) are currently the most widely used commercial structures, which include strip malls, power centres, warehouses, small and medium-sized industrial plants. The lateral seismic or wind forces acting on such low-rise structures are usually transferred from a metal roof-deck diaphragm to a system of vertical bracing members. Because these flexible roof diaphragms have a considerable effect on the dynamic response of SSBSFs during an earthquake, they also play an important role in the evaluation of the fundamental vibration period, a key parameter in determining the magnitude of the design seismic forces. It is therefore of utmost importance to reliably predict the fundamental period of SSBSFs. This paper presents the results of a four-year field measurement research project on the dynamic behaviour of SSBSFs. The goal of the project was to create a reliable database for the dynamic characteristics of SSBSFs (periods, mode shapes, and damping) and to find a relationship between them and the geometric parameters (height and plan dimensions). The field tests are described, along with the selected buildings and experimental setup. The measured fundamental periods are then compared to the National building code of Canada (NBCC) empirical equations. A statistical analysis of the data, based on different regression models, yielded new proposed building geometric parameters to be used in simple equations for the prediction of the fundamental period of SSBSFs. [ABSTRACT FROM AUTHOR]

This paper presents a laboratory investigation on the durability and structural performance of carbon fibre reinforced polymer (CFRP) - reinforced concrete (RC) slab specimens extracted from the Laurier-Taché Parking Garage (in the National Capital Region, Canada) after being subjected to service field conditions for about 8 years (1997-2005). The laboratory investigation comprised two phases. The first phase evaluated the durability of the CFRP bars, the concrete, and the interface between the two materials by conducting microstructural and chemical analyses on core samples extracted from the slabs. As part of this phase, five CFRP bar samples were extracted and tested in tension to investigate if the CFRP bars experienced any degradation in strength or stiffness. The second phase investigated the structural behaviour of the slabs by testing four slab segments (3.0 m long × 1.0 m wide × 0.2 m deep) in flexure. Test results showed that neither the CFRP bars nor the CFRP-RC slabs have been adversely affected after being in service for 8 years. [ABSTRACT FROM AUTHOR]

Full-scale tests provide valuable information on the characteristics of building structures that can be used to evaluate design methods, to calibrate modelling techniques, and to determine damage corresponding to loading levels. These tests are scarce due to the enormous requirements in testing space and specialized testing equipment. The seismic behaviour of a full-scale, two-storey, reinforced high-performance concrete building designed with moderate ductility detailing is evaluated by pseudo-dynamic testing, during which increasing seismic loads are applied, resulting in increasing levels of permanent damage to the structure. To monitor the level of damage, a series of successive forced-vibration tests are also carried out at each step of the process and are used to track changes in the key dynamic properties of the building. The paper presents the design of the test structure according to the new edition of the CSA A23.3-04 Design of concrete structures standard, the series of pseudo-dynamic tests simulating different levels of earthquake excitation consistent with the 2005 edition of the National building code of Canada, and the evaluation of the performance of the building. It is shown that the detailing requirements of CSA A23.3-04 are more than adequate to provide the ductility and overstrength expected. Les essais à grande échelle fournissent des informations importantes sur les caractéristiques des structures pouvant être utilisées pour évaluer les méthodes de dimensionnement, pour calibrer des techniques de modélisation, et pour déterminer l'endommagement correspondant à des niveaux de chargement. La rareté de ces essais est due principalement à la nécessité de disposer de grands espaces de laboratoire et d'équipements d'essais spécialisés. Dans cet article, le comportement d'un bâtiment en vraie grandeur de deux étages est évalué par essais pseudo-dynamiques dans lesquels le bâtiment est soumis à des niveaux d'excitation sismique croissants causant des dommages de plus en plus importants à la structure. Le bâtiment est construit en béton à hautes performances pour posséder une ductilité modérée. Des essais en vibration forcée sont utilisées pour évaluer les changements dans les propriétés dynamiques de la structure. L'article présente le dimensionnement de la structure d'après la nouvelle édition de la norme CSA A23.3-04, Dimensionnement des structures en béton, la suite des essais pseudo-dynamiques simulant les différents niveaux d'excitation des tremblements de terre consistants avec le Code national du bâtiment du Canada 2005, et l'évaluation de la performance du bâtiment. On montre que les règlements de la norme CSA A23.3-04 sont tout à fait adéquats pour assurer le niveau de ductilité et de surcapacité désiré. [ABSTRACT FROM AUTHOR]

