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2023 | Buch

Proceedings of the Canadian Society of Civil Engineering Annual Conference 2021

CSCE21 General Track Volume 2

herausgegeben von: Scott Walbridge, Mazdak Nik-Bakht, Kelvin Tsun Wai Ng, Manas Shome, M. Shahria Alam, Ashraf el Damatty, Gordon Lovegrove

Verlag: Springer Nature Singapore

Buchreihe : Lecture Notes in Civil Engineering


Über dieses Buch

This book comprises the proceedings of the Annual Conference of the Canadian Society of Civil Engineering 2021. The contents of this volume focus on specialty conferences in construction, environmental, hydrotechnical, materials, structures, transportation engineering, etc. This volume will prove a valuable resource for those in academia and industry.


Taloyoak, Nunavut—Sewage Treatment Feasibility Study

The Hamlet of Taloyoak in the Kitikmeot region of Nunavut utilizes trucked water distribution, and trucked wastewater collection to provide the community with water services. The wastewater is currently discharged into a natural two pond system for passive wastewater treatment, which flows through a natural wetland before discharging into the ocean. Concerns were raised by regulators and the community about this wastewater strategy, and in response to these concerns, the Government of Nunavut initiated a wastewater feasibility study to investigate alternative locations and alternative processes for the development of an engineered system. Six potential locations for a new facility were investigated, and four of the sites were eliminated from future consideration. An advanced reconnaissance program was completed on the two remaining sites which included a topographic survey, a geotechnical investigation, an ecological investigation of the wetland. This additional site information was applied to an analysis for the development of a wastewater system on the sites, along with the potential treatment processes, that included a passive lagoon system, an aerated lagoon system and a mechanical treatment system. A passive facultative lagoon system with a single cell lagoon and supplemental wetland system was selected as the most appropriate technology that would meet the effluent quality standards in the community’s water licence. The screening of the potential sites favoured Sites 3 and 4, and ultimately Site 4 was selected for the facility.

K. Johnson, D. Browne
Numerical Modelling of Reinforced Concrete Walls in Nuclear and Industrial Structures Under Seismic Loading

This year marks ten years since the Great East Japan Earthquake in 2011 and the following Fukushima Daiichi nuclear accident. This accident has created a critical need to quantify the seismic response of such critical structures under different levels of seismic hazard. Most seismic-related research studies have been conducted on reinforced concrete walls employed in conventional buildings; however, such walls in nuclear and industrial structures are uniquely designed with very low aspect ratios and relatively large thicknesses. Therefore, several studies have demonstrated that the seismic performance of reinforced concrete walls in nuclear and industrial structures has not been yet adequately quantified to enable robust seismic risk assessment. In this respect, the current study uses a multi-layer shell element in OpenSees to develop a numerical model that can simulate the seismic response of reinforced concrete shear walls with low aspect ratios similar to those used in nuclear and industrial structures. Subsequently, the developed model is validated against the results of several walls tested in previous experimental programs under cyclic loading. The validation results show that the developed model can capture the response of the walls including the initial stiffness, peak load, stiffness degradation, strength deterioration, hysteretic shape, and pinching behaviour at different drift levels.

Mohamed Abouyoussef, Mohamed Ezzeldin
Fresh and Mechanical Properties of One-Part Alkali-Activated Self-Consolidating Concrete

There is a significant potential for Alkali-activated self-consolidating concrete (AASCC) to be used in the construction industry. AASCC combines the benefits of both self-consolidating concrete (SCC) and sustainable development. The aim of this study was to develop an experimental program to investigate the potential production of one-part AASCCs mixtures of multi precursor dry-powder activator materials. Concrete mixtures are developed by incorporating different dosages (16%, 20%, and 25%) of dry-powder activators. The influences of activator dosages on the fresh (slump flow, L-box passing ability, and segregation index) and mechanical properties are critically assessed in terms of experimental findings. Results showed that the workability properties of AASCC highly depended on the dosages of the dry-powder activators. Also, results indicated an improvement in the mechanical properties as the dry-powder activator dosage increased. The findings of this study confirmed the potential for producing one-part AASCC with adequate workability and strength through adjusting activator dosage.

Dima M. Kanaan, Ahmed M. Soliman
A Review on Bond Performance and Splice Behavior of FRP Bars to Concrete

Replacing steel reinforcements with fiber-reinforced polymer (FRP) reinforcements is considered as one of the best solutions to the corrosion problem associated with steel-reinforced concrete (RC) structure. The bond behavior of FRP reinforcing bars in concrete is one of the most critical parameters that control the behavior of FRP materials in concrete structures. Lap splicing of reinforcing bars is inevitable in reinforced concrete structures. A comprehensive review of the bond strength and splice length of FRP reinforcing bars in reinforced concrete elements is carried out in this paper. After reviewing three North American standards and guidelines (CSA S806-12, CSA S6-19, and ACI 440.1R-15) provisions on development length and the bond strength, a discussion on the factors affecting the bond behavior is presented. A database including 74 specimens reinforced with FRP spliced bars was collected from literature to compare the code provisions on splice length. It was concluded that ACI 440.1R-15 is more conservative than two other design codes.

Bahareh Nader Tehrani, Ahmed S. Farghaly, Alireza Asadian, Brahim Benmokrane
A Novel Productivity Measure for Steel Fabrication Fitting Process

The fitting station is an important element of the industrial steel fabrication process. The fitting process happens towards the end of the fabrication and has the potential to cause upstream backlogs if productivity is not maintained. Due to the variations of each different assembly, it is difficult to quantify the productivity at the station. To help define an accurate productivity measure at fitting stations, a time study was proposed to collect pertinent data of different fitting processes and define a metric for the productivity. After observing and breaking the process into sequential phases, a productivity dataset was collected, and a correlation analysis was performed between different input variables and time measures. It was determined that the current metric on trial of ‘parts fit per man hour’ was not an accurate representation of the productivity at the fitting station. This metric fails to capture the significant differences between the process when the workers are either bolting, tack welding, or coping the different parts of an assembly. Hence, to account for these differences, it was proposed in this research that the process should be broken down. According to a correlation analysis, it was concluded that the fitting productivity should include the number of bolts, tacked parts, and coping cuts. The corresponding new metric improved the productivity quantification and time estimation by 42% over the trial metric. With these metrics specified, the productivity will be able to be equally determined for each assembly entering the station and will minimize productivity data variations.

L. Marshall, A. Suliman, Z. Lei
Iqaluit, Nunavut—Sewer Main Replacement in Permafrost

The water and sewer systems in Iqaluit generally consist of shallow-buried, urethane-foam insulated, high-density polyethylene pipe. A trunk sewer through the Lower Base neighourhood conveys sewage from approximately 20 percent of the community, and because of capacity and condition issues, this sewer needs replacement. The replacement is a complex project because of the technical issues associated with the permafrost ground conditions, the existing alignment of the pipes, the remedial work required on the access points of the system, legacy contamination concerns, and the logistics of providing temporary servicing. The permafrost ground conditions have an active layer that may extend as deep as 3 m and produce very wet and unstable ground conditions. The existing alignment of the services includes a water main, a water recirculation main, as well as the sewer main, which should be appropriately separated horizontally and vertically. In addition, all 3 pipes run through insulated metal access vaults. The replacement neighourhood is a commercial district of Iqaluit which will require temporary services for domestic use as well as fire flow. The design development has included options for replacing the water and sewer services within the same trench, and alternately, the development of an independent new sewer system. An independent system was selected as the most appropriate solution, which will allow continuous operation of the existing water and sewer system, provide an emergency bypass for future maintenance works, reduce the risk of watermain contamination and reduce temporary services requirements during construction.

I. Crawford, K. Johnson, S. Plourde, S. Turner, J. Harasimo, R. Sithole, M. Lafleur, C. Keung
Numerical Simulations of 15-Degree Inclined Dense Jets in Stagnate Water Over a Sloped Bottom

Improper discharge of brine will cause significant harm to the water environment and organisms near desalination plants or sewage discharge outfalls systems. Inclined dense jets are commonly used in discharge systems to enhance the mixing efficiency and minimize environmental impacts. Many studies focus on the inclined dense jet on a horizontal bottom, and they have provided plenty of valuable information on geometrical and mixing characteristics of inclined dense jet, which is important for outfall designs. Since the brine is usually denser than receiving water, it will eventually move along the seabed. This leads us to carry out this study about how mixing develops for the inclined dense jet on the bottom especially on a sloped one since the seabed always has the natural inclination. In the present study, the mixing of inclined dense jet on the sloped bottom is investigated by numerical simulations using the solver twoLiquidMixingFoam in OpenFOAM. A Reynolds Averaged Navier Strokes (RANS) turbulence models (Nonlinear k-ε) was chosen to perform the jet behavior analysis. Jets of inclination angle of 15° with four different initial conditions (Froude number = 10,15, 20, 25) on three different bed slope angles (0°, 3°and 6°) in stagnant water were studied. The results show that (1) the coefficients of the jet geometric characteristics have good agreement with previous studies; (2) After the impact point, the slope did enhance the dilution of the plume compared to the horizontal bed; (3) The dilution was thus affected by the slope and the dilution after the impact point on the slope appeared to be linearly related to the distance to the source;(4) The slope can approximately enhance the dilution up to 10% compared with the horizontal bed after the impact point. The present study can provide practical information for the design of desalination and industrial plants, especially for reducing the influence of the brine plume on the seabed and can lead research to focus on the bottom boundary condition at outfall systems.

