Day 2 :
Keynote Forum
Ted Garrison
New Construction Strategies
USA
Keynote: Why the Structural Steel Industry Needs to Pursue Integrated Project Delivery
Time : 09:00 - 09:25
Biography:
Ted Garrison has a civil engineering degree and has constructed approximately 10,000,000 square feet of construction projects as either the general contractor and developer. Since 1998, he has been an author, speaker, and consultant to the construction industry on strategic initiatives critical to the construction industry. He is currently working on a research project on Integrated Project Delivery funded by Electri International. He is the author of several books on strategy, strategic thinking and strategic planning. He has spoken on four continents.
Abstract:
The structural steel industry and its contractors should not only embrace integrated project delivery, but actively pursue and encourage its adoption. The reason is simple. At the project\'s inception is when the steel contractor can provide its greatest value to the project and has its greatest opportunity to influence the design. The steel contractor can use its knowledge and expertise to provide the guidance necessary to ensure the structure delivers the highest value for the owner’s investment. For example, if no steel contractor participates in the early structural design, ill-advised decisions might lead to the elimination of structural steel as an option. Potentially, a bigger problem for steel contractors is by not participating in the early structural steel design, people less knowledgeable and experienced about structural steel may make decisions that negatively impact the steel contractor and the project. Unfortunately, far too often when the steel contractor is finally asked for its opinions, it’s too late to implement their recommendations. Therefore, it’s in the steel contractor’s best interest to participate in the early structural design issues where its knowledge and experience can be used to its greatest advantage. In other words, when the steel contractor participates from inception, it can provide true value engineering on the structural steel designs. In other words, by participating from project inception, the steel contractor and steel industry can create a win-win environment by providing great project value and increasing the contractor\'s profitability.
Keynote Forum
Sherif Mohamed
Griffith University
Australia
Keynote: Building Resilience in Construction Site Operations: Shifting from Protective Safety to Productive Safety
Time : 10:00-10:30
Biography:
Sherif Mohamed is an accomplished educator with a strong blend of technical and management skills and formal qualifications gained through an international background in industry, government and university environments. He holds a Master as well as Doctorate degrees from the University of Southampton in the United Kingdom. He is one of leading system safety experts at the forefront of contemporary safety performance improvement endeavours. He is a regular speaker at international health and safety conferences, and also serves as an Associate Editor (Journal of Safety Science, Elsevier). Through his research and consulting work, he has worked with many major organisations in Europe, the Middle East and Australia. Over the years, he has developed and successfully delivered a large number of short courses to construction safety professionals worldwide.
Abstract:
This presentation challenges the traditional way of thinking about construction safety and presents a strong argument for moving beyond compliance. Throughout the world, construction organisations adopt a safety management system that is based on 4E’s (Environment: hazard identification, Engineering: risk reduction, Education: awareness; and Enforcement: regulations and policies. This well-tested system has survived for many years without much challenge. However, recent works on adaptive systems, complexity theory, and organisational sense-making have provided a fresh theoretical lens through which, we can examine construction safety.Safety Management Systems focus on protecting people from failure, standardising the ways of doing things to avoid failure. This presentation recognises that site conditions change all the time, so the focus should be on how people adjust their performance under different conditions to ensure doing things right. In other words, aiming to build resilience in construction site operations in order to respond to the continually changing conditions would ultimately lead to good safety outcomes. To enable building resilience, people would need to be empowered to actively notice and select cues in a changing situation, and relate them to a broader frame of reference (and not a standard procedure) to create a practical and safe environment for everyone. The presentation sheds some light on how a combination of sense-making and adaptive systems had the potential to mitigate latent risks on construction sites.
Keynote Forum
Eiki Yamaguchi
Kyushu Institute of Technology
Japan
Keynote: Stress Concentration due to Shear lag in Box Girder
Time : 10:30-11:00
Biography:
Eiki Yamaguchi has completed his Ph.D at the age of 28 years from Purdue University, USA. He is currently Head and Professor, Department of Civil Engineering, Kyushu Institute of Technology, Japan. He has published more than 100 papers and serves as an editorial board member of Journal of Constructional Steel Research and chief editor of Journal of Civil Engineering, Japan Society of Civil Engineers, Division A1, among others.
Abstract:
Existing research on shear lag gives a variety of stress concentration factors. Unlike the elementary beam theory, the application of load is not unique in reality. For example, a so-called concentrated load can be applied as a point load or a distributed load along the height of the web. No existing research works deal with this difference explicitly. This may be a reason for the discrepancy of the stress concentration factors in the existing studies. Although many researchers employed the finite element method and it is known that the finite element mesh must be constructed with great care to evaluate stress concentration, very few researches have taken into account the influence of the finite element mesh on the shear lag phenomenon. The present study investigates the stress concentration in a flange due to the shear lag in a box girder by the three-dimensional finite element method using shell elements. Extensive parametric study with respect to the geometry of a box girder is carried out. The effect of the way load is applied and the dependency of finite element mesh on the shear lag are carefully treated. Based on the numerical results thus obtained, empirical formulas are proposed to compute stress concentration factors due to the shear lag. Moreover, most of the researches on the shear lag have focused on simply supported girders and cantilever girders. The present study is therefore extended to the investigation of the shear lag effect on a continuous box girder.
- Track 3: Steel Construction
Track 7: Environmental Engineering
Track 9: Design and Behavior of Steel Structures and Members
Track 10: Construction Industry
Location: Ballroom section 3
Chair
Konstantinos Daniel Tsavdaridis
University of Leeds
UK
Co-Chair
M Manikandan
Gulf Consult
Kuwait
Session Introduction
Tarek Mahfouz
Ball State University
USA
Title: Decision Support for Project Prioritization in A/E/C Industry
Time : 11:15-11:35
Biography:
Tarek Mahfouz has earned a Ph.D. in Civil Engineering with a specialization in Construction Engineering and Management from Iowa State University. He is an Associate Professor of Construction Management at Ball State University. His expertise are in the areas of Knowledge Management, Machine Learning, Decision Support, Intelligent Information Modeling, Statistical modeling, among others. He has over 25 publications in reputable journals and conference proceedings. He has been serving as an editorial board member of repute. He is an Associate Member of the American Society of Civil Engineers (ASCE) and the Association of Technology, Management, and Applied Engineering (ATMAE).
