Showing papers in "Canadian Journal of Civil Engineering in 1991"
476 citations
TL;DR: Raudkivi et al. as discussed by the authors studied the physical processes involved in the interaction between air or liquid flow and the solid boundaries of its movement, showing how the properties of each material affect the dynamics between them.
Abstract: Loose Boundary Hydraulics-Arved J. Raudkivi 1998-01-01 Sediment transport, two-phase flow and loose boundary hydraulics are some of the problems of interaction between fluid flow (water or air) and boundaries that may be non-cohesive (alluvial) or cohesive. Unlike in classical hydraulics, these boundaries can change their shape and texture with changing flow conditions. Some of the material from the boundaries may be entrained into the flow, or sediment may be added to the flow, sometimes by tributaries as suspended matter. One instance is the transport of granular material in pipelines Since the changing boundaries are the central feature of most flow processes in nature, the term loose boundary hydraulics is here introduced. Examines the physical processes involved in the interaction between air or liquid flow and the solid boundaries of its movement, showing how the properties of each material affect the dynamics between them.
173 citations
TL;DR: In construction projects, it is virtually certain that there will be changes made during the course of the work, and that the owner or design professional and the contractor will seldom agree on t...
Abstract: In construction projects it is virtually certain that there will be changes made during the course of the work, and that the owner (or design professional) and the contractor will seldom agree on t...
65 citations
TL;DR: In this article, the authors reviewed examples of the severe damage and the collapse of bridges during the 1989 Loma Prieta earthquake and found that bridges were among the worst hit structures.
Abstract: Damage to buildings and bridges during the October 17, 1989, Loma Prieta earthquake prompted site visits by the authors. This paper first reviews examples of the severe damage and the collapse of b...
48 citations
TL;DR: In this article, a detailed analysis of data collected from mill records and on-site measurements was made to obtain statistical parameters of relevant geometric and material properties, including inelastic behaviour, residual strain patterns, o...
Abstract: The Canadian Standards Association Standard CAN-CSA-S16.1-M89 “Limit states design of steel structures” assigns welded wide flange (WWF) columns to the column curve for rolled H-shaped sections. This is conservative because of differences in the production of WWF and rolled sections. The WWFs are stipulated to have flame-cut edges. The residual stress pattern, with favourable tensile stresses, results in a delayed loss of stiffness as weak axis inelastic buckling occurs. Thus the weak axis and strong axis buckling curves lie closer together for WWF shapes than they do for rolled H-shapes. Automatic cutting and welding processes result in close tolerances on out-of-straightness. As well, the statistical variations in the geometric properties are favourable. A detailed analysis of data collected from mill records and on-site measurements was made to obtain statistical parameters of relevant geometric and material properties. A finite element program modelling inelastic behaviour, residual strain patterns, o...
45 citations
TL;DR: In this paper, the authors presented a model to minimize the number of cars carrying dangerous goods in a train derailment, based on the position of the railcars carrying the dangerous goods, which can affect their involvement in derailment.
Abstract: The position of railcars carrying dangerous goods in a train can affect their involvement in a derailment. A model is presented, which minimizes the number of cars carrying dangerous goods derailin...
41 citations
TL;DR: Freeze-thaw conditioning of water and wastewater sludges is known to be an effective and economical means of promoting dewatering when natural freezing is employed as mentioned in this paper, and when sludge freezes, both the su...
Abstract: Freeze–thaw conditioning of water and wastewater sludges is known to be an effective and economical means of promoting dewatering when natural freezing is employed. When sludge freezes, both the su...
41 citations
TL;DR: In this paper, an on-line book about the geotechnology of waste management is provided for every reader to read this book and what they will obtain is a great resource for waste management.
Abstract: Read more and get great! That's what the book enPDFd geotechnology of waste management will give for every reader to read this book. This is an on-line book provided in this website. Even this book becomes a choice of someone to read, many in the world also loves it so much. As what we talk, when you read more every page of this geotechnology of waste management, what you will obtain is something great.
39 citations
TL;DR: In this article, a review of the requirements in the National Building Code (NBC) and referenced CSA standards to the structural evaluation and upgrading of existing buildings in Canada is presented.
