bluuebunny/crossref_metadata_2025 huggingface dataset:
Behaviour of buried small flexible pipes
Authors: Ghobarah A. , Tso W. K.
Published: January 2010

An analytical and experimental investigation was conducted to study the behaviour of buried small diameter flexible plastic drain pipes when subjected to surface wheel loads. Tests were conducted on drain pipes buried under sand and also typical agriculture soil samples from Southern Ontario. In addition to soil types, the effect of soil compaction on the stresses and deformation of the pipe was evaluated.It was found that the modulus of soil reaction is highly dependent on the degree of compaction of the soil adjacent to the pipe. By using compacted sand around the pipe, the modulus of soil reaction can be increased significantly, thereby reducing the deformation of the pipe. Using the appropriate value of the modulus of soil reaction, it is shown that theoretical predictions of pipe deformation correlate well with test measurements. Key words: plastic, flexible, buried, pipe, experimental, deformation.
Le rôle de la conformation du fond dans l'estimation du transport solide en rivière
Authors: Sadok A. , Marche C.
Published: January 2010

Bed configuration is shown to be a relevant parameter of the saltation movement of solid particles in free surface flow. Analytical and statistical results confirm the importance of this parameter on bedload and suspended load. Key words: solid transport, entrainment, bed configuration, calculation formula, compared performance.
Serviceability considerations for guideways and bridges
Authors: Nowak Andrzej S. , Grouni Hid N.
Published: January 2010

Serviceability limit states such as fatigue, cracking, corrosion, permanent deformations (kinking), deflection, and vibration are considered. A probability-based approach to develop design criteria is proposed. Load history is represented by load histogram and ADTT (average daily truck traffic) volume. Criteria for the selection of acceptable serviceability levels can be derived from the available test data, bridge surveys, and theoretical studies. Simple format is suggested for the code, with a characteristic value representing load effect and an allowable stress or force representing the structural ability to absorb damage. In the case of deflection and vibration, human perception threshold levels are used as the acceptance criteria. Key words: bridges, damage accumulation, design criteria, limite states, serviceability.
Mobile boundary flow: an assessment of velocity and sediment discharge relationships
Authors: Peterson A. W. , Peterson A. E.
Published: January 2010

Using the data from Brownlie's update of the Compendium of Solids Transport Data, velocity and sediment discharge equations have been derived using regression analysis. Two velocity equations have been determined, one for the lower flow regime and the other for the upper flow regime. A single equation for sediment discharge covers both flow regimes. The equations provide estimation/prediction of sediment discharge and velocity that are simple to use.Plots of over 3000 test results show the relationship of sediment discharge, velocity, flow depth, energy gradient, and sediment size for the lower and upper flow regimes. Included in the plots are estimation and prediction limits for the velocity and sediment discharge relationships. Key words: sediment discharge, velocity, flow regime, weighted least squares, regression, prediction.
Roughness of reverse flow over dunes and its application to the modelling of the Pitt River
Authors: Lau Y. L.
Published: January 2010

Experiments using artificial dunes show that the friction factor is reduced when the steep face of the dune is on the upstream side, i.e., when the direction is reverse that of normal. Calculations using bedform regime relationships show that this configuration of reverse flow over dune profiles could have existed in the Pitt River, causing the decrease in bed roughness which was found during the calibration runs. Key words: friction factor, dunes, tidal flow, Fraser River, bedform roughness, Pitt River.
Multiple stud shear connections in deep ribbed metal deck
Authors: Robinson Hugh
Published: January 2010

This paper summarizes the results of push-out tests conducted on 17 different types of shear connections simulating three distinct components of a composite floor system: (1) an interior beam (perpendicular metal deck), (2) a spandrel beam (perpendicular metal deck), and (3) a girder (parallel metal deck). Each push-out specimen had a layer of 152 × 152 WM9.1 × WM9.1 welded wire mesh at mid-depth of each concrete slab.Two composite beams, each with ribbed shear connections typical of those in two of the types of push-out specimens representing ribbed shear connections in interior composite beams with ribbed metal deck, were tested with third-point loads over a simply supported span. Using the average ultimate shear strengths of the push-out specimens having the same configurations as the ribbed shear connections in the composite beam tests to calculate the ultimate flexural capacities of the composite beams resulted in a very close estimate of the measured ultimate flexural capacities of the composite beams. The average measured static yield strengths of the flanges and webs of the wide-flange sections used in the composite beam tests were included in the calculations of the ultimate flexural capacities of the composite beams. Key words: composite, push-out, ultimate shear, shear stud, ribbed metal deck, deep rib.
Turbulent wind loading of roofs with parapet configurations
Authors: Stathopoulos T. , Baskaran A.
Published: January 2010

