bluuebunny/crossref_metadata_2025 huggingface dataset:
Evaluation of base shear provisions in the 1985 edition of the National Building Code of Canada
Authors: Zhu T. J. , Tso W. K. , Heidebrecht A. C.
Published: January 2010

A statistical analysis is performed to evaluate the base shear provisions in the 1985 edition of the National Building Code of Canada (NBCC 1985). Three sets of real earthquake records are selected to represent seismic ground motions with low, normal, and high peak acceleration to velocity (a/v) ratios. Single degree of freedom stiffness degrading systems are used as structural models; three damage indicators are employed to measure structural damage. The yield strength of the systems is specified in two different ways: (a) a single seismic response factor is used, irrespective of the a/v ratios of the input ground motions; (b) three different seismic response factors are used in the short-period range, depending upon the a/v ratios of the input ground motions, as suggested in NBCC 1985. A comparison of the statistical results of the three damage parameters for the systems designed with these two methods of strength specification indicates that the NBCC 1985 base shear provisions provide consistent control over structural damage when the structural systems are subjected to ground motions with different a/v ratios. Key words: earthquakes, ground motions, response spectra, stiffness degrading systems, seismic design, base shear, yield strength, inelastic response, damage parameters.
Thermal budget of river ice covers during breakup
Authors: Prowse T. D. , Marsh P.
Published: January 2010

The magnitude and relative importance of atmosheric (air–ice) and hydrothermal (water–ice) heat fluxes to intact and fragmented river ice covers are studied for the case of a thermal breakup. Based on field measurements obtained from the Liard River, the atmospheric sources are shown to be dominant during the period of intact ice cover. Radiation was the primary heat source, but its effect was reduced by a granulation of the decaying columnar ice which increased the cover albedo to that comparable for melting snow. The hydrothermal heat input, even with frazil ice entrained within the flow, was comparable to that from atmospheric sources under low melt conditions. The hydrothermal heat flux dramatically increased with the arrival of the breakup front because of a rapid rise in water temperature and an increase in subsurface ice roughness. Higher surface roughness and lower albedo of the fragmented ice also increased the atmospheric heat fluxes, but these were small relative to the hydrothermal heat input near the leading edge of open water. Key words: floating ice, ice breakup, ice jams, ice melt.
Resolution considerations in using radar rainfall data for flood forecasting
Authors: Kouwen N. , Garland G.
Published: January 2010

The objectives of this paper are (1) to show the hydrological effects of changing the spatial resolution of radar-derived rainfall and (2) to show the effect of discretization of radar data on hydrological modeling for flood forecasting. Simulated hydrographs are compared for 2, 5, and 10 km basin grid sizes for the Grand River watershed in Ontario. An eight-level discretization of rainfall is compared with a 256-level scale of rainfall intensities. Spatial averaging tends to reduce the effect of erroneous radar readings and give comparable results with those obtained using finer resolutions. The appropriate level of discretization depends on the area being modeled and appropriate levels are recommended. The level of discretization of radar precipitation data does not significantly affect the generation of hydrographs. Hydrographs based on the radar-derived rainfall generally reproduced measured hydrographs better than those derived from the rain gauge data. Key words: hydrologic models, flood forecasting, weather radar.
Comportement dynamique des lignes aériennes de transport d'électricité dû aux bris de câbles. I. Modélisation mathématique
Authors: McClure Ghyslaine , Tinawi René
Published: January 2010

This paper presents a mathematical model for the nonlinear dynamic analysis of aerial electric transmission lines subjected to conductor breakage. The model uses existing finite elements and validated numerical techniques available in most commercial programs capable of handling nonlinear dynamic analysis. ADINA is used in this study. In comparison with other models, the novel approach presented here focusses on the discretization of the conductors as well as the supporting structures, specially near the breakage point. Dynamic interactions between all the structural components are therefore considered and comparisons with simpler models emphasize the importance of these interactions, the effects of geometric nonlinearities present in the conductors and in the supporting structures, and the contribution of higher modes.The mathematical model is validated with 7 of 56 tests conducted on reduced-scale physical models, reported in work done for the American Electric Power Research Institute.The results of the present study are very encouraging for designers interested in validating their design criteria for longitudinal dynamic loads by use of existing nonlinear dynamic finite element analysis packages. Key words: Nonlinear dynamic analysis, electric transmission lines, conductor breakage simulation.
Simplifying roadway cross sections without reducing volume accuracy
Authors: Easa Said M.
Published: January 2010

