Invited Lectures

(Alphabetizing By Last Name)

Tarek Abdoun, PhD, Professor

Associate Dean for Research & Graduate Education, Rensselaer Polytechnic Institute (RPI)
Thomas Iovino Chair Professor and Director, of Rensselaer Polytechnic Institute (RPI) Geo-Centrifuge Center

Professor Abdoun is the Thomas Iovino Chair Professor and Director, of Rensselaer Polytechnic Institute (RPI) Geo-Centrifuge Center. He received several awards from professional societies, including the American Society of Civil Engineers (ASCE) “Walter L. Huber Civil Engineering Excellence in Research Prize”, the US Army “Commander’s Award for Public Service with accompanying medal”, and “Shamsher Prakash International Research Award” for young engineers, scientists and researchers. He is also the recipient of several educational societies, including the American Society of Engineering Education (ASEE) north region “Outstanding Teaching Award”, the “Wharton QS-Stars Reimagine Education Bronze Award”, and Chi Epsilon National Civil Engineering Honor Society “Excellence in Teaching Award”; for the successful development & implementation of web-based education tools and mixed reality educational games in the undergraduate engineering education at several USA campuses. He authored or co-authored over 200 technical publications. His research interests cover geotechnical engineering, Advanced Field Monitoring, Centrifuge & Full-scale Testing, Soil-Structure Interaction, Soil Dynamics and Earthquake Engineering, Satellite Based InSAR Remote sensing, Modeling of Blast loading & Hurricane loading, and offshore systems. He served as chair or member of national and international professional committees of major projects associated with tunnels, dams, levees, and pipelines.

Recent Advances in Physical Modeling & Remote sensing of Civil Infrastructure Systems

Natural and man-made hazards are often associated with costly damages to civil infrastructure systems, such as buildings, bridges, Levees, dams, pipelines and offshore structures of all types. The lack of high-quality field and lab data of soil system response have eluded researchers and practitioners until recently. Recent advancements in physical modeling facilities (centrifuge & full scale) and advancement in remote sensing technology are leading to a new reality for the health assessment of soil-structure systems. This new reality is leading to a paradigm shift in the evaluation and modeling of soil-structure systems. Physical modeling, remote sensing and computational simulations are destined to replace the current empirical approaches and will ultimately become the main tool for analysis and design of soil-structure systems. The presentation will discuss the results of recent research studies utilizing physical modeling to simulate the response of critical soil-structure systems to natural and man-made hazards.

Gian Michele Calvi, Ph.D., Professor

Professor, University Institute for Advanced Studies (IUSS), Pavia.
Adjunct Professor at the North Carolina State University

Gian Michele Calvi is a Professor, vice-Rector for Research and Director of the Centre for Research and
Graduate Studies in Understanding and Managing Extremes (UME) at the University Institute for
Advanced Studies (IUSS), Pavia. He is also Adjunct Professor at the North Carolina State University.
He received a Master of Science from the University of California, Berkeley, a PhD from the Politecnico di Milano and an Honorary Doctorate from the University of Cujo, Mendoza, Argentina.
Professor Calvi has been the founder of the Eucentre Foundation and founder and director of the School in Reduction of Seismic Risk (the ROSE School), which originated the UME School; he has also been a member of the Board of Directors of the GEM Foundation and is one of the Directors of the International Association of Earthquake Engineering.
He is the author of hundreds of publications and of two major books: Seismic design and retrofit of bridges (with M.J.N. Priestley and F. Seible, 1996) and Displacement-Based Seismic Design of Structures (with M.J.N. Priestley and M.J. Kowalsky, 2007).
He has been designer, consultant or checker for hundreds of structural projects, including the Rion-Antirion cable stayed bridge (2883 m, in Greece), the Bolu viaduct (119 spans, in Turkey) and the new housing system after L’Aquila earthquake (2009), with 185 buildings seismically isolated with more than 7,000 devices, completed in about six months.
He is principal of two engineering companies, Studio Calvi, focused on structural design, and RED, focused on risk analysis.
He is associate editor of the Journal of Earthquake Engineering (Taylor and Francis) and editor of Progettazione Sismica (IUSS Press, Pavia), a journal in Italian addressed to practitioners.
He has been invited keynote speakers in tens of conferences, including two World and three European Conferences on Earthquake Engineering.
He has been always active in conceptual innovation in seismic design, focusing on masonry in his early days, on bridges, displacement–based design and seismic isolation from the nineties.