This paper reviews the available experimental data regarding the effect of parapet configurations on the wind loading of roofs of buildings of various geometries and under different exposures. Particular reference is given to the recent study carried out by the authors in a boundary layer wind tunnel. This study deals with the effects of wind on a variety of flat roofs with and without parapets when exposed to simulated open country and urban terrains. Geometrical parameters examined include the effect of building height (ranging from 12 to 145 m) and parapet height (0–3 m) on both local and area-averaged roof pressures for a variety of wind directions. Results show that parapets generally reduce the high suctions on roof edges and may slightly increase the suctions on the interior areas of the roof. Roof corner suctions, however, increase significantly for low parapet heights.Additional parapet configurations have been examined to reduce these high local corner suctions. Parapet cuts or slots around corners have proven to be effective in this respect. The effect of one-sided, as opposed to perimetrical, parapet has also been examined. Extensive comparisons of the data and recommendations for the wind load provisions of the National Building Code of Canada (NBCC) and the American National Standards Institute (ANSI) are also made. Key words: building, code, design, loads, pressure, project, roof, wind.
Dynamic response of two-span continuous composite bridges
Authors: Grace Nabil F. , Kennedy John B.
Published: January 2010

With the continuing trend towards lighter and more flexible continuous composite bridges, problems of vibration are becoming increasingly more important. Furthermore, fatigue cracking can be a real problem in such bridges when subjected to several thousands of resonance cycles over its life. In this paper the dynamic response of continuous composite bridges and the influence of repeated loading at resonance frequency on the structural response are investigated. A closed-form series solution based on orthotropic plate theory is developed to predict the natural frequencies of two-span continuous composite bridges. Expressions for the equivalent rigidities of a composite bridge are also given. The results are verified and substantiated by experimental results from 1/4-scale bridge model. Estimates of frequencies based on beam theory as well as the effects of concrete and fatigue cracking on the natural frequencies and strain range are examined. Finally, it is shown that a fatigue-cracked composite bridge, when properly repaired, can regain most of its stiffness and ultimate load-carrying capacity. Key words: bridges, composite, concrete, continuous, dynamics, fatigue, orthotropic, rigidities, steel, tests.
On distress in pipe-arches
Authors: Bakht Baidar , Agarwal Akhilesh C.
Published: January 2010

Cracking of bolt holes is a very common form of distress in pipe-arch type of soil–steel structures, the conduit walls of which are subjected to very large radial soil pressures in their lower haunches. This paper, in discussing the mechanics of this form of distress, concludes that the cracks are formed mainly due to the inability of the soil in the haunch areas to sustain the very high pressures. It also contains methods to alleviate these problems, both at the design and at the construction stage. Guidelines for proper bolt arrangements are given, and use of low-strength concrete around and under the haunches is recommended. Pouring of concrete in segments is suggested to avoid potential flotation of the pipe during construction. A case history incorporating this measure is given to demonstrate its feasibility. Key words: soil–steel structure, pipe-arch, culvert, highway bridges, bolt-hole tears.
Analytical modelling of large panel coupled walls for seismic loading
Authors: Kianoush M. Reza , Scanlon Andrew
Published: January 2010

Modelling techniques for analysis of large panel wall systems with coupling beams, subjected to earthquake loading, are described. The models, implemented in an existing general purpose computer program, are evaluated through a series of analyses involving comparisons with other reported analytical results and with limited available experimental data. The sensitivity of analytical results to assumed structural parameters is highlighted. Key words: beams, earthquake engineering, finite element method, joints, precast concrete, seismic, structural analysis, structural walls.
Computers in building design
Authors: Bédard Claude
Published: January 2010

The process of designing buildings presents characteristics that set it apart from the design process in other engineering fields. Traditionally, computers have been assigned the number-crunching and bookkeeping tasks in building design activities. Also, few participants in the design team have used computers on a regular basis. However, many changes are taking place which will affect the way a building design is carried out and the contribution computers could make in the process. All factors appear to advocate greater use of computers to achieve better designs. Three active areas of development are finally presented to illustrate new roles computers could assume in future building design projects. Key words: building design process, algorithm, synthesis/analysis, preliminary design, integration.
Earthmoving cost optimization by operational research
Authors: Christian John , Caldera Havindra
Published: January 2010

Among the wide variety of operations in many construction projects, the earthmoving operation is very significant in terms of cost and productivity. When there are several excavation and fill areas, the overall earthmoving cost can be minimized by optimizing the distribution of the cut and fill quantities along the various haul routes. A transportation model which optimizes the earthmoving cost is introduced in this paper. A numerical example is used to explain the simplicity of the application of the model. Key words: compaction, construction equipment, earthwork, economic analysis, excavation, operational research, optimization, transportation.
Role of saturated and unsaturated zone in soil disposal of septic tank effluent
Authors: Johnson K. R. , Atwater J. W.
Published: January 2010