A method for simplifying irregular ground profile of roadway cross sections by a straight line is presented. The presented method does not affect the accuracy of earthwork volume computations. Two types of cross sections are considered: cut (or fill) and transition sections. For a cut (or fill) section, the simplified section is designed such that its area equals that of the original section. This is accomplished by adjusting the least-squares (LS) parameters. Three cases of adjustments that depend on the area of the original section and the unadjusted LS parameters are presented. These cases preserve the section type (cut or fill) and, as much as possible, the general shape of the original section. For a transition section, the simplified section is designed such that its cut and fill areas equal those of the original section. These conditions of equal areas are used to develop formulas for designing the simplified section directly. Application of the method is illustrated by numerical examples. Key words: roadway, cross section, irregular, least squares, linear profile, earthwork volume.
High-level nuclear waste management: a geochemical perspective
Authors: Vandergraaf T. T.
Published: January 2010

Atomic Energy of Canada Limited is investigating the concept of the disposal of high-level radioactive waste in an underground vault in an intrusive crystalline rock formation. The environmental impact of such a disposal is, to a large extent, dictated by geochemical processes involving rock-forming minerals, groundwater, and fission products and actinides in the waste. These various geochemical processes impact on the transport of contaminants, including radionuclides and chemically toxic elements, from a used-fuel disposal vault towards the biosphere. The extent and importance of the geochemical processes on contaminant transport are discussed. The predominant processes controlling the velocity of contaminant transport are the various geochemical interactions of the dissolved contaminant species with the minerals lining the surfaces of conductive fractures and fracture systems. Key words: radionuclide, uranium, nuclear contaminant, transport, sorption, diffusion, geochemistry, fission products, granite.
Wind loading of large low buildings
Authors: Surry D. , Stopar E. M. F.
Published: January 2010

The paper aims to define an interior region on large low buildings within which lower external uplift pressures can be used for design rather than those recommended by the 1985 Supplement to the National Building Code of Canada. An extensive data base of pressures measured over tributary areas representative of those used for column design has been measured using 1:500 scale models of buildings ranging from 3500 to 90 000 m2 in plan area. Summary curves based on all the data have been determined and compared with data from other sources in the literature. An overall recommendation for specified pressure coefficients at various distances from the edge of nearly flat-roofed buildings is presented, which includes a reduction in the external loads beyond five roof heights by a factor of 2.5. Key words: wind pressure, wind loading, large low buildings, tributary area.
Suitability of unconsolidated sediments for hosting low-level radioactive waste disposal facilities
Authors: Devgun J. S.
Published: January 2010

Among the unconsolidated sediments, sand deposits are considered a rather unconventional geologic host medium for siting radioactive waste repositories, the clays being the preferred choice. A closer examination of the various geologic media, however, shows that in each case there are advantages and disadvantages. The key to safe and cost-effective disposal is to match the engineered design of the facility to the site's characteristics as well as the nature of the waste to be disposed of. In humid climates, free-draining sediments such as sand can provide the advantage of eliminating concern related to the “bathtub effect.”At Chalk River Nuclear Laboratories (CRNL), a sand dune has been proposed for hosting a low-level radioactive waste disposal facility. This paper discusses the suitability of unconsolidated sediments for radioactive waste disposal in general; in particular, it provides the rationalization for the selection of a sand dune as the host site at CRNL. Key words: radioactive waste, disposal facilities, unconsolidated sediments, site suitability, trench cover materials, sreismicity, soil liquefaction.
Design of a hydrodynamic leachate containment system
Authors: Haug M. D. , Forgie D. J. L. , Barbour S. L.
Published: January 2010

This paper presents the design concept for a case study sanitary landfill on a site that would not normally have been approved owing to the presence of a high water table. In this design, the base of the landfill was intentionally placed below the water table. A massive 2.5 m wide, 2.5 m high cutoff wall and a 0.3 m thick liner with hydraulic conductivities of approximately 5 × 10−10 m/s were constructed of recompacted glacial till to limit both groundwater intrusion into the landfill and leachate migration out of the landfill. In this case study, the landfill base was placed below the water table to (i) provide a relatively inexpensive source of cover material and (ii) use the hydrodynamic gradient from the high water table to help contain the leachate. Finite element modelling of the seepage and contaminant transport, for alternate designs for lined and unlined landfills placed above and below the groundwater table, is shown to confirm a previous, less-sophisticated, estimation that placing a lined landfill below the groundwater table has definite advantages in reducing both leachate seepage and contaminant transport. Key words: landfill, leachate, hydrodynamic containment, liners, compacted earth cutoff walls, seepage and contaminant transport modelling.
Robotics in construction: implementation and economic evaluation
Authors: Moselhi Osama , Hason Stanley
Published: January 2010

