bluuebunny/crossref_metadata_2025 huggingface dataset:
Flow establishment in helical corrugated pipe
Authors: Smit Cliff D.
Published: January 2010

Corrugated steel pipe suppliers have recently switched from annular rivetted corrugated pipe to helical lock seam corrugated pipe. This was done as a manufacturing expedient, but there has been an unexpected benefit in terms of reduced hydraulic resistance. Studies on full scale pipes have shown that the friction factor for full flow is lowered substantially as the helix angle of the corrugations is reduced. In fact at a helix angle of 52.5 ° the pipe resistance was found to be almost as low as for smooth pipe. However, these tests were concerned exclusively with determining rates of head loss for fully established flow. Drainage culverts for highways, grid roads, and farm crossings are usually relatively short structures. In some cases the length to diameter ratio may be as low as 10, and in most cases would not exceed 50. This immediately introduces the question of the length of culvert required to develop fully established helical flow, because before the flow becomes established the rate of head loss will be greater. In effect the friction factor will be highest at the culvert inlet and decrease along the length of the culvert, becoming a minimum after the flow is fully established. In theory the accumulated loss could be calculated by using a variable friction factor over the establishment length. This would be cumbersome and impractical. It would be simpler to calculate the pipe friction on the assumption that it is constant, at the minimum value, for the whole length of the pipe and then add a "development head loss" term to account for the extra loss. Experiments to determine the development head loss were conducted at the Hydraulics Laboratory, Department of Civil Engineering, University of Saskatchewan. The model pipes were 107 mm inside diameter and 2.13 m long. Standard corrugations were simulated and helix angles of 61.0 and 71.4° were tested. It was found that about 12 diameters of pipe length were required to obtain fully established flow, and a value for the development head loss of 0.2 times the velocity head was indicated. Key words: helical corrugated pipe, head losses, n values, flow establishment.
Wave and current forces on fixed offshore structures
Authors: Isaacson Michael
Published: January 2010

The Canadian Standards Association standard S471 "General requirements, design criteria, environment, and loads, Part 1 of the CSA code for the design, construction and installation of fixed offshore structures" contains an appendix "Wave and current loads." To compliment this appendix, the present paper provides a more detailed survey of this topic with a review of the recent literature and recommendations of hydrodynamic data needed in offshore design. In addition, hydrodynamic considerations in the calculation of earthquake and ice loads are mentioned. Key words: currents, current forces, hydrodynamics, ocean engineering, offshore structures, waves, wave forces.
An explicit algorithm to simulate transient transverse mixing in rivers
Authors: Beltaos S. , Arora V. K.
Published: January 2010

Because no analytical solution exists for transient mixing of contaminants in the transverse mixing zone of streams, numerical solutions must be used in pertinent engineering applications. Few numerical algorithms have been devehloped for this problem and the relatively simple explicit ones are subject to serious numerical "diffusion." It is suggested herein that such effects can be minimized using an irregular space grid such that the length of each element is exactly equal to the time step times the local flow velocity. Using also the well-known streamtube concept, a simple explicit algorithm is obtained and verified by means of three laboratory and one field test. Two of these tests include concentration data that are both transient and within the transverse mixing zone, which afford a more complete algorithm testing than has been done in the past. Possible improvements for increased accuracy, efficiency, and generalized natural stream application are discussed. Key words: advection, algorithm, channel, diffusion, dispersion, explicit, mixing, numerical, numerical diffusion, river, streamtube, test, transient, transverse.
Functional design of a swim basin in the Detroit River
Authors: Patterson H. R. , Becker N. K. , McCorquodale J. A.
Published: January 2010

Many urban beaches on fresh water lakes and rivers face closure during peak summer periods due to dangerous concentrations of fecal coliforms and other waterborne contaminants. One such example is the Lake Erie Metro Park which is located approximately 22 km (14 miles) downriver of Detroit, Michigan, and Windsor, Ontario, at the mouth of the Detroit River.N.K. Becker & Associates Ltd. was retained in 1985 to research and develop a functional design for a swim basin that will be formed by cordoning off an area of the Detroit River with a breakwater. A unique feature of this breakwater is that it is being designed to filter water from the Detroit River to the extent required for safe swimming. When it is constructed in 1988, it will be capable of accommodating approximately 1500 swimmers.Extensive hydraulic model studies were carried out at the universities of Windsor and Michigan to research and develop a functional design for this facility. The methodology used to develop the design concepts for this swim basin as well as the results of the testing program are described in this paper. Key words: fecal coliforms, swim basin, sand filter, breakwater, hydraulic model, beach, circulation, waves, water deficit, precast concrete cylinders.
Récupération de microalgues à l'aide d'un décanteur lamellaire
Authors: Létourneau M. , Sérodes J. B. , Noue J. de la
Published: January 2010

