bluuebunny/crossref_metadata_2025 huggingface dataset:
Evaluating Alternative Levels of Water and Sanitation Service for Communities in the Northwest Territories
Authors: Gamble Donald J. , Janssen Christian T. L.
Published: January 2010

The majority of communities in the Northwest Territories lack the water, sewage, and garbage facilities available in southern Canada. Recently, the Government of the Northwest Territories proposed a multimillion dollar ten-year program to upgrade the water and sanitation services of the sixty-odd communities under its jurisdiction. In this paper, which is a first report on an ongoing project to upgrade the sanitary conditions of settlements in the Northwest Territories, we develop a methodology whereby the cost of the alternative water, sewage, and garbage systems for each community can be determined, compared, and evaluated. This analysis defines the level of service to be recommended in each community.Cost data for sanitary installations in the north are generally not available and therefore need to be estimated. The costs associated with alternative systems are assessed as a function of some one hundred variables, including population, demand for water, distance to the water source, topography, terrain, weather conditions, severity of climate, existence of roads, availability and cost of gravel, general remoteness of the community, freight rates, etc.The basis for comparison of the various level of service alternatives is the net present value of the investment required over the duration of the program, including capital as well as operating expenditures. Actual data for some forty-five communities are used in the calculations.
Fatigue of Tee Type Composite Beams
Authors: Eyre Dale G.
Published: January 2010

Five steel-concrete composite beams having an inverted tee shape for fabricated steel section were tested to destruction under static load conditions. Prior to the static test, three of the beams had been subjected to two million cycles of loading. Two of the beams had only half the code-required number of stud shear connectors. It was found that the fatigue performance was satisfactory and all five beams surpassed their computed ultimate moment.
Ice Problems at Water Intakes
Authors: Foulds D. M.
Published: January 2010

Ice problems, leading to partial or almost complete shutdown, have occurred in Lakes Ontario, Erie, and Huron, while diverting water for either domestic or cooling purposes in amounts ranging from 25 to 2500 ft3/s (0.7 to 71 m3/s). All difficulties are initiated by relatively rare combinations of severe weather conditions. The location of an intake in relation to prevailing storm tracks is important, with onshore winds creating most of the problems except those due to frazil. So little published information exists that many designers tend towards incredulity when the problem occurs. Solutions exist and recommendations are provided.
The Impact of Fracture Mechanics on Engineering Practice
Authors: Bassim M. Nabil , Hay D. Robert
Published: January 2010

Fracture mechanics is a design philosophy which has evolved over the three decades since World War II and is beginning to find use in standard design. This concept for fracture-safe design recognizes the general existence of flaws in engineering materials and provides an analytical basis for prediction of the mechanical behavior of a structure constructed of a flaw-bearing material.This article reviews the basic concepts of fracture mechanics. The material parameters, such as plane-strain fracture toughness KIc are derived and the experimental technique for obtaining KIc is presented.The impact of fracture mechanics on engineering practice, i.e. material selection and fabrication, mechanical and structural design, and nondestructive testing is also examined.
Hydrological Studies for Churchill Falls
Authors: Atkinson C. H. , Keeping P. A. T.
Published: January 2010

Hydrological data for the design of the Churchill Falls 5225-MW hydro-electric power development in Labrador, Canada comprised a 10-year record. Extensive statistical correlation studies using data from rivers up to 500 miles (800 km) distant were undertaken to expand this record to 43 years. Subsequently, stochastic generation of stream-flow, utilizing Beard's method, was adopted to expand the length of record and to provide multiple sets of flow data for use in energy and revenue studies. The generated data influenced the operational rules and reservoir capacity because it produced additional values for rare events (e.g. spill, water shortage) which are not well defined in a short record.
Numerical Methods in Structural Dynamics
Authors: Humar J. L. , Wright E. W.
Published: January 2010

The dynamic analysis of a structure subjected to a random forcing function from a source such as earthquake, blast, or wind requires the use of a numerical integration technique. The efficiency and accuracy of the technique employed is of great importance for both research and practical design. The more effective methods of numerical integration belong to the category designated as ‘predictor-corrector’ methods. A systematic method is presented for the derivation of single-point and multiple-point predictor-corrector formulae. It is shown that most of the methods of numerical integration presently employed in structural dynamics are single-point predictor-corrector methods. A scheme of iteration is usually employed for the solution of the difference equations obtained by the application of these methods. It is shown that for problems in structural dynamics, it is not necessary to use an iterative scheme; a process of elimination is feasible and also gives considerable economy in computation time. It is further shown that the choice of an appropriate multi-point method for the numerical integration of the equations of motion of an elastic system can lead to a considerable saving in computation time and cost. One such multi-point method is presented, and its truncation error and stability are examined.
Beam-columns of Hollow Structural Sections
Authors: Pillai Unnikrishna S.
Published: January 2010