Abstract: Difficulties have been encountered in applying the requirements in the National Building Code (NBC) and referenced CSA standards to the structural evaluation and upgrading of existing buildings in Canada. The Associate Committee of the NBC has therefore initiated an effort to provide guidelines on the application of Part 4 of the NBC to existing buildings, allowing alternative requirements where needed. As an initial step towards fulfilling this goal, this paper reviews all aspects of limit states criteria for structural evaluation and proposes minimum load factors based on a life safety criterion. The proposed load factors allow more flexibility in practice but require more professional judgment. Key words: existing buildings, structural evaluation, criteria.
38 citations
TL;DR: In this paper, new provisions of the CSA standard for steel structures (CAN/CSA-S16.1-M89) dealing with detailing of concentrically braced frames for seismic design are described and related to requirements of the National Building Code of Canada.
Abstract: New provisions of the CSA standard for steel structures (CAN/CSA-S16.1-M89) dealing with detailing of concentrically braced frames for seismic design are described and related to requirements of the National Building Code of Canada. The basis of the new requirements is outlined, and an example eight-storey frame is used to outline a methodology for the design process for a ductile braced frame and to illustrate the impact of the provisions. Key words: design, structural engineering, steel, earthquakes, braced frame, standards.
38 citations
TL;DR: In this paper, the authors presented the results of an experimental study on the hydraulics of culvert fishways with spoiler baffles, and four designs were studied with the heights of the baffles equal to 0.09D and 0.1D.
Abstract: This paper presents the results of an experimental study on the hydraulics of culvert fishways with spoiler baffles. Four designs were studied with the heights of the baffles equal to 0.09D and 0.1...
TL;DR: In this article, reliability, resiliency, and vulnerability criteria are formulated as risk-based performance measures for the evaluation of a real-time reservoir operation model, which includes a multi-objective compromise programming algorithm to select, in real time, an optimal operating horizon for the reservoir operation.
Abstract: Reliability, resiliency, and vulnerability criteria are formulated as risk-based performance measures for the evaluation of a real-time reservoir operation model. The reservoir operation model includes a multi-objective compromise programming algorithm to select, in real time, an optimal operating horizon for the reservoir operation. The utility of the risk-based performance criteria for comparing operational strategies resulting from the selection of different parameters for the compromise programming algorithm is demonstrated. Although trade-offs exist between the performance evaluators, it is shown that appropriate compromises can be reached between the conflicting modeling goals. Key words: reservoir operation, real time, risk, optimization.
TL;DR: The most widely used form of wastewater treatment in Canada, particularly in the western provinces and northern territories, is the use of lagoons as discussed by the authors, and existing lagoon design guidelines developed for warm climate.
Abstract: Lagoons are the most widely used form of wastewater treatment in Canada, particularly in the western provinces and northern territories. Existing lagoon design guidelines developed for warm climate...
TL;DR: In this article, the authors show that spillways for medium and high head dams may be exposed to high velocity flows and the associated destructive phenomenon of cavitation, and that cavitation may occur at rough spots in the surface of the chut...
Abstract: Spillways for medium and high head dams may be exposed to high velocity flows and the associated destructive phenomenon of cavitation. Cavitation may occur at rough spots in the surface of the chut...
TL;DR: In this paper, linear wave theory and wave hindcasting are applied to derive an expression for the depth of water needed to prevent the wind-wave-induced suspension of sediments in mine tailings ponds.
Abstract: Linear wave theory and wave hindcasting are applied to derive an expression for the depth of water needed to prevent the wind-wave-induced suspension of sediments in mine tailings ponds. The depth ...
TL;DR: In this paper, the authors evaluated the behavior of recycled asphalt pavements with respect to low-temperature cracking and found that a recycled mix consisting of a mix of recycled mix and asphalt was more robust to low temperature cracking.
Abstract: This paper summarizes the results of a study conducted to evaluate the behaviour of recycled asphalt pavements with respect to low-temperature cracking. For this purpose, a recycled mix consisting ...
TL;DR: In this article, the effect of gradation of armour stones and the amount of rounded stones in the armour on dynamically stable breakwater was assessed in a 2-dimenaional wave flume.
Abstract: The effect of gradation of armour stones and the amount of rounded stones in the armour on dynamically stable breakwater was assessed in a 2-dimenaional wave flume. A total of 52 series of tests were undertaken at the Coastal Engineering Research Laboratory of Queens University, Kingston, Canada using irregular waves. Profiles of the structure during the various stages of reshaping were measured using a semiautomatic profiler developed for this study. Four gradations of armour stones were used, giving a range in uniformity coefficient of 1.35-5.4. The volume of stones and the initial berm width required for the development of a stable profile, along with the extent to which the toe of the strucutre progressed seaward, were chosen as representative parameters of the reshaped breakwater. The results indicated that the toe width formed as a result of reshaping and the area of stones required for reshaping were dependent on the gradation of the armour stones. The initial berm width reqired for reshaping was also found to be dependent on the gradation and the percentage of rounded stones in the armour.