The guidelines for the use of the septic tank – soil absorption system (ST–SAS) in the Province of British Columbia are very specific in regard to the separation distance between the ground surface and the groundwater table (minimum 1.2 m), and between the tile field and perimeter drains or ditches (minimum 3.0 m). A pilot-scale experiment employing waterproof channels filled with a saturated soil was used to evaluate the scientific basis for these guidelines. Septic tank effluent was applied to unsaturated columns and the inlet end of the channels and samples were taken at different points in the channels. Measurements were made of total and fecal coliforms, chemical oxygen demand, ammonia, nitrate, and orthophosphate. Coliform reductions within the channels were at least 30 000-fold with total coliform numbers generally lying below 200 coliforms/100 mL and fecal coliforms generally less than 50 coliforms/100 mL. Varying degrees of nitrification occurred in the unsaturated columns, resulting in relatively high concentrations of nitrate in some of the channel sections (1–7 mg/L in channels filled with sand and 0.1–1.0 mg/L in channels filled with loamy sand). The removal of orthophosphate was greater than 90% in all of the channel sections, independent of the saturated or unsaturated zones. Reductions in measured influent parameters were substantial in all of the channels. This suggests that the guidelines may be conservative with respect to these particular soils. Of concern are the high nitrate values observed in some of the channels, therefore consideration of nitrification potential should be made in conjunction with the potential for reduction of other contaminants. Key words: septic tank, soil absorption system, saturated soil, unsaturated soil, coliforms, nutrients.
Behavior of slab-stiffened culvert structures
Authors: Playdon David K. , Simmonds Sidney H.
Published: January 2010

Large span elliptical culverts stiffened over the upper portion with a concrete cap can be used economically in highway construction at locations where only a small soil cover is possible. The behavior of such structures based on analyses obtained using the finite element program ADINA is presented. Primary variables are the thickness of the concrete cap and the depth of the soil. The effects of both the construction sequence and highway loading are considered.The load-carrying mechanism for the composite structure is dependent primarily on the amount of lateral deformation permitted by the adjacent soil and the thickness of the concrete cap. It is concluded that the behavior of the structure is that of a flat arch; but, with the lateral deformations likely to occur, the concrete section should be proportioned as a simple beam. Key words: concrete cap, culverts, construction loads, deformations, finite element analysis, stresses.
A rule-based system for highway route location
Authors: Castilho Bernardo de , Navin Francis
Published: January 2010

Highway location is one of the basic but more complex problems in highway development. It is ill-structured by nature, involving the assessment of a variety of impacts, some of which are very difficult to quantify. Furthermore, the data available are often uncertain, especially in the early stages of the project.This paper outlines the use of Prolog for a prototype of a highway location assistant system. The main issues addressed are the way in which uncertain information is handled, the flexibility of the structures used to represent spatial data, and how conventional evaluation procedures can be combined with heuristic principles to solve the problem. Expert-system-like explanation facilities are also present. These facilities are useful to document the decision process and as a training tool for novice engineers, and they can also help in debugging and improving the system. Key words: highway route location, knowledge-based system, fuzzy numbers, Prolog programming.
Applicability of the Soil Conservation Service equations for runoff prediction in the Ottawa – St. Lawrence lowlands
Authors: Madramootoo C. A. , Enright P.
Published: January 2010

A study was conducted to assess the applicability of the Soil Conservation Service (SCS) equations for runoff prediction in the Ottawa – St. Lawrence lowlands. The equations were developed under climatic, soil, and topographic conditions very much different from this region. An analysis of 13 runoff events showed that time of concentration was underpredicted by empirical formulae and the upland method. There was also considerable variation between measured and predicted lag times and times of peak flow. Rainfall intensity was found to influence both time of concentration and lag time. Using antecedent moisture conditions (AMC) level 2, the SCS triangular hydrograph model generally underpredicted both runoff volume and peak flow. However, increasing the curve number to reflect AMC 3 resulted in improper synthesis of the flood hydrograph and gross overprediction of peak flow. From these results, it is evident that new criteria for antecedent moisture conditions and hydrologic soil groups must be derived for the Ottawa – St. Lawrence lowlands. Seasonal curve numbers should also be developed. Key words: hydrology, rainfall, runoff, peak flows, SCS model.
A brief introduction to the Revelstoke Project
Authors: Salmon Gary M.
Published: January 2010

When the Revelstoke Project reservoir was filled to elevation 560 m in March of 1984, 13 m below its normal operating level, a vertical transverse crack opened in the face of the concrete dam allowing as much as 15 000 L/min (0.25 m3/s) of water to leak into the drainage gallery. Within 2 weeks remedial measures had closed the crack and stopped the leakage. Two months later the powerplant came into service and all other features of the project performed as expected. This project, with its 2700 MW powerplant and 175 m high concrete gravity dam, is one of the largest in North America. It was planned, designed, and its construction administered by BC Hydro. This paper briefly describes the project features, planning decisions, design, and construction of the $2 billion project. Key words: hydroelectric, dam, powerplant, spillway, planning, design, construction.
A procedure for estimating the capital cost of Ontario wastewater treatment plant using CAPDET
Authors: Wright David G. , Patry Gilles G. , Letman Charles E. , Woods Donald R.
Published: January 2010