Abstract:
Project prioritization is a dilemma that faces all parties of the Construction Industry. At a time when the nations’ economies and infrastructures are in dire need for effective management practices to address their maintenance, the Architecture/Engineering/Construction (A/E/C) industry is in an escalating trend of efficiency loss. For owners, including governments, assessing high and low priority projects, while the need for essential services grows and project complexity increases, is overwhelming. It is often driven by limited budgets and they are frequently made with little economic, engineering, and/or operational rationale. It is the responsibility of the A/E/C professionals to facilitate decision making processes to guarantee the continued success of the industry. In an attempt to mitigate this drawback, researchers from the academic and professional domains have addressed this issue. These included Airfield Pavement Rehabilitation, Risk Factors in PPP Infrastructure, Best Management Practices, among others. These advancements have been very field specific due to type of project, nature of evaluator, and/or parameter of consideration. To assist decision making for multi-criteria projects, a five stepped robust methodology- build on weighted criteria, transparency, shareholder objectives, consistency, and goal alignment- is provided. The aforementioned methodology is augmented with automated decision support tool through the use of Machine Learning (ML) and information retrieval techniques. It has been proven to be successful in healthcare, automotive, and higher education projects. The proposed methodology is instigated to provide a better understanding of decision consequences as well as time and cost savings.
Robert G. Driver
University of Alberta
Canada
Title: University Leadership for Advancing the Steel Construction Industry—Regional Partnerships for Global Impact
Time : 11:35-11:55
Biography:
Robert Driver is Professor and Associate Chair of the Dept. of Civil and Environmental Engineering at the University of Alberta in Edmonton, Canada. He has a total of 30 years of experience in the steel fabrication industry, structural engineering consulting, applied engineering research, and education, having taught structural engineering undergraduate and post-graduate courses in Canada, the United States, and South Africa. He has received numerous awards for both research and teaching and is extensively involved in the development of structural design codes and standards in North America. He has published nearly 200 reports and papers in refereed journals and conference proceedings.
Abstract:
Informal relationships between individual steel fabrication companies and local universities are commonplace, and often take the form of scholarship sponsorship or the supply of free or discounted shop labour and materials for laboratory research. While these activities have advantages for both the participating firm and the institution to some degree, the benefits tend to be self-limiting due to their lack of vision beyond the present. For regions where steel industry technology clusters already exist (from the supply chain through to steel fabrication and erection expertise), collaborative industry partnerships with universities having strong engineering programs generate opportunities to create highly influential knowledge networks. These networks not only provide short-term benefits to the industry, but also can create strategic market growth in existing areas of expertise and establish ground-level shares in new and emerging construction markets. As the steel industry competes in a rapidly-changing construction climate, collective industry innovation, through direct links to university research programs and personnel, is the key to success and global competitiveness. The University of Alberta recently formed a unique partnership with Alberta-based steel fabricator/erectors and their direct collaborators and clients. Collective support raised has created foundational funding that can be leveraged through governmental research grants available only to universities, and this funding is most readily available when sustained industry backing is present through demonstrated cash and in-kind support. Major benefits are derived through a multiplicity of spin-offs from the core research programs, such as a better-educated regional work force and clientele due to an increase in engineers with graduate degrees specialising in steel construction. Other primary benefits include the direct involvement of the steel industry in guiding new developments in construction and fabrication technologies through research, the installment of student interns and summer employees into the sponsors’ operations for a bi-directional flow of knowledge, the creation of professional training opportunities for industry personnel through short courses and other continuing educational initiatives, and the natural promotion of the industry arising from the regular activities of the researchers.
Eunsoo Choi
Hongik University
Korea
Title: Behaviors of flag-shaped dampers using combination of magnetic friction and rubber springs
Time : 11:55-12:15
Biography:
Eunsoo Choi has completed his PhD at the age of 35 years from Georgia Institute of Technology. He is the associated profeesor in department of civil Engineering Hongik University. He has published more than 75 SCI papers in reputed journals.
Abstract:
This study proposes a new concept of a smart damper using the combination of magnetic friction and rubber springs. The magnet will provide energy dissipation, and the rubber springs with precompression contribute to increase recentering capacity of the damper. To verify their performance, this study conducts dynamic tests of magnet frictional dampers and precompressed rubber springs. For the purpose, hexahedron Neodymium (NdFeB) magents and polyurethane rubber cylinders are used. In the dynamic tests, loading frequency varies from 0.1 to 2.0 Hz. The magnets provide almost perfect rectangular behavior in force-deformation curve, and the frictional coefficient of the magnets is estimated through averaging and regression. The rubber springs re tested without or with precompression. The rubber springs show different loading path from the second cycle and remain residual deformation that is not recovered immediately. The rubber springs show larger rigid force with increasing precompression. Lastly, this study discusses combination of rigid-elastic behavior and friction to generate ‘flag-shaped’ behavior for a smart damper and suggests how to combine the magnets and the rubber springs to obtain the flag-shaped behavior. The performance of the magnets and precompressed rubber springs is verified through analytical models.
Cheng Yu
University of North Texas
USA
Title: Effective Strip Model for Cold-Formed Steel Sheet Shear Wall
Biography:
Cheng Yu, Associate Professor and Program Coordinator, is a faculty member of the Construction Engineering Technology program at University of North Texas. He earned both his Ph.D., and M.S. in Civil Engineering from Johns Hopkins University and received his B.E. in Civil Engineering from Tsinghua University, China in 1998. His research interests include structural behaviors of light framed steel buildings subjected to multi-hazards, structural design of cold-formed steel structures, earthquake engineering and structural control, innovative construction materials and structures, and Building Information Modeling, His current projects are focused on developing high-performance light steel structural systems for low- and mid-rise buildings. He serves on several technical committees in American Society of Civil Engineers, American Iron and Steel Institute, and Structural Stability Research Council. He is a recipient of 2010 Faculty Early Career Development Award from National Science Foundation.
Abstract:
The cold-formed steel framed shear wall sheathed with steel sheets (CFS sheet shear wall) is a code approved lateral force resisting system for light-framed construction in U.S. The shear strength of those shear walls in the design specifications is based on full-scale experiments of specified shear wall configurations. No analytical model or design formulae have been developed for predicting the nominal strength of CFS sheet shear walls. This paper presents a novel analytical model – Effective Strip Model for determining both the nominal strength and the deflection of CFS sheet shear walls subjected to either wind or seismic loads. The proposed design method is applicable to a relative large variety of shear wall configurations and demonstrates good agreements with experimental results. The statistical assessment indicates that the Effective Strip Model is a reliable alternative tool for the engineers to design the CFS sheet shear walls without conducting full-scale tests.
Zuheir Barsoum
Khalifa University
UAE
Title: Life extension, upgrade and repair of welded structures – Towards the use of High Strength Steels
Time : 12:15-12:35
Biography:
Zuheir Barsoum is an associate professor at KTH Royal Institute of Technology where he is directing a research group on steel structures. He is chairman within the International Institute of Welding (IIW). He has published more than 90 papers in reputed journals and international conferences and received awards for his research. He has been involved in, beside university curriculum development and teaching, in developing international vocational training program in welding and design. He is a frequently engaged consultant within the industry as an expert in structural integrity. He is currently a visiting associate professor at Khalifa University in Abu Dhabi.
