Doctor of Philosophy
Civil and Environmental Engineering
A. A. El Damatty
Precast concrete shear walls are used to resist lateral loads in low- to medium-rise buildings. An innovative joining technique is proposed to accelerate construction process and to reduce concrete damage possibility and capital loss during an earthquake event. Panels are jointed using steel anchor bolts, therefore, the system is designated "anchor-jointed precast structural wall system". In this system, anchors are utilized as a structural fuse. Damaged anchors are easily replaced after an earthquake, thus minimizing repair costs and serviceability disruptions. In the first part of this thesis, conceptual development of the system is carried out. A research program of combined analytical and experimental studies is initiated to characterize the system.
Four specimens are tested under monotonic horizontal load. Each specimen consists of a precast concrete wall panel and a base jointed through a horizontal joint. Joints tested in the current program are designed so that different failure modes could be investigated. A non-linear finite element model is developed. Through a model development process, model parameters are examined and rationally estimated to accurately replicate the behaviour. The model is then utilized to study the effect of selected parameters. The study reveals that anchor-jointed precast structural wall system has shown excellent structural behaviour with regards to their lateral capacity and ductility and may be used efficiently as a lateral-load-resisting system. However, further experimental and analytical studies are needed before that system can be adopted by relevant codes. Based on the analyses presented, it is concluded that applied gravity loads can greatly enhance the lateral capacity of the system. Also, varying the anchor bar length is an efficient parameter that may be used to reach a target performance level of ductility
In the first part of the thesis, a system for resisting later load has been developed. To augment the design of a building, the prestressed flat slab system is chosen as the main flooring system and its design is optimized. A robust numerical tool that integrates design, analysis, and optimization techniques is developed. Although the objective function, Cost, is simple and monotonic, the optimization problem is quiet challenging. Direct search methods and heuristic optimization techniques are considered. Results suggest that search should be conducted along a constraint
boundary using multi-objective evolutionary algorithm.
El Semelawy, Mohamed, "Experimental and Numerical Development of Anchor-Jointed Precast Structural Wall System and Optimum Design of Prestressed Slabs" (2011). Electronic Thesis and Dissertation Repository. 171.