CAPDET is a computer-assisted procedure for the design and evaluation of wastewater treatment facilities developed by the U.S. Army Corps of Engineers and the U.S. Environmental Protection Agency. The purpose of this study was to develop a procedure for applying CAPDET to the capital cost estimation of Canadian wastewater treatment plants without altering the source code. The proposed methodology is simple and efficient, requiring no additional data to that normally used in CAPDET.A total of 10 Canadian wastewater treatment plants were studied which included many of the treatment processes used in Canada. Six plants were used to develop the procedure while four plants were used to verify the procedure. The design flow for the selected plants ranged between 550 and 13 600 m3/d. Construction cost estimates generated using site-specific design information were compared with those obtained using the default database provided in CAPDET. The importance of the various unit costs on the total plant cost was also determined.Under the proposed methodology, unit costs are first adjusted to the date of construction using appropriate inflation indices. Wall concrete, slab concrete, and excavation costs are increased by an additional 15, 50, and 25%, respectively, to account for differences in construction practice. A final estimate reduction of 15% is performed to account for Canadian conditions.The procedure provides construction cost estimates that are within ± 20% of actual construction costs with a mean absolute error of 11% and an average error of 2.3%. Site-specific design data had little effect on the construction cost estimates with the exception of lagoon treatment facilities. Utilities and support facilities accounted for 20–30% of the cost estimates. The most significant cost parameters were the inflation index values and concrete and building unit costs. Key words: capital cost, construction cost estimation, wastewater treatment plant, mathematical modelling, calibration, verification.
Thermal stresses in double-glazed windows
Authors: Pilette C. F. , Taylor D. A.
Published: January 2010

Using finite elements, the authors studied temperatures and thermal stresses in 1.41 m wide by 2.12 m high sealed double-glazed windows of 6-mm glass with a 12-mm air space between the panes. The purpose was to find factors significantly influencing thermal stresses. Three types of commercially used windows subject to winter conditions (day and night) were analysed: both panes clear glass; outer pane heat absorbing and inner clear; and outer clear with a metallic film on its room-side surface and inner clear. A sensitivity analysis included variations in size of window, gasket and sealant stiffnesses, frame absorption, solar heat flux, exterior air film conductance, and outdoor air temperatures (−5 and −25 °C). Further, the influence of horizontal and vertical shadows was studied. For the calculation of thermal stresses, the authors found that the windows could be analyzed pane by pane rather than as a three-dimensional structure. Solar radiation and particularly shadows had a major influence on thermal stress, while window size and aspect ratio did not. A case study in which the predicted temperatures were compared with those measured by Sasaki in 1974 showed good agreement and indicated that a simpler steady-state rather than transient thermal analysis gave a close estimate of the temperature difference between the centre and edges of panes for design against thermal breakage. Key words: window breakage, thermal stresses, glass temperatures, shadows, double-glazing, finite elements.
Applications of state-of-the-art technology in vehicle data collection
Authors: Papagiannakis A. T. , Bergan A. T.
Published: January 2010

This paper discusses recent developments in the technology of vehicle load and traffic volume data collection and proposes methods for their application. Applications focus on innovative methods for calculating equivalent axle load (EAL) data. The first part of the study contains an example output of the state-of-the-art vehicle monitoring equipment. Typical output of weigh-in-motion scales (WIM), vehicle classifiers, and vehicle monitors are presented to demonstrate the potential of the new technology. In the second part of the study, WIM scale data covering a period of 1 year is analyzed to explore new methods for collecting EAL data. It is shown that, in terms of daily data, EAL repetitions correlate better with the volume of large vehicles (e.g., 5-axle semitrailer trucks) than with the total number of axle counts traditionally collected. Furthermore, the notion of using vehicle length to index broad vehicle classes is explored as a means of obtaining volume counts of the large vehicles. It is concluded that data obtained by vehicle monitors can indeed be used successfully to identify broad vehicle groups. Key words: weigh-in-motion, vehicle classifiers, vehicle monitors, vehicle length.
Shear–moment interaction of slab–column connections
Authors: Alexander S.D.B. , Simmonds S.H.
Published: January 2010

The factors that influence the shear–moment interaction of slab–column connections are examined. The Canadian design code, CAN3-A23.3-M84, is evaluated on the basis of its agreement with the observed connection behavior. Other approaches to modelling slab–column connections are examined. It is concluded that, although the code procedure appears to give satisfactory results in practice, it is not based on a rational model of the connection behavior. Of all the alternative methods examined, the truss model provides the best description of the shear–moment interaction behavior of any given connection. Key words: column–slab connections, shear–moment interaction, punching shear, reinforced concrete, analytical models.
Uncertainties in the single determination of river discharge: a literature review
Authors: Pelletier Patrice M.
Published: January 2010