Empirical interaction equations are recommended in various specifications for the design of biaxially bent beam-columns. In this paper, the strength requirements specified in the Canadian Standards Association Standard S16-1969 for the plastic design of biaxially loaded beam-columns are compared with theoretical relations. It is shown that the S16-1969 provisions lead to unduly conservative designs when applied to thin walled square and circular hollow structural sections. Based on the theoretical relations, simplified interaction equations are proposed herein, which are both satisfactory and far less conservative.
Structural Design Concepts for the Canadian National Tower, Toronto, Canada
Authors: Knoll Franz
Published: January 2010

This paper provides a general review of the basic principles for the structural design of the CN Tower. A discussion of the design is provided relating to each of the major portions of the structure. The following portions are treated separately and in relation to each other: concrete tower shaft; foundation; and upper accommodation building. Choice of geometry, materials, and construction methods is explained with respect to technical, architectural, and functional requirements and restrictions.
General Aspects of Water Supply and Treatment in Ontario
Authors: Lumsden T. W. , Knowles W. L. C.
Published: January 2010

This paper deals with various sources of water supply in Ontario and the methods and relative difficulties of treating these sources. Sources include the Great Lakes, southern Ontario rivers and groundwater, and northern rivers and lakes. Distinctive characteristics with respect to hardness, turbidity, colour, chemical constituents, and biological and bacteriological content require specific treatment approaches for the provision of safe and palatable supplies. The effects of urbanization and industrial development are also discussed.The current approach to water treatment in Ontario is reviewed, as well as some of the historical developments leading up to the present state-of-the-art. Future requirements are touched on. Provincial water quality objectives are described and compared with international drinking water standards.
Foundation Design Problems of Some Bridges near Welland, Ontario
Authors: Isaacs R. M. , Maitland S. T. , Mirza A. M.
Published: January 2010

Large-diameter piles socketed into bedrock support the abutments and piers of several large railway and highway bridges across the approach cuts of a tunnel near Welland, Ontario. The design of these piles was governed by the following considerations: (a) the large vertical and lateral loads involved, (b) the low shear strengths of the overburden and the low design factor of safety of the slopes of the approach cuts, (c) the effect of the construction of piers and abutments on the stability of the slopes, (d) the development of negative skin friction on the piles at the abutments and some piers, (e) chemical and micro-biological attack on steel, and sulfate attack on concrete by the constituents of the groundwater, (f) the low shear strength of the gypsum in the bedrock and its tendency to creep, and (g) the possibility that gypsum might be leached out of the bedrock as the groundwater regime changes.The piles used varied from 24 in. (61 cm) and 30 in. (76 cm) in diameter for the highway bridges to 48 in. (122 cm) in diameter for the railway bridges. Where settlement of the overburden was expected to occur, only groups of vertical piles were used and these were coated with coal tar to limit the maximum value of negative skin friction. As these piles also were required to resist large lateral loads, the steel casings used in construction were designed to contribute to the structural strength of the piles and were protected from chemical and microbiological attack by a coat of an epoxy resin beneath the coal tar. The design took into account the lateral resistance of the overburden and, where it was insufficient, that of the bedrock. This type of pile was installed in an overexcavated hole and the casing was concreted several feet into bedrock; where bedrock conditions warranted it, the vertical load on the pile was transferred to the rock by the wedge action of a tapered socket.Where negative skin friction was not a problem, combinations of raked and vertical piles were used. The contribution of the casing to the strength of the piles was ignored and the casings were not protected. Tapered sockets were used on some of these piles where rock conditions were unsatisfactory.All concrete was sulfate-resistant, and for casings socketed into bedrock a method of installation was used that ensured intimate contact of concrete with the casings and the surrounding bedrock.
The Design and Construction of Burton Bridge
Authors: Malloy R. B. , Davies D. J.
Published: January 2010

Burton Bridge spans the Saint John River about 14 miles (~22 km) downstream from the city of Fredericton, New Brunswick, replacing a ferry service between Maugerville on the Trans-Canada Highway along the north bank of the river, and the township of Burton on the south side of the river. The ferry service, said to have been in use for over two hundred years, met with increasing criticism in recent years and a demand for its replacement by a bridge has resulted in the present structure, completed and opened to traffic in the autumn of 1972. The main span is an arch bridge with a center navigation span of 600 ft (182.9 m), and an overall length of 1026.5 ft (312.9 m), flanked on each side by three 125 ft (38.1 m) approach spans. The total length of bridge between the abutments is 1784.5 ft (543.9 m), and its greatest height above normal river level in summer is 185 ft (56.4 m). Access to the bridge from the existing roads is accomplished by approach roads on new embankments, the one on the south side being relatively short, while those on the north bank form a complex of roads providing east and west access to the Trans-Canada Highway, over which a pre-stressed concrete overpass bridge has been built for one of the routes.
Curling Deformations and Stresses of Insulated Rigid Pavements
Authors: Sargious Michel A. , Ross Grant A. , Le Moal Gerald A.
Published: January 2010