Concepts and technologies for friction-based isolation of buildings

The presentation will start with a critical review of the historical development of base isolation concepts and techniques, discussing the reasons of an undeniable success in practical applications and focusing specifically on various alternatives friction-based technology.
In the last thirty years, devices based on sliding on curved surfaces, characterized by low friction coefficients, have become quite popular. It is well known that such devices are essentially blocked until the acting shear is larger than the vertical force multiplied by the friction coefficient and are then characterized by a stiffness value (K) that depends on borne weight (W) and radius of curvature (r), as: K = W/r. This second stiffness is considered fundamental to contain the residual displacement, but it implies two negative aspects, i.e.: the reduction of the energy dissipated per cycle (which implies a lower equivalent damping and a larger displacement demand) and the increased shear capacity (which implies designing the isolated structure for larger shear demand and more extensive nonstructural damage).
Consequently, some questions arise:
*Is it really fundamental to limit the residual displacement?
*Are alternative ways of limiting this displacement conceivable and applicable?

These and other relevant questions are related to technology advancement and reliability:
*How reliable is the definition of a nominal value for the friction coefficient?
*How relevant is the effect of stick slip? Can it be eliminated?
*How dependable is the friction coefficient at variable velocities and vertical forces?
*How accurately can friction coefficient and radius of curvature of the surfaces be varied?

These subjects will be examined and alternative technological solutions will be proposed, showing that it is theoretically and practically possible to obtain cycles of the kinds shown in the figure below.
Such cycle shapes imply noticeable variation in displacement demand, residual displacement and design shear. These aspects will be emphasized and critically analyzed referring to the results of an extensive numerical investigation.
The driven conclusions will address the problem of developing and applying the most cost-effective solutions, depending on seismicity, use of the building and target performances.

Laureano R. Hoyos, Ph.D., Full Professor

Professor, University of Texas at Arlington, Arlington, USA

Dr. Laureano R. Hoyos serves as Professor in the Civil Engineering Department of the University of Texas at Arlington (UTA). He earned a Ph.D. degree from the Georgia Institute of Technology, Atlanta, Georgia, and is a licensed Professional Engineer in the State of Texas. His research interests are in the areas of experimental and computational geomechanics for unsaturated and problematic soils. He has authored/co-authored over 140 refereed publications among book chapters, journal articles, and geotechnical special publications. He is the recipient of the Lockheed Martin Aeronautics Excellence in Teaching Award, the Research Excellence Award, the Outstanding Civil Engineering Instructor Award, and the Outstanding Early Career Faculty Award. He also served as Associate Dean of the Honors College. He currently serves as chair of the Unsaturated Soils committee of the Geo-Institute (ASCE); Associate Regional Editor of Environmental Geotechnics (Thomas Telford); and Editorial Board Member of Geotechnical Testing Journal (ASTM). He chairs the organizing committee of PanAm-UNSAT 2017: Second Pan American Conference on Unsaturated Soils, Dallas, Texas, November 12-15, 2017.

Experimental Modelling of Unsaturated Soil Behavior over a Whole Range of Paths and Modes of Deformation

Over the last few decades, intensive and sustained experimental efforts have been undertaken worldwide that have defined the threshold of our understanding of unsaturated soil behavior. The adoption of matric suction and the excess of total stress over air pressure, that is, net normal stress, as the relevant stress state variables, has facilitated the investigation of key features of unsaturated soil behavior via either axistranslation or vapor transfer technique. The present paper documents some of the most recent advances in experimental modeling of intermediate geomaterials, over a whole range of suction-controlled paths and modes of deformation. Its main sections describe the test protocols and corresponding results from suction-controlled resonant column, biaxial, triaxial, true triaxial, and ring shear testing programs recently accomplished at the Advanced Geomechanics Laboratory (AGL) of the University of Texas at Arlington, via either axis-translation or vapor transfer technique. The experimental data and related analyses are expected to be of extreme interest to both geotechnical and geological engineering communities worldwide, facilitating the incorporation of more reliable material properties in the analysis and design models of geotechnical infrastructure made of compacted soil or resting on unsaturated ground.