Abstract:
Many steel structures and installations, regardless of industry, around the world are reaching their original design life. Most of the operators chose to extend the service life of their assets rather than scrape them and/or build new. As a result of this trend the application of fatigue life improvement techniques and specifically High Frequency Mechanical Impact (HFMI) treatment has become very popular. However, the successful application of fatigue life improvement techniques must be based on the knowledge of the three main factors and their interaction affecting the endurance of welds of structural integrity concern: weld imperfections, geometrical stress concentrations and residual stresses. These three factors and their reciprocal influence are the target of any fatigue life improvement technique. Consequentially, it is only HFMI techniques which are able to tackle and/or improve these three weld features during one single working operation. The use of HFMI techniques have also lately gained attention within lightweight design, where high strength steels are used in welded structures with application of HFMI technique with promising fatigue life improvement. The current study will cover the latest development, treatment procedures specification, quality assessment and control of welds improved by HFMI techniques. Fatigue design recommendations for welded structures from plate thickness 5 to 50 mm and for yield strengths ranging from 235 MPa to 960 MPa. Finally, the in progress development of the international design and operations guidelines, under the framework of the International Institute of Welding (IIW) for these collection of techniques will be discussed.
M.Manikandan
Gulf Consult
Kuwait
Title: Design and Behavior of Steel Structures and Members from Constructability Perspectives
Time : 12:35-12:55
Biography:
M.Manikandan is the Sr. Structural Engineer at Gulf Consult-Kuwait with responsibility for Designing and Construction Consultation of the tall buildings, Colleges, Shopping Complexes, Multi story Car Parks, Hospitals, Bridges and Deep Underground structures by considering the Structural requirements and adequate construct able systems to complete the projects within allocated budget and time schedule. Prior to joining Gulf Consult-Kuwait, he has worked as Structural Engineer at several companies, including RECAFCO-Kuwait, SAEED HADI ALDOOSARY EST-Saudi Arabia, Where he has completed many Precast Structures and treatment plant including the deep underground structures with heavy equipment. Notable he is in the construction industry since past 15 years and has completed many land mark projects in Kuwait as well in Saudi. He is pursuing PhD in Risk Management in International Construction Projects as an External Part time researcher with Vels University Chennai-India and expected completion on end of 2015 and He has been received Civil Engineering Degree from Kamraj University Madurai-India on April, 2000 following that he has received MBA in Project Management from Sikkim Manipal University-India in 2012.
Abstract:
Nowadays the Engineers still tend to optimize a structure to a minimum of weight and optimum passing stress ratios, which is only the hard criterion that is available for an Engineer during the design of the structures, eventually this criterion leads to structures that are expensive and have a poor quality and complex constructability during the executions phase. For this presentation the 20 story steel building has been taken as an example to illustrate that the selection of adequate steel members and constructible connections, which leads to have a time reduction, high quality of the structure as a whole and within the budget. ETABS 2013 software has been used to obtain the design the systems with adequate steel section for beams, columns and bracing members from the standard set of steel sections with grade ASTM A572 Gr50 for W sections, plates and ASTM A500 Gr-50 for tubes. A three dimensional structure is taken with 5 horizontal bays of width 8m and 20 stories with story height 4m and Atrium up to 10th floor, where the Veirenderal system has been introduced to support the floor system above 11th floor on the Atrium, further the metal deck concrete 150mm thick with shear studs ASTM-A108 Gr 1020 dia. 19mm @300 on floor beams are considered as a floor slab, which also acting as a Diaphragm against lateral loads, Furthermore the vertical bracings are provided only in the peripheral corner bays to limit the Drift against lateral loads such as wind 100mph and Seismic Zone-1. Limcon-V 3.63 has been used to design the connections as per AISC-360 by considering the materials ASTM-A572 Gr 50, ASTM A490 and E70XX for Plates, Bolts and Welds respectively.
Zuheir Barsoum
Khalifa University
UAE
Title: Workshop on Advanced Design of Welded Structures Introduction to new design methods and IIW recommendations
Time : 13:40-15:10
Biography:
Zuheir Barsoum is an associate professor at KTH Royal Institute of Technology where he is directing a research group on steel structures. He is chairman within the International Institute of Welding (IIW). He has published more than 90 papers in reputed journals and international conferences and received awards for his research. He has been involved in, beside university curriculum development and teaching, in developing international vocational training program in welding and design. He is a frequently engaged consultant within the industry as an expert in structural integrity. He is currently a visiting associate professor at Khalifa University in Abu Dhabi.
Abstract:
The most frequently joining process of metallic materials and structures is welding. In order to guarantee the strength of welded structures different design codes have been developed during the last 30 years and have been applicable within the manufacturing industry with low accuracy and precision. However, nowadays high strength steels are utilized in load carrying structural applications in order to produce more lightweight welded structures which need more accurate design methods in order to assure the structural integrity. As the finite element analysis is nowadays a widely used tool new developed design codes are applicable with better accuracy and precision. In this workshop, methods for fatigue analysis of welded structures using FEM and fracture mechanics are covered. The workshop also includes several case studies where different approaches are used for fatigue life assessment.
Topics covered:
-Introduction to fatigue design of welded structures
-Notches, weld defects and welding residual stresses
-Fatigue assessment methods; nominal, hot spot, effective notch, LEFM
-Improvement techniques, spectrum loading, residual stress relaxation
-Weld quality systems
-FEM, Case studies and Exercises
Merve Sagiroglu
Erzurum Technical University
Turkey
Title: Evaluation of Connection Systems in Modular Constructions
Time : 15:10-15:30
Biography:
Dr. Merve Sağıroğlu is an Assistant Professor at Erzurum Technical University, Turkey. She received her Ph.D in Civil Engineering in 2013, from Atatürk University in Turkey. Currently, she is doing postdoctoral studies in the Architectural Engineering Department at Penn State University in the United States. She supported by the Scientific and Technological Research Council of Turkiye, in the framework of Postdoctoral Research Scholarship Programme.
Abstract:
Modular buildings are developed as an alternative to conventional on-site construction because of more predictable costs and faster construction. While the use of modular buildings is increasing rapidly and this construction system is becoming more popular, research activities on structural components and materials used in modules, analysis and design methods and connection systems in the modular building are needed and are continuing. Modular construction aims to optimize the use of materials, while forming spaces comparable in size to conventional construction and to offer benefits of installation speed. The modules act as the primary structural system of the building, while another stabilization system such as stair or elevation core can be used as well. Modules transfer gravity loads and resist lateral loads through the module-to-module connections. Therefore, the connections must be strong enough and have inherent ductility to transfer loads from one module to another and accommodate building deformation under gravity and lateral loads. The presentation will introduce commonly used connection systems in several types of modular construction. As modular systems are seldom used in high-rise building construction and because of limitations of structural and module-to-module connection systems, they are rather used in shorter than 7-8 stories. The presentation will explore the nature of these limitations and offer suggestion for improved structural-connection systems that provide desirable levels of strength, stiffness and ductility. In particular, the presentation discusses the possibility of using distributed isolation system as one option in such solution schemes.