Xinyun Wang, Abdolmajid Mohammadian
Optimal Design of Truss Structures with Natural Frequency Constraints Utilizing IWSA Algorithm

Constructing structures with the lowest possible use of the material has long been an interesting topic among engineers. In this regard, the resilience of structures in the face of natural hazards and their concomitant effects, such as the resonance phenomenon, should also be taken into account. Frequency-constrained optimization problems seek to not only construct structures with the least possible material amount, but also prevent the resonance phenomenon, enhancing the sustainability of the structures by reducing the total material consumption while minimizing the future damage cost incurred by structural components due to this effect. This article assesses the truss optimization problems with natural frequency constraints using the improved version of the newly developed meta-heuristic algorithm, referred to as the water strider algorithm (WSA). Improved water strider algorithm (IWSA) utilizes two mechanisms to improve the performance of WSA. The first one is the opposition-based learning (OBL) technique, and the other is a mutation method. The OBL technique for the initial population improves the convergence rate and the accuracy of the final result, and the mutation method helps it to approach the global optimum and avoid the local one. Three benchmark spatial truss optimization problems are selected from the literature to examine the efficiency of IWSA in comparison to other well-established algorithms as well as its standard version, WSA. The results reveal the viability and competitiveness of the IWSA algorithm in the framework of design optimization with frequency constraints in comparison to its standard version and other structural optimization algorithms.

Mohammad Farhadmanesh, Arash Asadi Abadi, Amirhossein Cheraghi
Evaluation of Shear Transfer Strength in FRP Concrete Composite Using Nonlinear Finite Element Analysis

Replacement of internal reinforcement steel bars with fiber-reinforced polymer rebar (FRP) in the reinforced concrete (RC) structures is considered an innovative solution to improve the durability and prolong these structures' serviceability. This study aims to evaluate a new application of the corrosion–free and nonmagnetic FRP as a shear transfer reinforcement in composite elements. Nonlinear finite element analysis of RC push-off specimens will be performed using ABAQUS software. The finite element model (FEM) will be verified against experimental tests conducted by other researchers. Seventeen push-off specimens with GFRP reinforcement across their joints will be investigated. All the specimens were subjected to concentric load along the interface shear plane of the push-off specimen. The test parameters were the GFRP stiffness and the dimensions of the shear plane. Based on the analytical procedure, a parametric analysis will be carried out to determine the influence of the different parameters which govern the performance.

Moataz Mahmoud, Mohamed Eladawy, Brahim Benmokrane
Numerical Modeling of Microplastics Fate and Transport in a Stretch of the Fraser River

Microplastics and their impact on the environment and human health have increasingly become a global issue. Rivers are the main sources of fresh-water for human activities, and the main route for pollution delivery to seas and oceans. Predicting the behavior of microplastics (i.e. plastic particles smaller than 5 mm) in river systems and identifying their accumulation zone is therefore important to understand their environmental impact, risk exposure assessment and mitigation/remediation planning. The presence of microplastics in the Fraser River has been previously shown in different studies through water sampling at different sites along the river. In an attempt to improve understanding of the fate and transport of microplastics within the Fraser River system, an innovative three-dimensional numerical model was used in this study to predict movement of these particles in a highly urbanized and industrialized 35 km stretch of the Fraser River. The modeling system used herein is based on coupling TELEMAC-3D hydrodynamic model with a three-dimensional Particle Tracking Model (PTM) which incorporates physical characteristic of microplastics in calculating their movement in the water. The hydrodynamic model has been calibrated using available data. The model results provide information on behavior and distribution of different types of microplastics within of the modeled stretch, and support identifying their sources and accumulation hotspots.

G. Babajamaaty, A. Mohammadian, A. Pilechi
Preliminary Analysis of Permafrost Degradation in Ingraham Trail, Northwest Territories

Global warming has become a critical issue that needs attention and remedies to the problems it causes. As the ground warms, the permafrost soil thaws and turns from continuous to discontinuous or sporadic, which induces various kinds oef impacts and risks to the globe. One major problem that the thawing permafrost brings is the differential settlement, which is primarily related to the damage of the human infrastructures in the permafrost area. Northwest Territories (NWT) is a typical region in Canada that is mostly covered by permafrost. Yellowknife is one of the most populated areas, where the permafrost is extensively discontinuously distributed. Ingraham Trail in NWT serves as major access to Yellowknife. This paper investigates the permafrost degradation impacts along Ingraham Trail by focusing on the vertical settlement of the pavement structure. A numerical model was generated to investigate such impacts during freeze–thaw cycles. The varied settlements were simulated for the same season from 2013 to 2020. In addition, with anticipated impacts of climate change and water table change caused by global warming, the increasing thaw settlements for November from 2020 to 2050 were projected. The settlements with the potential permafrost protection (i.e., insulation materials) were also analyzed using the model, corroborating its primary function with significantly decreased frost heaves in pavements.

Danrong Wang, Susan L. Tighe, Shunde Yin
What Modular and Offsite Construction Contract Administration Can Learn from Court Dispute Cases

Construction contracts become more complicated along with the increasing design complexity, construction process and technology. The frequency of contractual disputes and dispute amounts are also growing. Modular and offsite construction (MOC) has been attracting a high level of attention as a solution to improve productivity, quality, and safety in the construction industry. In practice, MOC adopts and modifies pre-printed standard contracts structured for conventional construction even though MOC has a different nature and features. In response to this gap, the root causes of contractual disputes and litigation, and their correlation with MOC's features are of urgent need. This paper responds to this demand by (i) developing an analysis framework representing contractual dispute causes, documented in the construction literature; (ii) examining the Canadian court cases to identify the major root causes of litigation disputes based on the proposed framework; and (iii) reviewing the terms from Canadian standard contracts that can address the major disputes identified in MOC project court cases. As a result, this paper helps the contract administration management to recognize common causes of disputes and take them into consideration in MOC when drafting and administering new contracts.

E. Chan, S. Han, M. Nik-Bakht
Conceptual Drainage Design of an Urban Rail Transit Project

Urban rail transit systems in Canada have been undergoing expansions in recent years. Many of these expansions are routed through existing developments and neighbourhoods with congested underground utilities. The installation of new rail lines requires new servicing infrastructure and relocation of existing utilities which can become quite complex. Additionally, new stations and platforms create more impervious surface which results in increased runoff; stormwater management strategies are needed to mitigate the impacts of this additional runoff on the existing drainage systems to prevent increasing the risk of flooding. This project included the conceptual design of the drainage and stormwater management systems, including identifying utility relocations. The proposed rail line consisted of an at-grade light rail line with crossings both at-grade and below-grade, which affects the stormwater management strategy. The proposed rail line alignment would intersect with developed neighbourhoods that were serviced by a mix of separated sewers (where water flows in separated storm and sanitary pipes) as well as older developments serviced by a combined sewer area (where storm and sanitary flows are carried within the same pipe). The proposed Light Rail Transit (LRT) design was analyzed from a drainage and stormwater perspective and included runoff volume calculations and flow increases. Several mitigation opportunities were identified, including low impact development measures, integration with existing and proposed regional flood mitigation measures, and underground storage. Conceptual infrastructure designs were prepared from the mitigation opportunities based on preliminary construction feasibility considerations and iteratively integrated with the other disciplines’ design elements on the project.

H. Minchau, A. Van Boven
Indigenous Housing Practices as Inspirations for Modern Green Buildings

Some of Canada’s Indigenous architecture and building technology is reviewed in conjunction with Indigenous environmental philosophy as a guide for green building design and sustainably sourced building materials. Most Indigenous knowledge has been camouflaged by decades of European oppression and Indigenous loss. While there is little data on historical Indigenous architecture, what data that is available offers insight towards the complex relationships that structures have with the ecosystem. The Indigenous groups targeted here are the Inuit of Sub-Arctic Canada and the Haida of Haida Gwaii, an island on the Western Coast of British Columbia. Every detail in Indigenous architecture is the result of generations of complex and in-depth knowledge of local climate and vegetation, guided by a spiritual link and respect to their environment. Considering such knowledge can aid in the adjustment towards green buildings and communities, as illustrated by Inuit igloo and Haida cedar plank houses. Microclimate assessment becomes increasingly important as buildings grow larger and more complex. Considering different components of buildings and analyzing the impacts of local temperature changes, winds, precipitation, and vegetation, can result in buildings that are more efficient in both energy and materials. Together with the use of local materials inspired by the cedar plank houses and the efficient form of the igloo creating a warm home in frigid weather, wisdom of the people from hundreds of years ago can be appreciated.