A prototype based on lamellar flocculation–settling has been developed to recover microalgae produced during the biological tertiary treatment of waste waters. The system has enabled the recovery of up to 85% of the initial suspension of algae, at a load of 17 L∙m−2∙min−1. This load corresponds to a detention time 80 times shorter than in a settling tank. Key words: lamellar settling, microalgae, flocculation. [Journal translation]
Hydraulics of offset baffle culvert fishways
Authors: Rajaratnam N. , Katopodis C. , Lodewyk S.
Published: January 2010

This paper presents the results of an experimental study on the hydraulics of culverts with offset baffles to pass fish. Using analytical considerations and experimental observations, a flow equation has been developed between the discharge, diameter, depth, and slope for a culvert fish way with the standard offset baffle system. The velocity field at the slot has also been evaluated. Some further experiments were performed to assess the effect of baffle spacing and height on the hydraulics of the culvert fishway. Key words: culverts, fishways, baffles, hydraulics, open-channel flow, turbulent flow.
On the elasticity of ice plates
Authors: Gold Lorne W.
Published: January 2010

The rigidity modulus is determined for simply supported, circular ice plates 0.5 and 1.22 m in diameter. Measurements for the 0.5 m diameter plates were made at −10 °C and for the 1.22 m plates in the range of −7 to −37 °C. The elastic moduli and Poisson's ratio, calculated from the rigidity modulus, are in the range of 6.0–12.0 GPa and 0.29–0.60 respectively, depending on ice type, temperature, and grain size. The plate characteristic lengths calculated from the measured values of the elastic moduli are compared with characteristic lengths determined from field measurements of the deflection of ice covers under load. Key words: ice, ice cover, rigidity modulus, elastic modulus, Poisson's ratio.
Role of computers in the design of energy-responsive buildings
Authors: Zmeureanu Radu , Fazio Paul
Published: January 2010

Closer collaboration of the traditional disciplines of architecture, structural engineering, and mechanical engineering is required at the design stage to better deal with the complexity of modern buildings, and to maintain the cost of energy low while providing a suitable indoor environment during the life of the building.The availability of personal computers and the development of interactive software provide more opportunities for an integrated approach to building design. This approach is useful in determining the impact of one subsystem on the performance of another subsystem and on the overall performance of the building. An example of such an integrated approach is presented in this paper, which determines the impact of a structural system (hollow core slab) and its mass on the energy consumption of the building. Key words: building design, computers, energy.
Pertes de charge des ancrages actifs injectés dans un massif rocheux
Authors: Benmokrane Brahim , Ballivy Gérard
Published: January 2010

Estimation of loss of prestress is an essential part of the design of permanent or temporary prstressed anchors since stability of the retained structure must not be compromised. Findings of a field study on long-term behaviour of prestressed anchors are presented herein: different lengths of anchors in solid rock were injected with cement grout or epoxy resin. Load variation in the anchors with time indicated two distinct stages of loss of prestress: an initial stage of rapid loss of prestress and a second stage of very minor and uniform loss ending about 6 months after prestressing. Our study also showed that restressing anchors after a period of time reduces subsequent prestress loss and that overdimensioning of the injected length does not. Key words: rock, prestressed injected anchor, grout, loss of prestress, creep, relaxation.
Structural response to rod mill vibration
Authors: Marzouk H.
Published: January 2010

An investigation was carried out to determine the response of an existing industrial plant to rod mill vibration. The disturbing forces and frequencies of the mill were estimated and compared with previous design and vibration measurements data on mill foundations. Owing to lack of space in the crushing area of the plant, it was decided to combine one of the building footings with the mill foundation. A dynamic analysis was carried out on the existing building to determine the structural response to the new mill vibration. The soil springs, geometric damping ratios, and rocking springs were calculated. Mill foundation and adjacent structures were modelled together using finite element dynamic program to calculate the natural frequencies, mode shapes, dynamic response, and amplification factors. Three design alternatives were considered. Based on the results of our analysis, one design was recommended to minimize the dynamic effect on the existing structure. The building structural system was altered accordingly. The new mill and the structural alternation were carried out during the spring of 1984. Since then, the new mill and the structure have performed satisfactorily. Key words: rod mill, foundation, vibrations, soil springs, dynamic analysis, structured response, dynamic amplitude ratios.
Efficient numerical modelling for the design of friction damped braced steel plane frames
Authors: Filiatrault A. , Cherry S.
Published: January 2010