The Canadian highway bridge design code (CHBDC) contains provisions for designing concrete members with fiber-reinforced polymer (FRP) reinforcement. In the second edition of the code, new shear design procedures for FRP-reinforced sections are provided. These procedures are consistent with those for steel-reinforced members in the code, in consideration of some modifications that account for the substantial differences between FRP and steel reinforcement. The shear approach adopted in the CHBDC follows the traditional approach of Vc + Vs for shear design. This paper presents an evaluation of this approach by comparing it with experimental shear strengths of available test data on beams longitudinally reinforced with FRP bars and with or without FRP stirrups. In addition, the CHBDC approach was compared with the FRP shear design provisions currently in effect in North America using the available test results. The comparison shows that the CHBDC method significantly underestimates the shear strength of FRP-reinforced concrete beams. A proposed modification to this method is presented and verified against available test results. Le Code canadien sur le calcul des ponts routiers (CCCPR) contient des dispositions pour la conception de membres de béton avec armature en polymères renforcés de fibres (PRF). Dans la 2e édition du code, de nouvelles procédures pour la conception de cisaillement pour les sections armées de PRF sont fournies. Ces procédures sont compatibles dans le code avec celles des membres armés d'acier en considérant certaines modifications pour tenir compte des différences substantielles entre les armatures en PRF et en acier. L'approche du cisaillement adoptée dans le CCCPR suit l'approche traditionnelle de Vc + Vs pour la conception du cisaillement. Cet article présente une évaluation de cette approche en la comparant à des forces de cisaillement expérimentales dans des données de test disponibles sur des poutres armées longitudinalement de barres de PRF, et sans ou avec étriers de PRF. En outre, l'approche du CCCPR a été comparée aux dispositions de conception de cisaillement PRF actuellement en vigueur en Amérique du Nord en utilisant les résultats de tests disponibles. La comparaison montre que la méthode du CCCPR sous-estime significativement la résistance au cisaillement des poutres armées en PRF. Une proposition de modification de cette méthode est présentée et vérifiée par rapport aux résultats des essais disponibles. [ABSTRACT FROM AUTHOR]

The economy of Canada depends largely on the performance of the hydrocarbon-based energy industry (oil and gas), which in turn is dependent on the performance of steel pipelines that are used for transporting crude oil, natural gas, and petroleum products. Field observations of buried pipelines indicate that it is not uncommon for geotechnical movements to impose large displacements on the pipelines, resulting in localized curvature, deformations, and strain in the pipe wall. Often these local deformations result in local buckling (wrinkling) in the pipe wall, and in the post-buckling range of response such wrinkles develop rapidly. Subsequent cyclic load histories may produce cyclic plastic strain reversals leading to the formation of fractures in the wrinkle region. This paper presents the development and application of a simple fracture-life assessment model that can be used successfully by the pipeline industries to assess the remaining life before fracture of wrinkled pipelines subject to strain reversals due to low cycle fatigue loadings. [ABSTRACT FROM AUTHOR]

This paper studies the state of companies that develop information technology (IT) for the construction industry in Canada. The study collects survey results and other data about these companies. It explores the number and nature of companies; their products and markets; and their opinions about IT trends, opportunities and barriers, and collaboration with government and university resources. The study concludes that a small construction IT industry exists in Canada, with some established successful companies and a number of younger ventures. These companies offer some products on par with the best construction IT in other countries, but they fall somewhat behind other countries in forming an advanced construction IT community of practice. [ABSTRACT FROM AUTHOR]

An overview of cohesive sediment transport processes is given in this paper, and a mass-balance equation that is commonly used to treat cohesive sediment transport is reviewed. The equation highlights transport parameters and processes that are important for modelling the transport of cohesive sediment. The flocculation mechanism that distinguishes cohesive sediment from its noncohesive counterpart is elaborated using a laboratory study that was carried out in a rotating circular flume using sediments from Hay River, Northwest Territories, Canada. A mathematical model of flocculation suitable for predicting flocculation of sediment in rotating circular flumes is reviewed. Other cohesive sediment transport processes such as erosion and deposition processes at the sediment-water interface, entrapment of fines in gravel beds, consolidation, fluid mud, and fluidization due to wave action are reviewed. Additional challenges and knowledge gaps that exist in the area of cohesive sediment transport are identified. [ABSTRACT FROM AUTHOR]

The extreme environmental conditions in Canada require the use of asphalt cement that can provide a high resistance to low-temperature cracking during the winter season and a high resistance to rutting due to the elevated temperatures in the summer. Earlier studies showed that such desired improvements in the quality of asphalt cement could be achieved using polymer-modified asphalt (PMA) cement. This paper presents a three-phase experimental program that was carried out to evaluate the expected performance of asphalt concrete mixtures with PMA compared to asphalt concrete mixtures with conventional and air-oxidized asphalt binders. The results of this study show that PMA in asphalt concrete mixes would significantly improve the resistance to cracking (loading and low-temperature). [ABSTRACT FROM AUTHOR]

This paper presents a synthesis of the design provisions of the second edition of the Canadian Highway Bridge Design Code (CHBDC) for fibre-reinforced structures. New design provisions for applications not covered by the first edition of the CHBDC and the rationale for those that remain unchanged from the first edition are given. Among the new design provisions are those for glass-fibre-reinforced polymer as both primary reinforcement and tendons in concrete; and for the rehabilitation of concrete and timber structures with externally bonded fibre-reinforced-polymer (FRP) systems or near-surface-mounted reinforcement. The provisions for fibre-reinforced concrete deck slabs in the first edition have been reorganized in the second edition to explicitly include deck slabs of both cast-in-place and precast construction and are now referred to as externally restrained deck slabs, whereas deck slabs containing internal FRP reinforcement are referred to as internally restrained deck slabs. Resistance factors in the second edition have been recast from those in the first edition and depend on the condition of use, with a further distinction made between factory- and field-produced FRP. In the second edition, the deformability requirements for FRP-reinforced and FRP-prestressed concrete beams and slabs of the first edition have been split into three subclauses covering the design for deformability, minimum flexural resistance, and crack-control reinforcement. The effect of sustained loads on the strength of FRPs is accounted for in the second edition by limits on stresses in FRP at the serviceability limit state. [ABSTRACT FROM AUTHOR]