The problems associated with freezing and thawing of the subgrade soil underneath highway and airfield pavements in countries with cold winters like Canada are well known. In the southern parts of Canada, the subgrade can be protected from freezing by a thick layer of granular material or a thin insulating layer. In northern regions, layers of granular materials or insulation can maintain the subgrade in a frozen condition.Previous studies have shown that extruded polystyrene foam is effective as an insulating material. However, the effect of this material on the physical behavior of pavements has not previously been investigated.To study the effect of a thin insulating layer on the curling deformation and thermal properties of rigid pavements two concrete slabs were cast in the field. One slab was laid over a 1½ in (4 cm) thick layer of styrofoam, while the second slab was cast over a 1½ in. (4 cm) thick layer of sand without insulation. A 10 in. (25 cm) subbase layer of compacted gravel was used underneath both slabs.Both slabs were instrumented from surface through foundation to determine the temperature distribution and to establish the curling behavior of the slabs. Periodic readings were taken during one warm and one cold weather period. The results derived from these readings have indicated that insulation reduces curling deformation of pavement slabs and does not significantly effect temperature gradients across their thickness.
Etude de la coagulation des eaux par fluorométrie
Authors: Sérodes Jean-B. , Soucy Alain
Published: January 2010

The use of a fluorometric method for the determination of residual aluminum salts used as coagulants in water treatment has permitted evaluation of the influence of some factors, particularly temperature, on the hydrolysis of these salts. The yield of hydrolysis is lessened by low temperatures and aluminum ion is more sensitive than aluminate ion. This new method is suggested for detecting abnormal working of water treatment plants.
Strength Values for Wood and Limit States Design
Authors: Madsen Borg
Published: January 2010

This paper describes the present method of deriving allowable stresses for wood. While this method has served adequately in the past its relevance to ‘limit states design’ is questioned and several of its shortcomings are pointed out.An alternative method of obtaining characteristic values for the strength properties of wood is suggested. A pilot investigation was carried out to ascertain the amount of work involved in obtaining the necessary data. It would appear possible and practical to derive the characteristic values needed for ‘limit states design’ based upon ‘in-grade testing’.It is suggested that such a method could result in improvements in the present grading rules and a more efficient use of our timber resource.
A National Commodity Flow Model
Authors: Hutchinson B. G. , O'Brien W. B. , Dawson I. N.
Published: January 2010

This paper describes a pilot study of the development of a national commodity flow model for Canada. The aim is to develop a modelling capability that can estimate the commodity movement implications of probable changes in development and in the transport system. The model described in this paper concentrates on estimating the implications of alternative development patterns. The basic inputs to the model are spatially disaggregated allocations of population and of employment by industry sector. The principal outputs from the model are the annual tonnages of freight on each link of each modal transport network. Data inputs to the model and the model parameters are derived principally from information collected and published by Statistics Canada.The structure of the model is similar to the model structure used in urban transport planning studies. It proceeds from the estimation of commodity productions and consumptions, through the estimation of commodity distributions patterns and modal split by mode to network assignment.Preliminary results from the commodity flow model using a 1971 data base are described along with a very limited appraisal of the model outputs using independent information on Canadian commodity flows. Plausible results were obtained from the model and the assembly of an improved data base should lead to a well-developed national commodity flow model for Canada. Such a model may then be used to examine the freight movement implications of alternative patterns of urbanization in Canada and to evaluate alternative transport supply decisions for the various modes of transport.
Simplified Analysis of Staggered Wall-beam Frames
Authors: Mee A. L. , Jordaan I. J.
Published: January 2010

Simplified analyses of wall-beam frames, based on previously determined equivalent member stiffnesses, are given. The analyses are based on two approaches: (i) using the methods of difference calculus and (ii) using the continuum method, commonly used in shear wall analysis, in which the beams connecting the columns are replaced by a continuous connecting medium. It is shown that the analyses using difference and differential calculus are equivalent if an approximation of the column bending is introduced. Comparison of the proposed approximate methods with exact skeletal analysis shows excellent agreement. One conclusion of practical importance is that many analyses applied to shear walls, and available in the literature, may be applied to wall-beam frames as well. It is suggested that in many cases it is possible in practice to neglect the column bending stiffness altogether and details of an analysis based on this assumption are also given.
Analysis of Shear Walls in Large-Panel Construction
Authors: Pollner Eugenio , Tso W. K. , Heidebrecht A. C.
Published: January 2010