A novel friction damping system for the aseismic design of framed buildings has been proposed by Canadian researchers. The system has been shown experimentally to perform very well and is an exciting development in earthquake resistant design.The design of a building equipped with the friction damping system is achieved by determining the optimum slip load distribution to minimize structural response. The optimum slip load distribution is usually determined using the general nonlinear dynamic computer program DRAIN-2D, which requires extensive computer time and is not practical for most design offices.This paper describes a new, efficient, numerical modelling approach for the design of friction damped braced frames. The hysteretic properties of the friction devices are derived theoretically and included in a friction damped braced frame analysis program, which is adaptable to a microcomputer environment. The optimum slip load distribution is determined by minimizing a relative performance index derived from energy concepts. The new numerical approach is much more economical to use than DRAIN-2D and is of great value for the practical design of friction damped braced frames. Key words: braced frames, brake lining, performance index, damping, dynamics, earthquakes, energy, friction.
Theoretical study of the buckling strength of compression members connected to coplanar tension members
Authors: Picard André , Beaulieu Denis
Published: January 2010

In structural systems like diagonal cross-bracings, the out-of-plane deformation of the compression members is restrained by the tension members. The purpose of the theoretical study presented in this paper is to determine the transverse stiffness provided by the tension members and to evaluate the effect of this stiffness on the out-of-plane buckling of the compression members. Two practical cases are considered. The compression member is restrained against out-of-plane buckling by one tension member connected at midpoint or by two tension members connected at third points.The theoretical study shows that the transverse stiffness provided by the tension members does not have to be very large to obtain a significant decrease in the effective length factor. It is also shown that the transverse stiffness depends on the ratio of the axial compression force to the axial tension force and that the effective length factor increases with this ratio. However, even for large values of this ratio, the effective length factor is much smaller than 1.0. For instance, when the axial tension force is 0 and the ratio of the out-of-plane moment of inertia of the tension member to that of the compression member is 1.0, the effective length factor is approximately equal to 0.71 instead of 1.0 for both practical cases studied. Key words: stability, elastic buckling, elastic supports.
Experimental study of the buckling strength of compression members connected to coplanar tension members
Authors: Picard André , Beaulieu Denis
Published: January 2010

In structural systems using cross braces, the compression members are restrained against out-of-plane buckling by the tension members. It was shown in a theoretical study that the transverse stiffness provided by a tension member depends on the tension force in the member and on the flexural stiffness against out-of-plane deformation of the tension member. Equations were derived to determine the effective length factor of the compression member, taking into account the transverse stiffness of the tension member.This paper presents the results of a small-scale experimental study, which shows that the proposed equations slightly underestimate the transverse stiffness and overestimate the effective length factor. These equations are therefore conservative, but they indicate that an effective length factor much smaller than 1.0 can be used. Key words: stability, elastic buckling, elastic supports, cross braces.
Revised ground snow loads for the 1990 National Building Code of Canada
Authors: Newark M. J. , Welsh L. E. , Morris R. J. , Dnes W. V.
Published: January 2010

The last systematic recalculation of ground snow loads in the Supplement to the National Building Code of Canada was made in 1977 and used data up to 1975. Data from three times as many stations are now available and there is also an additional 10 years of record. Using this expanded data base, ground snow loads have been recalculated for the 1990 Supplement.Several changes in methods have been utilized, the most significant of which is the use of an objective technique to estimate ground snow loads at Code (or other) locations. It explicitly incorporates an assumed dependence of the snow load on topographical elevation, and accounts for the magnitude of errors at snow depth observation sites. Other differences include (a) the use of the method of moments to fit the Gumbel extreme value distribution for the purpose of estimating the 30-year return period snow depth; (b) the use of geographically varying snow pack densities; and (c) using probabilistic rain components of the total snow load and estimating this component by use of a snow pack model.Results show an average national decrease of 6.6% in the 1990 loads compared with those in the 1985 Supplement. A regional exception is in the Northwest Territories where the use of a greater snow density has led to an average increase of about 16% in the loads. A reduction in the standard deviation about the mean load suggests a more spatially consistent set of values for the 1990 Supplement. Key words: snow, loads, building, code.
Fire endurance analysis of reinforced concrete columns
Authors: Ng Ah Book , Mirza M. Saeed , Lie T. T.
Published: January 2010

This paper presents a summary of the fire resistance computer program FRCP developed to analyze the influence of selected parameters on the response and behaviour of axially loaded square reinforced concrete columns subjected to fire. The mechanical and thermal properties of the concrete used in the reinforced concrete column and the variation of the elastic moduli of the concrete and the reinforcing steel with temperature need to be determined experimentally, prior to analysis using the FRCP computer program. Very good agreement (±15%) was obtained between the computed and the experimental responses of prototype and model columns. Key words: axial load resistance, computer program, concrete cover thickness, deterioration of strength and stiffness, direct models, fire endurance, reinforced concrete columns, temperature–time relationships.
Nonlinear analysis of grid systems
Authors: Tharmabala Tharmalingham
Published: January 2010