Z. Kelly, A. Iqbal
Numerical Modeling of Jets Near a Hydraulic Jump

Liquid wastes from municipal and desalination activities are often discharged into the receiving water body in the form of wastewater jets. Such jets can significantly jeopardize the environment and ecology, so it is important to understand better the mixing properties of wastewater jets for an efficient design of the outfall systems and accurate evaluation of the environmental and ecological impacts. A hydraulic jump is a phenomenon in the science of hydraulics which is frequently observed in open channel flow such as rivers and spillways. When liquid at high velocity discharges into a zone of lower velocity, a rather abrupt rise occurs. The rapidly flowing liquid is abruptly slowed and increases in height, converting some of the flow's initial kinetic energy into an increase in potential energy, with some energy irreversibly lost through turbulence to heat. The hydraulic jump may significantly influence the mixing properties of a wastewater jet, so it is necessary to simulate the processes. However, numerical modeling of a wastewater jet near a hydraulic jump has rarely been previously reported, which motivated this research. In this study, a total of three cases are studied: a hydraulic jump without a jet, a hydraulic jump with a weaker jet, and a hydraulic jump with a stronger jet. A key novel observation from this study is that the jet trajectory is not stable probably because of the strong turbulence near the hydraulic jump. This study has established a basic numerical model for a jet near a hydraulic jump, which can be further used to investigate the influences of the locations and inclinations of the jets, and to conduct simulations of buoyant or negatively buoyant jets near a hydraulic jump.

X. Chen, X. Yan, A. Mohammadian
Shear Behaviour of Reinforced-Concrete Circular-Beams Without Web-Reinforcement

In the current assay, the outcomes of a numerical analysis and an experimental program to investigate the effect of bar type on the behaviour of three full scale circular reinforced-concrete (RC) beams, subjected to shear-load, are presented. One beam was reinforced with conventional steel bars, one with sand-coated GFRP bars, and one with sand-coated CFRP bars. The beams had a length of 3000 mm and a diameter of 500 mm. The beams were subjected to two-points shear force, at a constant rate of 0.6 mm/min. All beams failed in diagonal tensions failure. The test results showed that, the beams reinforced with sand-coated GFRP and CFRP bars had 73 and 80% capacity, respectively, compared to the steel reinforced one. Finite element models (FEM) were built to imitate and investigate the shear behaviour of those beams. The accuracy of the FE prototypes was checked with the outcomes of the beams that were tested and experimentally. The results of the FE prototypes exhibited that, the fabricated models were able to prognosticate the conduct of the members, tested experimentally, with good accuracy. The average value of the shear capacity obtained experimentally to the shear strength obtained by the FE model, (Vexp/VModel) for the prototypes, is 1.04 ± 0.02 with 2% COV.

A. Gouda, A. Ali, H. M. Mohamed
Cross-Sectional Water Velocity in Unsteady Flow Conditions by Pressure Sensors

Experiments in a laboratory flume have been conducted with unsteady flow conditions to investigate a new method to measure cross-sectional water velocity with the use of pressure sensors for a temporal discretization $$\Delta {(t)}$$ Δ ( t ) of one second. The unsteady flows are generated by an instant opening of a steel gate separating the flume from a water tank. Therefore, the initial water level in the tank is the experimental parameter that controls the intensity of the flood. In order to evaluate the precision and accuracy of the method, a validation process compares the computed and measured total flooded volume measured directly from the tank. The coefficients of variation of the experiments varies from $${{C}}{{V}}_{{min}}{=2.04 \%}$$ C V min = 2.04 % to $${{C}}{{V}}_{{max}}{=10.3 \%}$$ C V max = 10.3 % and the relative errors from $${{{e}}_{{r}}}_{{min}}{=0.09 \%}$$ e r min = 0.09 % to $${{{e}}_{{r}}}_{{max}}{=5.07 \%}$$ e r max = 5.07 % . The maximum measured water velocity varies between 1.29 m/s and 1.87 m/s depending on the initial water level in the tank. The study shows promising results for the new simple method to measure average water flow velocity in unsteady flow conditions with pressure sensors.

G. Metri, T.-F. Mahdi
The Effects of Foundation Stiffness on Surface Fault Rupture in Reverse Faults

The occurrence of intense earthquakes in cities placed near active faults is unavoidable. The characteristics of these earthquakes are different from those occurring in the sites placed in the far-field. After destructive earthquakes, such as Landers-California (1992), Kobe-Japan (1995), Chi-Chi-Taiwan (1999), Duzce and Kocaeli-Turkey (1999), engineering societies and scientific committees realized that these characteristics should be considered in the analysis and design of structures placed in near-faults. One of the destructive characteristics of near-fault earthquakes that has caused great loss of lives and severe structural damages is surface fault rupture. However, it was observed that some structures survived this phenomenon and the rupture path was changed and passed through the vicinity of structures without severe foundation damages. In most of the standards of seismic design of structures, this characteristic is denied; in some other standards, fault avoidance zones are considered to deal with surface rupture, but these zones are usually inadequate. In this investigation, the effect of foundation stiffness on the surface fault rupture path is studied using numerical studies. The possible effects of soil properties are considered via modeling 2 different soil mediums. Moreover, the mat foundations with different dimensional characteristics are modeled considering soil-foundation interaction. This FE study shows that the foundation stiffness has a significant effect on the rupture path; increasing stiffness of the foundation by increasing the thickness or decreasing the length, affects fault rupture path.

M Moradi Shaghaghi, M. Tehranizadeh, B Moradi Shaghaghi
Simplified Approach for Fragility Analysis of Highway Bridges

In the Province of Québec seismic hazard is considered as moderate except for Charlevoix high seismicity region. However, the high population density in urban areas has the potential to increase the level of seismic risk. In this context, the evaluation of seismic impacts on urban bridges is crucial to mitigation, emergency and recovery planning for transportation network. The degree of bridge damage determines the cost and time required for repairs and the level of post-earthquake functionality of the bridge is determined by its capacity to carry traffic flow. For urban bridges network, potential damage is estimated by fragility analysis of typical prototype models representing bridge classes. The aim of this study is to propose a simplified fragility model to estimate potential seismic damage to bridges in Québec area. A simplified approach that has been implemented in Hazus earthquake loss estimation software is adapted to the seismic hazard and bridges properties in the province of Québec. Geometrical and material properties for typical bridges are applied to estimate bridges capacity. Median and standard deviation of respective capacity values are combined with demand spectra compatible to the regional seismicity in view of generating fragility curves for four damage states. Results are compared with literature fragility functions based on dynamic analysis of typical bridges in Québec.

A. Diot, A. Farzam, M.-J. Nollet, A. Abo El Ezz
Proximity Detection on Construction Sites, Using Bluetooth Low Energy Beacons

Construction sites can be hazardous when workers perform their work in proximity of danger zones, which might lead to workplace fatalities. The majority of injuries and fatalities result from workers being struck by moving vehicles and entering danger zones. This paper presents a newly developed proximity detection system for estimating workers’ location using Bluetooth Low Energy (BLE) technology. The paper focuses on the development of an RSSI-distance relationship model between the transmitting and receiving beacons. Such a model is critical for the deployment of any BLE-based localization system. A set of laboratory experiments were designed and performed to develop that distance prediction model while evaluating the impact of contextual features on the model’s performance. A variety of machine learning models, as well as conventional curve-fitting methods, were evaluated for their respective suitability in the development of the RSS-distance relationship. The results show that the model with the best performance achieves an average error of 64 cm in distance prediction, through Random Forest ensemble learning. This level of accuracy is an improvement compared to the previous literature and can be considered good enough for most proximity detection use cases on construction jobsites. The impact of environmental conditions, such as the weather, availability of metal and construction equipment, on the model’s performance must be studied in future works.

Khazen Mohammadali, Nik-Bakht Mazdak, Moselhi Osama
Community Resilience Classification Under Climate Change Challenges

In the past decades, the United States of America and Canada have witnessed a continuous increase in the frequency and magnitude of climate change-induced natural disasters. These events include droughts, floods, wildfires, and most recently, tornadoes. In 2016, climate change induced damage was estimated to be $8.6 billion in Canada, while in the United States of America, floods are becoming one of the costliest and highest in occurrence of all climate change induced hazards, costing an average of $8 billion dollars annually. Also, hurricanes such as hurricane Sandy cost over $67 billion dollars of total damage, while more recently. hurricane Florence resulted in an estimated damage of $5 billion so far. It is thus clear that the effect of climate change is already costing North Americans billions of dollars annually, at an increasing rate. Coupled with climate change, the expansive developments of urban areas are causing a significant increase in flood-related disasters worldwide. However, most flood risk analysis and categorization efforts have been focused solely on the hydrologic features of flood hazards (e.g., inundation depth and duration) without considering the resulting long-term consequences in terms of losses and recovery time, and thus the community’s flood resilience. The aim of this study is to develop a flood resilience classification system at a community level that can be used in the development of disaster managerial insights and risk mitigation measures, to better prepare urban areas from future flood risks. This data-driven model will categorize communities using Machine learning classification techniques, bypassing the complexity and probabilistic nature of physics-based models.