This paper presents the results of a literature review of more than 140 publications on the uncertainties in the determination of river discharge. The uncertainties in a single determination of discharge, which includes uncertainties in sampling the cross-sectional area and the mean velocity in time and in space and uncertainties in the current meter, are emphasized. The objectives of the literature review were to determine all the possible sources of uncertainties in a current meter measurement, to quantify these uncertainties based on past investigations, and to determine if additional research was required to improve the overall accuracy of hydrometric data in Canada. Because of lack of available information on the performance of the current meter in combination with the velocity–area method under conditions of small streams or low velocities, research is required. Research is also required to assess the uncertainties in the determination of discharge under ice conditions. Key words: accuracy, current meter, error, hydrometric data, river discharge, uncertainty, velocity–area method.
Diaphragms in skew box girder bridges
Authors: Dilger Walter H. , Ghoneim Gamal A. , Tadros Gamil S.
Published: January 2010

A theoretical study of the effect of diaphragms on the reactions, internal forces, and behaviour of skew box girder bridges was carried out. Three different cases were studied: (1) the traditional skew diaphragms, (2) orthogonal diaphragms, and (3) no diaphragms. The aim of the study was to compare the different cases and to find out whether the easier to construct arrangements (2) and (3) would be viable options for design of skew box girder bridges. Key words: skew bridges, box girder, diaphragms, orthagonal, prestressed concrete.
Losses in partially prestressed concrete
Authors: Batchelor B. DeV. , Srinivasan Jayanth , Green Mark F.
Published: January 2010

The calculation of prestress losses by the age-adjusted effective modulus method is analyzed and compared with the Ontario highway bridge design code predictions for partially prestressed concrete. Specifically, the effect of nonprestressed reinforcement on prestress losses is studied. The age-adjusted effective modulus method for calculating prestress losses is outlined, and plots of prestress losses versus partial prestressing ratio are presented and analyzed. It is shown that prestress losses decrease with increasing amounts of nonprestressed reinforcement. Also, the Ontario highway bridge design code expressions, which are intended for use with fully prestressed sections, are not suitable for use in the design of partially prestressed concrete members. Key words: concrete (prestress), design, partial prestressing, prestress losses.
Strength of reinforced concrete panels
Authors: Balakrishnan S. , Murray D. W.
Published: January 2010

Equilibrium equations for cracked net-reinforced concrete panels are derived and interpreted with the aid of Mohr's circles. Limiting values of the strength of such panels based upon three different modes of failure are presented. Cracking and failure envelopes for concrete in the tension–compression region are presented which obviate the need for an effectiveness factor or for a strain-related strength criterion to evaluate ultimate strength. Comparisons with test results indicate the proposed technique is as reliable as alternative techniques and is attractive because of its simplicity. Key words: concrete, reinforced concrete, panels, limit analysis.
Design aids for rectangular reinforced concrete sections under combined bending and axial forces
Authors: Riva P. , Cohn M. Z.
Published: January 2010

Design interaction diagrams, Pr–Mr, for rectangular reinforced concrete sections under combined bending and axial compression or tension forces in accordance with the current Canadian code are presented. The interest of the note is that the interaction diagrams eliminate the limitations of those in the Canadian Portland Cement Association Handbook. Their format can be extended to other section shapes and reinforcement layouts. Key words: Combined bending, design aids, interaction diagrams, rectangular sections, reinforced concrete, short columns, strength analysis.
L'intégration en conception assistée par ordinateur pour les projets pluridisciplinaires de génie civil
Authors: Camarero R. , Granger L. , Marche C. , Soulié M. , Tinawi R.
Published: January 2010

CASTOR is a major project which involves the development and the integration of the software of a computer aided design for hydro projects. Based on a university–industry collaboration, the project involves a number of specialties such as hydraulics, hydrology, reservoir simulation, site characterization, geotechnical engineering, structures, turbines, and computer science. The integration of all components is presented as an advantage despite the restrictions that it could create. The integration covers the basic philosophy in development strategy, the proposed design methodology for users, the sharing of utilities, and the relations with a central data base. A rigorous quality assurance plan is adapted for each module. Key words: computer aided design, hydro development projects, engineering software.
Design and evaluation of an automated oxygen uptake rate measurement system
Authors: Aidun Bijan , Smith Daniel W.
Published: January 2010

The design and operating procedure for a newly developed automatic oxygen uptake rate (OUR) measurement apparatus is presented. This unit, with the aid of a microcomputer, is capable of collecting a volume of sample, aerating the sample, measuring the oxygen concentration at preselected times, and calculating the oxygen uptake rate on a routine basis. The OUR unit was evaluated using three different performance testing procedures. These were (1) a calibration and general performance test, (2) a long-term performance test, and (3) a detailed comparative performance test. The results of each of these tests are presented. The value and alternative uses of routine monitoring of OUR are discussed along the possible applications such as detection of toxic compounds entering the plant and adjustment of sludge return rates to match OUR values. Key words: oxygen uptake rate, activated sludge, microcomputer, process control, oxygen consumption.
A design formula for glass in buildings
Authors: Lind Niels C.
Published: January 2010