This paper presents a review of current worldwide efforts in automation and robotization for construction. Over a dozen countries are currently involved in such research efforts to overcome mainly declining productivity, increasing labor costs, hazards in the workplace, and scarcity of skilled labor. Research and development progress of Japanese contractors is emphasized, as they are aggressively introducing robots on site. A number of their leading contractors are visited, and applications of robotic equipment utilized on building construction sites in Japan are summarized. The Canadian construction industry, existing in a harsh climate and affected by shortages of skilled labor and high labor costs, needs to carefully consider construction robotics in order to meet its changing needs. The characteristics of the Canadian environment are presented and factors that have a direct bearing on the feasibility and implementation of robotics are emphasized. Different methods for the evaluation of the value of a construction robot are presented and applied to a numerical example. Comparisons are then made between the U.S. and Canada. It is believed that, given existing technology, economical constraints will either force or impede the implementation of robotics. Key words: Canadian construction industry, construction robot, automation, building construction, productivity, feasibility.
Behaviour of headed studs in composite beams: full-size tests
Authors: Jayas B. S. , Hosain M. U.
Published: January 2010

This paper summarizes the results of tests conducted on four full-size composite beams and two full-size push-off specimens which are companions of the first two beams. In these specimens, the ribbed metal deck was placed perpendicular to the beam span. Concrete pull-out was the principal mode of failure. The ultimate horizontal shear loads observed in the push-off specimens agreed reasonably well with those predicted using an empirical equation proposed by the authors. The predicted values of flexural capacity, calculated indirectly using the same equation, were in good agreement with those observed in the four beam specimens. Key words: composite beam, headed shear stud, stud shear capacity, stud pull-out failure, full-size tests, perpendicular ribbed metal deck.
A Kalman filter modelling of space-time rainfall using radar and raingauge observations
Authors: Adamowski Kaz , Muir J.
Published: January 2010

Conventional raingauge networks have proven to be inadequate to describe the temporal and spatial distribution of rainfall, but raingauge data combined with radar data can provide a very useful technique for monitoring the quantitative distribution of rainfall in time and space. A square grid mean areal rainfall model is developed, which utilizes raingauge measurements and a Kalman filter state-space model of the Z–R relationship from radar measurements. The developed method applies in areas where radar information exists, and it has been tested for only one watershed. Key words: space-time rainfall model, radar, raingauge, Kalman filter.
Influence de la température sur le rendement des filtres au charbon activé biologique
Authors: Letendre Sylvie , Desjardins Raymond , Fortin Line , Lafranche Pierre , Brière François G.
Published: January 2010

To evaluate the performance of the biological activated carbon filters at the Sainte-Rose water treatment plant in Ville de Laval (Québec), water and carbon samples were taken over a period of 150 days. Sampling began 1 year after filter start-up. The filters were then in a pseudo-equilibrium state. During winter, the removal rate of organic material is reduced because of lower water temperatures which affect bacterial activity. Bacterial density in the upper layers of the filter is influenced by temperature variations. During the warm season, bacteria counts are higher in the upper layer of the carbon, in the filter effluent, and in the backwash water. For equal carbon masses, bituminous carbon and peat-based extruded carbon have similar removal rates. However, for equal volumes, bituminous carbon is more efficient. Key words: biological activated carbon, adsorption, filtration, drinking water, organic matter.
Masonry infilled steel frames subjected to dynamic load
Authors: Dawe J. L. , Schriver A. B. , Sofocleous C.
Published: January 2010

Experimentally determined dynamic responses of ten scale models of masonry infilled steel frames were compared with the results of three simple analytical models. Effects investigated included stiffening and strengthening contribution of the masonry infill, degradation of the system, motion intensity, frame stiffness, and rotational joint rigidity at slab-to-column intersections. Tests on one-third scale models, subjected to sinusoidal motions, revealed that masonry infill markedly increases the dynamic strength and stiffness of the system. At weak-to-moderate motions (below 0.5 g), models exhibited a nonlinear response before the final failure, while strong motions accelerated the system degradation rate. Stiffer frames and rotationally rigid joints resulted in significantly increased system dynamic strength. A braced frame model wherein cross-bracing replaces the panel action adequately predicted linear and lower-region nonlinear responses of infilled frames with flexible column-to-slab rotational conditions. Satisfactory predictions of the linear response of framed walls with rigid column-to-slab rotational conditions were made with a single degree of freedom model. The third analytical model based on an equivalent strut technique was found to be unsatisfactory for predicting dynamic response of masonry infilled frames. Key words: masonry panel, steel frame, shear, dynamic, analytical, experimental.
Solving a harbor accretion problem: the case of Miller and, Îles-de-la-Madeleine, Quebec
Authors: Ouellet Yvon , Anctil François , Desjardins Louis
Published: January 2010