TL;DR: In this paper, the authors describe the sloshing of a liquid in a rigid circular cylindrical tank subjected both to harmonic and to irregular base motion, and present a simplified method of estimating maximum forces using a modal analysis and involving earthquake response spectra.
Abstract: The present paper describes the sloshing of a liquid in a rigid circular cylindrical tank subjected both to harmonic and to irregular base motion. Initially, the boundary value problem for the case of an inviscid fluid and a harmonic base motion is solved on the basis of linearized potential flow theory. The case of energy dissipation of a real fluid is then treated by a simple extension to this, which involves an assumption of dissipation at the free surface and a corresponding modification to the free surface boundary condition. In order to treat earthquake-induced motions, this solution is then extended to (i) the stochastic response to a base motion which describes a stationary random process; (ii) the time-domain response to a specified base acceleration record; and (iii) a simplified method of estimating maximum forces using a modal analysis and involving earthquake response spectra. The estimation of hydrodynamic damping is briefly considered, and example applications are provided. Key words: added...
TL;DR: In this paper, the elastic stiffness under moderate lateral loads and good ductility when subjected to severe seismic loading conditions was investigated. But, under extreme loading conditions, the in-place elastic stiffness was not as good as the external stiffness.
Abstract: Eccentrically braced steel frames have excellent elastic stiffness under moderate lateral loads and good ductility when subjected to severe seismic loading conditions. Under extreme loading, the in...
TL;DR: The application of discrete choice models (e.g., logit, probit) to study modal choice in passenger transportation has had a wide acceptance in the literature.
Abstract: The application of discrete choice models (e.g., logit, probit) to study modal choice in passenger transportation has had a wide acceptance in the literature. However, little success had been repor...
TL;DR: In this paper, an experimental investigation was conducted at the structural laboratory at Memorial University of Newfoundland to examine the behaviour of high-strength concrete two-way slabs, and it was evident that...
Abstract: An experimental investigation was conducted at the structural laboratory at Memorial University of Newfoundland to examine the behaviour of high-strength concrete two-way slabs. It was evident that...
TL;DR: Some of the factors to be considered in performing impact assessments for proposed municipal and non-hazardous waste landfill sites are discussed in this paper, including the effect of the mass of co...
Abstract: Some of the factors to be considered in performing impact assessments for proposed municipal and non-hazardous waste landfill sites are discussed. These factors include the effect of the mass of co...
TL;DR: In this article, an analytical model of behaviour is presented, which uses one-dimensional finite element approximations to predict the short-term load - slip response of a single fastener joint.
Abstract: An analytical model of behaviour is presented, which uses one-dimensional finite element approximations to predict the short-term load – slip response of a single fastener joint. The model treats the elastoplastic behaviour of the fastener as well as the nonlinear, nonelastic properties of the wood. It accounts for some of the distinctive behaviour of timber joints such as fastener withdrawal, rotational restraint at the fastener ends, joint interface characteristics, and combined fastener bending and axial tension. Good agreement is obtained between model predictions and test behaviour for single fastener glulam rivet, nail, and bolt joints. The model can be adapted to include the variability in wood and fastener properties, and can be incorporated into a large number of computer simulations in order to predict the fifth fractiles of the populations of joint resistances, which can be used in a limit states design approach. Key words: timber structures, glulam rivet connections, nailed connections, bolted...
TL;DR: In this paper, the most commonly used method, the slope-area method, is examined and it is argued that there is likely to be a strong upward bias in these flood estimates.
Abstract: The high accuracy of normal river discharge measurements is contrasted with the approximate methods used to estimate large floods. The most commonly used method, the slope–area method, is examined and it is argued that there is likely to be a strong upward bias in these flood estimates. Sources of error are subdivided into four main types: (i) error in the Manning friction coefficient, (ii) error in after-flood measurements of channel cross section, (iii) estimation of surface slope and energy grade line from high-water marks, and (iv) the effects of erosion and sediment transport. These various factors are seen to be influenced by channel curvature and meandering, floodplain flow and interaction with the main channel, and changes to channel geometry during a flood. From theoretical work on high sediment transport, it is argued that up to one third of the channel slope is required for moving the sediment, so that only two thirds of the slope is available for transporting the water. Key words: floods, rive...
