Xia C.,Rescan Environmental Services |
Benedicenti L.,University of Regina |
Field T.,Delcan Corporation
International Journal for Numerical Methods in Fluids | Year: 2013
A new mathematical algorithm is proposed to address the essential details of vertical distributions of horizontal velocity for one-dimensional steady open-channel flow. This new algorithm comprises a system of weighted averaged equations developed from corresponding Reynolds equations by performing weighted average operations instead of conventional depth average operations. It is the system of weighted averaged equations, instead of the vertical grids, that allows for more hydraulic coefficients identifiable. It can be thought of as an extension of the St. Venant equations to address the vertical distributions of horizontal velocities, as well as the water surface profiles.To avoid the difficult expansion of governing partial differential equations in high order, an indirect scheme is proposed to solve hydraulic variables through their weighted average values. The governing partial differential equations are generated by using a variety of weight functions, and the weighted averages of relevant hydraulic variables are taken as the unknown independent variables to be solved first. Then, on the basis of the values and polynomial expansions of these weighted averaged velocities, a system of linear algebraic equations is generated and the unknown hydraulic variables or their coefficients are easily solved.Note that the new model is not proposed to compete with any three-dimensional models in modeling accuracy or accommodation ability to all conditions. It just provides a valuable option to study the vertical structure of flow in open channels where only essential detail and reasonable accuracy of vertical distributions are required, and the data availability and other conditions limit the application of fully three-dimensional models. The performance of the model is evaluated with experimental data of flows in two different flumes. It is shown that the model well predicted the velocity profiles of sections along the centerlines of these flumes with reasonable accuracy and essential details of vertical distributions of horizontal velocity. © 2013 John Wiley & Sons, Ltd.
Van De Ven M.,Croon Elektrotechniek |
Hulse J.,Delcan Corporation
22nd Annual International Symposium of the International Council on Systems Engineering, INCOSE 2012 and the 8th Biennial European Systems Engineering Conference 2012, EuSEC 2012 | Year: 2012
There is emerging consensus within the Systems Engineering (SE) community that, while the principles underpinning SE remain the same across the lifecycle: . Some of the issues concerned with sustaining existing systems are more problematic than when realizing new systems; and . The existing SE Body of Knowledge and the competences of SE practitioners tend to focus on the issues that are more important when realizing new systems than on the issues that are more important when changing existing systems. A UK working group on Applying SE to In-Service Systems looked into difficulties in this area and produced a report containing draft guidance and recommendations for further action. These recommendations were recognized by INCOSE and consequently the International In-Service Systems Working Group ("the ISSWG") was set up in 2009 with the following objectives: • To consider the work of the UK Working Group and extend and adjust it as necessary in order to provide improved advice on the difficulties encountered in practice in applying authoritative guidance on SE, including the INCOSE SE Handbook, to systems which are in service and best current practice in adapting SE guidance to overcome these difficulties; and • To consider the current channels by which INCOSE promulgates advice on good SE practice, including the SE Handbook and the SE Book of Knowledge and make recommendations on how additional guidance on performing SE on in-service systems should be integrated into these channels. © 2012 by Marcel Van De Ven, Jon Hulse and Joe Talik. Published and used by INCOSE with permission.
Brijmohan A.,Delcan Corporation |
Khan A.,Carleton University
Journal of Advanced Transportation | Year: 2013
Land border crossings in North America, such as those between Canada and U.S.A., are expected to experience severe imbalance of travel demand and capacity of processors. During peak travel periods, this is already the case at high traffic locations. The land border crossing authorities have to address problems of congestion, national security and environmental impacts in the operation of the existing systems and to continue to address these problems as a part of infrastructure expansion plans. There is a need to adapt the crossing system management in order to accommodate efficiency and productivity-oriented priority crossing measures. From a methodological perspective, it is a challenge to evaluate the role of priority crossing measures within the complex border crossing system. This paper reports research on modelling priority crossing initiatives. A microsimulation approach was used to model and analyse integrated processors of the Peace Bridge crossing system between Fort Erie (Ontario) and Buffalo (New York) under different scenarios of travel demand, customs processing times, priority crossing and queue jump lanes for automobile and truck traffic. Findings show the extent to which a border crossing system with priority crossing and queue jump lanes is more efficient and productive than one without these innovations. Copyright © 2011 John Wiley & Sons, Ltd. Copyright © 2011 John Wiley & Sons, Ltd.