A study is made on the behavior of shear wall systems made from large precast panels. Three commonly used wall arrangements are studied. The loading consists of monotonically increasing lateral uniform load. Realistic vertical joint and connecting lintel characteristics are incorporated into the mathematical model. A step by step calculation technique is used to study the vertical joint and lintel behavior and its effect on the overall stiffness degradation of the system as load increases. The effect of flexible foundation on the overall behavior is also studied.
Performance of Light Coastal Structures Under Normal and High Water Conditions
Authors: Kamphuis J. W.
Published: January 2010

A number of lightweight coastal protection structures, built on the Lake Erie shore are discussed in this paper. There were two constraints on the design; limited funds and a very precarious downdrift beach. Thus the structures were inexpensive and the protection was low-key to prevent damage downdrift. In 1972–1974 these structures were subjected to a combination of large waves and high water levels and thus they were tested well beyond their design limits.The paper discusses the structures, their performance under normal conditions, and their performance during and after the abnormally high water levels. It is found that inexpensive, low-key structures are sufficiently strong to survive normal conditions, but fail by overtopping and flanking under conditions beyond their low design limits.
Arching of Fragmented Ice Covers
Authors: Calkins Darryl J. , Ashton George D.
Published: January 2010

Among the problems associated with the extension of the winter navigation season on the Great Lakes and the St. Lawrence River, the obstruction of navigation posed by a continuous ice boom across a water body may possibly be solved by creating a gap or opening in the boom, through which vessels may pass, but which will promote retention of floating ice pieces by arching. A laboratory study of arching by fragmented ice floes across a gap in a surface obstacle was conducted in a 0.9 m wide hydraulic flume using simulated ice floes. Polyethylene blocks, 37 mm and 74 mm square by 6.4 mm thick, were used in both single-sized runs and combination-sized runs. The simulated ice was released upstream at a controlled rate and the occurrence or nonoccurrence of a stable arch was observed and recorded by time-lapse photography. The threshold of arching was found to be described by a correlation between the supply rate of simulated floes Qi (in terms of total floe surface area per unit time), normalized by Vb, the product of water surface velocity and gap width, and a/b, the ratio of block size to gap width of the form[Formula: see text]In a corollary series of experiments an arch, once formed, was subjected to a disturbance simulating the passage of a vessel through the ice field. The area of ice floes released as a result of the disturbance before arching reoccurred was found to be, on average, equivalent to b2, the square of the gap width.
Cobble Lined Drop Structures
Authors: Smith C. D. , Murray D. G.
Published: January 2010

This paper describes the concept and the experimental study made to determine the design criteria for a drop structure comprised entirely of loose dumped rock. The three principal components of the design were: (1) the weir at the top of the slope, (2) the sloping portion downstream from the weir, and (3) the horizontal apron at the bottom. The rock weir was intended to prevent excessive drawdown and control upstream velocities. The sloping portion was a hydraulically steep reach, on which supercritical velocity occurred. The apron was intended to accommodate the transition back to subcritical flow at the end of the drop structure.The initial investigation involved study of the structure in two-dimensional flow. It was determined that the critical area for stability was in the terminal velocity region of the steeply sloping portion of the structure. The stone size and layer thickness required for channel stabilization was found to be a function of the channel slope and flow depth at terminal velocity. Eight combinations of variables were tested and included four different slopes, three different stone sizes, and two different layer thicknesses. Each combination was tested to failure.The failure process was unique in that there was an initial failure and an ultimate failure. Initial failure occurred when some stone at the lower end of the slope was displaced, exposing the subgrade. The exposed area was rapidly filled in by downstream migration of stones from further up the slope. The migration process continued until it was arrested at the top of the slope by the rock weir, and the structure became stable once again. A further large increase in discharge was required to precipitate a second or ultimate failure.Design criteria were formulated, including a recommended factor of safety based on initial failure, and the design was verified on a three-dimensional model.
Feeder Bus Service for Commuter Rail
Authors: Shortreed John H. , Ireland John A.
Published: January 2010

A feeder bus system for a suburban community commuter rail station is designed. The paper develops a design methodology utilizing cost–effectiveness methods. A demand model for feeder bus ridership is developed with input variables – location of rail users, income of users transit fare, level of transit service, and walk time to bus route. In applying the methodology to a study area which included three commuter rail stations it was found that all feeder bus systems would operate at a loss. Bus routes with loops in residential areas and direct service to the rail stations had the best ridership levels. The cost–effectiveness approach and the model developed are effective design methods.
On Seismic Risk Analysis of Nuclear Plants Safety Systems
Authors: Anderson D. L. , Charlwood R. G. , Chapman C. B.
Published: January 2010