TL;DR: In this article, the seismic force reduction factors proposed in the seismic provisions of the National Building Code of Canada 1990 (NBCC 1990) are examined using ground motion records from two recent Canadian earthquakes.
Abstract: The seismic force reduction factors proposed in the seismic provisions of the National Building Code of Canada 1990 (NBCC 1990) are examined using ground motion records from two recent Canadian earthquakes. The displacement ductility demands are analyzed for structural systems with different ductility capacity. It is found that the NBCC 1990 force reduction factors, which are period independent, lead to a very high ductility demand for short-period structural systems. To avoid this, two types of period-dependent force reduction factors for short-period structures are investigated. The results show that the linearly varying period-dependent reduction factor represents a viable means to resolve the high ductility problems associated with short-period structural systems. Key words: earthquake, seismic, design, code, response, spectra, ductility, reduction factor, base shear.
TL;DR: In this article, a nonparametric regression model was proposed to investigate the relationship between groundwater level fluctuations and streamflow time series observations, and the results from the analysis indicate that the non-parametric method gives more accurate prediction results than those obtained from parametric regression.
Abstract: A new nonparametric regression model is proposed to investigate the relationship between groundwater level fluctuations and streamflow time series observations. The developed nonparametric model does not force the relationship between variables into a rigidly defined class (i.e., linear regression) and is capable of inferring complicated relationships. The results from the analysis indicate that the nonparametric method gives more accurate prediction results than those obtained from parametric regression. A split-sample experiment shows that nonparametric regression gives accurate prediction (extrapolation) results at the validation stage. Key words: nonparametric regression, cross-validation method, groundwater level, streamflow.
TL;DR: In this paper, the authors present the rationale behind the development of design load specifications in the preliminary standard S.471 "General requirements, design criteria, the environment, and loads." As part of this development, background calibration studies were conducted in tandem with the work of various committees.
Abstract: The Canadian Standards Association (CSA) initiated effort in 1984 aimed at the development of an offshore code for production structures in the oil and gas industry. The present paper summarizes the rationale behind the development of design load specifications in the preliminary standard S.471 "General requirements, design criteria, the environment, and loads." As part of this development, background calibration studies were conducted in tandem with the work of various committees. Selected results from these studies are also discussed in this paper. The basic objectives and tools for developing load criteria for the design of offshore installations are discussed. The use of economic analyses of cost versus safety of structures does not provide clear guidance, and the perspective taken is that of acceptable risks to an individual. This is used in the context of limit states design, which, in S.471, incorporates two safety classes. In order to provide consistent safety levels, the environmental loads are d...
TL;DR: In this article, the influence of the following factors on trace metal concentrations in 1-L first-flush drinking water samples and running hot water samples was investigated: building height, location, plumbing age, type of plumbing, and type of building.
Abstract: Samples were taken from 72 high-rise apartment suites (6 suites in 12 individual high-rise towers) and 60 single-family houses located within the Greater Vancouver Regional District. The influence of the following factors on trace metal concentrations in 1-L first-flush drinking water samples and “running” hot water samples was investigated: building height, location, plumbing age, type of plumbing, and type of building. Results of this survey show that with the exception of building height, all factors had a correlation with one or more of the trace metals investigated. The trace metals examined were lead, copper, iron, and zinc. Lead was influenced primarily by building type, copper by plumbing age and type of plumbing, and iron by location. Elevated lead levels were associated with high-rise samples. New copper plumbing systems resulted in high copper levels. Highest iron levels in the drinking water were measured in the East Vancouver location. Zinc did not show a distinct correlation with any of the ...
TL;DR: In this paper, a pilot-scale study was conducted to evaluate the treatment performance of an upflow anaerobic filter (AF) on a slaughterhouse effluent, and the effluent flow rate through the AF was changed for seven...
Abstract: A pilot-scale study was conducted to evaluate the treatment performance of an upflow anaerobic filter (AF) on a slaughterhouse effluent. The effluent flow rate through the AF was changed for seven ...
TL;DR: In this paper, the authors present an approach to effectively manage facility impacts and siting of waste disposal facilities in the absence of very serious physical impacts, in order to effectively managing facility impacts.
Abstract: Host communities often very strongly oppose municipal waste disposal facilities despite the absence of very serious physical impacts. In order to effectively manage facility impacts and siting proc...