Ahmad S.S.,Delcan Corporation |
Simonovic S.P.,University of Western Ontario
Urban Water Journal | Year: 2013
Urban flood risk assessment requires quantification of uncertainty that is spatially and temporally variable. This paper presents a new approach to urban flood risk assessment by: (a) integrating objective and subjective uncertainties and (b) providing full insight into spatial and temporal change of flood risk. A 1-D storm sewer model and a 2-D surface flow model are integrated to describe the dynamic interactions between overland flow on the streets and flow through the storm sewer network. The fuzzy set theory approach is used to assess spatial and temporal variability of urban flood damage, and the acceptable level of partial flood damage. The spatial and temporal variability of fuzzy performance indices: (i) combined reliability-vulnerability; (ii) robustness and (iii) resiliency, are generated as the outcome of the urban flood risk analysis. The methodology is illustrated using the residential community of Cedar Hollow (London, Ontario, Canada) as a case study. © 2013 Copyright Taylor and Francis Group, LLC.
Ahmad S.S.,Delcan Corporation |
Simonovic S.P.,University of Western Ontario
Journal of Flood Risk Management | Year: 2011
This paper presents a methodology for assessing spatial and temporal uncertainty associated with flood risk management. Traditional modelling approaches focus on either temporal or spatial variability, but not both. There is a need to understand the dynamic characteristics of flood risk and its spatial variability. The traditional two-dimensional (2D) fuzzy set, with one dimension for the universe of discourse and the other dimension for its membership degree, is not sufficient to handle both, spatial and temporal variation of flood risk. The theoretical foundation of this study is based on the development of a three-dimensional (3D) fuzzy set that includes flood risk variability in space and time. The proposed methodology extends the acceptance level of partial flood damage concept to a 3D representation and allows capturing change of decision makers' preferences in time and space. The main objective of the paper is to present an original methodology for flood risk management that is capable of (a) addressing uncertainty caused by spatial and temporal variability and ambiguity; (b) integrating objective and subjective risks; and (c) assisting flood management decision making based on a more detailed understanding of temporal and spatial variability of risk. Presented methodology is illustrated using the Red River flood of 1997 (Manitoba, Canada) as a case study. © 2011 The Chartered Institution of Water and Environmental Management.
Adamowski J.,McGill University |
Adamowski K.,University of Ottawa |
Bougadis J.,Delcan Corporation
Water Resources Management | Year: 2010
Design storms (DS) that are determined from intensity-duration-frequency (IDF) relationships are required in many water resources engineering applications. Short duration DS are of particular importance in municipal applications. In this paper, linear trends were estimated for different combinations of durations and frequencies (return periods) of annual short-duration extreme rainfall. Numerical analysis was performed for 15 meteorological stations from the province of Ontario, Canada. The estimated magnitude (rate mm/h) and direction of trend (increasing, decreasing, or no trend) were estimated and then used to quantify the effect of trend on the frequency of design storms. Significant trends were detected for all durations. It was determined that due to the existence of trends (which might be attributed to climate change), the design storms of a given duration might occur more frequently in the future by approximately as much as 36 years depending on the duration and return period. © Springer Science+Business Media B.V. 2009.