A formula giving the required thickness of glass plates as a function of the nominal material strength, the design pressure, and the dimensions of the plate has been developed for a proposed Canadian standard for the design of glass in buildings. The paper describes the background and the reasons for the choice of the formula. It also gives an analysis of the performance of the formula in the context of a limit states design standard. Performance is expressed in terms of expected failure probabilities and initial cost. It is concluded that a simple formula is capable of accurate design aiming for constant and optimal reliability, comparable to analysis by the more complex theory available (the failure prediction method). Key words: building, glass, formula, design, standard, optimization, probability, failure.
Electronic licence plate technology: automatic vehicle location and identification
Authors: Bergan A. T. , Henion Loyd , Krukar Milan , Taylor Brani
Published: January 2010

The purpose of this paper is to discuss the current level of technology in automatic vehicle identification (AVI). The technology is often referred to as electronic licence plate technology, due to the use of unique vehicle identity transponders (electronic licence plates) affixed to particular highway vehicles. Interrogator or roadside receiver units placed at strategic locations or nodes on a highway network can locate and identify the particular vehicle.The main thrust of the paper is on the different types of AVI systems and the technologies employed. The discussion includes the widespread applications for AVI from both a highway administrator and road transport industry point of view. Finally, the paper discusses two AVI demonstration projects. These projects are the urban system implemented in Hong Kong and the highway system in the United States and parts of Canada known as the Heavy Vehicle and Electronic Licence Plate Project (HELP). Key words: automatic vehicle identification, electronic licence plate, road pricing, automatic vehicle classification, weigh-in-motion, commercial transportation, vehicular traffic control, pavement, Heavy Truck and Electronic Licence Plate Project.
Repair and upgrading of concrete structures in Mexico City after the 1985 earthquake
Authors: Mitchell Denis , Dandurand Alain , Paultre Patrick
Published: January 2010

The September 19, 1985, magnitude 8.1 earthquake and its magnitude 7.5 aftershock caused unprecedented damage to structures in Mexico City. The types of structural damage and the emergency changes to the building code that occurred in 1985 are summarized and a number of examples of repair and strengthening techniques that were used to satisfy the emergency code requirements are presented. Key words: seismic, earthquake, Mexico, structures, upgrading, repair.
Joint use of the HEC-2 model and a physical model for floodline delineation upstream of a bridge
Authors: Wisner P. , Townsend R. , Sabourin J. , Leitch D.
Published: January 2010

This paper reports the findings of a physical model study of backwaters generated in the vicinity of the Queen Street bridge crossing of the North Thames River in the town of St. Marys, Ontario. Flood profiles generated in the physical model are compared with those observed in the field and with "HEC-2"-generated profiles. Certain limitations of the HEC-2 model, in regards to bridge hydraulics, are identified. The physical model is also used to compare several flood protection alternatives for the town, for both the 100- and the 500-year flows. Floodline delineation was based on both physical model and HEC-2 simulations. The former were adopted for the reach simulated by the physical model, with the latter being employed for the reaches upstream of the physically modelled reach. Key words: physical model, numerical model, bridge backwater, floodline delineation.
Rehabilitation of prestressed concrete box beam deck of an elevated expressway
Authors: Tork Andres
Published: January 2010

The object of this paper is to share the experience gained from a 4-year rehabilitation program on a section of the F. G. Gardiner Expressway in Toronto. The paper describes the latex-modified shotcrete repairs at locations of rusting strands at beam soffits and the conversion of original simply supported spans into continuous beams with the resulting elimination of nearly three fourths of the expansion joints. The benefits of continuity, reduction of expansion joints, new reinforced deck slab, and new drainage system are discussed and essential cost figures are provided. Key words: concrete, prestressed, bridge, rehabilitation, expressway, transportation, urban, shotcrete, continuity, expansion joint, composite deck, epoxied dowels, drainage.
Effectiveness of concrete confinement on lap splice performance in concrete beams under reversed inelastic loading
Authors: MacKay B. , Schmidt D. , Rezansoff T.
Published: January 2010