A method is proposed for the nonlinear analysis of grid systems. The structure is loaded incrementally and the current stiffness matrices of each member are evaluated using a numerical procedure and the moment–curvature and torsion–twist relationships of the grid elements. The member stiffness matrices are used to develop the global stiffness matrix of the grid structure. In other respects, the method is very much similar to linear elastic analysis of grid framework. A bridge structure is analyzed using a computer program, developed by incorporating the proposed method. The program is able to predict the nonlinear characteristics of the structure such that it can reduce the girder moments and (or) the total material costs. Key words: bridges, nonlinear analysis, slab-on-girder bridges, grillage analysis, ultimate load capacity.
Leachate: production and characterization
Authors: Farquhar G. J.
Published: January 2010

Leachate production deals with the creation of contaminated liquid at the base of a landfill. It involves the elements of a water balance in which precipitation either runs off from the landfill or infiltrates. Some infiltration will evapotranspire, some may be stored within the landfill, and the balance becomes percolate and eventually leachate. Examples of the water balance method are presented and consideration is given to the sequence of landfill development and the effect that it has on leachate flow. Information is provided on the microbial decomposition of municipal solid waste and the conditions which influence decomposition rates. The impact of the microbial processes on leachate contaminant composition is examined. Leachate characterization requires that estimates be made of contaminant types and concentrations as a function of refuse age. Data describing contaminant production from various sources are examined. A procedure is presented to combine the water balance method and contaminant production curves to predict leachate flow and strength with respect to site age. A simpler alternative involving a set of tables showing expected contaminant types and ranges of concentrations as a function of refuse age is also provided. Key words: landfill, leachate, flow, composition, estimation, model.
Assessing the risks associated with the transport of dangerous goods by truck and rail using the RISKMOD model
Authors: Van Aerde M. , Shortreed J. , Stewart A. M. , Matthews M.
Published: January 2010

To provide an objective tool for assessing the risks involved in the transport of dangerous goods, a model called RISKMOD-I was developed for Transport Canada by the Institute for Risk Research. The model implements the computational aspects of a comprehensive risk assessment methodology which addresses both the quantitative and qualitative aspects of dangerous goods releases following a transport incident. This paper describes the model's implementation, data requirements, and outputs.The risk assessment model consists of an analysis of link-specific accident rates and a fault tree analysis to determine the probability of a dangerous good release of a particular type. In parallel, a series of commodity-specified damage models compute the impact areas associated with representative sizes and types of releases. The impact areas for each damage threshold are then multiplied by the population density and property exposure along each link to determine the total risk associated with a dangerous goods shipment that uses the link. This estimate of total risk can optimally be further converted into a risk cost value in monetary terms and summarized for the entire route. Both the risk and risk cost estimates are intended to be used in conjunction with other subjective analyses and performance measures to provide a comprehensive decision-making aid for risk managers. Key words: dangerous goods transport, truck and rail accidents, risk analysis.
Comportement dynamique des lignes aériennes de transport d'électricité dû aux bris de câbles. II. Problèmes numériques associés à la modélisation mathématique
Authors: McClure Ghyslaine , Tinawi René
Published: January 2010

The evaluation of the response of an aerial power line section subjected to cable breakage is a complex dynamic problem in which geometric nonlinearities are important. The solution of the equations of motion of the model calls for direct integration methods for which the stability and behavior, in nonlinear situations, are difficult to predict. Seven numerical models are analyzed with the Wilson-θ and the Newmark-β algorithms and results are compared with those of small-scale tests of the American Electric Power Research Institute. This comparison emphasizes the importance of the high frequency modes in the response and the artificial damping induced by the Wilson-θ method. This method allows up to three times the time increment required by the trapezoidal rule that does not filter the contribution of higher frequencies but is limited by a convergence criterion. Many observations made in this particular study are also applicable to multi-degree-of-freedom nonlinear dynamic problems using direct time-step integration. Key words: Nonlinear dynamic analysis, direct integration methods, aerial electric transmission lines, cable breakage simulation.
Hydraulics of culvert fishways II: slotted-weir culvert fishways
Authors: Rajaratnam N. , Katopodis C. , McQuitty N.
Published: January 2010

This paper presents the results of an experimental study on the hydraulics of culvert fishways with a slotted-weir baffle system. Six designs with two baffle heights and three spacings were tested. A flow equation has been developed to predict the flow depth for any given discharge, diameter, and slope. The barrier velocity that would exist at the slot in the baffles has also been predicted in a general manner. This relatively simple slotted-weir baffle system has been found to match the performance of the more complicated but frequently used offset baffle system of similar dimensions. Key words: culverts, fishways, baffles, hydraulics, turbulent flow, open-channel flow.
Behaviour and ultimate tensile strength of partial joint penetration groove welds
Authors: Gagnon Darrel P. , Kennedy D. J. Laurie
Published: January 2010