Construction contracts are becoming more complicated, and the increase in complexity of construction processes, documents, and conditions of contracts has contributed to a higher possibility of disputes and conflicting interpretations. The judicial system has been the means for dispute resolution for claims that cannot be solved through other means such as negotiation and arbitration. Knowledge of previous outcomes of judicial processes will both inform participants in a dispute and increase the likelihood of a less-expensive out-of-court dispute-resolution process. This paper presents a methodology to classify, categorize, and analyze Canadian case-law construction claims. In total, 567 Canadian construction court cases have been collected from 10 different sources and are classified into 12 categories that follow the Canadian Construction Documents Committee (CCDC) standard construction contract document CCDC 2-1994. The proposed methodology is implemented in a computer-integrated system called the Canadian construction claim tracker (CCCT), which consists of one central database and three modules, namely a statistical module, a prediction module, and a classification module. The CCCT provides its users with easy and quick access to past case-law claim information. [ABSTRACT FROM AUTHOR]

Design guidelines for laterally loaded light-gauge steel-frame – wood structural panel shear walls are not available in Canadian codes. A design method for the calculation of shear stiffness and strength has been developed for use with the 2005 National Building Code of Canada (NBCC), however. This method was based on the analysis, using an equivalent energy elastic–plastic (EEEP) approach, of over 180 single-storey shear wall tests of various configurations. Ductility-related (Rd) and overstrength-related (Ro) force modification factors also need to be defined to calculate equivalent static seismic forces following the 2005 NBCC. This paper describes the development of these two factors based on the EEEP analysis of the shear wall test results. To verify the "test-based" Rd and Ro values, nonlinear time-history dynamic analyses of two representative buildings were carried out using a suite of 10 earthquake records scaled to the 2% in 50 year uniform hazard spectrum (UHS) for Vancouver, British Columbia. Preliminary values have been determined for the force modification factors, namely Rd = 2.5 and Ro = 1.7. [ABSTRACT FROM AUTHOR]

There is an increasing interest in reuse and recycling in the Canadian construction industry. This interest is driven partly by the recent adoption in Canada of the Leadership in Energy and Environmental Design (LEED®) Green Building Rating System and partly by a greater general awareness of environmental issues. Designers are beginning to look at how to incorporate reused steel components into construction projects, thereby reducing greenhouse gas emissions by saving on primary steel production. However, although some designers are willing to redesign their projects to make use of available reclaimed structural steel components, it is often difficult to identify suitable materials in the local area at the appropriate time in the life of a project. A limiting factor is that designers, construction companies, and others perceive a lack of a well-established and easily available mechanism for exchange of reclaimed components. This paper reviews the issues that are relevant to increasing recycling and reuse in construction and focuses on examples that illustrate the benefits that steel can bring to sustainable construction. In particular, it discusses the issues relevant to designing to enable future disassembly and the way in which steel components can be readily reused. [ABSTRACT FROM AUTHOR]

The Canadian Highway Bridge Design Code (CHBDC) provides two alternative methods for evaluating the strength of existing bridges. The load and resistance factor method provides a general approach and covers the most extreme load situations that can occur in a general bridge population. The mean load method considers the uncertainties of loads acting on a specific bridge, the method of analysis, and resistance of the structure involved, and thus can provide a more accurate evaluation of individual bridges. Since traffic load represents a major portion of bridge loads, a better evaluation of specific bridges is obtained by using the statistical parameters of traffic loads observed on the structure. However, the overall accuracy depends heavily on capturing the most critical loading conditions during the survey periods. The mean load method is particularly valuable where actual traffic loads are expected to be significantly lower than those used in code calibration and when the potential economic benefits arising from a more realistic evaluation outweigh the extra costs of live load data collection and analysis. This paper demonstrates that the mean load method using site-specific traffic loading information can lead to a significantly higher live load-carrying capacity of a bridge. [ABSTRACT FROM AUTHOR]

Wood transmission structures, such as H frames, have been extensively used to support electrical transmission lines throughout Canada. The transmission infrastructure is in general aging, and fungal decay of wood crossarms poses a significant risk of failure under adverse weather conditions. A crossarm failure in the transmission system can result in forced outages and customer disruptions that lead to significant economic losses. This paper presents a condition assessment model to prioritize the replacement of transmission crossarms that are near the end of their service life. The proposed standard involves a visual condition rating system, which is validated by results of full-scale testing of a sample of in-service crossarms. Aerial inspection of transmission lines using the proposed visual rating system is a simple, economical, fast, and effective method of assessment. The proposed approach would ensure a more consistent compliance with the condition-based replacement standard specified in the Canadian (Canadian Standards Association Standard CSA 22.3 No. 1-01) and North American (US National Electric Safety Code 2002 edition) standards. [ABSTRACT FROM AUTHOR]

The environmental and human health impacts of engineering activities have reshaped the way engineers make decisions. Increasingly, engineering decision-making is taking into consideration the full life cycle implications of engineering activities. This paper details the development and application of a national economic input–output-based life cycle assessment model, a tool for guiding engineering decision-making, for the Canadian economy. The model consists of 61 industries and 103 commodities and incorporates economic and environmental–resource data, including marginal resource consumption, energy use, releases of National Pollutant Release Inventory compounds, and emissions of greenhouse gases. The model is useful for evaluating various development strategies and analyzing the potential direct and indirect impacts of alternative public policies on the Canadian economy and environment. The model is applied to various sectors of the Canadian economy, and the life-cycle implications of demands for different commodities are determined, including demand for electricity and construction materials for highway design. [ABSTRACT FROM AUTHOR]

