Day 2 :
Keynote Forum
Lu Deng
Hunan University, China
Keynote: Study on rotation construction control of a hybrid-girder cable-stayed bridge with single pylon and single cable plane
Time : 09:15 to 10:00
Biography:
Lu Deng has obtained his PhD degree in Civil Engineering from Louisiana State University in 2009 and worked as a Research Engineer in the Offshore Structure Division at ExxonMobil for 3 years. He is currently a Full Professor in the College of Civil Engineering at Hunan University. He is an Associate Editor of the ASCE Journal of Bridge Engineering and Guest Editor of ASCE Journal of Aerospace Engineering. His areas of expertise include bridge safety evaluation, bridge fatigue and bridge-vehicle coupled vibration. He has published over 100 technical papers, including more than 40 peer-reviewed journal papers in English.
Abstract:
The structure of hybrid girder cable-stayed bridges with single pylon and single cable plane is very complex, which leads to the difficulty in predicting their structural behavior during construction and operation. In this study, the rotation construction process of such a bridge is analyzed. The bridge under consideration is a highway bridge that crosses the railway and has a main span of 169 m. The ZTQZ-350MN rotating system, which is the largest of its kind that has ever been adopted in the rotation construction of bridges, is adopted for this bridge to avoid the interruption of the railway operation. The structural design for the rotation construction of the bridge, the construction of the steel-concrete hybrid girder, and the mechanical behavior of the rotating parts of the bridge during rotation and its construction control are investigated. The structural behavior of the bridge during the construction process is analyzed using the commercial finite element software Midas/Civil. The displacement and the stress of the main girder are calculated, which then provide useful information for the determination of the line shape and the stress control of the bridge. The dynamic analysis model of the bridge is established and is used to investigate the stresses of the bridge during the accelerated and decelerated rotation process. Based on the analysis results, the threshold value for the acceleration/deceleration rate during the rotation process is determined. The findings from this study provide useful reference for the construction control of hybrid girder cable-stayed bridges with single pylon and single cable plane.
Keynote Forum
Feroz Alam
Public Works Authority, Qatar
Keynote: Innovative concept on structural engineering of mega tall buildings: Applied to one kilometer high concrete skyscraper and concept of concrete reduction from shear walls of tall buildings
Time : 10:AM to 11:00
Biography:
Feroz Alam has invented a structural concept for mega tall buildings which can build one kilometer tower where no additional structural supporting systems are required like belt truss, outriggers and bracings, etc. Currently he is working for Qatar Government as a Design Engineer.
Abstract:
Structural system of tall buildings have undergone dramatic changes since the demise of the conventional rigid frames in the 1960s as the predominant type of structural system for steel or concrete tall buildings. There are numerous structural lateral systems used in high-rise building design such as shear frames, frames with shear core, framed tubes, tube in tube, super frames which can construct for up to 140 stories. Later developed structural systems like outriggers and the buttress core has allowed for even higher buildings, can design for up to 160 stories. This study is intended to model an advanced structural system for tall buildings which can build taller than the tallest existing one in the world. In this innovative concept, “One Kilometer Mega Structure’’ analyzed where several parallel shear walls have been arranged in both directions and connected with beams and slabs. The shear walls are continuous down to the base to which they are rigidly attached to form vertical cantilevers. Their high in plane stiffness and strength make them well suited for bracing buildings up to about 278 stories (where drift at top 1930 mm, allowable H/500=2000 mm). Dynamic analysis of this I KM tower shows that the habitable floor is at height 723 m (Record breaking habitable height at 201 storied) besides, by introducing TMD can make the top habitable. Also it is found by research that, when this structural arrangement is applied to around 831 m tall structure with aspect ratio 8.14:1, no additional structural supporting system is required and habitable floor is at 831 m (231 stories). Whereas existing world tallest one have habitable floor at 535 m (160 stories). This shear walls arrangement is applicable for tall buildings of any height to avoid additional supports to resist the lateral forces while taking advantage of the creative approach of this concept.
Keynote Forum
Airong Liu
Guangzhou University, China
Keynote: Experimental research on stable ultimate bearing capacity of leaning-type arch rib systems
Time : 11:15 to 12.00
Biography:
Airong Liu has received her PhD degree in Solid Mechanics from Southwest Jiaotong University and has worked in Guangzhou University for over 16 years. Currently she is mainly engaged in structural vibration and stability research of large span bridge and is the Vice Director of China International Science and Technology Cooperation Base and the Council Member of The Chinese Society of Theoretical and Applied Mechanics on Civil Engineering. She is also the Reviewer of Journal of Bridge Engineering and International of Structural Stability and Vibration.