Kim J.,Northwestern University |
Mahmassani H.,Northwestern University |
Vovsha P.,Parsons Brinckerhoff |
Stogios Y.,Delcan Corporation |
Dong J.,Iowa State University
Transportation Research Record | Year: 2013
This study established a conceptual framework for capturing the probabilistic nature of travel times with the use of existing traffic simulation models. The framework features three components: scenario manager, traffic simulation models, and trajectory processor. The scenario manager captures exogenous sources of variation in travel times through external scenarios consistent with real-world roadway disruptions. The traffic simulation models then produce individual vehicle trajectories for input scenarios while further introducing randomness that stems from endogenous sources of variation. Finally, the trajectory processor constructs distributions of travel time either for each scenario or for multiple scenarios to allow users to investigate scenario-specific impact on variability in travel times and overall system reliability. Within this framework, the paper discusses methodologies for performing scenario-based reliability analysis that focuses on (a) approaches to obtaining distributions of travel times from scenario-specific outputs and (b) issues and practices associated with designing and generating input scenarios. The proposed scenario-based approach was applied to a real-world network to show detailed procedures, analysis results, and their implications.
Phillips P.,Delcan Corporation |
El-Hacha R.,University of Calgary
Concrete Repair, Rehabilitation and Retrofitting III - Proceedings of the 3rd International Conference on Concrete Repair, Rehabilitation and Retrofitting, ICCRRR 2012 | Year: 2012
The Sikanni Chief River Bridge, 256.1 km of the Alaska Highway, British Columbia, Canada, is a five-span structure which was built in 1968. Results from five detailed visual condition evaluations of this bridge, completed over the last decade, are provided within this paper. Findings from the load rating of this structure are also outlined. Deficiencies were detected both from the inspections and the load rating calculations; however, the deficiencies noted based on the load ratings are in fact not observable in the field. The focus of this paper is to show that the findings from the two evaluations differed and to provide the decisions that were made with respect to those differing findings. © 2012 Taylor & Francis Group.
Phillips P.,Delcan Corporation |
El-Hacha R.,University of Calgary
Bridge Maintenance, Safety, Management, Resilience and Sustainability - Proceedings of the Sixth International Conference on Bridge Maintenance, Safety and Management | Year: 2012
This paper outlines how bridge and culvert structure maintenance, repairs, rehabilitations, and/or strengthenings can be prioritized based on existing condition rating data. The sixty-three structures located along the British Columbian (Canada) portion of the Alaska Highway are used as examples. Results from four detailed visual condition evaluation sessions of these structures, completed over the last decade, are provided and compared and contrasted with time. Where deficiencies, structural or otherwise, were found in the field, strategies for rectifying such issues were recommended to the Owner of these structures. Then, how these recommendations can be prioritized, based on severities of the existing conditions, risk to public safety, cost, and possibility of total structure replacement verses repairs to deficient structures, is described. © 2012 Taylor & Francis Group.
Papasotiriou N.,DELCAN CORPORATION
Assessment, Upgrading and Refurbishment of Infrastructures | Year: 2013
This paper presents a quick but accurate method for the assessment of bending moments and deflections in simply supported bridge decks by the use of distribution coefficients under the action of Load Model 1 (LM1) as per, EN 1991-Part 2: Traffic loads on bridges. The current work builds on previous research presented by the author and Ryall M. J.  as the assessment of stress resultants and displacements in bridge decks by the use of distribution coefficients. The method named as D-type is based in the assumption that the bridge deck can be analysed as a continuum or semi-continuum and can be defined by the use of characterizing parameters α and θ which model the flexural and torsional rigidities of the deck and they are unique for a particular orthotropic deck. The loads are analysed in harmonic components and the width of the deck and the distance of the load from the edge of the deck are considered as controlling factors. A simple distribution factor D is defined, relating the maximum overall longitudinal bending moment due to the design vehicle load to the peak of the transverse distribution across the deck. A computer program has been developed and used to carry out a parametric study resulting in distribution coefficient values for a wide range a bridge decks due to a variety of live loading specifications. The results can be presented in the form of tables or charts. The program also enables the user to analyse a single bridge deck and obtain a transverse distribution profile of the shear forces, bending moments, torsion moments, rotations and deflections at a given section under the action of various traffic loadings specifications.