Louay Mohammad, Ph.D., Professor

Professor, Louisiana State University, USA

Dr. Louay Mohammad is a national and international expert in the area of pavement materials and sustainable asphalt construction. He is the holder of the Irma Louise Rush Stewart Distinguished Professor and the Transportation Faculty Group Coordinator at Louisiana State University (LSU). He also serves as the director of the Engineering Materials Characterization and Research Facility at the Louisiana Transportation Research Center (LTRC). Dr. Mohammad teaches and conducts research in the area of Highway Construction Materials, Pavement Engineering, Accelerated Pavement Testing, Advanced Materials Characterization and Modeling, and Infrastructure Sustainability. Dr. Mohammad has served as the PI or Co-PI on more than 58 research projects (NCHRP Project 9-40 and 9-40A, NCHRP Project 9-48, NCHRP 9-49A, NCHRP 10-84, NCHRP Project 20-07/Task 361, etc.) totaling over U.S. $12.4 million. He has authored/coauthored more than 270 publications in pavement engineering including over 150 refereed papers and delivered over 170 keynote and invited presentations at national and international conferences. He has developed many standard test methods (AASHTO TP 114, AASHTO TP 115, and Louisiana DOTD TR 330) and mechanistic models that have impacted pavement materials characterization and performance, and contributed to changes of asphalt specifications. He is the Chair of ASTM subcommittee D 4.25 on Bituminous Mixture Analysis, Past Chair of the TRB Committees AFK40 on Characteristics of Bituminous-Aggregate Combinations to Meet Surface Requirements and member of TRB committee AFK50 on Characteristics of Bituminous Paving Mixtures to Meet Structural Requirement, and TRB committee AFK30 on Characteristics of Non-Asphalt Components of Asphalt Paving Mixtures. Dr. Mohammad currently serves as the Flexible Pavement Section Editor of ASCE Journal of Materials in Civil Engineering, Associate Editor of the Journal of Engineering Research and International Journal of Pavement Research and Technology. Dr. Mohammad has been recognized with the 2013 Best Paper Award of the 8th International Conference on Road and Airfield Pavement Technology, 2010 Distinguished Research Paper of the Journal of Engineering Research, the 2009, 2012, and 2015 Asphalt Rubber Ambassador Award, and the 2002 Association of Asphalt Paving Technologists Board of Directors Award of Recognition.

Implementation of a Balanced Asphalt Mixture Design Procedure: Louisiana's Approach

Conventional asphalt mixture design methodologies such as Superpave, Marshall, and Hveem are used to determine the optimum asphalt binder content by means of physical and volumetric laboratory measurements. All three procedures ensure the materials proportion and quantity of the asphalt cement binder are adequate to meet stability and durability concerns. However, with the increased use of recycled materials, there is a need to develop laboratory mechanical tests in order to evaluate the quality of the asphalt cement binder to complement the Superpave volumetric mixture design procedure. An important component to successful mixture design is the balance between volumetric composition and material compatibility. Balanced asphalt mixture design offers innovation in designing mixtures for performance and evaluation of the quality of a mix design relative to anticipated performance using a rational approach. This presentation documents the selection of laboratory mechanical tests, in addition to volumetric requirements, that can ascertain a mixture’s resistance to common asphalt pavement distresses. Factors in the selection of laboratory mechanical tests such as availability of standard test procedures, advantages and limitations, laboratory-to-field correlations, and sensitivity to mixture composition will be reviewed. Further, an implementation framework and case histories will also be discussed.

Osama Moselhi, PhD, Professor

Professor of Engineering, Concordia University, Montreal, Canada

Dr. Moselhi is Professor of Engineering in the Department of Building, Civil and Environmental Engineering at Concordia University. He has over 40 years of professional and academic experience. He is Fellow of AACE International, ASCE, CSCE and CAE. Since joining Concordia in 1985, after a decade of industry experience, Dr. Moselhi supervised and co-supervised over 95 Masters and Ph.D. graduates, authored and co-authored over 370 scientific publications. His industry experience spans tall buildings, bridges, nuclear power plants, harbor and offshore facilities. He is recipient of numerous honours and awards, including the prestigious Walter Shanly Award of the Canadian Society for Civil Engineering (CSCE) in recognition of “outstanding contributions to the development and practice of construction engineering in Canada” and the Tucker-Hasegawa Award of the International Association for Automation and Robotics in Construction (IAARC) in recognition of his “major and sustained contribution to the field of automation and robotics in construction”. He is member of the Provost's Circle of Distinction. Dr. Moselhi served as international consultant on academic affairs and on construction projects in Canada, USA and the Middle East. His research interest encompasses optimized value driven asset management for sustainable civil infrastructure, including non-invasive and non-destructive condition assessment and rating, deterioration modeling, reliability, resilience assessment and optimized budget allocation; project delivery systems, planning, procurement, resource allocation, tracking and control for efficient management of construction projects, with a focus on risk management, productivity analysis, management of construction claims and development of decision support systems embracing information technology, remote sensing, web-enabling and spatial technologies.