M. N. Abdel-Mooty, W. El-Dakhakhni, P. Coulibaly
Investigation of a Proposed Morphologic Change in the Squamish Estuary System

As a part of the Central Estuary Restoration Project (CERP), the Squamish River Watershed Society (SRWS) plans to remove part of the 1970’s era Squamish Training Berm within the fish and wildlife habitat area of the estuary. SNC-Lavalin conducted a comprehensive hydrodynamic and sediment transport model, coupled with wave modelling, to provide a comparative assessment of the training berm removal. The study assessed the impacts on navigation (current speeds), water levels, and sedimentation in the region. The results show that removal could result in somewhat larger currents and slightly higher waves in the upper central channel and Squamish Terminal areas.

N. Asadollahi, G. Maciel-Jobb, J. S. Readshaw
Scenarios to Valorize Treated Spent Pot Lining in Cement and Concrete

Concrete is the most used building material around the world. Cement is the most common binder and its production requires renewable and non-renewable energy, and generates greenhouse gas emissions. The reduction of environmental impacts in the cement and concrete industries has led to a growing global concern for environmental sustainability. Supplementary cementitious materials (SCM) allow to replace the cement and the concrete, but the availability is becoming more limited. Among the supplementary cementitious materials, there is treated spent pot linings which are waste products from the production of primary aluminum or SPL (Spent Pot Lining) which is a hazardous material. However, an industrial solution has been developed to eliminate the hazardous properties of treated spent pot lined and to produce industrial and valuable products. This process is called Low-Caustic Leaching and Liming (LCL&L), the Rio Tinto plant can produce an inert material called LCLL ash from the SPL refractory materials. This inert material is composed of 60–70% SiO2 and Al2O3 and can be used as a raw material for clinker in the manufacture of cement and concrete. This study present Life Cycle Assessment (LCA) scenarios to valorize treated spent pot lining (SPL) in cement and concrete productions: first option is to landfill the treated SPL. The second option is use treated SPL as a raw material to produce clinker (high temperature process). Last and less sustainable scenario is to calcine the treated SPL through a lower temperature process (1050 °C) than clinker in order to be used as SCM.

N. Camara, C. Ouellet-Plamondon
Deterioration Prediction Model Development and Analysis for Alberta’s Provincial Highway Road Network's Pavement Condition

Road and highway networks are among the most critical infrastructures that significantly impact society. Therefore, predictive analysis is needed to investigate these networks' future performance to better understand their efficient maintenance management and resource allocation. In this research, a dataset containing the provincial highway network's pavement conditions in Canada's Alberta Province for several consecutive years has been selected. By implementing the Artificial Neural Network (ANN) model and different regression methods, pavement performance prediction has been conducted based on the literature and previous research works. The models are developed and processed to achieve the most accurate deterioration model by obtaining numerical results. Finally, appropriate degradation models have been selected representing some important pavement condition factors such as the International Roughness Index (IRI) and rutting data. The corresponding departments and organizations and could perform activity planning and project prioritization by having a proper prediction model. For different road networks, decision-makers may establish and design the necessary corrective measures and actions such as maintenance and rehabilitation for highways and roads.

Foad Esmaeili, Mostafa Fadaeefath Abadi, Fuzhan Nasiri
Comparison of the Seismic Performance of Steel Moment-Resisting Frames and Moment-Resisting Knee Braced Frames

Ductile steel moment-resisting frame (MRF) structures offer an ideal solution to resist seismic loads in high seismic regions due to their reliable yielding mechanism and architectural versatility. Despite their large ductility capacity under seismic loading, lower lateral stiffness and prohibitively complex beam-to-column connections have been the motivations to use knee braces with the intension of bracing the storeys while beams are moment-connected to beam stubs. This paper aims to compare and contrast the seismic response of conventional Type D (Ductile) MRFs and new moment-resisting knee braced frames (MRKBFs). The lateral load-resisting system of a five-storey office building located in Vancouver, Canada was designed once using MRFs and then using MRKBFs. A numerical model of both frames accounting for material and geometric nonlinearities was then developed. The frames were analysed under gravity and seismic loads. The results obtained from the design and numerical analyses of the frames were used to evaluate the economy and seismic response, including lateral stiffness, drift demands and load-carrying capacity, of the selected frames. The results suggest that although a higher lateral stiffness can be expected from MRKBFs compared to MRFs, additional connections required in MRKBFs can negatively affect the cost-efficiency of MRKBFs over MRFs.

Mahdi Mokhtari, Abrar Islam, Ali Imanpour
A Canadian First: Developing a Climate Change Action Plan for Engineers and Geoscientists BC

This paper describes the development and engagement process that Engineers & Geoscientists BC took to create a Climate Change Action Plan that guides the regulatory body in supporting its registrants to fulfill their responsibilities in considering climate change risks in professional practice. The Plan and development process is an example that other organizations may reference in their own activities to integrate climate change risk into their business, organizational or legislated objectives.

Charling C. Li, Harshan Radhakrishnan, Malcolm L. Shield
Structural Defects Classification and Detection Using Convolutional Neural Network (CNN): A Review

Assessing the structures’ condition is mostly dependent on physical site reconnaissance and expert opinion, which involves systematical collection and storage of data and interpretation of data. With the increasing demand of clients, especially during the time of the pandemic, stakeholders are more focused on time-saving, minimized physical presence, and cost-effective means in decision making, before these structures can endanger the community and the occupants. In traditional ways, structural investigations are laborious, time-consuming, expensive, and in some cases health hazardous. This study aims at reviewing supervised learning of Convolutional Neural Networks (CNN), which can work in an automated manner to detect, identify and localize the defects, e.g., crack, surface deterioration, spalling, moisture damage, corrosion, etc., from images in a safe and budget-friendly manner, employing built-on and pre-trained CNN classifier models. While using the different type of CNN classifier models, prior studies have evaluated the models performance mostly based on accuracy, precision, recall, Intersection over Union (IoU), root mean square value (RMSE). This paper summarizes the important aspects of a CNN architecture for damage detection such as dataset preparation, random weight initialization, different learning rate, fine-tuning the hyper-parameters, and the working method with fast-forward pass and back-propagation. Finally, this paper will outline some of the challenges of using CNN in structural condition assessment and identify some future scopes.

P. Arafin, A. H. M. M. Billah
Nonlinear Buckling Analysis of Conical Steel Tanks Considering Field-Measured Imperfections—A Case Study

Geometric imperfections caused by fabrication and welding reduce the buckling capacity of steel conical tanks. The reduction is sensitive to the shape and amplitude of imperfections. Many imperfection shapes have been studied in the literature. But few to none considered field-measured geometric imperfections in such type of shell structures. The current paper carries out elastoplastic finite element analyses (FEA) to evaluate the buckling capacity of a full-scale stiffened conical steel water tank by considering its initial imperfections extracted from high-resolution laser scan data. Both global and local initial imperfections on the steel tank are obtained by comparing the laser scan data with the nominal tank geometry. The FEA is implemented using the commercial FEA package ANSYS; a four-node shell element with a six degrees of freedom per node is utilized in the model with a triangular option. The arclength method is applied to evaluate the buckling capacity of the steel tank under the hydrostatic pressure. To validate the finite element model developed in this study, the buckling capacity of a steel water tank in Fredericton, NB is evaluated and compared with those reported in the literature. Results of the case study shed light on the shapes and magnitudes of global and local imperfections in an existing stiffened steel conical tank and their impact on the buckling capacity of the tank. Furthermore, the adequacy of initial imperfections recommended in widely used design standards for steel tanks is examined with comparison between the measured and code-recommended initial imperfections.

H. Zhang, A. M. El Ansary, W. Zhou
On the Analysis and Design of Reinforced Railway Embankments in Cold Climate: A Review

Railway embankments built in cold regions are exposed to particularly harsh environmental conditions. Railroad support structures must be designed to maintain adequate track alignment and geometry and ensure optimal riding quality for passing trains. However, railway embankments constructed in cold regions face additional challenges associated with the climate’s effect on the components of their substructure. Avoiding frost action is of paramount importance since the phenomena it triggers, namely frost heave and thaw softening, have particularly detrimental impacts on the structural integrity of embankments, leading to undesirable and potentially dangerous track riding conditions. This paper provides an overview of the different strategies used to analyze and design railway embankments in cold regions and describes how soil reinforcement techniques may be used to mitigate the effects of cold temperatures on the performance and stability of railroad support structures.

R. Desbrousses, M. Meguid
Applications of Flow-Drilled Connections in Modular Construction

The use of modular construction is on the rise due to the increased speed, efficiency, and quality that it brings in comparison to traditional construction practices. The emphasis on efficiency in modular construction makes it imperative for the accompanying connection methods used to be efficient as well. A proprietary method of modular steel construction currently exists that utilizes modules made from hollow structural steel (HSS) members. The tubular geometry of the HSS members used in these modules limits the access of bolts in bolted connections to only one face of the HSS member. This access limitation prevents the use of nuts as well. A potential method to efficiently use these one-sided connections is using flow drilling and flow tapping techniques. This paper explores and presents the findings of an extensive experimental parametric study to examine the structural behavior of flow drilled connections on HSS members under shear and tension loads. The parameters considered were HSS wall thickness, screw threads per unit length, screw hole drilling technique, and tapping technique. This resulted in a total of 150 specimens, half of which were subjected to axial tension and half in shear. The results of this study showed that flow drilled connections can significantly increase the tension capacity of one-sided connections in comparison to standard drilled connections but does not have a great influence on the shear capacity. This study also identified potential failure modes and developed analytical equations that can be used to predict the sequence of failure of the connections.