Abstract:
The stability of a leaning arch structural system was investigated experimentally in this study. Scaled models of five structural systems including a single arch, a parallel arch, and leaning arch systems with a 10, 20, and 30 degree inclined angles between the main and the stabilizing arches were constructed. Each of these models was tested under five point loads spaced equally along the arch. Results show that adding stabilizing arches increased arch’s lateral stability as well as its ultimate bearing capacity. Comparing against the single arch the parallel arch, 10 degree, 20 degree and 30 degree arch system had 14.3%, 15.6%, 13.7%, and 12.9% increase in ultimate bearing capacity, respectively. As the inclined angle of the leaning arch increased, the failure mode changed from out-of-plane buckling to in-plane buckling. Out-of-plane buckling failure was observed in the single arch, parallel arch, and 10 degree arch system, while in-plane buckling failure was observed in the 20 degree and 30 degree arch rib system. Among the five models tested, the 10 degree leaning arch system had the highest ultimate bearing capacity.
Keynote Forum
Meheddene M Machaka
Beirut Arab University, Lebanon
Keynote: Composite shear walls: An efficient seismic resistant system for multi-story buildings
Time : 12.00 to 13.00
Biography:
Meheddene M Mashaka is an Adjunct Professor in the Department of Civil and Environmental Engineering at Beirut Arab University and Rafik Hariri University in the field of structural analysis and construction materials. He has received his Bachelor of Science in Civil Engineering in 1992 at BAU, MSc in Structural Engineering in 2005 and PhD degree in 2015 at Beirut Arab University, Lebanon. He is the Technical Manager for United Engineers Office at Beirut city from 1994 to till date and a Faculty Member in the Department of Civil Engineering.
Abstract:
Steel-concrete composite systems have seen widespread use in recent decades because of the benefits achieved by merging the two materials. Due to their high stiffness and lateral load resistance, reinforced-concrete shear walls (RCSW) and steel-plate shear walls (SPSW) are considered ideal for resisting earthquake lateral loads in moderate and high-rise buildings. Recently, various schemes of composite shear walls (CSW) have been the focus of recent research. The objective of this paper is to investigate analytically the behavior of composite shear walls as a lateral-load resisting system in comparison to RCSW. The investigation is performed on buildings with variable heights provided with either (RCSW) or (CSW). Three dimensional models for the case-study buildings are assembled using ETABS, computer software based on the finite element method. The buildings are analyzed for static lateral forces computed by the equivalent static load method (UBC-1997), response spectra dynamic analyses and dynamic time-history linear analyses using IZMIT earthquake record. Results are compared and interpreted so as the major findings include: First, to highlight on the structural characteristics and behavior of composite shear walls as a seismic resistant system. Secondly, to compare between the structural behavior of RCSW and CSW concerning their drifts, base shear and strength.
Keynote Forum
Hieng Ho Lau
Curtin University Sarawak, Malaysia
Keynote: Non-linear behavior of back-to-back built-up cold-formed steel columns under compression: Finite element modeling and parametric study
Time : 14:00 to 14:45
Biography:
Hieng Ho Lau is currently the Dean of Faculty of Engineering and Science, Curtin University Malaysia. He is a Member of Curtin University Malaysia Campus Community where he has accumulated over 14 years of teaching experience in the field of civil engineering. He is a Professional Engineer with Practicing Certificate registered with Board of Engineers Malaysia (BEM) and also Chartered Professional Engineer with Engineers Australia.
Abstract:
This paper presents a numerical investigation on the behavior and design of back-to-back built-up cold-formed steel channel columns subjected to axial compression. Numerical models were developed using general purpose ï¬nite element (FE) package ABAQUS and have been veriï¬ed using experimental data reported by the authors recently (ting. et. al (2017). Developed finite element models included material nonlinearities as well as initial geo- metric imperfections. Axial strength of columns, failure modes, deformed shapes at failure, load-displacements were predicted from the finite element analyses and obtained comparisons with test results showed considerable match. A comprehensive parametric study has been carried out covering a wide range of slenderness for the considered back-to-back built-up columns. Axial capacities obtained from the numerical study were used to assess the performance of the current North American standards(NAS) and Australian and New Zealand Standards when applied for cold-formed back-to-back built up columns; obtained comparisons showed that NAS and the Australian and New Zealand Standards are un-conservative for stub and short columns sections which were failed by local buckling whereas standards were over-conservative for the strength of columns which were failed mainly by overall member buckling.