Partial joint penetration groove welds may be used in columns, for example, when it is not necessary to develop the full tensile capacity of the cross section. Also, where it is not feasible to make a full joint penetration groove weld because welding can be done from one side only, the strength of a partial joint penetration groove weld may be adequate. Limited experimental data have shown that the strength of partial penetration welds are proportional to their areas.A series of 75 tests on 25 mm thick, grade 300W and grade 350A steel plates, with welds made with matching electrodes and with 20–100% penetration, were conducted. The overall behaviour, the effects of percent penetration, plate strength, and the eccentricity of the load were investigated. The inherent ductility of the welds allows lateral deflections and straining to take place so that eccentrically loaded welds are as strong as concentrically loaded welds. The strength of welds is greater than the strength of the plate multiplied by the percent penetration and increases with the increasing lateral restraint that occurs with decreasing penetration. Design equations and resistance factors, based on weld strengths at least equal to the percent penetration multiplied by the ultimate tensile resistance of the plate, are proposed. Recommendations for fabrication are presented. Key words: behaviour, groove weld, limit states, partial joint penetration, strength, resistance factor, tension, ultimate.
Étude comparative de trois modèles dynamiques de boues activées
Authors: Couillard D. , D'amours F. , Patry G.
Published: January 2010

Three complete dynamic models are proposed to simulate the transient behaviour of the activated sludge process. The authors compare the responses obtained by simulation with datas found in the literature for the Norwich wastewater plant (England). A structured biological model with bi-substrate component (particles and soluble material) together with a nitrification model taking into account the organic nitrogen content of the affluent present the most realistic profils for the conditions studied. A sensitivity analysis reveals that a generalization of the model is possible if some parameters identified as critical are adjusted. Key words: mathematical model, activated sludge, water treatment, dynamic modelling, comparison of models.
Field test of an open deck railway bridge with concrete ties
Authors: Igwemezie Jude O. , Saeed mirza M. , Scott J. F.
Published: January 2010

Prestressed concrete ties offer an alternative to the timber ties which are used presently on North American open deck railway bridges. This paper presents the results of a field study of an open deck railway bridge equipped with precast prestressed concrete ties subjected to a special work train and regular railway traffic. The results of the study show that a train with smooth wheels does not overload the bridge deck. When wheel defects are present, the bridge deck loading is speed-dependent and consists of distinct static and dynamic components. Test results show that the tie design loads are underestimated. The impact on the bridge deck due to the defective wheels was also found not to amplify the response of the bridge longitudinal steel girders. Key words: bearing pads, impact load, railway bridge, load distribution, dynamic load factor, open deck, precast prestressed concrete, ties, wheels.
Application of compound finite strip method in soil–steel structures
Authors: Ekhande Shantaram G. , Abdel-Sayed George
Published: January 2010

The method of compound finite strip is applied for the three-dimensional analysis of corrugated soil–steel structures with and without curved stiffeners. Displacement functions are suggested for the analysis of soil–steel structures during and after backfilling. The eccentricity between the middle surfaces of stiffened elements and the adjacent shell elements is considered in the displacement functions so that the continuity of the shell is satisfied between the strips. The formulation presented herein incorporates the stiffness contribution of surrounding soil media directly in the strip element stiffness matrix. Examples of soil–steel structures are analyzed by the proposed method and the results are compared with experimental results. Key words: cylindrical shells, finite strip, soil–steel structures, stiffeners.
Scale-model testing of reinforced concrete under impact loading conditions
Authors: Sato J. A. , Vecchio F. J. , Andre H. M.
Published: January 2010

Aspects of scaling theory relating to the response of reinforced concrete structures under impact load conditions are reviewed. Details for modelling concrete and reinforcement, to be consistent with similitude requirements, are also discussed. A test program is described in which models of varying size were constructed, drop tested, and compared with prototype response. An analysis of the test data is made, indicating that, within certain limitations, the predictions of scaling theory are applicable to reinforced concrete subjected to extreme impact loads. Key words: cracking, impact, loads, modelling, reinforced concrete, scaling, stresses, structures, tests.
Une analyse numérique des possibilités de résonance d'un bassin portuaire de profondeur variable
Authors: Serhir-Taleb Najat , Marche Claude
Published: January 2010

Creating, enlarging and excavating a harbour can modify the dynamic response of the basin. A verification of the resonance modes is common practice before undertaking the related work. This can be done numerically if the necessary assumptions are justifiable. It can be done on a small-scale model if the basin has an irregular shape or if the depth varies from one area to the other.A computer-programmed analytical method of resonance modes is presented. It is derived from the direct measure principle of successive oscillation superposition used in the laboratory. Validation is obtained by applying the method to existing theoretical solutions and to the analysis of a small creek of the Gaspe Peninsula where the importance of refraction in the analytical results is demonstrated. Key words: harbour, vibration, agitation, ocean waves, diffraction, refraction, numerical model, application. [Journal translation]
In-plane buckling of trusses
Authors: Dumonteil Pierre
Published: January 2010