L. Kalam, J. Dhanapal, S. Das, H. Ghaednia
Behavior of Vectorbloc Beam-Column Connections

Modular construction is a sustainable mode of construction whose speed, efficiency, and improved quality control sets it apart from traditional construction practices. A key component in modular construction is the connection between the individual modules, which hold the modules together against applied loads such as gravity, snow, wind, and earthquake. A state-of-the-art cast steel connector, named the VectorBloc connector, is presently used in the connections between steel modules made from hollow structural steel (HSS) members. The novelty of the VectorBloc connector is that it provides both beam-column connection in a module and inter-modular connection between modules. This study presents the behavior of a typical corner beam-column connection under uniaxial bending, biaxial bending, axial tension, and axial compression loads in comparison with predetermined design loads. The connection was studied through full-scale experimental testing and finite element analysis (FEA) methods. The results of this study confirmed the connection can safely withstand the design loads and identified the modes of failure under the varying load types. In addition, a parametric study was conducted using FEA that identified possible ways in which the design of the connector could be further optimized. This study concludes that the weight of the connector can be reduced while still maintaining enough capacity to withstand the design loads and the location of the screws can be adjusted to improve the tension capacity of the connection.

L. Kalam, J. Dhanapal, S. Das, H. Ghaednia
Step Through the Noise: Insight into Resilience-Driven Power Asset Management

The amount of data accumulated by utility companies is growing in volume and variety each year. Such data can be a very valuable asset to utilities, but because it is generally viewed only through traditional tables and charts, it has not yet been used to its full potential. A utility can make better use of its data by employing machine learning techniques to recognize patterns that are hidden when traditional techniques are used. Association rule analysis is one of numerous machine learning techniques, that has been widely used in business and some engineering fields to identify important feature correlations previously hidden due to the volume of data under analysis, but it is not widely adopted in the asset management sector. This project applies association rule analysis to a historical transmission line outage event database through a resilience-based asset management lens, distinguishing patterns and developing rules that relate to the occurrence of input features together with long-duration outages.

E. Goforth, W. El-Dakhakhni, L. Wiebe
Shell Analysis of Steel Frames Considering Low-Cycle Fatigue Within the Continuum-Damage-Plasticity Framework

In the event of an earthquake, steel-frames are subjected to cyclic loads, which can cause strain accumulation in ductile members that lead to micro-scale fracture due to low-cycle fatigue. As a result, early yielding and stiffness degradation can be observed at macro-scale stress–strain relations. Steel moment resisting frame members are made of thin-walled cross-sections, for which local or lateral-torsional buckling failure modes may occur. In order to capture inelastic material behaviour and local, as well as, lateral-torsional buckling modes, shell-type modelling approaches could be adopted. When shell elements are used, multi-axial material models are required. Continuum Damage Plasticity (CDP) framework can be used to build inelastic constitutive models. The CDP has the capability of representing both the permanent deformations due to the plastic component and the degradation of elastic moduli due to the damage component. In this paper, a shell-element based modelling approach was presented for the geometrical and material nonlinearity. Moreover, the low-cycle fatigue effects were considered within the CDP framework. After validation of the proposed approach using case studies from the literature, the possibilities of modelling different failure modes were investigated. It is shown that considerations of local- and lateral-buckling modes, as well as, the low-cycle fatigue effect may cause significant differences in predicting the behaviour of steel frames under cyclic loads.

S. Delir, E. Erkmen, L. Tirca
Basis of Sustainable Infrastructure Project Decisions

Infrastructure systems are essential pillars for the prosperous development of a country since they act as vectors that connect buildings and industrial nodes as well as provide services and goods within the built environment. Despite the vital goals and obvious significance of civil infrastructure systems, these projects are often plagued with schedule delays, cost overruns, and failure to meet their sustainability objectives. Therefore, incorporating traditional planning is vital to address some of those challenges, yet Front-End Planning (FEP) remains paramount. Given the complex nature of infrastructure projects as well as their environmental and social threats to the built environment, a promising solution to address these challenges can be through coupling the effective tools of FEP with sustainable infrastructure certifications. Although sustainability and FEP tools may pave the way for enhanced project performance, such tools and certifications are not meant to serve as a standalone solution but rather should complement each other to foster success for sustainable infrastructure projects. The goal of this paper is to investigate the existing synergies between sustainability credits and FEP elements to provide a basis to sustainable infrastructure project decisions. To achieve this goal, the research team created a matrix that correlates sustainability criteria with the elements included in the FEP phase: Basis of Project Decision. To assess the developed matrix, approximately a hundred case-study surveys were conducted with stakeholders of sustainable infrastructure projects. This study serves as a framework to support project teams in planning, assessing risks, and managing sustainable infrastructure projects by providing a basis to the decisions that assist in diligent FEP for sustainable infrastructure projects.

V. Ferrer, P. Pradhananga, M. ElZomor
Assessing Suitability of Geopolymer Composites Under Chloride Exposure

Chloride ingress is primarily responsible for initiating corrosion of the embedded reinforcement within concrete, especially in marine zones where reinforced concrete structures are often exposed to harsh chloride environment. Thus, it is often deemed essential to assess concrete resistance against chloride penetration. However, such deterioration of geopolymer concrete structures instigated by chloride exposure, has had inadequate examination. This study investigated the performance of developed fiber reinforced geopolymer composites against ingress of chloride ions. The mixes have been prepared by incorporating combination of Fly Ash (FA) and Ground Granulated Blast Furnace Slag (GGBFS) as source materials, powder-based alkaline activators and Poly-Vinyl Alcohol (PVA) fiber under ambient curing. The chloride resistance of the developed mixes was measured through Rapid Chloride Permeability Test (RCPT). Additional transport properties such as water absorption, surface resistivity and sorptivity along with mechanical properties in terms of compressive strength and ultrasonic pulse velocity (UPV) had also been evaluated. The study showed suitability of high calcium FA and GGBFS over low calcium FA based geopolymer composites for applications where chloride-related durability is concerned. Based on the observed transport property values, the influence of source material and activator variation was assessed to evaluate an optimum and suitable mix combinations to address chloride-related durability concerns. The mixes with high calcium were observed to produce denser matrix showing prospect against chloride permeability. This paper aims to provide with a base guideline to assist engineers in designing a durable geopolymer composite when exposed to chloride environments.

M. J. Hasan, K. M. A. Hossain
Integrated Project Delivery Perception and Application in Washington State

Integrated Project Delivery (IPD) is fast becoming a part of the common vernacular in the construction industry. IPD is a collaborative approach to project delivery that requires a change from the traditional non-cooperative mindset that historically has been pervasive throughout the construction industry. For decades, project team members (i.e., owners, contractors, subcontractors, designers, and other project participants) rarely cooperated, which further ingrained a siloed structure and non-cooperative spirit among project team members. Recently, many of these members have begun to consider alternative, newer contractual means to avoid the more traditional, less cooperative delivery methods that too often engaged project members against each other. As a more recent form of project delivery, IPD is structured to distribute risk and reward equally among all parties, thus incentivizing each to cooperate to maximize their efficiency, mitigate risks, and avoid disputes or legal action. This paper aims to identify the constructors’ exposure to IPD and review the breadth and depth of IPD's application in Washington State. Through survey results distributed to several construction constituents, it was determined that the level of exposure and application of IPD in Washington State was mixed. In contrast, the level of IPD understanding among those surveyed was minimal, and IPD's application is limited to just a few projects.

D. Martin, H. Dang, W. Plugge
Earthquake-Induced Damage Assessment of Segmental Post-tensioned Precast Concrete Bridge Pier

Traffic disruptions and downtime due to bridge repair or replacement can cause significant socioeconomic losses. ‘Accelerated Bridge Construction’ (ABC) can minimize the impact of bridge construction on roadside safety by reducing the duration of on-site projects. Precast concrete bridge elements and systems have been recognized as key technology of ABC. However, they are significantly under-utilized in seismicity areas for bridge substructures. This is because the seismic design guidelines for using precast concrete have not been fully developed. The lack of code provisions stems from the challenge in the definition of appropriate damage states in relation to the functionality of the bridge. To address this challenge, the objective of this paper is to understand the damage modes of segmental post-tensioned precast concrete bridge pier under earthquake loading. In this respect, a nonlinear finite element approach is used to analyze the lateral load behaviour of precast concrete piers. Previous laboratory test results are collected to cover different design scenarios. The accuracy of the developed finite element model is experimentally validated by comparing the calculated and measured response in terms of a variety of seismic performance metrics, including lateral stiffness/strength and the variation of post-tension force versus lateral displacements. The validated finite element model is used to investigate the influence of energy dissipation bars on the damage condition and failure mode of the segmental precast concrete bridge pier.