Motivated by Canada's infrastructure crisis, the Intelligent Sensing for Innovative Structures (ISIS) Canada Research Network has developed and demonstrated the efficacy of innovative materials and monitoring technologies to support infrastructure design and renewal efforts. To quantify the potential benefits of these technologies across a diverse range of infrastructure applications, a rational, pragmatic and flexible method of life cycle costing (LCC) is needed. The purpose of this paper is to review and broadly classify LCC methods evident in pertinent literature. Through this process, a state-of-the-art LCC method is identified and described. Its noted strengths and limitations suggest promising avenues for future research. [ABSTRACT FROM AUTHOR]

Portland cement production in Canada increased from 1.7 million tonnes in 1946 to more than 13 million tonnes in 2002. Although the industry is a major player in meeting infrastructural needs of Canadians, it is also a major user of natural resources such as water, natural minerals, and aggregates. Moreover, for each tonne of cement clinker produced, 1 t of CO2 is released into the atmosphere. At the same time, Canada produces nearly 5 million tonnes of fly ash each year, and yet the use of fly ash as cement replacement remains dismally low at around 17%. It is believed that through product and process innovations, more fly ash can be used in concrete, thus preserving natural resources, reducing CO2 emissions, and helping Canada meet the requirements of the Kyoto Protocol. Forecasting the future impact of using fly ash in concrete has been based on qualitative and linear estimates, however, without accounting for the complexity of the problem and its dynamic feedbacks. In this paper, a novel application of system dynamics modeling, a feedback-based object-oriented modeling paradigm, is proposed to create a rational model that departs from current approaches used in modeling CO2 emissions of cement production. The model accounts for the various enablers and barriers for using fly ash in concrete, including market dynamics and technology development. It allows the user to test a wide variety of scenarios and policies, its flexible architecture permits coupling it with general economic or service life models, and its modular nature allows expanding its boundaries to include other facets of the holistic CO2 emissions problem in Canada. [ABSTRACT FROM AUTHOR]

Canada exhibits high per capita energy consumption. This paper examines energy use in Canada by region and sector, focusing on four sectors most relevant to civil engineering activities: residential, commercial–institutional, construction, and transportation. Environmental impacts associated with major energy sources including coal, petroleum products, natural gas and electricity are reviewed. The relationships between energy consumption and infrastructure design are analysed. Opportunities for reductions are identified in building design, water and waste-water systems, urban form, and transportation. Large improvements in commercial and residential energy efficiency can be achieved through the implementation of existing technologies in building upgrades, retrofits, and rebuilds. Increasing surface albedos and more extensive use of vegetative shading and consideration of the geometric properties of urban canyons and their microclimatic effects also allow for considerable energy savings. The incorporation of mixed-modal transit, walking and cycling paths, and community-scale design as elements of long-term transportation planning and the development of alternative transportation technologies have the potential to considerably reduce per capita energy use. The development and implementation of alternative energy supply technologies include energy recovery from waste-water treatment. [ABSTRACT FROM AUTHOR]

The data gathered on the current situation of supplementary cementing materials (SCMs) in Canada have shown that around 524 000, 347 000, and 37 000 t of fly ash, ground granulated blast furnace slag (GGBFS), and silica fume were used in cement and concrete applications in 2001, respectively, which represents 11%, 90%, and 185% of the quantity produced. The remaining 10% of GGBFS produced was used in the US, and 17 000 t of silica fume were imported from the US and Norway to meet market demand. Fly ash appears to be the only material that is underused and that represents a potential for increased use of SCMs in Canada. For the GGBFS, the quantity produced can be increased if the demand increases. This investigation has shown, however, that there are policy, technical, and economic barriers to the increased use of SCMs in Canada. Some solutions were proposed to overcome these barriers and are summarized in the conclusions of the paper. [ABSTRACT FROM AUTHOR]

This paper describes results from a study of the dynamic performance of the Confederation Bridge during traffic load tests and a storm with high winds that occurred at the bridge site on 7 November 2001. The traffic load tests were conducted over a three-span segment of the bridge and consisted of single and double truck configurations at different speeds. The winds during the storm of 7 November 2001 were the strongest that have ever been measured at the bridge site since the opening of the bridge. The vibrations of the bridge during both the load tests and the storm were recorded by a network of 76 accelerometers. By processing the recorded vibrations, vertical deflections and dynamic amplification factors due to the traffic load tests and vertical and lateral deflections due to the wind during the storm were computed. The computed values were compared with those used in the design. It was found that both the deflections and the dynamic amplification factors were much smaller than the design values. [ABSTRACT FROM AUTHOR]