Cigdem Avci-Karatas
Yalova University
Turkey
Title: Comparison of Steel and Composite Analysis of a Multi-storey Building
Time : 15:30-15:50
Biography:
Cigdem Avci-Karatas received her PhD from the Department of Civil Engineering at the Technical University of Istanbul. She joined the department of Transportation Engineering at the University of Yalova as an assistant professor in June 2014. Her research area focuses on structural engineering, earthquake engineering, and some specific issues of steel structures. She has developed, designed, fabricated, and tested metallic seismic energy dissipation device labeled as TURKBRACE-BRB in her doctoral research work. She has received 2013 the Best PhD Thesis Award at Structural Engineering in ITU. She is a member of the scientific board of the World Sustainable Energy Institute
Abstract:
Turkey is well-known a country of high level of seismicity; on the other hand steel-composite structures appear competitive today in this country by comparison with other types of structures, for example only-steel or concrete structures. Composite construction is the dominant form of construction for the multi-storey building sector. The reason why composite construction is often so good can be expressed in one simple way - concrete is good in compression and steel is good in tension. The scope of this paper covers analysis, materials take-off, cost analysis and economic comparisons of a multi-storey building with composite and steel frames. The aim of this work is to show that designing load carrying systems as composite is more economical than designing as steel. Design of the nine stories building which is under consideration is done according to the regulation of the Turkish Earthquake Code and by using static and dynamic analysis methods. For the analyses of the steel and composite systems, plastic analysis methods have been used and whereas steel system analyses have been checked in compliance with EC3 and composite system analyses have been checked in compliance with EC4. At the end of the comparisons, it is revealed that composite load carrying systems analysis is more economical than the steel load carrying systems analysis considering the materials to be used in the load carrying system and the workmanship to be spent for this job.
Mostafa Fahmi Hassanein
Tanta University
Egypt
Title: Advances on shear strength and behavior of bridge girders with steel corrugated webs
Time : 15:50-16:10
Biography:
Mostafa Fahmi Hassanein has completed his Ph.D at the age of 31 years from Tanta University, Egypt. He is currently an Associate Professor of Structural Engineering at the Department of Structural Engineering at the same University. He has published 26 papers in international journals. He has served as a reviewer for different reputed journals and conferences. He has also invited to the 8th European Solid Mechanics Conference (ESMC), Graz, Austria, 2012 as an \"Invited Speaker\". Recently, he has awarded the \"State\'s Incentive Award in the Engineering Sciences\" in 2015 from the Academy of Scientific Research and Technology, Egypt.
Abstract:
This paper provides the recent advances related to the shear strength and behaviour of bridge girders with steel corrugated webs. The real behaviour at the juncture between the corrugated web and flanges of bridge girders is studied using elastic bifurcation buckling analyses using ABAQUS software. The results obviously indicated that when the flanges are rigid enough ( ), the girder segments exhibit shear failure mechanisms and the realistic support condition at the juncture is nearly fixed. Hence, a new interactive shear buckling strength formula is proposed for the case of fixed juncture. The shear strength of bridge girders with corrugated webs (BGCWs) using the realistic initial imperfection amplitudes is investigated. The models are well verified using available experimental results. It is found that stocky corrugated webs cannot practically reach the yield shear strength. However, among the strengths using the proposed interactive shear buckling strength formula, the one adopting Sause and Braxtan equation is found to be the most suitable. On the other hand, the existing literature on bridge girders with steel corrugated webs (BGCWs) is focused on prismatic girders; i.e. with constant depth. To the authors’ best knowledge, no work has been done on the shear stability of tapered BGCWs although they have been increasingly used in bridges in recent years. Webs in different typologies of tapered girders with steel corrugated webs are investigated. Accordingly, the critical shear buckling stress ( ) of the corrugated webs of tapered BGCWs is evaluated and it is found that predicting values for the tapered webs based on prismatic web calculations is not accurate. Therefore, critical buckling stresses for the tapered webs are proposed based on the stresses of prismatic webs, with different equation for each typology. The paper is, then, extended to investigate the nonlinear shear strengths of the BGCWs. The available design shear strength formulas for prismatic girders are compared with the FE shear strengths of the tapered BGCWs. Based on these comparisons, design strengths for different tapered BGCWs cases are suggested.
Antoine N. Gergess
University of Balamand
Lebanon
Title: Cold Bending Steel Beams: a State-of The-Art Engineering Solution that Meets Industry Challenges
Time : 17:00-17:20
Biography:
Antoine N. Gergess has completed his Ph.D from the University of South Florida, Tampa, USA. Currently, he is the dean of students and professor of Civil Engineering at the University of Balamand, Lebanon and consultant for bridge design and construction in the UAE. He has published more than 25 papers in reputed journals and serves as the secretary for the American Society of Civil Engineers (ASCE) Lebanon Group. He is a licensed professional engineer in Florida and Lebanon, an ASCE fellow and the recipient of the ASCE South Florida Section “Young Engineer†Award (1991).
Abstract:
Cold bending practice in the steel bridge industry is ambiguous. AASHTO allows cold straightening and cambering, but not curving. AASHTO’s major concern is loss of fracture toughness (CVN) of the base metal and cracking of the weld due to fatigue. Alternatively, heat curving is widely used. Controversy in heat curving appeared as a recent study by Texas DOT on the effects of bending on the ductility of flange plates showed that when heat was applied to assist in the bending operation, particularly to reduce the bending forces, bridge fabricators have, on occasion, experienced the formation of cracks in the flange plate. Moreover, results showed that for heat-assisted bending operations, strain levels above 10 percent reduced the ductility and fracture toughness of the plate. Such controversy and unjustified reluctance for adopting cold bending for curving has jeopardized steel’s competitive advantage in curved bridge applications, especially High Performance Steel (HPS) which demonstrates a high yield strength, high toughness and high formability in cold bending. An urgent need was therefore identified by steel fabricators to use cold bending for curving for efficiency, economy and time saving. A simple, versatile and cost-effective proprietary cold curving process was developed for this purpose and systematized by deriving closed-form solution that relate bending loads to curvatures. Its applicability and accuracy were verified based on comparisons with experimental results from a full-scale test girder. Visual inspection did not identify any localized damages, signs of distress or fracture which prove the legitimacy of cold bending within certain strain limits.
Merve Sagiroglu
Erzurum Technical University
Turkey
Title: Experimental Investigation of Moment-Rotation Curves of End-Plate Connection using Sinusoidal Beam
Time : 17:20-17:40
Biography:
Dr. Merve Sağıroğlu is an Assistant Professor at Erzurum Technical University, Turkey. She received her Ph.D in Civil Engineering in 2013, from Atatürk University in Turkey. She completed postdoctoral studies in Penn State University, USA in July, 2015. Her research interest include structural behavior of steel connections, modular buildings and structural analysis. She is keeping on her researches with a research group works on steel connections.