Chanh Nien Luong, Cancan Yang, Mohamed Ezzeldin
Analysis of Retrofitted Concrete Columns Using 3D Elastic-Plastic-Damage Modelling

Fiber Reinforced Polymer (FRP) jacketing is frequently used to enhance the performance of concrete columns. The strength and ductility of a concrete column increase after FRP jacketing mainly because of concrete’s improved behaviour under confinement. To achieve a reliable retrofit design, engineers often need to understand how much the performance is improved after FRP jacketing. For that purpose, numerical modelling is often necessary. The success of finite element analysis depends on an accurate concrete constitutive model and therefore, to capture confinement changes within a finite element model, concrete multi-axial behaviour needs to be adopted. Phenomenological elastic-plastic-damage models are widely used for the numerical modelling of concrete because of their capability of representing 3D concrete behaviour considering permanent inelastic deformations as well as degradation of material moduli beyond the elastic range. This paper aims to implement an elastic-plastic-damage model to simulate FRP-jacketed concrete columns. The material model is validated against existing experimental data and comparisons with the results of models developed in ABAQUS software. It is shown that the proposed modelling approach is capable of providing an accurate behaviour of square concrete columns confined with reinforcements and FRP jackets under compression. After the validation of the model, a parametric study was conducted to illustrate the effect of partial wrapping on the behaviour of retrofitted columns.

Z. Al-Maadhidi, R. E. Erkmen
Exploratory Investigation on Diversity and Inclusion Programs in Large Construction Companies from the Private Sector in the United States of America

Equal contracting opportunity is an essential element of our economic growth and critical to successful small or disadvantaged businesses. Although most government agencies have regulatory or mandatory programs for ensuring equal contracting opportunities in the construction industry, the private sector does not necessarily have the same requirements. Some companies have their initiatives to create a diverse, equal, and inclusive environment for their subcontracting work even it is not mandated. The author collected documents, surveys, and interviews data to synthesize diversity and inclusion programs in several case studies. These case studies offer an innovative and comprehensive solution for construction companies to create a diverse, equal, and inclusive environment for their subcontracting business. Most programs are similar and include a contact database, an interview process, capabilities statement, reliability assessment, and training workshops. These programs also promote and offer networking conferences and opportunities. The outcomes of these programs have a profound impact on the economic growth and success of small or disadvantaged businesses in the construction industry.

H. Dang
Current Trends and Future of Advanced Simulations in Facility Management—An Owner’s Perspective

Building Information Management (BIM) in facility management has been successfully implemented over the past several years. However, owners are still struggling to move towards the next level of advanced simulations, such as digital twins and augmented reality. This paper provides a literature review on the existing successful national and international implementation of advanced simulations in facility management. Furthermore, a conceptual framework is developed for moving towards the next generation of advanced technologies in capital projects in a large institutional owner, the Office of Physical Plant (OPP) at the Pennsylvania State University (Penn State) which is a leading institution of BIM adoption for facility management in the US. Finally, a potential use case is identified in which advanced technology can be utilized and potential benefits could be tracked. Future research includes developing a taxonomy for advanced simulation implementation in facility management for large institutional owners.

Z. Ghorbani, C. Dubler
Effect of Using Alternative Stress–Strain Definitions on the Buckling Load Predictions of Thin-Walled Members

Thin-walled structural components are widely used in many industries including aerospace, building, aircraft, and shipbuilding. These types of structures are susceptible to buckling and it is important to predict their response accurately. Effect of shear deformation on buckling behaviour of thin-walled members can become significant, especially for short and stocky sections and/or when materials with relatively low shear modulus are used. There are two well-known approaches in the literature that produce contradictory results when elastic Hooke’s material is adopted for the shear deformable buckling analysis of columns. The first one is developed by Engesser and the second one by Haringx. The difference between the two methods has been attributed to different assumptions for the axial force orientation at the deformed state of the column. Engesser assumes that the axial force is parallel to the beam axis in the loading state whereas, in Haringx theory, the axial force is assumed to be perpendicular to the cross-section of the beam. This difference in the assumption of force directions can be traced down to the difference in the definitions of adopted stress–strain pairs within the Doyle-Ericksen family of strains. Although several shear deformable finite element formulations have been proposed for the buckling analysis of thin-walled beams, the differences that alternative stress–strain definitions might cause were not identified in the finite element context. In this paper, it is shown that alternative stress–strain definitions lead to changes in the geometric stiffness matrices of thin-walled beam finite element formulations. The effect of changes in the geometric stiffness matrix on buckling capacity predictions of thin-walled beams is illustrated through numerical tests on short FRP pultruded beams with low shear modulus.

R. E. Erkmen, H. Moradpoor, A. Bhowmick
An Experimental Design Approach for the Design of Two-Lift Concrete Pavements

Now-a-days concrete pavements are gaining more and more importance to eliminate regular maintenance of asphalt pavement, damaged due heavy traffic and moisture. Several types of plain concrete pavement are in use in various countries depending upon the climate, availability of materials, soil types, experience, and traffic. It is therefore necessary to improve the current pavement design with a sound analytical approach. To lower the cost of construction of concrete pavements, researchers came to a new type of concrete pavement construction named Two-Lift Concrete Pavement (TLCP). In this type of pavement construction, Pavement Quality Concrete (PQC) can be bonded to lean concrete (LC) when both layers are constructed one over the other with two pavers (“fresh-on-fresh” or “wet-on-wet”). No analytical techniques are available to compute the stresses in TLCPs. To compute the stress in TLCP under various environmental and loading conditions, a finite-element programming software (ANSYS) is used. These stresses place an important role in determining the design of concrete pavements. To achieve this, a Central-Composite design with face-centered statistical design is utilised. In this design, statistical assumptions such as Normality, constant variance and Independence are checked and found that all assumptions are acceptable, but box-cox suggested to transform the model to square root. So, the model is transformed to square root form. The statistical model is validated using four random points and it is noticed that the model satisfies all the points. Conclusions are drawn from the interaction plots of the model. From the model, it is noticed that the factors such as temperature gradient over the depth of the slab and modulus of subgrade reaction are insignificant but when it interacts with other factor (PQC thickness and LC thickness), the interaction became highly significant.

Surya T. Swarna, Kamal Hossain
Experimental Investigation of Tornado Induced Pressures on Residential Buildings

Several tornadoes occur each year in Canada, while design guidelines for building structures to withstand tornado events are still in incipient stage. The novel Wind-induced Damage Simulator (WDS) built at the University of Ottawa, capable of simulating pressures induced by multidirectional and tornadic winds was used to test a 1:100 scaled house model in a simulated tornado of 16.5 m/s maximum tangential wind velocity. Three orientation angles of the model placed at three locations along the radius of the tornado were investigated. This replicated different conditions the tornadic flow would approach a residential house. These locations were selected based on a preliminary analysis conducted for 750RPM, 825RPM and 900RPM fan velocities, to characterize the tornado maximum velocity and radius simulated in the WDS facility. The model was instrumented with 96 pressure taps along the roof and the lateral walls and the external pressure coefficients were determined. Negative pressure coefficients of up to −1, were recorded for the roof and wall sides exposed to the tangential velocity of the tornado, for all the investigated cases. The magnitude of the pressure coefficients was found to be in good agreement with the results reported by [2], for same dimensions house model tested in a laboratory simulated tornado, however the pressure distributions on the surface of the tested model were different due to the different tangential velocity simulated in the WDS facility.

J. Williams, E. Dragomirescu
Drought Proneness Analysis of Southern Saskatchewan Province Using Markov Chain Model

The southern Saskatchewan region has been recognized for persistent droughts due to its continual rainfall deficiency. To estimate drought severity, a first-order and five-state Markov chain model is used in this study. Long-term daily precipitation records of three stations (Broadview, Last Mountain CS, and Swift Current CDA) were considered for the analysis. The Standard Precipitation Index (SPI) was used to classify the drought severity into five different classes (no drought, mild drought, moderate drought, severe drought, and extreme drought) to develop Markov models. Transition Probability Matrices (TPM) were calculated for each of the stations, and the chances of drought occurrence were estimated from the steady state matrix. Expected drought duration, mean first passage time of drought, and mean recurrence time of drought were also calculated from TPM to understand the drought characteristics in the long run. The results indicate that mild drought has more than 35% chance of occurrence, and the expected drought duration of extreme drought can exceed over a month. Furthermore, for extreme drought, the mean recurrence time and the mean first passage time can be varied from 102.09 to 168.20 months and 14.47 to 20.20 months, respectively. The Markovian approach is an efficient method to estimate and understand the drought characteristics, providing crucial information in agricultural sectors, planning, and other related professional fields to adapt and plan accordingly.