This paper evaluates the moment equation in the 2000 Canadian highway bridge design code (CHBDC) for soil–metal arch structures. This equation is adopted from Duncan's moment equation (1978), which is based on his finding from finite element analyses that the maximum moment occurs at the quarter point of soil-metal structures. However, finite element analyses carried out for this study demonstrate that the maximum moment in soil–metal arch structures with spans greater than approximately 11 m occurs at the crown point. In this study, the location and magnitude of the maximum moment was examined for soil–metal arch structures having spans of 6–20 m under three construction stages; backfill up to the crown, backfill up to the cover depth, and live loading. Based on the location of the maximum moment, two sets of moment equations dependant on span length were found necessary. Moment coefficients and moment reduction factors in moment equations are proposed from the results of numerous finite element analyses for semi-circular arch and part-arch types of soil–metal structures considering the various design variables, such as span length, structural shapes, section properties, and backfill conditions. The validity of the coefficients and reduction factors in the moment equation of the 2000 CHBDC is investigated by comparison with those proposed in this study. The comparison demonstrates that the moment equation of the 2000 CHBDC is still valid and a little conservative. The effects of design variables on the variations of moments of soil–metal arch structures during construction stages are also examined. [ABSTRACT FROM AUTHOR]

The benefits of intelligent transportation systems (ITS) are indirectly represented by the annual world market for ITS, which according to ITS Canada (2002) will be $90 billion CAN by 2011. Improved safety is often cited as the top goal of implementing ITS. Despite the magnitude of these investments and their underlying goal to improve transportation safety, there are deficiencies in the quantity and quality of reported ITS safety benefits. Many of the benefits reported to date suffer from poor data, lack of an evaluation framework, and inconsistent terminology used to attribute benefits to ITS application areas. This paper explores these issues, while attempting to address one of them, namely the lack of an evaluation framework for assessing the safety benefits of ITS. Accordingly, a unique framework is developed based on the Canadian ITS architecture. The framework includes the identification of evaluation metrics that are mapped to the market packages in the Canadian ITS architecture and correlated with each other to capture the "cause" and "effect" flow of benefits. This framework will benefit future ITS safety evaluations by providing a structure for undertaking evaluations using terminology consistent with the Canadian ITS architecture. [ABSTRACT FROM AUTHOR]

Many models have been developed to evaluate the operating speeds on two-lane rural highways. However, provided information usually lacks details essential to assess their applicability at locations other than where they were developed. This paper presents a procedure to interpret raw data collected on three horizontal curve sites of different two-lane rural highway classes in Ontario. The speed observations were categorized into three vehicle classes (passenger car, light truck, and multi-axle heavy truck) and four light condition categories (day, night, and two transition periods). The minimum headway and percentile value to define the operating speed were examined, and a revision of the current practice deemed not warranted. The findings also indicated that operating speeds do not depend on the time or vehicle class. Finally, the horizontal alignment affects the operating speed, but the speeds of the two travel directions on a horizontal curve may differ even with little contribution of the vertical alignment. [ABSTRACT FROM AUTHOR]

Recent advances in the fields of data communication and automated controls make the implementation of automated highway systems (AHSs) more possible. Currently, substantial research effort is being made on the design of intelligent transportation system (ITS) architectures in Europe, Japan, the United States, and Canada. These architectures, however, have major limitations inherit in the design methodology used. Most ITS developers use a process-oriented approach for the design of the architecture that reduces its quality attributes (stability and flexibility) to future changes. This paper presents an approach to implement object-oriented design methodology in the Canadian intelligent transportation system (C-ITS) architecture for AHS. It was also shown that the C-ITS architecture needs a backup communication system to be integrated within the C-ITS architecture. Such a backup system would aid the reliability of future transportation systems to be developed based on this architecture. The proposed C-ITS architecture promotes flexibility, stability, and communication and, as such, should be of interest to ITS developers and researchers. [ABSTRACT FROM AUTHOR]

Although bridges were among the first civil engineering structures to use structural health monitoring (SHM) technologies, research is now expanding to explore other types of applications, including Manitoba's famous Golden Boy statue. Global research is identifying the value of using SHM technologies for civil engineering applications. Structural health monitoring uses a variety of sensors to gather information about the behaviour of a structure. The information creates a valuable knowledge base that can be analyzed to help identify potential structural risks, develop safer and more efficient new structures, and determine more effective ways to rehabilitate existing structures. This paper briefly describes the history of the Manitoba Legislative Building and the Golden Boy and also the use of SHM technologies to help preserve the Golden Boy statue, an icon of provincial heritage. [ABSTRACT FROM AUTHOR]