This paper summarizes a group of studies regarding Millerand harbor, located on the Îles-de-la-Madeleine coast, which blocks most of the local littoral drift. The understanding and quantification of this sedimentological problem was first carried out using numerical models. Various schemes were then tested in two mobile-bed physical models. Finally, the impact of these solutions on the wave climate in the harbor and in the entrance channel was compared using a diffraction–reflection numerical model. The results show that accretion in Millerand harbor will only be controlled by the construction of a breakwater. This breakwater must close the east side of the harbor and must reach at least 2 m depth at its toe. It is also strongly recommended that two groins be built on the east-side beach to control the erosion of the cliff. The results of the diffraction–reflection model finally give some latitude to the harbor planners, as several schemes present satisfactory wave agitation maps. Key words: erosion, accretion, breakwater, diffraction–reflection, harbor, littoral drift, numerical model, physical model, wave hindcasting.
Influence of structural parameters on abrasion-erosion resistance of various repairing mortars
Authors: Mirza J. , Turenne S. , Masounave J.
Published: January 2010

Slurry erosion tests were performed on various types of repairing mortars in order to determine the factors influencing the abrasion-erosion resistance of some mortars. An in-house built apparatus was used, which produced a slurry jet that impinged the surface of mortar specimens with an incidence angle of 45° and a velocity of 18.5 m/s. The results showed that the epoxy mortars were the most erosion resistant compared with cementitious grouts and polymer-modified cement-based mortars. The erosion of mortars is controlled by the wear of the binder (epoxy or cement paste), and a strong relation exists between the erosion resistance of the mortar and the absence of microporosity in the binder. The results also suggest that to minimize the exposed areas of the binder, well-graded, i.e., small- and large-size, sand particles should be used. Key words: abrasion, erosion, repair mortars, cementitious grouts, polymer-modified cement-based mortars, epoxy mortars, hydraulic structures.
Short-term strength of glulam rivet connections made with spruce and Douglas-fir glulam and Douglas-fir solid timber
Authors: Karacabeyli Erol , Fraser Henley
Published: January 2010

The 1984 edition of the Canadian Standards Association Standard 086 restricts the use of glulam rivets to Douglas-fir– larch glued-laminated timber (glulam) only. This study, undertaken in order to extend the use of glulam rivets to both spruce glulam and solid timber, presents the results from the short-term ramp testing of 33 glulam rivet connections assembled using white spruce and Douglas-fir glulam beams and Douglas-fir solid wood joists. Half of these connections were tested to failure with load applied parallel to the grain of the wood member; the other half were tested with load applied perpendicular to the grain. A species factor of 0.80 is recommended for application to the design values of Douglas-fir–larch glulam rivet connections in order to obtain values for spruce glulam rivet conne-ctions. Also, small (less than 4%) differences were found between the lateral load-carrying capacities of glulam rivet connections made with Douglas-fir glulam and connections made with Douglas-fir solid timber free from major checks and (or) splits. To provide theoretical representations of the load–slip curves of the experimental treatment groups, an exponential function was fitted to the test data. Key words: glulam rivet, timber engineering, fasteners, nails, glued-laminated, wood connectors.
Les resurfaçages minces adhérents en béton renforcé de fibres comme méthode de réhabilitation des chaussées de béton
Authors: Chanvillard Gilles , Aïtcin Pierre-Claude
Published: January 2010

The progressive and rapid deterioration of cement concrete road systems makes frequent rehabilitation necessary if an acceptable level of service is to be maintained. When a road's structural capacity is still satisfactory, simple resurfacing to correct surface faults is an acceptable option. Several different types of resurfacing are possible, depending on adhesion developed at the interface. Dimensioning and selection of application techniques are still today purely empirical matters. However, major discoveries have been made about the behaviour of overlays, especially regarding cracking. For example, reflection in the overlay of the cracks of the old pavement is inevitable with a bonded interface. The old cracks must, therefore, be repaired first. However, with steel fibre reinforced concrete, the knitting effect of the fibres will stabilize the cracks. Road-work performed along autoroute 40 in the suburbs of Montreal provided an opportunity to monitor the behaviour of a thin bonded overlay of fibre-reinforced concrete. Examination of the road more than 2 years after it was recommissioned clearly indicated that the fibres had a positive effect on the condition of the road. Key words: rehabilitation, resurfacing, roads, concrete, steel fibre, cracking, bonding. [Journal translation]
Waste management schemes of potash mines in Saskatchewan
Authors: Tallin J. E. , Pufahl D. E. , Barbour S. L.
Published: January 2010