One of the main influences in the design of planar triangulated trusses is the choice of effective lengths for the various members. The article proposes an iterative method which converges to the exact buckling load for each of the members according to the bifurcation theory. Using the concept of equivalent modulus in compression, the method is then extended to the inelastic domain. Member resistances are compared with exact results published in Europe. It is shown that, for conventional trusses, good accuracy may be expected. The influence of joint flexibility and eccentricity in tubular trusses is examined to show that, while moderate eccentricities may be altogether disregarded, angular joint flexibilities tend to increase the buckling length of web members. Key words: buckling, eccentricity, effective, flexibility, joint, resistance, triangulated, truss, tubular.
A computer program for the evaluation of wind-induced forces and vibrations of buildings
Authors: Stathopoulos T. , Tan M. H.
Published: January 2010

The paper presents a microcomputer program designed for the evaluation of wind-induced forces, displacements, and accelerations of rectangular buildings in accordance with the stipulations and the methodology of the National Building Code of Canada. Meteorological data for Canadian cities have been included in a database file, so it is sufficient to provide information about the geometric, dynamic, and exposure characteristics of the building along with the name of the city of its location for a complete analysis by using either the detailed procedure or both the simple and detailed procedures. The program has been used in a parametric study to provide data of maximum displacements and accelerations of buildings. These data have been organized in charts useful to the professional engineer for preliminary design purposes. Key words: acceleration, building, code, design, displacement, pressure, wind, vibration.
Permeability protocol for the compacted clay liner at Metropolitan Toronto's Keele Valley Landfill
Authors: Richards Peter A. L. , Thompson Christopher D.
Published: January 2010

The Provisional Certificate of Approval to construct a sanitary landfill for municipal waste in an old gravel pit in the Oak Ridges Moraine north of Toronto, Ontario, required that a 1.2 m thick compacted clay liner with a permeability of less than 10−8 cm/s should be placed beneath any refuse. Preliminary testing indicated that the native tills from the immediate vicinity were marginally capable of providing such a liner, as long as they were carefully selected and compacted at moisture contents just above optimum values. However, it was clear that the variability of material and (or) testing was such that some liner samples could have permeabilities greater than 10−8 cm/s. Additionally, there was concern that the sampling and testing procedures could affect the results. This paper details the trials which were carried out at the beginning of construction to establish acceptable sampling and testing techniques.These were finally determined to consist of carefully obtained Shelby tube samples, the permeability of which was tested at representative pressures in triaxial cells. The paper then presents the statistical analyses which were used to verify that the overall permeability of the liner is less than 10−8 cm/s. It also outlines other testing and instrumentation which has been undertaken to verify the liner permeability and integrity. It is concluded that, to date, the permeability testing and protocol are suitable control procedures to verify compliance with the condition of the Provisional Certificate of Approval that a liner permeability of 10−8 cm/s be achieved. Key words: clay liner, permeability, protocol, quality control, sanitary landfill, sampling, statistical analysis, testing.
A disaggregate logit model of intercity common carrier passenger modal choice
Authors: Ridout Rowena , Miller Eric J.
Published: January 2010

The use of the logit functional form is common in traditional, aggregate intercity passenger demand models. The use of disaggregate logit models (that is, models calibrated on data pertaining to individual travellers' behaviour and derivable from explicit assumptions concerning travellers' decision-making processes) in the intercity context is surprisingly rare. The major obstacle to such usage would appear to be a general lack of the disaggregate data required to calibrate these models. The major rationale for their use, on the other hand, is the potential that they possess for achieving a more “behavioural” representation of travellers' decision-making and actions.The paper presents a primarily empirical study of the use of disaggregate choice models to represent one component of intercity travel demand, choice of mode. Using 1969 Canadian Transport Commission (CTC) survey data for the Windsor–Quebec City corridor, a disaggregate logit model of common carrier modal choice is presented and discussed. Despite its age and the lack of the auto mode, the CTC data set was used in this study because it appears to be the best disaggregate data set currently available in Canada. The paper also discusses several key issues involved in the development of this model and in its use in intercity passenger demand forecasting, including model data requirements and comparison of the model's predictive performance with traditional aggregate models. Key words: intercity passenger travel, mode choice, disaggregate logit model.
Behaviour of fillet welds as a function of the angle of loading
Authors: Miazga Gregory S. , Kennedy D. J. Laurie
Published: January 2010