The recent United States Atomic Energy Commission study (WASH-1400), using a simplified analysis, has estimated the probability of earthquake initiated accidents of typical U.S. nuclear plants to be in the range 10−5 to 10−8 per year, and has concluded that these are sufficiently small compared to other causes as to be safely ignored in assessing overall plant safety.An event tree model is presented in this paper to assess the failure probabilities from seismic events of single and multiple component safety systems. The ground motion, response spectra, and failure criteria are treated as probabilistic quantities. The model is applied to a Canadian site and failure probabilites are predicted for several levels of design. The sensitivity of uncertainties in the input data on the failure probabilities is also investigated.The results show the importance of considering common mode failures when determining seismically initiated system failure probabilities. Also, in assessing system failure probabilities of the order of 10−6 it is shown that the input with the highest sensitivity is the probability distribution of large magnitude earthquakes and the component failure probabilities.It is recommended that the design basis earthquake be determined from the desired system failure probability level, and that more effort should be placed on estimating the probability of occurrence of large magnitude earthquakes and in determining component failure probabilities.
A Critical Review of the Seismic Design Provisions for Ductile Shear Walls of the Canadian Code and Commentary
Authors: Paulay T. , Uzumeri S. M.
Published: January 2010

The 1975 Canadian Building Code for the design of reinforced concrete shear wall buildings in high seismic risk areas includes provisions that are new and significant. This paper critically examines some of these provisions, especially as they apply to cantilever shear walls. Clarifications in the definitions of curvature, member, and system ductilities are attempted. The relationship between curvature and system ductility is examined. Code provisions on allowable shear stress in the wall in the plastic hinge region and the provisions for the classification of the walls are discussed. Attention of the designer is drawn to some aspects of the code and the commentary that may result in structures of doubtful safety.
Empirical Equation for the Fundamental Natural Period
Authors: Suko Masaaki , Adams Peter F.
Published: January 2010

An empirical method has been developed to predict the fundamental natural period of a multistory, multibay frame. Average values of beam stiffness, column stiffness, story height, and mass per story are used to enter charts from which the natural period is determined. The results are more accurate than those obtained using other approximate techniques. The rational of the method is discussed and example calculations are presented.
A statistical study on artificially generated earthquake records
Authors: Tso W. K. , Guru B. P.
Published: January 2010

A statistical study has been done to investigate (i) the variation of spectral responses of structures due to artificially generated earthquake records with identical statistical properties, (ii) the effect of duration of strong shaking phase of artificial earthquakes on the response of structures, and (iii) the number of earthquake records needed for time-history response analysis of a structure in a seismic region. The results indicate that the flexible structures are more sensitive to the inherent statistical variations among statistically identical earthquake records. Consequently several records must be used for time-history response analysis. A sample of eight or more records appear to provide a good estimate of mean maximum response. The duration of strong shaking can significantly affect the maximum response. Based on the results, it is suggested that for the purpose of estimating peak response, the strong shaking duration of the input earthquake motion should be at least four times the natural period of the structure. The maximum responses due to statistically identical ground motion records are observed to fit approximately the type 1 extreme value distribution. Thus, it is rationally possible to choose a design value based on the mean, standard deviation of the spectral response values and tolerable probability of exceedance.
Application of linear programming optimization to a Northern Ontario hydro power system
Authors: Draper D. W. , Adamowski K.
Published: January 2010

In this paper a linear programming technique is used as an aid in selecting storage reservoirs for a hydroelectric power development system at the feasibility stage of investigation, and for maximizing system guaranteed hydroelectric power by optimum regulation of discharge through power plants and from diversions for a selected time period. The linear programming technique is used as an allocation or screening model that provides information on system operation and response which would be useful in the preliminary design of hydroelectric power producing facilities and from which basic data and guidelines could be extracted for extending the investigation to the study of long-term system response by use of simulation models.
Mass concrete sections and the maturity concept
Authors: Nisbet E. G. , Maitland S. T.
Published: January 2010

The 28 day strength of concrete cylinders cured under standard laboratory conditions can now be reliably predicted at early ages by use of (a) the Modified Boiling Test or (b) the Autogenous Curing Test. The availability of early strength indicators for concrete can be used to great advantage during construction provided these strengths can be related to the strength of the structural elements.To permit an estimate to be made of the strength of in-place concrete on structures appurtenant to the Welland Channel By-pass, the temperature rise of the structural elements was monitored with an automatic 16 point recording potentiometer. The time temperature curve of the in-place concrete was compared to that of 6 in. by 12 in. (150 mm by 300 mm) concrete cylinders taken during casting of the structure and cured autogenously for 48 h, thus permitting an estimate of the in-place concrete strength to be made from the results of the 48 h autogenous strengths.On the basis of the in-place concrete strength estimates, decisions were made regarding the application of post tensioning forces and/or the removal of formwork and supporting shoring.
Proportioning of concrete mixes incorporating fly ash
Authors: Ghosh Ram S.
Published: January 2010