Saskatchewan's potash industry, when operating at capacity, produces 28 × 106 t of salt tailings and 11 × 106 m3 of concentrated brine per year. As a result, in excess of 250 × 106 t of tailings and lesser amounts of brine are stored on the ground surface in waste disposal basins consisting of a system of ponds and dykes. While the substantial quantities of solid waste represent an enormous task for eventual decommissioning, it is the seepage of brine into the surrounding soil and groundwater that is presently of most concern. Four general models are proposed to illustrate the role of hydrogeology in the selection of techniques for containment of potash wastes. This paper reviews waste management schemes in the Saskatchewan potash industry over the past 27 years and presents observations and qualitative evaluations of waste disposal practice of four mines that are representative of the proposed hydrological models. The four case histories identify problems that are common to all mines. The importance of design, operation, and proper monitoring programs is emphasized. The study found that a combination of different seepage barriers have been reasonably successful in preventing serious brine contamination. Shortcomings, where they exist, have been caused largely by unsatisfactory design and construction practices. These inadequacies are of concern to the industry and government regulatory agencies, but they have not yet seriously impeded orderly potash waste disposal. Key words: waste management, potash tailings, brine disposal, brine containment, seepage barriers, seepage control, refining practices, brine ponds.
Définition d'un site réel répondant aux conditions d'une simulation d'une couche superficielle de l'atmosphère
Authors: Louchez P. R. , Druez J.
Published: January 2010

Given the difficulty of numerically modelling atmospheric turbulence, laboratory wind-tunnel simulations have been used to solve a variety of design problems involving pollution, wind pressure on structures, etc. Most often, a dry, homogeneous, stationary, barotropic, and neutral surface layer is assumed for the simulation. However, such an assumption severely limits the applicability of the findings. This paper presents a definition of a real site for solving the types of design problems mentioned. A simple numeric application is performed on a simulation of wind drag on a vehicle travelling in the countryside under particular stationary-state and thermic-neutrality conditions. [Journal translation]
Analyse des structures avec joints à rigidité partielle: une approche unifiée
Authors: Fafard Mario , Picard André , Beaulieu Denis
Published: January 2010

In this paper, the authors are proposing a unified approach for the analysis of tridimensional structures with partial stiffness joints. The proposed approach allows for the quick modification of a software in order to take into account partial stiffness joints. After a review of the theory, we present two matrices to correct the fixed-end shear of flanges with partial stiffness joints. One of the matrix is concerned with bending, and the other deals with torsion. We also present two general cases of loading (bending and torsion) for the design of fixed-end shear and demonstrate how a tridimensional finite element can easily be modified to account for partial stiffness joints. We finally present a numerical technique that can generate equivalent nodal shear for situations where loads are partially distributed on one finite element of beam. Key words: analysis, joints, finite elements, software, matrix, stiffness, structure. [Journal translation]
Simulation hydrodynamique de l'estuaire supérieur du fleuve Saint-Laurent (Canada) avec un modèle aux éléments finis couvrant–découvrant
Authors: Leclerc Michel , Bellemare Jean-François , Trussard Serge
Published: January 2010

Some problems are described in connection with the survey of currents in an estuary influenced both by tides and runoff (the upper estuary of the St. Lawrence River, Canada). The use of numerical modelling is proposed as a reliable and cheap alternative to intensive hydrographic field surveys. A two-dimensional finite element hydrodynamic model with moving boundaries (drying–wetting) is outlined. An application of this model to the St. Lawrence River between Lotbinière and Sainte-Anne-de-la-Pérade is used as an illustration of the approach. The calibration method is first presented. Then, some results for a typical event (mean tide and river flow) are briefly described. Finally, emphasis is placed on the great potential of this approach to increase our knowledge (at least our insight) of estuarian systems as far as current-related phenomena are concerned (sediment transport, fish habitat, water quality, etc.). Key words: St. Lawrence River, hydrodynamics, modelling, simulation, finite elements, currents, drying and wetting, moving boundaries, tidal flow, estuary.
Rationalization of simplified methods of analyzing cantilever slabs
Authors: Jaeger Leslie G. , Bakht Baidar
Published: January 2010

Earlier simplified methods of analyzing elastic cantilever slabs subjected to concentrated loads involve the use of a cosh function along with graphical charts of a coefficient. It is shown that in the simplified methods, the cosh function, which was derived empirically, may be an approximation of a simple algebraic function. An example is presented to compare the results of rigorous analysis with those obtained by simplified methods incorporating the cosh and algebraic functions, respectively. Key words: cantilever slab, concentrated load, cosh function, deck slab overhang, simplified method.
Hydraulics of culvert fishways V: Alberta fish weirs and baffles
Authors: Rajaratnam N. , Katopodis C. , Fairbairn M. A.
Published: January 2010

This paper presents the results of a laboratory study of the hydraulic performance of fish weirs and fish baffles used by Alberta Transportation for improving the fish-passing capacity of culverts. It was found that if the longitudinal spacing of the weirs is limited to 0.6 and 1.2 times the diameter of the culvert, their performance is comparable to that of the corresponding weir and slotted-weir baffle systems, with regard to the depth of pool between the baffles as well as the barrier velocity. On the other hand, the fish baffles did not perform as well as the fish weirs under the conditions tested. Key words: culverts, fishways, baffles, turbulent flow, hydraulics, open-channel flow.
Finite element prediction of temperature gradients in walls of cylindrical concrete storage structures
Authors: Jofriet J. C. , Jiang S. , Tang S. W.
Published: January 2010