Fillet welds subjected to longitudinal shear have been recognized as being weaker than those loaded at other angles, particularly transversely, since the early 1930's. However, the lack of an analytical method to relate the strength of fillet welds to the angle of loading has led to a reluctance to utilize the increased weld strength for other loading angles. Designers have taken a lower-bound approach basing the strength of fillet welds on the strength of longitudinal fillets regardless of the loading direction. Methods are available that predict ultimate strengths reasonably well but may not correlate well with all fracture observations.A rational analytical model for determining the ultimate strength of fillet welds loaded in shear dependent on the angle of loading is developed, relating the ultimate strength to the inclination of the fracture surface and the restraint conditions at the root of the weld. Good correlations of the variation of both the fracture angles and ultimate strengths with angle of loading exist between the results of 42 fillet welded specimens tested in tension and predictions based on this model. Correlations with the test strengths of others, while showing greater scatter, are also demonstrated. The model, extended to limited tests by others on fillet welded specimens loaded in compression, provides substantial correlation for these weaker welds. While weld deformations vary considerably with the loading direction, weld strains are found to be independent of the loading direction. Key words: analytical model, behaviour, fillet welds, fracture angle, loading angle.
Seismic response of reinforced concrete frame subassemblages — a Canadian code perspective
Authors: Paultre Patrick , Castele Daniel , Rattray Suzanne , Mitchell Denis
Published: January 2010

The 1984 CSA standard for the design of concrete structures for buildings provided new seismic design and detailing requirements for concrete structures. Full-scale, reversed cyclic loading tests of reinforced concrete beam–slab–column subassemblages were carried out to investigate the seismic performance of frame structures designed with the latest Canadian code. The test results indicate the importance of including the influence of slab reinforcement in computing the beam capacity as well as the need to carefully design the joint regions for shear. The test results indicate the excellent performance of frame components designed with K = 0.7 (R = 4.0) and the poor performance of those designed and detailed with K = 2.0 (R = 1.5). The performance of subassemblages designed with K = 1.3 (R = 2.0) depends on the column to beam strength ratio and on the shear strength of the joints. Models to predict the flexural response as well as the shear response of key elements are described and the role of the spandrel beam in limiting the effective slab width is explained. Key words: seismic design, reinforced concrete, detailing, structures, codes.
Élimination des boues résiduaires urbaines par la fertilisation sylvicole
Authors: Couillard Denis
Published: January 2010

Governments have initiated wastewater treatment programs to solve the problem of water pollution. The goal is commendable, but the inevitable result is the production of sewage sludge which can be considered as waste. If it is buried, incinerated, or discharged in the sea, the problem is not solved and we are back to square one. Moreover, we have wasted a potentially useful substance. The only promising solution is the transformation of sewage sludge into fertilizers. This study shows that sewage sludge produced by water treatment plants can be used as an efficient forest fertilizer which increases the size and height of trees. The fertilization of larch tree samples in green houses using anaerobic sludge from the Valcartier Wastewater Treatment Plant resulted in a 300% increase in height and 210% increase in diameter. Key words: management, recycling, sewage sludge, anaerobic sludge, fertilization, water pollution, forestry. [Journal translation]
L'utilisation des bétons à très haute résistance au Canada
Authors: Laplante Pierre , Aïtcin Pierre-Claude
Published: January 2010

In the late sixties, several concrete producers in the Chicago area developed very high strength concrete. The compressive strength of this new type of concrete was increased gradually, and it is now possible to buy 100 MPa ready-mixed concrete in several places in North America. Of significant technological importance, very high strength concrete is becoming popular all over North America due to its profitability. As to why and how very high strength concrete is made, the readily available answers to the first question contrast with the predominately empirical approach that has characterized research into producing very high strength concrete up to now. In fact, there are no miracle mixes that will universally guarantee the availability of 100 MPa ready-to-use concretes. Nonetheless, some guidelines have been established that should be followed in order to avoid various pitfalls. In Canada, very high strength concrete is beginning to be used in the Toronto and Montreal areas. This paper summarizes the principal results obtained on two specific projects: the construction of an experimental column in Montreal in 1984, and the construction of Nova Scotia Plaza in Toronto in 1986. Key words: high-strength concrete, water/cement ratio, superplasticizer, silica fume, slag.
Runoff modelling under noise-corrupted rainfall conditions
Authors: Patry G. G. , Kennedy A. , Potter S.
Published: January 2010