Advanced Sensing Technologies for Condition Assessment of Civil Infrastructures: theory and practice

The deteriorating condition of civil infrastructure systems and the rather limited resources assigned for the maintenance of these major assets, necessitate the development and use of reliable and cost efficient condition assessment and rating methods. The purpose of this keynote address is to describe recent advancements in technologies and methods for non-invasive and non-destructive condition assessment of transportation and municipal infrastructure assets, with a focus on reinforced concrete bridges as well as water distribution networks and sewer mains. Presented in this lecture are the findings of recent research on the use of digital imaging, infrared thermography (IR) and ground penetrating radar (GPR) technologies for condition assessment of reinforced concrete bridges. Described also will be data fusion methods that enables the integrated use of the inspection data captured individually by these technologies in order to improve the accuracy of the predicted condition and better represents the condition state of the scanned bridge element. The application of the developed integrated method in the field will be described considering a single span bridge in Montreal Canada. The bridge is of reinforced concrete and was inspected by the Department of Transportation in Quebec using visual inspection augmented by the hammer sound method and the defective areas were determined and accordingly the condition of the bridge deck was rated. The condition necessitated the replacement of the deck. The developed method was also applied to determine the condition of the deck prior to its replacement. GPR with pushing cart with antenna 1.5 GHZ was used to scan the bridge deck and Therma CAM S60 camera from FLIR was used in the inspection as well. The 3D GPR image was processed using RADAN7 software which represents the GPR deck condition at the surface as plane as that of the IR image. The results obtained by the developed method are compared to the actual condition as determined by the Department of Transportation in Quebec and were found close. Presented also will be newly developed methods for inspection and condition assessment of water distribution networks using IR, GPR and acoustic-based technologies. Field applications of these methods for detecting and locating leaks in water distribution networks will be described. The application and essential features of a patented method for detection, classification and location of defects in sewer mains will also be presented.

Joao Pombo, Ph.D., Professor

Heriot-Watt University, UK

Joao Pombo is a Railway Engineering Professor at Heriot-Watt University, UK, with a PhD in Mechanical Engineering by the University of Lisbon, Portugal.He is a specialist in railway dynamics with 18 years’ experience and has been involved in the development of several computer codes with applications to railway engineering. He has led and participated in several projects in close collaboration with leading international research centres and industry players. He also has more than three years’ working experience at BOMBARDIER and ALSTOM. Joao Pombo’s research and development activities have been awarded four innovation prizes and he is author of more than 80 papers in refereed journals and international conferences. He is the editor-in-chief of the “International Journal of Railway Technology” and chairman of the "International Conference on Railway Technology" series.

Rail Vehicle Design Optimization for Operation in a Mountainous Railway Track

The use of reliable computational tools and of validated vehicle and track models allow studying the railway vehicles performance in realistic operation conditions. The use of such advanced tools permits performing the so-called virtual homologation, which means that most of the criteria defined in the standards and regulations for vehicle acceptance can be verified numerically. This approach reduces the need of the expensive on-track tests, but also permits performing design optimization of several vehicle components, namely, the suspension elements, in order to improve its operational performance in terms of running safety, ride quality, track loading. The realism of the numerical simulations depends strongly on the model assumptions. In this work, all the mechanical elements that compose the rail vehicle are modelled properly. Then, a realistic and fully three-dimensional track, containing the measured track irregularities, is used. Finally, for a realistic running representation of the vehicle in the track, a prescribed motion of the powered wheelsets is adopted to adjust the vehicle speed as function of the track characteristics, namely, its curvature, cant angle and grade. The aim of this research is to develop a methodology to optimize the design of a rail vehicle in a mountainous track based on virtual homologation procedure. For this purpose, an optimization method is used to run the numerical simulations in batch mode and the dynamic performance of the rail vehicle is quantified based on the safety and ride quality indices defined in the standards. In addition, the optimization procedure uses a penalty term that penalizes cases where the vehicle presents an unacceptable dynamic behaviour. The design variables considered are the suspension characteristics. As a result, this work provides an optimal design of the rail vehicle that leads to optimal dynamic performance in terms of running safety and ride quality.