U. Sumaiya, M. Ghaith, S. Hassini, W. El-Dakhakhni
Development of a Virtual Visit Model Based on a Bim Model and a Game Engine

In an ever-changing world, the construction industry must adapt to the emergence of new digital technologies. One of the most important characteristics of this industry is its fragmentation and the fact that the different actors involved in construction projects come from different organizations and have to work together on a temporary basis to achieve a common goal. Therefore, to improve productivity and collaboration, the use of information technology is inevitable and has long been seen as a potential solution to the issue. In this context, numerous research studies have addressed the potential of Building Information Modeling (BIM) to improve collaboration and productivity in the industry. BIM has many benefits such as increased constructability, reduced conflicts, and reduced cost estimation times, as well as many other opportunities. However, there are many challenges associated with adopting this approach within the construction industry, and the adoption rates appear to be lower than expected. Not all BIM users have all the knowledge needed to take full advantage of the potential of this approach, whether it be for communication between project teams, the use and visualization of the model, or the dissemination of information between different trades. There is also a lack of client commitment to BIM in the industry, but also a targeted deployment of BIM in a few uses by a limited number of construction industry stakeholders. To overcome these challenges, it is necessary to propose more integrative BIM solutions, with ease of understanding and capable of accommodating different profiles and backgrounds. In this context, to facilitate the deployment and application of BIM, easily accessible technologies such as immersive systems and interfaces could be a promising alternative. Thus, Virtual Reality (VR) is emerging as a promising asset to the BIM approach. However, very few research works have been dedicated to the interoperability between BIM and VR environments. This research project aims to propose a VR-based intuitive visualization and interaction environment, allowing involving the project owners and the public in the choice of project options. The paper first presents the different steps and methods that allowed the design of a virtual tour model using Unreal Engine. The final result allows navigating realistically in an environment where a user can intuitively interact with objects and project options.

Mouhamadou Moustapha Gueye, Conrad Boton
A Damage Detection Procedure Using Spectral Element Method

Damage detection often requires non-destructive testing. Among various damage detection techniques those that identify the damage based on changes in the natural frequencies of the system are widely adopted. Detection of the damage location and its severity based on the observed frequency change, however, is an inverse problem where usually a search algorithm and a model update procedure are required to match the output of a damaged model with the observations. Capturing small damage requires analysis at higher frequencies. Wavelengths get shorter at higher frequencies therefore; the standard finite element simulation of wave propagation phenomena requires a high resolution of the discretization. Using standard finite element approaches, this may rapidly exceed the available computer resources, rendering the numerical simulations unfeasible. To avoid limitations of FEM in numerical modelling, the spectral element method has been adopted by many researchers as a viable option, in which the element shape functions are built based on the frequency content considered in the analysis. In the present work, the spectral element approach is adopted in the context of damaged elastic beam analysis to minimize the size of the model in spatial discretization of the damaged beam. The Wittrick-Willams procedure has been implemented to identify the natural frequencies from the frequency- dependent dynamic stiffness matrix of the system. Numerical cost of each step of the spectral analysis is illustrated. The genetic algorithm has been used for the search of the damaged case and the frequency range for a successful outcome is illustrated.

M. Delpasand, R. Erkmen, R. Ganesan
Effective Bond Length of FRP Sheet Bonded to Concrete

Fiber-reinforced polymers (FRP) have shown outstanding performance in shear and flexural strengthening of concrete structures when anchored appropriately. However, premature de-bonding failure of the FRP sheet can limit its strength enhancement capacity. Numerous experimental and analytical studies have been carried out to evaluate the effective bond length, but huge discrepancies exist in the results due to a lack of a standard testing procedure and analysis method. Therefore, a specific empirical or analytical equation cannot be adopted to determine the effective bond length. This paper presents the findings from double shear tests conducted to evaluate the effective bond length using the strain distribution profiles. The variables studied were the length of bond, 75–150 mm, and type of FRPs, carbon FRP (CFRP) and glass FRP (GFRP). Test results showed that increasing the bond length beyond the effective length did not increase the failure load but increased deformations mainly due to elastic elongation of de-bonded FRP sheet. Effective bond lengths of approximately 70 and 100 mm were measured for GFRP and CFRP, respectively. Increased FRP stiffness appears to result in a greater effective bond length and higher average bond stress, however, bond slip remain unaffected. A comparative study of the effective bond length models available in different FRP standards was carried out using the current test data along with the database from past studies and a model was proposed to capture the effective bond length. Recommendations are made to modify the current effective bond length model in the CSA-S806-17 standard.

M. F. Qureshi, S. A. Sheikh
Self-Sensing Properties of Engineered Geopolymer Composites

The development of geopolymers as sustainable construction materials is of growing interest. However, available literature shows studies addressing the quasi-brittle weakness of geopolymer through development, characterization, and implementation of fiber-reinforced composites but inadequate in number. This study investigates the self-sensing performance of fiber-reinforced Engineered Geopolymer Composites (EGCs), prepared to overcome the quasi-brittle behavior. The EGC mixes were developed using Polyvinyl alcohol (PVA) fiber, powder-based alkali activators, and multi-wall carbon nanotubes (MWCNTs), which were added as a self-sensing agent. The EGC mixes with MWCNTs contained nanotube concentrations of 0.0, 0.3 and 0.6% by mass of binder. These mixes were prepared using three types of source materials: Granulated Blast Furnace Slag (GGBFS), class F Fly Ash (FA-F) and class C Fly Ash (FA-C). The fresh state properties were measured in terms of setting time, slump flow and fresh density. The hardened properties and conductivity of the developed mixes were also being evaluated. The piezoresistive characteristics of the EGC mixes were observed and evaluated through observing the variation of electrical resistivity during compression testing of specimens. The types of alkaline activator, uniform dispersion of MWCNTs, and good interaction between MWCNTs and geopolymer matrix were found to contribute to the improvement of flexural/compressive strength and conductivity of the developed mixes. The outcomes of experimental investigations were found to be quite promising and suggested the importance of conducting further comprehensive studies for developing design guidelines for EGCs with self-sensing capabilities.

M. A. Hossain, K. M. A. Hossain
Analysis of Reinforced Concrete Shear Walls Using Elastic–Plastic-Damage Modelling

Shear walls are useful structural tools in redistributing the stresses and controlling the damage in reinforced concrete buildings under earthquake loads. Due to their comparatively large cross-sections, they carry significant portion of the base bending moment and shear under lateral load. Analysis of shear walls requires incorporation of inelastic material models as often the stresses the elastic threshold under extreme lateral loading such as earthquake. On the other hand, analysis and design tools used for buildings often employ beam-type 1D finite element formulations for shear walls as well as beams and columns as such models are computationally faster which is especially important in nonlinear time-history analysis and the results are easier to interpret for design purposes. In 1D finite element formulations often uniaxial material models are used. In this study we have employed a multi-axial concrete model within a 1D finite element formulation so that effect of shear stresses can be considered in the material behaviour. The accuracy of the proposed numerical approach is illustrated by comparing its predictions with experimental results from literature.

R. E. Erkmen, A. Sarikaya, O. Arat, K. Galal
Determination of Chloride Ion Penetration Depth of Blended Mortar Using Electrochemical Impedance Spectroscopy

In this study, the influence of silica fume and fly ash on the chloride ion penetration of prestressed concrete cylinder pipe (PCCP) mortar coatings immersed in a 9.5% NaCl solution was evaluated using the electrochemical data obtained from the electrochemical impedance spectroscopy (EIS) approach. The novel equivalent circuit model (i.e. Dong’s EC model) that considers the ions diffusion and the charge transfer in the cement paste was used to predict the chloride ion migration of the blended mortars. The results indicate that the EIS fitting parameter $${R}_{ct1}$$ R c t 1 can be used to predict the chloride ion migration depth of mortar blended with silica fume and fly ash in an acceptable manner under chloride penetration conditions. This study contributes towards the development of chloride resisting PCCP mortar coating.

S. Hassi, B. Menu, M. Ebn Touhami
Numerical Investigation of the Structural Performance of Post-Tensioned Friction-Based Slab Column Connections in Two-Way Modular Precast Concrete Systems

Nonlinear finite element analyses (NLFEA) of idealized friction-based modular slab-column connections under simulated gravity and reversed cyclic lateral loading were carried out to numerically examine the performance of friction-based post-tensioned two-way slab-column connections employed in PACE precast modular building systems. The NLFEA were conducted using the commercial software program ABAQUS in an effort to (i) assess the gravity load resisting performance of PACE connections and estimate the controlling modes of failure, (ii) estimate the hysteretic performance of the friction-based slab-column connections under lateral load reversals, and (iii) examine the significance of the slip-friction response contributions of the post-tensioned connections. Based on the numerical results obtained, it was estimated that slip displacements of the friction-based connections did not ultimately control the load capacity of the modular slab system under gravity or lateral loading conditions. Opening and slip displacements at the locations of the connections adjoining the precast slab modules and column were negligible under gravity load levels that far exceeded anticipated service gravity loads. The numerical results also suggest that the friction-based connection relieved stresses within critical concrete and grout slab-column connections regions in a manner that led to an apparent increase in connection ductility under simulated fully reversed cyclic loading.