Aboveground concrete cylindrical storage tanks must be designed for temperature differences between inside and outside faces of the wall. The stresses in the cylinder wall are a linear function of the temperature difference. A number of transient heat transfer finite element analyses were carried out to determine reasonable design values for this temperature difference. Extreme summer and winter conditions for southern Ontario were assumed in the analyses. It was found that for water stand-pipes supplied by groundwater the temperature difference can be as high as 25 °C, based on a summer water temperature of 10 °C. The maximum winter temperature difference was also 25 °C, based on a winter water temperature of 5 °C. For farm tower silos, a design temperature difference of 15 °C is probably more appropriate. Storage structures for other liquids can be judged if the temperature of the contained liquid is known. Key words: standpipes, structural design, temperature load, water reservoir, finite element prediction.
Risk-based performance criteria for real-time reservoir operation
Authors: Burn Donald H. , Venema Henry D. , Simonovic Slobodan P.
Published: January 2010

Reliability, resiliency, and vulnerability criteria are formulated as risk-based performance measures for the evaluation of a real-time reservoir operation model. The reservoir operation model includes a multi-objective compromise programming algorithm to select, in real time, an optimal operating horizon for the reservoir operation. The utility of the risk-based performance criteria for comparing operational strategies resulting from the selection of different parameters for the compromise programming algorithm is demonstrated. Although trade-offs exist between the performance evaluators, it is shown that appropriate compromises can be reached between the conflicting modeling goals. Key words: reservoir operation, real time, risk, optimization.
Flow through gated conduits at partial and full gate openings
Authors: Powley Richard L. , Haid Bradley H.
Published: January 2010

A general method of analysing flows in gated circular and rectangular conduits was developed, and empirical contraction coefficients were determined for typical gates in circular conduits. A momentum analysis of the flow immediately downstream of a submerged gate was also conducted. Key words: gated conduits, contraction coefficient, hydraulic jump, jet, development length.
Hydrometric data collection and interpretation in the prairie provinces and Northwest Territories
Authors: Perks A. R. , McLaurin I. S. , Harvey K. D. , Wedel J. H. , Johnson B. N. , Warner L. A.
Published: January 2010

This paper outlines the current status of the hydrometric network of the Prairie provinces and the Northwest Territories, the data and information available, general hydrologic characteristics of the region, and efforts being made to ensure that the network continues to meet the needs of Canadians in the future. Key words: hydrology, hydrometric network, streamflow, water level, sediment.
Establishing derailment profiles by position for corridor shipments of dangerous goods
Authors: Saccomanno F. F. , El-Hage S. M.
Published: January 2010

The position of railcars carrying dangerous goods in a train can affect their involvement in a derailment. A model is presented, which minimizes the number of cars carrying dangerous goods derailing for different marshalling strategies and rail corridor conditions. An application of the model to the Sarnia–Toronto rail corridor is presented. The results of this analysis suggest that marshalling strategies for cars carrying dangerous goods need to be sensitive to corridor conditions that affect the causes of train derailments. Current Canadian Transport Commission directives governing the placement of cars carrying dangerous goods along a train were found to be ineffective in reducing their derailment probability when compared to a low-cost unregulated option. Effective marshalling strategies can substitute for speed controls on the shipment of dangerous goods, resulting in a similar or improved derailment profiles and lower operating costs. Key words: dangerous goods, derailment, rail, marshalling, railcars.
Reliability-based design of mechanically connected built-up wood columns
Authors: Malhotra S. K. , Sukumar A. P.
Published: January 2010

Built-up wood structural components and systems have been in use in the building industry for decades. Though easy to construct, they are rather complex to analyze because of numerous factors affecting their strength and behaviour. This paper explains the development of a reliability-based design formulation in limit states for built-up columns, using a rational mathematical model for the analysis and design. Also, a brief discussion is given on a set of simplified design rules for layered columns which have been incorporated into the Canadian Standards Association Standard CAN3-086.1-M89 "Code for engineering design in wood (limit states design)." The rational model as well as the simplified rules are subjected to reliability analysis.The Canadian specifications for the design of wood structures in limit states format have been available since December 1984. These specifications are essentially a soft conversion of the previous working stress design code. The 1989 edition of the code is mostly based on the principles of reliability-based design. Some portions of the code are still not fully based on reliability approach, as additional information is needed for the establishment of a reliable data base upon which the "uncertainty factors" could be redefined in a more rational and logical manner. This paper provides that type of information and the details of reliability analysis as applied to mechanically connected built-up timber columns. The reliability analyses are performed based on first-order second-moment methods, using a data base of column strengths. The data base consists of experimental as well as simulated results. Two reliability analysis programs, BUCREL (built-up column reliability analysis) and POINT (reliability analysis using design point algorithm), are developed. Design recommendations are derived in a reliability-based design format. Key words: buckling, columns, design specifications, efficiency, joints, layered columns, rational model, reliability, resistance factor, slip, spaced columns, timber, wood.
Cross-section elements to accommodate passing lanes and vehicle storage during avalanche control for the Trans-Canada Highway in Rogers Pass
Authors: Morrall John
Published: January 2010

