The Role of Aerodynamic Modifications in the Form of Tall Buildings Against Wind Excitation

Modern tall buildings go higher and higher with the advances in structural design and high strength materials. However, every advance in height comes with a new difficulty. Efficient structural systems, high strength materials, and increased height, result with decrease in building weight and damping, and increase in slenderness. On the other hand, as the height and slenderness increase, buildings suffer from increased flexibility, which has negative effects in wind loading. Flexible structures are affected by vibration under the action of wind which cause building motion, and plays an important role in the structural and architectural designs. Understandably, contemporary tall buildings are much more vulnerable to wind excitation than their predecessors. Hence, different design methods and modifications are possible in order to ensure the functional performance of flexible structures and control the wind induced motion of tall buildings. An extremely important and effective design approach among these methods is aerodynamic modifications in architecture. In this context, the authors classify these aerodynamic modifications in architecture for resisting the lateral loads. Wind safe tall building design begins with the architect, and the influence of the wind action must be taken into consideration from the very beginning of the architectural design process by considering building aerodynamics

Deflections of reinforced concrete beams and columns

Ph.D. - Doctoral Progra

A proposal for the classification of structural systems of tall buildings

In the early structures at the beginning of the 20th century, structural members were assumed to carry primarily the gravity loads. Today, however, by the advances in structural design/systems and high-strength materials, building weight is reduced, and slenderness is increased, which necessitates taking into consideration mainly the lateral loads such as wind and earthquake. Understandably, especially for the tall buildings, as the slenderness, and so the flexibility increases, buildings suffer from the lateral loads resulting from wind and earthquake more and more. As a general rule, when other things being equal, the taller the building, the more necessary it is to identify the proper structural system for resisting the lateral loads. Currently, there are many structural systems that can be used for the lateral resistance of tall buildings. In this context, authors classify these systems based on the basic reaction mechanism/structural behavior for resisting the lateral loads

A CRITICAL REEVALUATION OF STRESSES GENERATED DURING VERTICAL AND LATERAL CONDENSATION OF GUTTA-PERCHA IN THE ROOT-CANAL

The finite element method was used to calculate the stresses in a maxillary canine tooth produced during lateral and vertical condensation. Description of the biological domain to be analyzed, and conversion of the manual operations of the endodontist to realistic load representation are intricate problems which must be overcome before stresses are recovered and plotted. The stresses in dentin are in general of comparable magnitudes during lateral or vertical condensation, but these magnitudes generally remain much below those presented in a previous study. From these calculations it appears that root fractures reported by some investigators may be explained in terms of stress concentrations and local irregularities of the samples tested

Main stadium structures of summer Olympic Games: efficiency assessment of their physical performances

Main stadium structures of Summer Olympic Games are large scale structures which are designed in such a way to accommodate thousands of spectators, a crowded athlete population and many sports competitions during Olympic Games. There are many written documents on some architectural and technological features of those structures; however there is scarcity of knowledge on assessment of their physical performances/capacities. The study was shaped to examine the inherent physical performances of main stadiums for summer Olympic Games and to better understand their appropriateness, specifically potentials and limitations, for international and regional prospective events

A study on main architectural and structural design considerations of contemporary supertall buildings

The design of supertall buildings (300m+) involves many professionals from several disciplines. The need for coordination among numerous experts, increases complexity of the entire process, which is typically conducted under the leadership of the architect, or sometimes the contractor. Consequently, the architects designing supertall buildings must be aware of architectural and structural design considerations and their interrelations. In this paper, the main architectural design considerations and structural system details of supertall buildings are studied; these include 93 completed or under construction buildings from the 1980s onwards. This study analyses the contemporary trends in main architectural and structural design considerations and corresponding interrelations. In addition, more inclusive and consistent classifications of structural system, building form, and core planning are proposed. The comparison between design considerations over the new proposed classifications is intended to aid and direct architects in the planning and development of supertall building projects as a basic guideline