Abstract:
A structural engineer aims to optimize dimensions of the buildings in order to obtain the frames have high moment resistance with reduced weight. The pre-stressed composite girders or high-strength steel can be used for this purpose. Another way to provide the optimum solution is to make some changes in the shape of beams. Beam-to-column connections play an important role in behavior of steel frames. To model the behavior of connections, the moment-rotation curve must be used. Full-scale experiments is carried out to obtain real moment-rotation characteristics of connections. The rotation and moment are determined by using displacements of the beam connections in the experiments. The designed connections form various moment-rotation curves according to the elements of connection and the shape of placement. That is, the moment and rotation is dependent on the geometric parameters of the elements used in the connection. A new beam model called sinusoidal beam is suggested in this study. Various experiments was carried out for four beam models; two sinus beams, one simple model and one IPE beam model. Results are compared with experiments performed with IPE profiles. It was aimed to investigate the effect of the sinus degrees in the web I beam on their moment-rotation curve. The presentation exhibit the moment-rotation curves of fixed end-plate connection made from sinusoidal beams and evaluation the structural performance of sinusoidal beams.
Said Kenai
University of Blida
Algeria
Title: Performance of ordinary and self compacting concrete using recycled concrete aggregates
Time : 17:40-18:00
Biography:
Said KENAI is a Professor and chairman of the civil engineering research laboratory at the University of Bilda, Algeria. He obtained his PhD from Leeds University (England) in 1988. His main interests include building materials, concrete technology, cement replacement materials, durability, non destructive testing and repair of concrete structures. He has published more than 50 papers in international journals and is serving as an editorial member of many reputed journals. He is also member of RILEM TC-ISC technical committee.
Abstract:
Construction industry consumes a lot of mineral resources and is the most energy intensive sector. In addition, it is responsible for a high percentage of green house gas emissions and hence has large environmental impact. The use of recycled concrete aggregates from rubble and demolition waste in combination with cementitious additions could contribute to an environment friendly construction by reducing CO2 emissions and reducing the consumption of natural resources. In this paper, the performance at the fresh and hardened state of an eco-concrete (ordinary and self compacting) made of recycled concrete aggregates and either natural pouzzolana or granulated blast furnace slag is discussed. Natural aggregates were either partially or fully substituted by recycled aggregates and cement was partially substituted by either natural pouzzolana or slag. The results showed that an ordinary recycled aggregates concrete with comparable mechanical properties and durability to natural aggregates concrete could be produced. The use of recycled aggregates gives a self compacting concrete with comparable rheological properties to that of control concrete. The substitution of cement by natural pouzzolana decreases the workability of the control concrete whereas the use of slag improves it. However, an improvement has been noted for SCC made with recycled concrete aggregates.
Ayman M. Okeil
Louisiana State University
USA
Title: Effect of Stiffener Configuration on Efficiency of SBS for Shear Deficient Steel Beams
Biography:
Ayman M. Okeil completed his PhD from North Carolina State University in 1995. He is the director of the Structures Research Laboratory at Louisiana State University.He has published more than 80 papers in reputed journals and conference proceedings has been serving as an editorial board member of the ASCE Journal of Composites for Construction.
Abstract:
Structural engineers are often involved in projects to strengthen deficient structures as a feasible alternative to cost-prohibitive full replacement of the structure. The use of composite materials to strengthen existing concrete structures by externally bonding thin laminates or strips is mature enough that design codes and guidelines are available for flexural, shear, and axial strengthening applications. Researchers have also investigated strengthening steel structures using composite material, however, the field is not as mature as it is for concrete applications. This paper presents a new strengthening technique where pultruded GFRP sections are bonded to shear deficient regions to enhance the local buckling resistance of the thin walled steel structures. The technique, referred to as Strengthening-By-Stiffening or SBS, was developed at Louisiana State University. An experimental program was designed to study the effect of FRP stiffener configuration on the efficiency of SBS. Different orientations, web slenderness values and aspect ratios were tested monotonically up to failure. The ultimate shear capacities beams were enhanced by a minimum of 30% when one stiffener was used on a beam with a square panel and a maximum of 56%. Post yielding behavior including the transition from a tension field to sway-frame load path will also be discussed.
Adel ElSafty
University of North Florida
USA
Title: Repair of damaged steel beams composite with concrete deck using carbon fiber reinforced polymers (CFRP)
Biography:
Adel ElSafty is a Professor in the Civil Engineering Department at the University of North Florida (UNF). Prior to joining UNF in 2005, he was a founding faculty of Civil Engineering Department at Florida State University, Panama City campus from 2003 to 2005 and served as a Visiting Assistant Professor at the University of Central Florida from 2002 to 2003. He conducted Post-doctoral research at North Carolina State University (NCSU) and University of Sherbrooke-Canada, in addition to Florida Department of Transportation. He worked in the industry as a Consultant, Structural Engineer at a Bridge Design firm in Florida, and as a Specifications Manager at FOSROC, a British Construction Chemical Company. He earned his PhD from North Carolina State University in 1994.
Abstract:
Repair using carbon fiber reinforced polymers (CFRP) sheets and strips for damaged steel girders has been investigated in this study. An experimental program was devised to study the efficiency of CFRP strengthening of damaged composite steel beams with concrete decking. The flexural testing of five steel beams (HP 10 x 42) composite with concrete decks of (2½ ft x 4 in x 12 ft) and strengthened with CFRP was conducted. The steel-concrete composite beams had a simulated collision damage imposed before installing the CFRP strips. The collision damage was simulated by cutting a notch in the tension steel flange. A 4†CFRP laminate strip was applied to the bottom steel flange. Some repaired beams were wrapped with CFRP U-shaped strips at different locations to anchor the longitudinal CFRP strips. After the adhesives for the CFRP was cured and gained strength, the beams were loaded until failure. LVDTs and strain gages were mounted at mid-span to measure deflections and strains. A 100-kip [445 kN] displacement-controlled hydraulic actuator was used to apply static loading at mid-span. An automatic data acquisition system was used to record the loads, displacements, and strains. Continuous visual inspection was also performed to determine if any possible debonding between the CFRP membranes and the steel beams occurred. Analysis of the experimental results was discussed and conclusions were drawn. The results indicated a restoration of capacity for the strengthened beam when compared to the control damaged beam without CFRP strengthening. The repair of pre-damaged beams with CFRP laminates restored their flexural capacity to reach a capacity greater than the load actuator.
Adel ElSafty
University of North Florida
USA
Title: Repair of damaged steel beams composite with concrete deck using carbon fiber reinforced polymers (CFRP)
Biography:
Adel ElSafty is a Professor in the Civil Engineering Department at the University of North Florida (UNF). Prior to joining UNF in 2005, he was a founding faculty of Civil Engineering Department at Florida State University, Panama City campus from 2003 to 2005 and served as a Visiting Assistant Professor at the University of Central Florida from 2002 to 2003. He conducted Post-doctoral research at North Carolina State University (NCSU) and University of Sherbrooke-Canada, in addition to Florida Department of Transportation. He worked in the industry as a Consultant, Structural Engineer at a Bridge Design firm in Florida, and as a Specifications Manager at FOSROC, a British Construction Chemical Company. He earned his PhD from North Carolina State University in 1994.