The two basic problems facing the Trans-Canada Highway through Rogers Pass, namely the winter problem of adequate vehicle storage areas during avalanche control and the summer problem of maintaining an acceptable level of service by ensuring adequate passing opportunities, may be linked through a common denominator — passing lanes. This paper presents the findings of a recently completed study of the Trans-Canada Highway through Mount Revelstoke and Glacier National Park. The study method is based on the fact that traffic flow characteristics, highway conditions, and operational requirements vary considerably from season to season. Thus, the analysis was broken into two parts, namely a separate analysis of winter and summer conditions. A traffic simulation model was used to determine those locations that could serve as potential sites for passing lanes during summer. The traffic simulation model developed for the passing lane analysis utilized files that describe road geometry, summer traffic flow and composition, and vehicle performance. A separate simulation model was developed to determine vehicle storage requirements of ponding areas during avalanche control. The model developed for winter traffic characteristics also provided the basis for a flexible traffic management strategy. Cross-section elements were developed to accommodate an auxiliary lane to be used as a passing lane in summer and as a parking lane to increase the capacity of ponding areas during avalanche control in winter. Design requirements called for triple stacking of vehicles in ponding areas during avalanche control. To accommodate design year traffic volumes at an acceptable level of service during the summer months, 12 passing lanes totalling 23 km in length were recommended. Six ponding areas, totalling 4 km in length, are coincident with four of the passing lane locations. The paper concludes with a general discussion on the benefits of linking traffic simulation with geometric design to demonstrate how the design life of rural two-lane highways can be extended by the use of low-cost operational improvements such as passing lanes. Key words: highway planning and engineering, two-lane highways traffic management during avalanche stabilization, passing lanes, cross-section elements, Trans-Canada Highway.
Static and dynamic behaviours of an 85-year-old steel railway bridge
Authors: Pietraszek Tomasz T. , Oommen George
Published: January 2010

This paper presents the results of an investigation regarding the static and dynamic behaviours of a railway bridge being in service for more than 85 years. The age of the bridge and the recent introduction of a new type of freight train to operate at high speeds (above 95 km/h) made the bridge testing necessary. A full-scale railway bridge test is a complex and expensive undertaking involving cooperation of various departments in a railway organization. This fact limits this type of bridge evaluation to a few very important cases each year. A computerized data acquisition system permitted recording strains and deflections from 21 strain gauge circuits and 6 displacement transducers. A special test train was used to study the behaviour of the bridge under controlled loads and speeds. Measurements were also carried out for regular traffic (passenger and freight trains). This paper covers the following topics: (i) instrumentation and test loads; (ii) test results (static and dynamic stresses and deflections); (iii) comparisons of measured static stresses and deflections with theoretical values; and (iv) dynamic characteristics of the tested span (influence of train speed on stresses, deflections, and lateral forces). Key words: bridge, data acquisition, impact factors, strains, strain gauges, testing, test loads, vibrations.
A stochastic study of floods in Canada: frequency analysis and regionalization
Authors: Caissie Daniel , El-Jabi Nassir
Published: January 2010

Peak stream discharge is a hydrologic parameter that is very important for the determination of flood risk, design of engineering works, and management of water resources. In this study, some 237 stream records across Canada were analyzed using the theory of stochastic processes applied to extreme values. This model, based on partial duration series analysis, was applied to each stream record, considering the time of occurrence of floods to be a Poisson process. In addition, exceedances (values above a given discharge level or truncation level) were considered to be independent random variables identically distributed over a one-year time interval. After this frequency analysis of each stream record, a regionalization of the flood frequency characteristics in Canada was performed using two different approaches: multiple regression analysis and index-flood method. A comparison of the two approaches was carried out by examining mean relative error and root-mean-square error. It was determined that the level of difficulty in applying the stochastic flood model was not the same across Canada. Moreover, error associated with the index-flood method is mainly due to error in estimating low return floods. Key words: flood, partial duration series, regional hydrology, index-flood method, low return flood.
Finite difference modelling of the variation in piezometric head within a rockfill embankment
Authors: Townsend Ronald D. , Garga Vinod K. , Hansen David
Published: January 2010