A method is described for proportioning fly ash concretes to produce similar compressive strengths as normal Portland cement concrete at 3, 7, 28, and 90 days. The method is primarily based on the Abrams' law relating compressive strength and water–cement ratio. Curves are also presented, for estimating the most economical fly ash to cement ratio for a particular strength and cost of fly ash.
Etude comparative de deux modèles mathématiques dans l'analyse de rejets thermiques à Gentilly
Authors: Marche Claude , Robillard Luc
Published: January 2010

On August 8th 1974, infrared photographic data of the hot water plume at the Gentilly nuclear powerplant were obtained from an aerial survey of the St. Lawrence River. Important parameters such as the longitudinal decrease of temperature or lateral spread of the rejected water become available together with hydraulic and thermal ambient conditions.At first, a three-dimensional model, already developed at the Massachusetts Institute of Technology, was applied to the actual volume of water rejected and predicted a dilution rate much higher than the actual one. The use of a different geometric scheme has reduced the gap between predicted and actual values. The same scheme has been tried on a two-dimensional model. The two-dimensional approach is justified by consideration of the bottom topography.The discussion of results concerns: first, the establishment of an adequate geometric scheme and second, the error brought by the two-dimensional approach.
On flow induced vibrations in hydraulic structures and their alleviation
Authors: Weaver D. S.
Published: January 2010

Flow-induced vibrations are characterized as dynamic response, self-controlled and self-excited vibrations, the latter two being the principal subjects of this paper. Such classification is shown to be a helpful guide for designing against destructive vibrations. While the obvious choices of increased stiffness or additional damping may prove effective in some cases, counter-examples are presented. A change in structural geometry which modifies the flow characteristics may be the best or only avenue for eliminating vibration problems in service.The general nature of mathematical models of these phenomena is presented briefly as well as those aspects of hydro-elasticity which distinguishes it from aeroelasticity. In particular, the effects of virtual mass are emphasized.A variety of different problems are reviewed with an effort to summarize and interpret current knowledge and to provide some physical insight. Specifically treated are stability of fluid-conveying pipes, vibrations of hydraulic gates, valves, and seals, and the singing of propellor blades, guide vanes, and control surfaces. In each case, methods of alleviation are discussed.
Predicting the performance of structures in regions of high seismicity
Authors: Penzien Joseph
Published: January 2010

The complete seismic design process of certain important structures based on time-history dynamic analyses is traced from the initial preliminary design stage through the final stage of predicting lifetime performance to strong motion earthquakes. Emphasis is placed upon (1) selection of sound design procedures, (2) consideration of field and laboratory evidence, (3) application of present day knowledge, and (4) recognition of uncertainties involved in the complete process. It is concluded that meaningful predictions of performance can be made only when formulated in a probabilistic sense.
Vibration criteria for long-span floors
Authors: Allen D. E. , Rainer J. H.
Published: January 2010

Annoyance criteria are derived for walking vibrations of long-span floors. The criteria are developed primarily for steel beam or joist construction with concrete deck, spans greater than about 25 ft (8 m) and natural frequencies less than about 10 Hz. The criteria are expressed in terms of the dynamic properties of a floor as measured by a heel impact test. The advantage of the heel impact test is that it provides a tool for design calculation.
Moment connections between wide flange beams and square tubular columns
Authors: Picard A. , Giroux Y.-M.
Published: January 2010

This paper presents the design and development of moment connections between wide flange beams and square tubular columns in rigid frames. The connection is effected by means of coped strap angles used to transfer stress from the beam flanges to the sides of the column. The testing program comprised 23 specimens, including two standard rigid joints introduced to give a comparison basis for the [Formula: see text] curves.The results indicate that after adequate precautions have been taken to prevent the occurrence of brittle fracture in the strap angles a connection is obtained which can develop MP and sustain appreciable inelastic deformation, making it suitable for plastically designed frames. The rigidity of the connection is less than that of a standard connection but high enough for the joint to be termed 'nearly rigid'. Preliminary theoretical studies indicate that the effect of the relative loss of rigidity on the sway behaviour of multistory frames may be significant and that P-Δ effects should be investigated.All joints considered here comprised beams of flange width equal to that of a column face.A design method is proposed in the Appendix.
A square grid model for assessing the effect of alternative land uses on water quality
Authors: Constable Thomas W. , Kouwen Nicholas , Solomon Shully I.
Published: January 2010