Abstract:
Repair using carbon fiber reinforced polymers (CFRP) sheets and strips for damaged steel girders has been investigated in this study. An experimental program was devised to study the efficiency of CFRP strengthening of damaged composite steel beams with concrete decking. The flexural testing of five steel beams (HP 10 x 42) composite with concrete decks of (2½ ft x 4 in x 12 ft) and strengthened with CFRP was conducted. The steel-concrete composite beams had a simulated collision damage imposed before installing the CFRP strips. The collision damage was simulated by cutting a notch in the tension steel flange. A 4†CFRP laminate strip was applied to the bottom steel flange. Some repaired beams were wrapped with CFRP U-shaped strips at different locations to anchor the longitudinal CFRP strips. After the adhesives for the CFRP was cured and gained strength, the beams were loaded until failure. LVDTs and strain gages were mounted at mid-span to measure deflections and strains. A 100-kip [445 kN] displacement-controlled hydraulic actuator was used to apply static loading at mid-span. An automatic data acquisition system was used to record the loads, displacements, and strains. Continuous visual inspection was also performed to determine if any possible debonding between the CFRP membranes and the steel beams occurred. Analysis of the experimental results was discussed and conclusions were drawn. The results indicated a restoration of capacity for the strengthened beam when compared to the control damaged beam without CFRP strengthening. The repair of pre-damaged beams with CFRP laminates restored their flexural capacity to reach a capacity greater than the load actuator.
Khandaker M. Anwar Hossain
Ryerson University
Canada
Title: Structural performance of novel Composite Walling System with Profiled Steel and High Performance Concretes
Biography:
Khandaker M. Anwar Hossain is an Associate Professor of Civil Engineering at Ryerson University, Canada. He received PhD from Strathclyde University, Glasgow, UK. He has over 25 years of experience as academic, researcher and consultant engineer in various parts of the world. Dr. Hossain’s research interests include: high performance engineered concrete, smart self-healing materials and steel-concrete composite construction. He is serving as a member of ACI Committee 213 and 232, CSCE: materials and mechanics division and as an editorial board member of several journals. He has published over 300 publications including over 175 journal papers.
Abstract:
Composite walling system consisting of two skins of profiled steel sheeting and an infill of concrete is novel form of construction. Such walling system has great potential to be used as gravity and lateral load resisting elements in buildings. The strength, stiffness, ductility and energy absorbing capacity of composite walls subjected to axial, monotonic/cyclic shear and impact loadings will be described based on comprehensive experimental and theoretical investigations. The fire durability of the walls subjected to high temperatures will also be presented based on residual strength/stiffness/energy absorption capacity. The innovative feature of such walls is the use new engineered high performance concretes (HPCs) with high strength, high ductility (strain hardening capacity) and micro-cracking characteristics developed at Ryerson University for the last few years. Such HPC composite walls have shown superior performance compared to those made with traditional concrete in terms of strength, ductility, energy absorbing capacity and durability as well as post-impact strength/stiffness/energy absorbing capacity. Analytical models/ design equations for the load resistance of composite walls are developed and their performance validated through experimental and finite element modeling.
Hamid Moharrami
Tarbiat Modares University
Iran
Title: Side-Sway Control in Semi-Supported Steel Shear Walls
Biography:
Hamid Moharrami is the Associate Professor in Civil and Environmental Engineering Department of Tarbiat Modares University Tehran, Iran. His Specialization is mainly based on Design Optimization in Civil and Structural Engineering. He has completed his PhD degree in Civil Engineering, from the University of Waterloo, Canada in Oct. 1993.Since Oct. 1993 he is the faculty in in Tarbiat Modarres University, Tehran, Iran. He was also the Vice Chancellor in Planning & Development, Tarbiat Modarres University, and Tehran from August 1995 to Feb.1998. He was the Chancellor in The University of Zanjan, Iran, from Feb. 1998 to Sept. 1999.His Fields of Special Interest are Numerical Methods in engineering, Nonlinear Analysis, Design Optimization, Stability of Structures, Genetic Algorithms and Neural Networks. He has more than 25 publications. He was also the member of ASCE during 1995 to 2002.
Abstract:
Control of drift in high-rise buildings is a major design problem. Many valuable attempts have been made in the literature to simplify the evaluation of side-sway in steel shear walls. Although semi-supported steel shear walls have many similarities with ordinary steel shear walls, they are designed somehow differently because of some considerations in their behavior. In this paper, a novel method, that can also be used for ordinary steel shear walls, has been suggested for side-sway evaluation of semi-supported steel shear walls undergoing a shear and overturning moment. The results are compared to that of analysis with commercial engineering software and showed relatively good compliance between the two.
Stephen Hicks
Heavy Engineering Research Association
New Zealand
Title: Global Eurocodes Implementation
Biography:
Stephen Hicks is General Manager of Structural Systems at the NZ Heavy Engineering Research Association (HERA). Prior to joining HERA in 2008, Stephen spent 11-years at the UK Steel Construction Institute, where he was formerly Senior Manager of Building Engineering. He was the UK representative on CEN Sub-committee 4 (CEN/TC250/SC4) responsible for Eurocode 4, as well as a member of BSI Subcommittee B/525/4, responsible for BS5950-3.1, -4 and the UK National Annexes to Eurocode 4. He is well known internationally as an expert on composite construction, floor vibrations and the Eurocodes. As well as providing training in Europe, more recently, he has delivered several Eurocode training courses in China and Singapore.
Abstract:
This paper will provide a general overview of the Eurocodes and, drawing on personal experience, will also discuss the challenges and opportunities faced from adopting these design standards. The topics discussed will include:
• Introduction to the Eurocodes.
• Differences between the earlier National Standards and the Eurocodes.
• Execution and Product Standards.
• Non-Contradictory Complementary Information (NCCI).
• Eurocode transition tools and resources.
• Future evolution of the Eurocodes.
• Development of new products and technologies.
The practical benefits of adopting the Eurocodes will be illustrated through a selection of case studies on recently completed buildings and structures.
Lin-Hai Han
Tsinghua University
China
Title: Performance and Design of concrete-filled steel tubular (CFST) chord to hollow tubular brace truss
Biography:
Lin-Hai Han is the HOD of Department of Civil Engineering, School of Civil Engineering, Tsinghua University, Beijing, China. He has published 4 books, more than 100 refereed journal papers (including 80 international journal papers), and 60 refereed international conference papers. He is one of the outstanding Young Researchers awarded by the National Natural Science Foundation of China. He is widely consulted by the industry and government authorities on a wide range of structural engineering projects.He has played an important role in drafting several designing codes on steel-concrete composite structures in China. Prof. Han holds roles on the Editorial Board for the Elsevier Journal of Constructional Steel Research, the Techno-Press Steel and Composite Structures, the Hong Kong Institute of Steel Construction (HKISC) International Journal of Advanced Steel Construction, the Multi-Science Publishing Journal of Structural Fire Engineering, and four national journals in civil engineering in China.His current research interests include steel-concrete composite and mixed structures under different loadings, such as static, dynamic and fire.