The subject of flow through rockfill is of increasing interest in Canada. Rockfill drains are presently used by mining companies in order to permit existing creeks to flow through the base of mine waste dumps. There is potential for the use of flow through rockfill dams for mini-hydro schemes because the adoption of a costly concrete spillway may be unnecessary in some cases. An important issue in the design of flow through rockfill structures is the pore pressure distribution and the associated hydraulic gradients, neither of which are associated with Darcy's law. For such determinations the finite difference scheme of Curtis and Lawson, which is based on the partial differential equation presented by Parkin et al., was investigated. However, expressions for edge nodes under this non-Darcy finite difference scheme do no exist. This paper presents the effect on the results of using more direct expressions for the edge nodes. Analytical results are compared with observed piezometric heads in the case of two model flow through rockfill dams. Further, it is shown that through the use of a standard electronic spreadsheet, piezometric heads for non-Darcy flow in porous media and the associated hydraulic gradients can be modelled directly without the need of complex computer programming. Key words: flow through rockfill embankment, piezometric head, finite difference method, non-Darcy flow.
Conversion of a suspension bridge into a cable-stayed bridge
Authors: Buckland Peter G. , Morgenstern Brian D.
Published: January 2010

After many years of use, the Belgo suspension bridge, used to convey logs, was clearly in need of repairs. Because of uncertainty about the condition of the anchorages, it was decided to convert it from a suspension bridge to a cable-stayed bridge. This would produce the least disruption to the operations of the mill, while providing a solution to all the identified deficiencies. Although such a conversion has been proposed before, this is thought to be the first time it has been accomplished. The exercise provided valuable experience in the intricacies of altering a suspension bridge to a cable-stayed bridge, particularly during the period when the bridge is partly supported by both systems. The process is rendered more challenging by the requirement to keep the bridge operational for most of the construction period, and by the knowledge that stresses are already unacceptably high and must not be increased during the alterations. Key words: bridges, cable-stayed, suspension, conveyor, rehabilitation.
Case histories of attempts to remove three small ice jams
Authors: Doyle P. F.
Published: January 2010

Blasting proved ineffective in removing one ice jam and mechanical removal by heavy equiment at three ice jam locations on small rivers had mixed results in reducing flood levels or accelerating jam removal. In all cases, diminishing discharge in conjunction with thermal deterioration of the jammed ice gradually had reduced the flooding problems at all sites prior to the earnest efforts to remove the jams. Frequently, there are environmental drawbacks to both blasting and mechanical removal techniques and other difficulties such as access and safety which can combine to make the utility of these ice jam control methods doubtful in many instances. Key words: ice jams, ice, ice jam removal, ice jam control, flooding.
Field verification of a new asphalt compactor, AMIR
Authors: Svec Otto J. , Abd El Halim A. O.
Published: January 2010

A prototype of a new asphalt compactor termed "asphalt multi-integrated roller (AMIR)" was built as a joint venture between the National Research Council of Canada (NRC) and a Canadian manufacturer, Lovat Tunnel Equipment, Inc. The purpose of this project was to prove this new compaction concept in a full-scale environment. This paper describes one of the field trials carried out on the campus of the NRC and reports the results quantifying the quality of the AMIR compaction. Key words: compactor, asphalt mix, field trials, laboratory testing.
The construction and operation of the First, Second, and Third Welland canals
Authors: Jackson John N.
Published: January 2010

The Welland canals are features of great Canadian renown in terms of engineering, as transportation arteries, and through their contributions to industrial development and urban achievement. Their instigator was William Hamilton Merritt, a St. Catharines businessman. Functionally, they must be perceived as an inland extension of the St. Lawrence system of waterways. These contributions began when the First Welland Canal opened in 1829, and extend continuously up to the present. The First Welland Canal, fed from the Grand River, was constructed through the canalization of rivers north of the Niagara Escarpment, by locks across this relief barrier, and a man-made cut to the south. The canal then took advantage of the Welland and Niagara rivers to reach Lake Erie. Hardly a feature of this achievement was as anticipated and, in 1833, the route was changed by a cut direct to Lake Erie at Port Colborne. The Second Canal, opened in 1845, followed essentially the same route, but with stone locks and a new channel constructed slightly to the west of its predecessor. The Third Canal was wider and deeper. It offered fewer locks and, though retaining Port Dalhousie as its northern outlet on Lake Ontario, its alignment was now a cut east of St. Catharines and Thorold across the Ontario Plain. The Second Canal remained in use at the two ends for the smaller-sized vessels to serve St. Catharines and Thorold, and its water supply continued to power industry until hydroelectricity was obtained from the power projects on the Niagara River at Niagara Falls. Key words: Welland Canal, St. Lawrence–Great Lakes water system, William Hamilton Merritt, transportation, Grand River, Lake Erie, Lake Ontario, water power, industrial location, urban growth.