Hydrological models are now routinely used in planning, design, operation, and control of water resources systems. However, all models, no matter how complex, are approximations of the real world and consequently are subject to various levels of errors. The analysis of uncertainty in hydrological models can provide valuable insight into the limitations and advantages of various surface runoff models. The benefits derived from such an analysis are many: first, it provides the modeller with a direct estimate of runoff prediction errors under specific rainfall conditions; second, it enables the user to analyze the trade-offs between different rainfall-runoff models; and finally, it can provide useful information for the design of data collection systems designed to achieve a given level of performance. This paper describes the application of uncertainty analysis to rainfall-runoff modelling under noise-corrupted rainfall conditions. The statistical properties of surface runoff subject to noise-corrupted rainfall conditions are examined. Methods of analysis described in this paper include (a) derived probability distribution, (b) first-order analysis, and (c) Monte Carlo simulations. The techniques are applied to linear and nonlinear runoff models, including the unit hydrograph, and the Soil Conservation Service model. Key words: runoff, uncertainty, error analysis, statistics, stochastic modelling, first-order analysis, Monte Carlo simulation, SCS model, unit hydrograph.
Practical simulation of sediment transport in urban runoff
Authors: Schroeter H. O. , Watt W. E.
Published: January 2010

A model for simulating sediment transport in urban areas has been developed based on the concept of "equivalent solids reservoirs." The processes of erosion, deposition, and routing have been represented by simple algorithms, which are applied to typical urban drainage elements (surfaces, gutters, pipes, and detention ponds). Input requirements are limited and include two sediment characteristics (particle size and relative density), scour and deposition parameters, and initial sediment loadings. Hydraulic properties of the drainage elements and the inflow hydrograph to each element are also required. This sediment transport submodel is an integral part of Q'URM, the Queen's University Urban Runoff Model. It has been developed and calibrated on the basis of data from a stormwater quality sampling program on the Calvin Park basin in Kingston, Ontario, and verified on the basis of data from an independent study of runoff quality in the Malvern basin in Burlington, Ontario. Key words: urban hydrology, sediment transport, simulation, measurement.
Shear strength of prestressed concrete edge slab–column connections with and without shear stud reinforcement
Authors: Dilger Walter H. , Shatila Marwan
Published: January 2010

Results are reported of tests to failure on six full-scale unbonded post-tensioned prestressed concrete slab–edge column specimens. The objective is to study experimentally the strength and behaviour of this type of connections. The variables are quantity and distribution of stud shear reinforcement and length of overhang. The relevant design equations suggested by Dilger and Ghali as well as several models by others for predicting the strength of prestressed concrete slab–edge column connections are compared with test results. It is concluded that the ACI and CSA provisions for predicting the strength of such connections are conservative, and that the presence of stud shear reinforcement is a good means of increasing the strength and ductility of this type of connections. Key words: shear strength, flat slabs, prestressed concrete, unbonded tendons, shear reinforcement, design, ductility.
Nonlinear analysis of prestressed concrete box girder bridges under flexure
Authors: Razaqpur A. G. , Nofal Mostafa , Mirza M. S.
Published: January 2010

One-seventh scale direct models of single-cell and two-cell prestressed concrete box girder bridges, tested to destruction at McGill University, are analyzed by the nonlinear finite element technique. The nonlinear program NONLACS, utilized in the analysis, is described in detail together with the material models employed. The objective of the current study is to demonstrate the capabilities of the finite element program NONLACS in predicting the ultimate strength and complete response of prestressed concrete box girder bridges at all stages of loading up to the ultimate load. The load–deflection curves, concrete and steel stresses, and deflected shapes of the bridges at different load levels are compared with the corresponding experimental data. The results verify the applicability of the nonlinear finite element method as an economical and expedient alternative, in some cases, to expensive experimental work aimed at the investigation of the complete response of complex structures to applied loads. Key words: box girder bridges, concrete, concrete and steel strains, experimental data, finite element, load–deflection characteristics, nonlinear analysis, prestressing.
Behaviour of masonry infilled steel frames
Authors: Dawe J. L. , Seah C. K.
Published: January 2010

Masonry shear panels used as infilling in steel frames are investigated experimentally. Twenty-eight large-scale specimens were tested to ultimate panel strength under in-plane, horizontal loading applied at roof level. Of the parameters varied in the test series, interface conditions between panel edges and frame were found to significantly affect the strength and behaviour. Column-to-panel ties were found to be ineffective in increasing ultimate strength while initial stiffness was only marginally increased. A 20 mm gap between the upper edge of a panel and roof beam was particularly detrimental to the system shear capacity. While panel openings reduced initial major crack load, the same was not necessarily true for their effect on ultimate strength. Reinforced bond beams at one third and two thirds of the panel height forced initial major cracking to occur quite close to ultimate, which itself was only marginally increased. The lowest initial major cracking and ultimate loads were recorded for those specimens consisting of a panel in a hinge frame with a 20 mm gap between the upper edge of the panel and roof beam. Key words: masonry, infilled panel, steel frame, experimental, in-plane, behaviour, strength.