Abstract:
Concrete filled steel tubular (CFST) chord to hollow tubular brace truss (referred to as CFST truss for short) is a type of truss which uses CFST members as its chords and hollow tubes as its braces. A concrete slab can be provided on the CFST truss to form a hybrid CFST truss. The new type of trusses can be used in bridge structures and other large span structures. This paper thus presents a preliminary study on the performance and design of such CFST trusses. A finite element analysis (FEA) modeling of CFST trusses subjected to flexural loading was developed and verified against reported experimental data, the predicted performances showed generally good agreement with the test results. The FEA modeling was then used to carry out analysis on the typical failure modes and full-range load-deformation relation of CFST truss subjected to flexural loading. The stress distribution and load-transfer mechanism was also analyzed. Based on this, together with the previous relevant investigations of the authors', the design methodologies for critical issues of practical CFST trusses were presented, including the design formulae for local bearing condition at the connection area, typical joints in truss structures, as well as CFST trusses with or without RC slabs.
Ranjith Dissanayake
University of Peradeniya
Sri Lanka
Title: Green Construction: Reuse of Materials in Retrofitting of Damaged Bridges
Biography:
Ranjith Dissanayake is the HOD and Professor of Civil Engineering, University of Peradeniya, Sri Lanka. He was a Fulbright Scholar in 2008 Columbia University, USA and Endeavour Fellow in 2008 Monash University Australia, JASSO Research Fellowship Ehime University, Japan in 2007. He has published over 140 papers. He was awarded Australia Alumni Excellence Award 2012 and has chaired FIVE international conferences. He is a founding member of the Green Building Council of Sri Lanka and presently the Vice President. He is Chairing the International Conference on Structural Engineering and Construction Management which will be held in Sri Lanka in 2015.
Abstract:
Building new bridges generally consumes more resources and time than repairing and retrofitting of damaged bridges. Therefore, the latter can be considered more sustainable. However, proper methods are necessary to assess the level of damages and to verify the fitness of such bridges prior to repair and retrofitting. In the assessment, there are two important criteria to consider. One is the amount of fatigue damage to the bridge due to usual past vehicle loading and hence the remaining fatigue life of the bridge. The other is the magnitude of damage caused to the bridge by the unexpected loading. The case study is about a 34 m long, 5.2 m wide, single spanned, double lattice girded, wrought iron Railway Bridge which was built about 40 years ago and damaged and displaced from its abutments by floods. The bridge was then placed on temporary timber abutments for several years. Then an analysis was done by modeling the bridge and validating the FEM by using results of a field loading test. Both static and dynamic loading tests were carried out. The cost for retrofitting work and constructing new reinforced concrete abutments was much less than that for constructing a new bridge. Therefore it was decided that rehabilitation of the bridge with necessary retrofitting work is more sustainable than demolishing it and constructing a new one. The bridge is now in use after being repaired, retrofitted and placed on new abutments.
Riccardo Zanon
ArcelorMittal Europe
Luxembourg
Title: Heavy sections – tailor made solutions and high strenght steel – recent developments in bridge applications
Biography:
Riccardo Zanon is Head of Sales Bridges & Export within ArcelorMittal Europe – EuroStructures Beam Finishing. He began his career in ArcelorMittal R&D in Luxembourg as Research Engineer on the topics of: fire safety engineering and its application to real buildings; cold and fire design of car parks and cellular beams; research on instability phenomena of cold formed thin-walled sheet piles. Afterwards he acted as Technical Sales Engineer with the role of technical responsible for pre-design and development of bridges with rolled sections within the Technical Advisory team. Joining the EuroStructures Beam Finishing facilities, he is technical and commercial responsible for projects with beam finishing in the fields of bridges and the export markets.He holds a MSc Degree of the University of Trento, Italy, in Civil Engineering and a MSc Degree of the University of Dresden, Germany, in Structural Engineering.
Abstract:
Long products may be rolled as tailor-made shapes in order to fit specific customer needs. For heavy sections, the concept was firstly developed in 1979 at the rolling mill of Differdan-ge, in Luxembourg. The production implies the adaptation of the rolling stands for stock sec-tions concerning the geometrical shapes, as well as the heating and cooling process concerning the mechanical properties. The first application of these heavy sections was as columns for high-rise buildings, where the connection of high strength steel with optimized cross-section thicknesses leads to sub-stantial weight and cost savings. Several skyscrapers around the world used this technology. In latest years, this concept has been successfully implemented also in some remarkable bridge applications. In particular, three high-speed railway bridges on the Contournement of Nimes and Montpellier, as well as the launching equipment for steel deck on the Saint-Petersburg ring were developed with tailor-made sections. In these cases, the intrinsic fatigue resistance as well as in-shape stability of rolled sections are major factors that make these products highly competitive. Another factor of interest, the tallest H section ever rolled in his-tory were developed as tailor made for one of these railway bridges. In this paper, in a first step the industrial process of tailor-making in connection with a clas-sic rolling mill for heavy shapes will be explained. The technical limits as well as some rolling constraints will be discussed. Furthermore, some future projections concerning developments in shape and steel grades will be given. In a second part, it will be presented an historic overview of the main heavy sections appli-cations over the last decades up to the newest relevant projects, showing when and how these products reveal to be advantageous. Recent applications for major bridge projects will be dis-cussed in detail.
Medhat S. El-Mahllawy
Housing and Building National Research Center
Egypt
Title: Effect of activation of granulated blast- furnace slag on the properties of unfired eco-friendly clay bricks
Biography:
Medhat El-Mahllawy received his Ph.D. degree in engineering geology at 2004 from faculty of science, Zagazig University, Egypt and completed his postdoctoral studies from Wollongong University, Australia. He is working for Housing and Building National Research Centre (HBRC), Raw Building Materials and Processing Technology Research Institute, Egypt. Currently, he is the quality manager for the 17025 ISO accredited testing labs earned from IAS, USA. He has published more than 25 papers in local and international journals and he is a reviewer for a number of international journals.