A mathematical model has been developed which can aid in assessing the effect of the modification of land use patterns on the water quantity and water quality regime of a watershed. The basin under study is divided into a number of elements using a square grid technique. The hydrologic and water quality components are evaluated at each element in the basin at successive time intervals, and flows are routed through the elements by use of a streamflow network system. The model can be used to assist in evaluating the effects of alternative land use configurations in a watershed, such as urbanization, the removal or growth of forests, the construction of dams, etc., on water quantity and water quality. It can also be used in the preliminary design of an urbanized area to estimate the size of storm sewers, artificial ponds, etc.
Creep deflection of metal beams in transient heating processes, with particular reference to fire
Authors: Harmathy T. Z.
Published: January 2010

A new numerical technique is described by which the process of creep bending under transient heating conditions can be predicted. It utilizes a convenient creep model, proposed by Dorn and expanded by this author.The computer simulation of the behavior of three protected steel beams during standard fire tests is discussed. The close agreement between the experimental and computed midspan deflection histories is regarded as the proof for the accuracy of the technique as well as of the creep model employed.
Determination of design hydrographs on small catchments by the state variable model
Authors: Muzik Ivan
Published: January 2010

Derivation of a design hydrograph from rainfall data is a typical problem when dealing with small catchments; in most cases there are no streamflow data available. Numerical solutions of unsteady flow equations are difficult to adopt for flow on natural catchments because of the uncertainity about the initial and boundary conditions. A simplified approach is suggested in which a catchment topography is characterized by a number of planes and channels. Flow over the planes and the channel flow are computed by a numerical solution of the state variable equations of unsteady gradually varied flow. The state variable model of surface flow offers simplicity and calculating speed compared with the numerical solutions of the complete unsteady flow equations, yet it maintains a reasonable approximation of the physical reality. Example problems of the use of the model in derivation of a design hydrograph for a small catchment, using rainfall intensities and durations as inputs, are presented. The computer program is provided at a nominal charge from the Depository of Unpublished Data, CISTI, National Research Council of Canada, Ottawa, Canada K1A 0S2.
Notch toughness as a criterion of material quality
Authors: Firth M. , Williams W. M.
Published: January 2010

Notch-toughness, viewed as a criterion of steel quality and as an engineering parameter, is discussed in relation to the design of dynamically loaded engineering structures. The absence of a direct relationship to the normally quoted tensile values of a material is pointed out. Four case histories dealing with recent major engineering failures are outlined in order to illustrate the necessity of specifying minimum notch-toughness at the lowest temperature of operation in addition to adequate strength and ductility.
Dynamic ice forces on piers and piles. An assessment of design guidelines in the light of recent research
Authors: Neill Charles R.
Published: January 2010

The first part of the paper reviews and assesses various analytical approaches and design formulas used to estimate forces due to the impact of moving ice on piles, piers, and towers. The application of dimensional analysis to the problem is outlined briefly. The second part reviews and assesses full-scale data available from research structures and from reported evaluations of structure performance, and attempts to summarize their more significant findings. The third part reviews a number of recent small-scale laboratory investigations. Finally, suggestions are made for improvement of current design guidelines and practices. It is suggested that a group formed from those with the best knowledge available in Canada be assembled to develop design guidelines for ice forces on all types of structures.
Seasonal salinity changes in the Fraser River Estuary
Authors: Ward Peter R. B.
Published: January 2010

The Fraser Estuary in British Columbia is characterized by a salt water wedge, which underlies the fresh surface water. The stage of the tide and the fresh water discharge in the Fraser River are the two primary factors influencing the maximum intrusion of the salt water wedge.A systematic set of measurements are presented, documenting the change in the position of the tip of the salt water wedge as a function of fresh water discharge. Tidal conditions did not affect the measurements, since all measurements were made at times when the stage of the tide was the same. The tip of the salt water wedge is shown to be displaced a distance of 22 km (13.8 mi) seawards, as the fresh water discharge increased from 850 to 9000 m3/s (30 000 to 317 000 ft3/s).Vigorous surface to bottom mixing was observed during large ebb flows. The mixing was sufficiently strong to break up the wedge over a large part of the estuary. A calculation is presented showing that this was due to the existence of a strong velocity shear between the saline bottom water and the fresh water surface flow.
Determining the capacity of the Canadian trans-mountain highway system
Authors: Morrall John F. , Cameron Neville , Werner Al
Published: January 2010