Proposals from Cornell University for seismic design of lap splices, where the strength provided to the lap splice by the concrete confinement is considered insignificant, were evaluated. The concrete confining the splice length is assumed to deteriorate after high-intensity (inelastic) reversed load cycling so that the performance is mainly dependent on the amount of transverse reinforcement provided to confine the lap splice. Lap lengths of 30–40 bar diameters are proposed, along with heavy transverse reinforcement. Longer lap lengths are considered to be less effective. By contrast, for static loading the concrete confining the splice is known to play a major role in transferring load between the bars along the splice.The current program consisted of testing six reinforced concrete beams under fully reversed cycled loading. The three similar beams in each of the two series contained equal stirrup confinement (number of stirrups) along the lap length to satisfy the Cornell University recommendations for seismic loading for the measured reinforcing yield strength, while the splice length was varied. Splices were located in the bottom face of the test beams and were positioned in a region of maximum moment to ensure severe stressing. Each series of specimens exhibited only small strength gains with increasing splice lengths; however, the performance, when evaluated on the basis of the ductility achieved and the hysteretic energy absorbed prior to failure, was superior with long splices. Since the main reinforcement in the test beams was loaded past yielding, large increases in deformation capacity resulted in only small increases in load.Full reversal inelastic load cycling is very detrimental to the concrete that confines the splice region when compared to static (monotonic) loading or one-directional repeated loading to failure. Splice failure loads under reversal loading in the current study were below predicted static strengths for the same beam configurations, and with the longer lap lengths, static failure would have been flexural rather than in the splice. Key words: reinforced concrete, beams, splices (lap), confinement, seismic design, cycled loading, ductility, strength.
Behaviour of nonlinear coupled shear walls with flexible bases
Authors: Pekau O. A. , Cistera V.
Published: January 2010

This paper examines the importance of base flexibility on the nonlinear behaviour of coupled shear walls subjected to pseudo-static lateral loading. The classic continuum method is adopted, with the base flexibility modelled by effective rotational and vertical elastic stiffnesses, Kθ and Kv, respectively. Since the magnitudes of these stiffnesses depend on the properties of the supporting soil and also on the characteristics of the foundation itself, different soils as well as the type of foundation are considered. The latter consists of separate footings under each wall as well as a single combined foundation under the coupled walls. In general, the results show that base flexibility becomes especially important for the overall lateral stiffness at all load levels, whereas internal stresses are affected in only the lower portion of the structure for service loading. Key words: shear walls, coupled, nonlinear, continuum method, flexible bases, separate footings, combined foundation.
Two-dimensional modelling for the analysis of symmetrical structures that twist
Authors: Smith Bryan Stafford , Cruvellier Mark
Published: January 2010

A method of two-dimensional modelling for the analysis of symmetrical structures subjected to eccentric transverse loading is presented. The three-dimensional behaviour of the structure is decomposed into separate translational and twisting behaviour under the respective transverse and torque loadings. A two-dimensional model is formed and analyzed for each mode of behaviour and the results are combined to represent the total behaviour of the structure. The method is suitable for structures consisting of bents parallel to the direction of transverse loading. The bents can be of any type and may vary in their properties over the height. Key words: structural analysis, symmetrical structures, two-dimensional model.
Modèles d'évolution du manteau nival et de la fonte des neiges
Authors: Bennis Saâd , Brunelle Paul-Édouard
Published: January 2010

The predictive snowmelt runoff model (SRM), previously suggested by other authors, is reliable and easy to use. Furthermore, the only parameters required are temperature and precipitation, and density and thickness of the snow pack. The literature available indicates that simulation results with this model are generally satisfactory. However, data on the extent of the snow cover are not always available; this means that the snow pack must be calculated before the SRM can be used. Our purpose herein is to develop a model to evaluate the snowpack, which is to be used in conjunction with the SRM. The SRM was modified in that maximum daily temperature was used instead of the number of degrees-days. The snowmelt and snow cover models were calibrated and tested along the drainage basin of the Eaton River, a tributary of the Saint-François River in the province of Quebec. Key words: snowmelt, prediction, flooding. [Journal translation]
Ultimate strength of columns laterally braced by girt–diaphragm systems
Authors: Massicotte Bruno , Beaulieu Denis , Picard André
Published: January 2010

This paper deals with the stabilizing effect of girts and cladding on columns in light industrial buildings. The construction aspects of such systems are briefly reviewed and a description of their behavior is presented. Solutions available to determine column strength in column–girt–diaphragm systems are reviewed. The use of a finite-element-based software is proposed as the only practical way to analyze this type of structural system. Results of a large parametric study using a finite element model are presented and a method to evaluate the ultimate strength of actual columns is introduced. Finally, a simple hand design method is derived. Key words: diaphragm, design, finite element, girt, column, stability, statistics.
A statistical long-range transport model for simulation of wet sulphate deposition
Authors: Byrne J. M. , McBean E. A. , Shipley K. B. , Farquhar G. J.
Published: January 2010

A statistical long-range transport of air pollutants model (UW-LRT) is utilized to simulate wet SO4 deposition in eastern North America in 1980. Model results compare favorably to an analyzed deposition field. In a comparison of the relative errors associated with four long-range transport models, the UW-LRT model demonstrates the lowest variation from recorded, analyzed deposition data. The UW-LRT model has modest data input and central processor unit time requirements. Key words: acid rain, long-range transport, spatial deposition, mathematical models.
A study of water quality in an urban river and potential improvement using a prototype instream aerator
Authors: Town C. A. , Mavinic D. S. , Moore B.
Published: January 2010