During the past decade, composite steel-free deck bridges came to reality in Canada through the construction of five bridges. The new structural system enables the construction of a concrete deck that is totally devoid of all internal steel reinforcement. Traditionally, reinforced concrete bridge decks are designed to sustain loads in flexure. The steel-free deck bridge system develops internal compressive forces "internal arching," which leads to failure by punching shear at substantially higher loads than the flexural design load. The fibre-reinforced concrete deck is usually attached to the steel girders through flexible shear connectors. These steel girders are transversely tied together by steel straps and cross frames. In this paper, the concept of the new bridge system is briefly discussed. The generations of the deck slabs are introduced. Brief outlines of the bridges built to date with this new technology are presented. A three-dimensional finite element model is then proposed to study the behaviour of the main structural component of the new system. The model is verified against previous experimental results and is used to perform a parametric study on some aspects which are thought to significantly affect the behaviour of the new steel-free deck bridge system.Key words: bridges, composite girders, finite element method, steel-free deck, steel straps.Durant la dernière décennie, les ponts à tablier composé sans acier sont devenus réalité au Canada grâce à la construction de cinq ponts. Ce nouveau système structural permet la construction d'un tablier en béton qui est complètement dépourvu de tout renforcement interne en acier. Traditionnellement, les tabliers de pont en béton armé sont conçus afin de supporter des charges en flexion. Le système de tablier de pont sans acier développe des forces internes en compression « cintrage interne » et résulte en une rupture par poinçonnement en cisaillement pour une charge substantiellement plus grande que les charges en flexion de conception. Le tablier en béton renforcé de fibres est habituellement attaché aux poutres d'acier à l'aide de connexions de cisaillement flexibles. Ces poutres d'acier sont attachées ensemble transversalement à l'aide de liens d'acier et de contreventements. Dans cet article, le concept de ce nouveau système est brièvement discuté. Les générations des tabliers en dalles sont introduites. Un bref aperçu des ponts construits à ce jour avec cette nouvelle technologie est présenté. Un modèle par éléments finis tirdimensionnel est par la suite proposé afin d'étudier le comportement des composants structurels principaux du nouveau système. Le modèle est confronté aux résultats expérimentaux obtenus par d'autres dans le passé. Ensuite, il est utilisé afin de performer une étude paramétrique sur quelques aspects qui sont suspectés d'affecter de façon significative le comportement de ce nouveau système de tablier de pont sans acier.Mots clés : ponts, poutres composées, méthode par éléments finis, tablier sans acier, liens d'acier.[Traduit par la Rédaction] [ABSTRACT FROM AUTHOR]

This paper reviews the factors and criteria for the design of new and the retrofitting of existing dry detention ponds to enhance removal of total suspended solids (TSS) from stormwater. Detention time is discussed as the most important factor affecting TSS removal. Two-stage facilities and multi-level outlet design are important means of enhancing TSS removal in dry ponds. Two dry ponds within the city of Edmonton were selected to evaluate their TSS removal. The level of expected TSS removal is low owing to the relatively short detention times for both ponds. Methods for retrofitting the dry ponds to enhance TSS removal are discussed.Key words: dry pond, stormwater, TSS removal, detention time, retrofitting.Cet article passe en revue les facteurs et critères de conception de nouveaux étangs de rétention, et de modification de ceux déjà existants, avec pour but d'améliorer la capacité d'enlèvement des substances solides totales en suspension (SST) contenues dans les eaux de ruissellement. Le temps de rétention est examiné en tant que facteur principal affectant l'enlèvement des SST. Les installations à deux étages et la conception de sorties multi-niveaux sont des procédés importants qui améliorent l'enlèvement des SST dans les étangs. Deux étangs de la Ville d'Edmonton ont été sélectionnés et leur capacité de rétention a été évaluée. Le niveau d'enlèvement des SST escompté est bas compte-tenu des temps de rétention relativement courts de ces deux étangs. Les méthodes de modification des étangs visant à améliorer l'enlèvement des SST sont examinées.Mots clés : étang, eaux de ruissellement, enlèvement des SST, temps de rétention, réajustement.[Traduit par la Rédaction] [ABSTRACT FROM AUTHOR]

This paper reports the results of a laboratory study of the effects of (i) manhole proximity to installation site, (ii) pipe slope (i.e., approach velocity), (iii) upstream head measurement location, and (iv) submergence on the "hydraulics" of two types of sewer weirs used by the City of Ottawa. The City's streamlined form of broad-crested weir and its compound-shaped sharp-crested weir were initially calibrated for a "pipe straight"-arrangement (no upstream manhole is present) for a wide range of flow conditions at 0.2%, 0.4%, and 1.0% pipe slopes. The calibration tests were then repeated with the weirs positioned immediately downstream of a model manhole structure ("manhole"-arrangement). Corresponding data sets were compared to determine the effects of (i) approach velocity and (ii) manhole proximity (for two different shapes of manhole "benching") on the respective weir discharge coefficients.Key words: sewer weirs, broad-crested weir, compound sharp-crested weir, calibration, sewer benching, discharge coefficients.Cet article rapporte les résultats d'une étude en laboratoire sur les effets de : (i) la proximité des bouches d'égout du site d'installation, (ii) la pente des conduites (i.e., vélocité d'approche), (iii) l'emplacement des mesures de la hauteur de la colonne d'eau en amont, et (iv) la submersion sur « l'hydraulique » de deux types de crêtes pour égouts utilisés par la ville d'Ottawa. Les profils d'écoulement des crêtes rectangulaires de la ville et de ses crêtes triangulaires on été calibrés au départ pour un arrangement de « conduites droites » (aucune bouche d'égout présente en amont), pour une variété de conditions d'écoulement ayant des pentes de conduites de 0,2%, 0,4% et 1,0%. Les tests de calibration ont été répétés avec les crêtes positionnées immédiatement en aval d'un modèle d'une structure de bouche d'égout (arrangement « bouche d'égout »). Les banques de données correspondantes ont été comparées afin de déterminer les effets de : (i) la vélocité d'approche, et (ii) la proximité de la bouche d'égout (pour deux types différents de formes de bouche d'égout) sur les coefficients d'écoulement des crêtes respectives.Mots clés : crêtes pour égouts, crête rectangulaire, crête triangulaire, calibration, structure de support pour égouts, coefficients de déversement.[Traduit par la Rédaction] [ABSTRACT FROM AUTHOR]