Trans-mountain highway capacity is sensitive to the percentage of recreational vehicles in the traffic stream, the manner in which passenger car equivalents for recreational vehicles are used in capacity computations, terrain classification, and the choice of design hourly volume. The sensitivity of capacity to these factors is demonstrated for the trans-mountain portion of the Trans-Canada highway which is a two-lane highway, characterized in many locations by long steep grades. This particular highway has a high percentage of recreational vehicles during summer months. The Highway Capacity Manual does not make any provision for the effect of such vehicles and previous highway planning studies have used the adjustment factors for trucks and buses to estimate their effect. Neglecting the effect of recreational vehicles and/or improper use of their passenger car equivalents in capacity computations can result in serious errors in the determination of highway capacity especially in mountainous areas. Further research is required in the areas of terrain definition, selection of design hourly volume, and the present concept of level of service.
Impact of land use changes on transportation networks
Authors: Soliman Afifi H. , Sharma Satish C.
Published: January 2010

The purpose of this paper is to simulate and predict the changes caused in the existing commuter travel pattern by new land development schemes within the framework of a specific community. Particularly, this study is concerned with developing a residential location distribution model with special emphasis on the effect of socioeconomic factors of commuters on the travel time parameter of the model. The findings of the study may be helpful to the siting of new land development activities in the existing infrastructure of an urban system.The study utilizes socioeconomically stratified samples of workers from Fort Garry Industrial Park and Canadian National Railway Yard. Both of these employment centers are located in the Greater Winnipeg Area.The parameters of the model developed here clearly indicate that the workers of a low socioeconomic group generally have more tendency to live close to the place of employment as compared to a high socioeconomic group. The low group may choose to live close to the place of employment depending on neighbourhood affiliation, land use infrastructure, type of housing, transit availability, or merely because the part of the income spent on commuting seems disproportionately large.
An evaluation of compression prism, shear bond, and bending bond control tests for clay brick masonry
Authors: Huizer A.
Published: January 2010

Both Australia and the United States have standardized new tests to determine the compressive strength of masonry using a stack-bonded prism specimen and the bond strength of masonry using a flexure type bond test.In the past design engineers have relied upon individual unit tests and the 28 day compressive strength of masonry mortar cubes both for design and quality control.In order to evaluate the prism and bond tests for Canadian materials, a large number of tests were performed utilizing these new methods and results correlated to the properties of site sampled mortars. The results, so obtained, appear to support the acceptance of such tests for the quality control of load bearing clay brick masonry.
The effects of column out-of-plumbs on the stability of core-braced buildings
Authors: Beaulieu Denis , Perlynn Mike , Dunbar Alastair , Adams Peter F. , Kelker Douglas
Published: January 2010

A brief review of the most common first and second order methods of analysis for core-braced buildings is given. Three types of horizontal forces which must be resisted by the structural elements to maintain the integrity of the structures are isolated. Original statistical data on column out-of-plumbs are also presented and an analysis of the resulting effects in terms of forces transmitted to the core is performed.
Design criteria for steel I columns under axial load and biaxial bending
Authors: Ross D. A. , Chen W. F.
Published: January 2010

The design code, Canadian Standard S16.1-1974, permits ultimate strength design steel H columns subjected to axial load and biaxial bending moment. However, this is permitted only for sections in which the flange width to section depth ratio is equal to or greater than 0.8. In this paper a simple modification to the previous formulas is proposed which enables the restriction on flange width to section depth ratio to be removed so that they are also applicable to steel I columns.
Safety and limit states design for reinforced concrete
Authors: MacGregor J. G.
Published: January 2010

This state-of-art paper reviews the concept of limit states design. Following a brief review of statistical definitions the sources of variability in reinforced concrete structures are reviewed. Methods of defining structural safety are reviewed. Following a derivation of the procedures used to compute load and [Formula: see text] factors, a series of [Formula: see text] factors compatible with the 1975 National Building Code of Canada load factors are computed. With the exception of the value for shear the new [Formula: see text] factors are lower than the current American Concrete Institute and Canadian Standards Association values by about the amount of the ratio of load factors in National Building Code of Canada and American Concrete Institute. The computed [Formula: see text] for shear is considerably lower than the corresponding value from the American Concrete Institute Code. An Appendix traces the development of the American Concrete Institute load and [Formula: see text] factors.
A manual method for the elastic analysis of wide cantilever slabs of linearly varying thickness
Authors: Bakht Baidar , Holland D. A.
Published: January 2010

A semi-graphical simplified solution to give results similar to the classical solution to the problem of concentrated loads on elastic cantilever slabs, made of isotropic material, is presented. This method, whose validity is checked by other well established methods of analysis, is expected to provide accurate and quick results to the problems of overhanging slabs of box girders, subjected to concentrated loads.