Urban encroachment and intensive agricultural activity within the Serpentine–Nicomekl watershed (near Vancouver, B.C.) have caused a series of fish (salmon) kills on the Serpentine River since 1980. Low dissolved oxygen was responsible for these kills. This field project investigated some of the dynamic chemical and biological relationships within the river, as well as the use of an instream aerator as a temporary, in situ, water quality improvement measure. Weekly sampling for a 6-month period during the latter half of 1985 established a solid data base for deriving and interpreting meaningful interrelationships. A strong correlation between chlorophyll a and dissolved oxygen levels before the algae die-off supported the hypothesis that algae blooms dying in the fall could create a serious oxygen demand. Because of these environmental conditions, the river is unable to sustain healthy dissolved oxygen levels during this period. As such, a prototype, 460 m artificial aeration line was designed, installed, and monitored to evaluate its potential for alleviating low dissolved oxygen conditions and improving overall water quality during the critical fall period.The instream aerator ran continuously for over 2 months, starting in September 1985. Despite better-than-expected weather conditions (i.e., cool, wet weather) and relatively high dissolved oxygen levels during the fall of 1985, the data base appeared to support the use of this prototype aeration unit as a means of "upgrading" a stretch of an urban river subject to periodic, low dissolved oxygen levels. As a result, a 2-year follow-up study and river monitoring was initiated. In both 1986 and 1987, late summer and early fall river conditions resulted in the potential for serious salmon kills, due to higher-than-normal river temperatures and very low dissolved oxygen. In both instances, the instream aerator prevented such fish kills in a key stretch of the river. Expansion of the system to include other critical stretches of the Serpentine and other urban river systems, near Vancouver, is being considered. Key words: algae, aerator, chlorophyll a, eutrophic, fish kills, instream aeration, river improvement, urban river.
Methods to measure apparent diffusion coefficients in compacted bentonite clays and data interpretation
Authors: Cheung S. C. H.
Published: January 2010

The methods used to determine apparent diffusion coefficients and the appropriate parameters for modelling diffusion through compacted bentonite–water systems are assessed and discussed. The measured apparent diffusion coefficient can vary between methods. The discrepancies are shown to be due to heterogeneous diffusivities arising from the proximity of the surface of clay particles. Two different diffusivity pathways are identified and the diffusive flux is shown to be dictated by the charge of diffusing species, diffusion time, and soil fabric. Key words: apparent diffusion coefficient, methods, compacted bentonite, heterogeneous diffusion, parameters, pathways.
Technologies for the containment, immobilization, and disposal of radioactive wastes
Authors: Tait J. C. , Hayward P. J. , Devgun J. S.
Published: January 2010

Atomic Energy of Canada Limited is developing methods for the management and safe disposal of radioactive wastes. These wastes range from the highly radioactive (high-level) UO2 fuel arising from the nuclear generation of electrical power to the low- and intermediate-level wastes arising from research in various Canadian institutions using radioactive isotopes. This paper reviews the current research programs on materials and processes for the immobilization and containment of UO2 fuel wastes and the technical aspects of programs demonstrating the various technologies needed for implementing a disposal program for low-level wastes. Key words: waste management, radioactive, nuclear fuel waste, high-level waste, low-level waste, disposal, immobilization, glass, containment, siting, land burial, geological disposal.
A simulation–optimization algorithm for reservoir capacity calculation: the effect of inflow data set length
Authors: Barlishen Kim D. , Simonovic Slobodan P. , Burn Donald H.
Published: January 2010

A simultion–optimization algorithm for sizing potential reservoirs on a river basin has been used to demonstrate the effects of the streamflow record length on capacity requirements. The sizing procedure involves the generation of synthetic streamflows and a reservoir reliability analysis. Two levels of reliability are present: the reliability in meeting water supply requirements, and the probability level associated with the final capacity selection. The procedure was applied to synthetic sequences generated from an 81-year inflow record and subsets of this sequence to produce frequency distributions of required capacities. The capacities with a 5% probability of exceedence were compared. Relying on short inflow sequences can lead to substantial overestimations or underestimations of capacity. A key factor is the presence of the critical period in the analysis. An open question remains regarding the effect of the final probability level selection on the range of capacities observed. Key words: design reservoirs, water supply, simulation, optimization, reliability, record length, synthetic streamflows.
Radial flow stilling basins with baffle blocks
Authors: Nettleton Peter C. , McCorquodale John A.
Published: January 2010

A total of 120 tests of forced radial flow hydraulic jumps have been analyzed in order to develop curves and equations for the design of radial stilling basins. The jump depth, the water surface profile, wave amplitudes, the allowable flare angle, and the jump length are defined in terms of entrance conditions, the baffle position, and the baffle height. An example design is given and compared with a USBR (U.S. Bureau of Reclamation) Type III stilling basin. Key words: forced hydraulic jump, radial flow, design, stilling basins, baffles, radial hydraulic jump, circular hydraulic jump.