Abstract:
This laboratory study was undertaken to evaluate the properties of eco-friendly clay specimens incorporating ground granulated blast-furnace steel slag (GGBS) which activated by cement kiln dust (CKD) and quicklime (QL) of various dosages (5-10wt.%). The use of activated GGBS in the manufacture of unfired clay bricks is, however, still a novel process in Egypt although it has been used previously in some countries. Five mixes were prepared and laboratory specimens were made and cured up to 60 days. X-ray diffraction (XRD) and differential thermal analysis (DTA) were used to characterize the raw materials and specimens. In addition, physical and mechanical properties of the hydrated specimens were measured and their results were illustrated graphically. Also, durability of the cured specimens against collapsibility in water was assessed. The addition of quicklime and cement kiln dust to the GGBS improved the investigated engineering properties of the unfired stabilized specimens. This is due to the pozzolanic reaction that results in the accumulation of additional calcium silicate hydrates (CSH) and calcium aluminate hydrates (CAH) gel within the pore structure. This resulted in the enhancement of the properties in the investigated mixes after 7 days of curing, particularly 14 days, with superiority to the clay-cement-lime-GGBS mix rather than the clay-cement – CKD- GGBS mix. In general, the specimens contained GGBS activated by 5wt.% quicklime had the most potential effect on the studied properties.
Elie G. Hantouche
American University of Beirut
Lebanon
Title: Behavior of Full Strength Built-up T-stub Connections for Seismic Areas
Biography:
Elie G. Hantouche is currently an Assistant Professor of Structural Engineering at the American University of Beirut, Lebanon. He has completed his Ph.D. at University of Cincinnati, USA. His research focuses on structural resistance to extreme loads, particularly earthquake and fire. His research expertise is focused particularly on the behavior of steel framed structures during earthquake and fire conditions, and improving the performance of reinforced concrete structures subjected to earthquakes. His research work has both computational and experimental aspects and is focused on the development of improved design standards for structural resistance to extreme loads. His work has been published in both US and international journals and has been presented at conferences in the U.S., Canada, Europe, and Asia.
Abstract:
This research aims at widening the applicability of T-stub connections by investigating the behavior of thick-flange built-up T-stubs needed for deep beams which meet the prequalification requirements for moment resisting frames (MRF) in seismic areas. Often the heavy rolled profiles needed to fabricate the T-stub for such deep beams are not immediately available to fabricators and so built-up sections are the only alternative. In this study, finite element (FE) simulations and experimental testing are used to provide the data set needed to develop mathematical models to predict the behavior of thick-flange T-stub connections. First, results obtained from plates tested to evaluate the influence of the hole fabrication practices show that standard drilled or standard flame cut can be used in detailing T-stub connections. Thick-flange T-stub components tested to establish design guidelines and to detail full-scale specimens for prequalification in MRF used with deep beams show that both thick-flange T-stub components built-up either by complete joint penetration (CJP) or fillet welds are acceptable. The T-stub component tests results are also used to validate the prediction of the load-deformation behavior up to failure obtained from three dimensional (3D) FE models. A failure limit state is highlighted, which is partial yielding at the K-zone followed by bolt fracture, with or without prying. Second, using the results from a parametric study, cases for thick-flange T-stub connection geometries needed for deep beams are identified, and 3D FE models are developed. Using FE results, two separate prying strength models for thick-flange T-stubs with CJP and fillet welds are developed. The models are validated by comparing with FE and experimental results obtained for connections designed for deep beams. Third, a mechanistic model based on a combination of stiffness approach modified with FE results is developed. The connection response is modeled on the basis of beam representation for the flange, multi-linear spring for the bolt forces, nonlinear torsion spring at the K-zone to account for the partial yielding, and accounting for prying phenomenon. The model shows excellent agreement with finite element results obtained for the same full-scale connections considered for the prying strength study. Fourth, 3D FE models were extended to include the column-side of the connection. The results are used to evaluate the effect of secondary prying in the T-flange/column-flange systems with and without continuity plates. Criteria for providing continuity plates are developed to guide the designer in the detailing process. Also, a model that quantifies the amount of total prying is developed. Finally, a design methodology for thick-flange T-stub connections in seismic areas which provides designers a workable option for practical application is proposed.
Merve Sagiroglu
Erzurum Technical University
Turkey
Title: Evaluation of Connection Systems in Modular Constructions
Biography:
Dr. Merve Sağıroğlu is an Assistant Professor at Erzurum Technical University, Turkey. She received her Ph.D in Civil Engineering in 2013, from Atatürk University in Turkey. Currently, she is doing postdoctoral studies in the Architectural Engineering Department at Penn State University in the United States. She supported by the Scientific and Technological Research Council of Turkiye, in the framework of Postdoctoral Research Scholarship Programme.
Abstract:
Modular buildings are developed as an alternative to conventional on-site construction because of more predictable costs and faster construction. While the use of modular buildings is increasing rapidly and this construction system is becoming more popular, research activities on structural components and materials used in modules, analysis and design methods and connection systems in the modular building are needed and are continuing. Modular construction aims to optimize the use of materials, while forming spaces comparable in size to conventional construction and to offer benefits of installation speed. The modules act as the primary structural system of the building, while another stabilization system such as stair or elevation core can be used as well. Modules transfer gravity loads and resist lateral loads through the module-to-module connections. Therefore, the connections must be strong enough and have inherent ductility to transfer loads from one module to another and accommodate building deformation under gravity and lateral loads. The presentation will introduce commonly used connection systems in several types of modular construction. As modular systems are seldom used in high-rise building construction and because of limitations of structural and module-to-module connection systems, they are rather used in shorter than 7-8 stories. The presentation will explore the nature of these limitations and offer suggestion for improved structural-connection systems that provide desirable levels of strength, stiffness and ductility. In particular, the presentation discusses the possibility of using distributed isolation system as one option in such solution schemes.
Mehran Zeynalian
University of Isfahan
Iran
Title: Seismic Performance of Cold-Formed steel shear walls
Biography:
Mehran Zeynalian, PhD, MSc, is Assistant professor of civil engineering at the University of Isfahan. He received a master of science in civil engineering from Isfahan University of Technology in Iran in 2002. He also received his PhD in the field of structures and construction management from the University of Queensland, 2012. He has published more than 20 papers in reputed journals and specialty conferences. His main research interests are lateral performances of cold formed steel structures, and risk analysis and management of the projects.
Abstract:
The use of cold formed steel structures has grown dramatically in recent years all over the world but with greater rate of growth in non-seismic regions. Adequate bracing and brace performance is of paramount importance to improve the acceptability of these systems in earthquake prone regions. In this speech, the lateral performance of different configurations of cold-formed steel shear walls will be discussed based on some experimental tests on full scale walls of 2.4 m × 2.4 m under cyclic loading. Also, application of non-linear finite element analyses for investigating the seismic characteristics of the cold formed steel shear walls will be illustrated highlighting different structural characteristics including: material nonlinearity, geometrical imperfection, residual stresses and perforations. Of particular interest are specimens maximum lateral load capacities, load-deformation behavior, and evaluated seismic response modification factors. The speech also looks at the failure modes of the systems and investigates the main factors contributing to the ductile response of the CFS walls in order to suggest improvements so that the shear steel walls respond plastically with a significant drift and without any risk of brittle failure such as connection failure or stud buckling. In addition, prescribed seismic response modification factors for different CFS configurations by the standards will be examined. It becomes clear that while the suggested R factors in AISI-standard for some configurations are conservative, the values recommended by AS4600 seem to be too low.