M. Zhou, T. Hrynyk, S. Walbridge, D. Dikic, G. Rutledge, M. Arsenault
An Integrated Framework for the Design of Climate-Resilient Buildings in Canada

With a rapidly changing climate, resilience of buildings has become an important consideration for Canada’s built environment. Buildings are a complex system composed of many different components that are interdependent. As such, enabling resilience in buildings requires understanding of interdependent building components that are affected by changing climate. In this paper, we discuss the role of three major building components—structure, building systems, and occupants and their interdependencies in building resilience in the context of Canada’s climate risks. We also propose an integrated framework to the resilience paradigm that complements and maximizes the performance of individual building components in climate response. Based on this proposed framework, future work will investigate specific relationship between building components and develop integrated solutions that can establish best practices for resilient building design and operation and inform building standards and regulations.

J. Kim, E. Kim, K. Kapsis, D. Lacroix
Geogrid Reinforcement in the Treated Base Layer of Flexible Pavements

This paper aims to tackle the issue of enhancing the performance of flexible pavements. Enhanced performance is associated with the pavement's ability to withstand and resist the heavy traffic loads. In this study, geogrids are placed at different positions in the treated base (binder course) layer of the flexible pavement structure and compared to a control unreinforced pavement. The methodology consists of two phases, the first phase is an experimental work program, and the second is a pavement numerical modeling. The experimental work entails lab material testing and full-scale testing. Lab material testing was conducted to determine the physical and mechanical properties of the materials used, while full-scale testing was conducted to represent the pavement's behavior. A control large-scale model was subjected to dynamic traffic simulated loading. In the second phase, a numerical model was created, using finite element modeling software that included the reinforcing geogrid. Using this numerical model, several iterations and trials were made to investigate the effect of the geogrids’ various locations in the treated base layer; hence determine its optimum position for enhanced pavement performance. The results indicated that geogrid reinforcement in the treated base layer has significantly enhanced performance, in terms of reduced permanent deformation in the AC surface layer as well as better distribution of induced stresses throughout the flexible pavement structure. The optimum location for the geogrid in the binder course layer was determined to be at the middle of the binder course. Results showed that geogrids provide better enhanced performance of the pavement if installed in the treated base layer than that if it is installed in the untreated base layer.

Susanna Mattar, Moustafa Tammam, Jolavian Mekhail, Omar Mahran, Nadine Soliman, Yara Badawy, Safwan Khedr, Omar El-Kadi, Zahra Zayed
Defect Based Condition Assessment of Steel Bridges

Steel bridges deterioration has been one of the problems in North America for the last years. Steel bridges deterioration mainly attributed to the difficult weather and environmental conditions. Steel bridges suffer mainly from fatigue cracks and Corrosion, which necessitate Frequent inspection. Visual inspection is the most common technique for steel bridges inspection but it depends on the inspector experience and conditions associated with uncertainty and subjectivity inherent in human judgments. So many NDE models have been developed use Non-destructive technologies to be more accurate, reliable and non-human dependent. Non-destructive techniques such as The Eddy Current Method, The Radiographic Method (RT), Ultra-Sonic Method (UT), Infra-red thermography and Laser technology have been used. After Reviewing the latest steel bridge NDT, it was found that the best solution is to combine two or more technology to have the most reliable Bridge evaluation. In researcher’s other publication a proposed NDE combine two method, image processing, and IR thermography. As a result of using more than one measure for inspection it was a must to develop a model which combine defects different measures and come with a unified condition rating. This paper presents systematic procedure to develop a detailed steel bridge condition assessment model by comprehensive aggregation of possible defects. Using fuzzy membership-based defect rating the proposed model will be able to translate uncertain measurements of defects into a reliable bridge condition rating.

A. Elbeheri, A. Bagchi, T. Zayed
Use of Equivalent Standard Fire Duration to Evaluate the Internal Temperatures in Rc Walls Exposed to Fire

Reinforced Concrete (RC) walls are important structural elements that resist lateral loads and act as fire barriers. Since most of the established design and analysis approaches are based on standard fire curves, it is essential to develop a practical method to utilize these approaches for natural fire incidents. This study aims at developing a method to evaluate the standard fire duration equivalent to a natural fire considering the developed temperature distribution in RC walls. A parametric study was conducted and the internal temperature profile for natural fire incidents was evaluated. Durations of standard fire incidents that result in a similar profile were then evaluated. Simplified equations were developed to allow engineers and researchers to easily evaluate the equivalent standard fire duration for a RC wall exposed to a natural fire.

M. Lazhari, M. A. Youssef, S. F. EL-Fitiany
Feasibility of Using Fiber-Reinforced Polymer Bars as Internal Reinforcement in Concrete Arch Slab Bridges

This study investigates the performance of concrete arch slabs reinforced with GFRP bars. Four arch slabs were constructed with 0.5 m width, 0.975 m maximum height, and 3.92 m span. The thickness varied between 100 at the middle and 175 mm at the ends. One arch was reinforced with steel and three arches were reinforced with different ratios of GFRP bars. All arches were pin supported and were tested under two concentrated loads. All the GFRP reinforced arches showed higher mid-span deflection at their maximum loads compared to the reference arch reinforced with steel. All arches showed good capacities ranging between 154 and 248 kN. The ultimate capacity of the reference arch was slightly higher (16%) than the ultimate capacity of the GFRP reinforced concrete arch with the same reinforcement ratio. Increasing the GFRP reinforcement ratio increased the cracking load, the number of cracks at failure, and the capacity of the GFRP reinforced concrete arches. Based on the test results of this research study, it can be concluded that the GFRP reinforced concrete arches showed good and comparable behavior to the steel-RC arch. This demonstrates that the GFRP bars can be used to replace steel reinforcement in arch slab bridges in corrosive environments.

S. El-Gamal, H. Al-Shukeili, A. Al-Nuaimi
Developing and Investigating the Performance of Thermal Insulation Lightweight Sandwich Wall Panels

This research aims to develop and investigate the performance of sandwich wall panels (500 mm height × 500 mm width × 200 mm thick) with two outer concrete layers and inner expanded polystyrene layer. The test parameters include the concrete mix type of the two outer concrete layers where different ratios (53, 68, and 84%) of polystyrene beads and vermiculite aggregates were used to replace the natural coarse aggregates. The effect of using glass fiber reinforced (GFRP) shear ties to connect the two outer layers of the panels was also investigated. The average density, compressive strength, and thermal conductivity of the sandwich panels with normal aggregates were 750 kg/m3, 11.3 MPa, and 0.68 W/m.K, respectively. Using the GFRP shear ties was effective to connect the two outer layers of the panels. The results revealed that as the amount of the polystyrene beads and the vermiculite increased, the density, the compressive strength, and the thermal conductivity of the sandwich panels decreased. These values ranged from 596 to 486 kg/m3, 4.21 to 2.02 MPa, and 0.41 to 0.25 W/m.K, respectively, for the panels with polystyrene beads. For the panels with vermiculite aggregates, these values were 646 to 626 kg/m3, 3.14 to 1.96 MPa, and 0.46 to 0.34 W/m.K, respectively. This indicates that the panels with polystyrene beads were lighter, stronger, and had better thermal insulation properties. Using of the developed panels will help to reduce the self-weigh of walls resulting in smaller structural elements. In addition, the excellent thermal properties of the developed panels are expected to reduce the power consumption in buildings.

S. El-Gamal, A. Al-Kalbani, O. Al-Hatmi
Consequences on Residential Buildings in Greater Montreal for a Repeat of the 1732 M5.8 Montreal Earthquake

A seismic scenario based on the repeat of the 1732 M5.8 Montreal earthquake was performed to estimate its actual impacts on residential buildings and the population of the Montreal Metropolitan Community (MMC). At the time of the event, the population of Montreal was 3000, and 300 out of 400 buildings, which were mostly wood structures with walls made of timber planks, suffered some damage to chimneys and cracked walls. Nowadays, the MMC comprises a population of over 4 million and around 870′000 buildings were compiled using the latest evaluation roles. The majority (>90%) of the residential houses are wood light frame structures, and single-family houses represent 74% of the building stock. The total value of the building exposure is estimated around 285 billion of Can$, with the content accounting for 55% of the total. For this scenario, ground motions are calculated by combining several GMPEs validated for central and eastern North America and a soil microzonation derived from seismic measures and borehole data. About 12% of the building stock would suffer extensive and complete damage, this value decreasing to 1.2% for the municipalities outside Montreal. The total monetary losses would amount to 12% of the value of the portfolio in Montreal and around 0.04% outside Montreal, non-structural damage accounting for 80% of the damage on average. Debris generated from the damage is estimated at 7 million tons, wood and brick materials representing more than 65% of the total.

P. Rosset, L. Chouinard, M.-J. Nollet
Proceedings of the Canadian Society of Civil Engineering Annual Conference 2021
herausgegeben von
Scott Walbridge
Mazdak Nik-Bakht
Kelvin Tsun Wai Ng
Manas Shome
M. Shahria Alam
Ashraf el Damatty
Gordon Lovegrove
Springer Nature Singapore
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