This paper presents the results of an analytical study on the nonlinear deformation and ductility response of reinforced concrete ductile coupled shear walls (CSWs) under seismic loadings. The CSWs were designed, calculated, and detailed in compliance with the National Building Code of Canada (NBCC) 1995 and the Canadian Concrete Standard CAN3-A23.3-94. The parameters and assumptions of the study as well as the description of the models and the procedure were fully described elsewhere. Results indicated that the maximum interstorey drift from dynamic analyses was well below that obtained from static analyses with NBCC specified lateral forces. It was also found to be substantially lower for tall CSWs compared to short or medium-height walls, and decreased only slightly as the degree of coupling increased within the range considered in this study. It was also highest for seismic records with low PGA/PGV ratios. Plastic hinge rotations as well as accumulated plastic hinge rotations generally decreased as the number of storeys increased. The maximum displacement ductility demand factor remained below the NBCC value of 4.0 specified for ductile CSWs. The influence of degree of coupling on the maximum displacement ductility demand factor was found negligible. Also, the maximum displacement ductility demand factor generally decreased as the number of storeys increased. The maximum rotational ductility demand factor in coupling beams decreased as the number of storeys increased and was generally less than the practical accepted limit of 10, except for a few short CSWs.Key words: coupled shear walls, reinforced concrete, seismic, degree of coupling, frequency content, interstorey drift, plastic hinge deformation, ductility.Cet article présente les résultats d'une étude analytique sur les déformations non-linéaires et la réponse ductile de murs de refend couplés (« coupled shear walls », CSWs) ductiles en béton armé sous des charges sismiques. Les CSWs sont conçus, calculés et détaillés en respectant le Code national du bâtiment du Canada (CNBC) de 1995 et les Normes canadiennes sur le béton CAN3-A23.3-94. Les paramètres et hypothèses de l'étude de même que la description des modèles et de la procédure sont décrits ailleurs de façon détaillée. Les résultats indiquent que le mouvement maximal inter-étages provenant des analyses dynamiques est bien en-deça de celui obtenu à partir des analyses statiques avec les forces latérales spécifiées par le CNBC. Il a aussi été trouvé qu'il est subtantiellement plus bas pour des CSWs élevés comparés à des CSWs délévation moyenne à basse, et décroît légèrement seulement lorsque le degré de couplage s'accroît à l'intérieur de l'intervalle considéré dans cette étude. Il a aussi été le plus grand pour des enregistrements sismiques avec des rapports PGA/PGV bas. Les rotations plastiques à la rotule de même que les rotations plastiques à la rotule accumulées, en général, diminuent lorsque le nombre d'étages augmente. Le facteur de ductilité en déplacement maximal reste sous la valeur de 4,0 specifiée par le CNBC pour des CSWs ductiles. L'influence du degré de couplage sur le facteur de ductilité en déplacement ductile maximale a été trouvé comme étant négligible. Aussi, le facteur de ductilité en déplacement maximal décroît lorsque lorsque le nombre d'étages s'accroît. Le facteur de ductilité rotationnelle maximal dans le couplage des poutres décroît lorsque le nombre d'étages s'accroît, et a été en géneral moindre que la limite pratique acceptée de 10, sauf pour quelques CSWs courts.Mots clés : murs de refend, béton armé, sismique, degrée de couplage, contenu de fréquence, mouvement inter-étages, déformation plastique à la rotule, ductile.[Traduit par la Rédaction] [ABSTRACT FROM AUTHOR]

This paper reviews the flood frequency characteristics of the Red River at Winnipeg. The impacts of persistence in the flood series on estimates of flood quantiles and their associated confidence intervals are examined. This is done by generating a large number of data sequences using a mixed noise model that preserves the short-term and long-term correlation structures of the observed flood series. The results reveal that persistence in the data series can lead to a slight increase in the expected flood magnitude for a given return period. More importantly, persistence is shown to dramatically increase the uncertainty associated with estimated flood quantiles. The 117-year flood series for the Red River at Winnipeg is demonstrated to be equivalent to roughly 45 years of independent data.Key words: flood frequency, extreme events, simulation, historical data.Cet article examine les caractéristiques de la fréquence des crues de la rivière Rouge à Winnipeg. Les impacts de la persistance dans la série de débits sur les estimés des quantiles de crues et leurs intervalles de confiance associés sont examinés. Ceci est effectué en générant un large nombre de séquences de données en utilisant un modèle avec bruits mixtes qui préserve la structure de corrélation à court et à long terme de la série de débits observés. Les résultats révèlent que la persistance dans la série de données peut mener à une légère augmentation de la magnitude anticipée de la crue pour une certaine période de retour. Plus important encore, il a été montré que la persistance augmente dramatiquement l'incertitude associée avec l'estimation des quantiles de crues. La série de 117 ans de débits pour la rivière Rouge à Winnipeg a démontrée être équivalente à 45 ans de données indépendantes.Mots clés : fréquence de crues, événements extrêmes, simulation, données historiques.[Traduit par la Rédaction] [ABSTRACT FROM AUTHOR]

The R.H. Saunders dam is one of over one hundred concrete dams, worldwide, suffering from structural and operational problems due to the expansion of concrete resulting from alkali–aggregate reaction. A laboratory test methodology for measuring the residual expansion rate in these dams with simulation of field environment has been developed. This paper describes the test principles and method of interpretation of the different tests developed. Results of various expansion tests performed on samples recovered from the R.H Saunders dam (Canada) are presented. Results showed that the expansion rates measured in laboratory are consistent with those measured by extensive instrumentation in the field (in situ rebar tests, levelling data, stress meters, and in situ overcoring data). It is believed that the test methodology developed provides the necessary and inexpensive tools for measuring the stress-dependent residual expansion potentials in concrete dams. It would also have an impact on the design of remedial measures and the prediction of future performance because of the reliability and versatility of the test method.Key words: dams, concrete, expansion, alkalis, aggregate, reaction, cement.L'ouvrage de retenue en béton R.H. Saunders, parmis une centaine à travers le monde, souffre de problèmes structuraux et opérationnels liés à l'expansion du béton suite à une réaction alcali–granulat. Une méthodologie basée sur des tests en laboratoire simulant l'environnement du terrain a été développée pour mesurer la vitesse de l'expansion résiduelle dans ces barrages. Cette étude décrit les principes des tests et la méthode afin d'interpréter les différents tests développés. Les résultats des différents tests d'expansion effectués sur des spécimens provenant du barrage R.H. Saunders (Canada) sont présentés. Les résultats ont montrés que les vitesses d'expansion mesurées en laboratoire concordent avec celles mesurées par une vaste instrumentation sur le terrain (test in situ de l'armature, données de nivellement, relevé des contraintes et données in situ de carottages). Il est convenable de croire que la méthodologie développée donne les outils nécessaires et abordables afin de mesurer les potentiels dépendants des contraintes d'expansion résiduelle des barrages en béton. La méthodologie devrait avoir un impact sur la conception de méthodes de réhabilitation et sur les prédictions de performances futures à cause de sa fiabilité et sa polyvalence.Mots clés : barrage, béton, expansion, alcalis, granulat, réaction, ciment.[Traduit par la Rédaction] [ABSTRACT FROM AUTHOR]

The seismic attenuation in concrete has seldom been studied, although it is an important parameter for survey design. In this paper, the seismic Q factor is estimated from data measured at the Carillon dam. Three methods were used for this study: amplitude decay yielding a value of 5.1 ± 1.6, spectral ratio giving a value of 8.3 ± 3.5, and a value of 7.5 ± 14.9 was obtained from the rise-time technique. These values are weak compared with what is generally observed in rocks, and slightly lower than values obtained on laboratory concrete samples. However, the average P wave velocity measured on the investigated area is 4081 ± 95 m·s[sup –1] , an indication of the good quality of the material. Consequently, this strong attenuation could be attributed on one hand to energy loss, and on the other hand to scattering caused by the intrinsic cement–aggregate composition of concrete. It is also possible that an inadequate sensor coupling had the effect of reducing the observed Q value. Key words: seismic attenuation, concrete dams, microseismic monitoring, coupling.Paramètre important pour la planification de levés sismiques, l'atténuation sismique a été peu étudiée dans les bétons. Dans cet article, le facteur de qualité sismique Q est évalué au barrage de Carillon selon les méthodes du rapport des amplitudes, du rapport des spectres d'amplitude et du temps de montée. Les mesures obtenues sont respectivement de 5,1 ± 1,6, de 8,3 ± 3,5 et de 7,5 ± 14,9. Ces valeurs sont faibles en regard de ce qui est généralement observé dans les roches, et légèrement plus faibles que des valeurs mesurées sur des bétons en laboratoire. Par ailleurs, le béton de la partie du barrage auscultée présente une vitesse d'onde P moyenne de 4081 ± 95 m·s[sup –1] , indiquant une bonne qualité du matériau. En conséquence, la forte atténuation pourrait être attribuable d'une part à la perte de l'énergie sismique sous forme de friction, et d'autre part à une atténuation de diffusion occasionnée par la composition ciment-granulat intrinsèque du béton. Il est également possible qu'un couplage inadéquat des capteurs ait pour effet de réduire la valeur observée de Q. Mots clés : atténuation sismique, barrages en béton, auscultation microsismique, couplage. [ABSTRACT FROM AUTHOR]

Environmental engineering education has been an active option for engineers from all disciplines for nearly 50 years at the graduate level. Some graduate programs expanded to integrate students with undergraduate science degrees with the engineering programs, since the cross discipline interaction is required outside the academic programs. In the mid-1980s interest increased to such a level that undergraduate programs began to form. Several of these programs have been accredited in their various forms recognizing the diversity of the field and those presenting the programs. The progression from graduate-degree-based specializations to broad-based undergraduate programs reflects both the increased knowledge in the field and the increased demand for professional engineers capable of responding to public health and environmental protection issues. Graduate programs greatly expand fundamental knowledge of physical, chemical, and biological processes and their application to protection problems. Of course, the doctorate is dedicated to the development of significant new knowledge. This paper defines several of the basic components of the environmental engineering profession and the educational process needed to produce qualified environmental engineers. [ABSTRACT FROM AUTHOR]

The article offers information on the editorial policy implemented by the "Canadian Journal of Civil Engineering." The journal, which is intended to reflect and stimulate the practice of civil engineering in Canada, is said to be recognized as the official technical journal of the Canadian Society for Civil Engineering and is published monthly by the National Research Council. It is not claimed to publish papers that are clearly in the domain of the "Canadian Geotechnical Journal" or the "Canadian Surveyor."