Mir M. Ali

Structural Developments in Tall Buildings: Current Trends and Future Prospects

Abstract Tall building developments have been rapidly increasing worldwide. This paper reviews the evolution of tall buildings structural systems and the technological driving force behind tall building developments. For the primary structural systems, a new classification—interior structures and exterior structures—is presented. While most representative structural systems for tall buildings are discussed, the emphasis in this review paper is on current trends such as outrigger systems and diagrid structures. Auxiliary damping systems controlling building motion are also discussed. Further, contemporary “out-of-the-box” architectural design trends, such as aerodynamic and twisted forms, which directly or indirectly affect the structural performance of tall buildings, are reviewed. Finally, the future of structural developments in tall buildings is envisioned briefly.

Parametric study of thermal mass property of concrete buildings in US climate zones

Considering the ubiquity of concretes structural, architectural, and environmental applications in buildings, a research study was carried out to determine how the thermal mass property of concrete could improve the energy performance of buildings. The results have shown that extreme climate zones can better exploit the thermal mass property of the material. This article initially reviews the fundamental concepts of thermal mass. It then specifically explores the impact of thermal mass concrete on building energy performance in six U.S. climate zones through Energy Plus simulation and analysis. The building occupancy types (office and residential), window-to-wall area ratio, and height are chosen as the parameters to evaluate the impact of thermal mass on building energy performance. In addition, the annual heating and cooling energy demands are selected as the measurement indices of building energy consumption. This article presents the results of the study, interprets them, and draws conclusions about the potential benefits of thermal mass for both residential and office occupancies, which are deemed to be important to researchers and design professionals. These results indicate that other influential design variables such as slab thickness and thermal mass distribution could also be taken into account to demonstrate broader implications and benefits of thermal mass in different climate zones.

Contribution of Thermal Mass to Energy Performance of Buildings: A Comparative Analysis

Concrete has structural, architectural, and environmental applications in buildings. As one of its advantages, the thermal mass property of concrete plays an important role in a buildings energy performance and reduces heating and cooling loads. In this paper, results of an investigation of the effect of thermal mass of concrete on a buildings energy consumption in comparison with steel and masonry are presented. For the purpose of this research, three major parameters including height, occupancy, and location of buildings in six US climate zones were considered and maximum cooling load was chosen as the main measuring index of building energy performance. The results have shown that in residential and commercial buildings, the thermal mass property of concrete could reduce the maximum cooling load by 7% to 10%. Office and commercial buildings in Phoenix, AZ and residential buildings in Fargo, ND have shown the highest cooling load reduction of nearly 10% compared with other studied locations. Furthermo...

An Overview of Structural and Aesthetic Developments in Tall Buildings Using Exterior Bracing and Diagrid Systems

There is much architectural and engineering literature which discusses the virtues of exterior bracing and diagrid systems in regards to sustainability - two systems which generally reduce building materials, enhance structural performance, and decrease overall construction cost. By surveying past, present as well as possible future towers, this paper examines another attribute of these structural systems - the blend of structural functionality and aesthetics. Given the external nature of these structural systems, diagrids and exterior bracings can visually communicate the inherent structural logic of a building while also serving as a medium for artistic effect. Viewed in this light, the visual appeal of these systems can be enhanced to give a tower a more distinct urban identity. This entails the creation of structural elements that are aesthetically pleasing, geometrically coherent and that demonstrate dexterity of application in regards to a buildings composition, while also respecting the laws of physics and mechanics. In this fashion, an artistic approach can exhibit structural systems as not just purely rational features that enable the construction of tall buildings, but as important visual components that afford opportunities for creative expression. This paper, therefore, synthesizes the concepts of structural performance and creative artistry to facilitate a better understanding of the aesthetic developments in skyscrapers worldwide.

Integration of Tall Building Systems

The focus of this paper is to look at the process of integration of tall building systems and how these buildings interact with the city. The design of tall buildings poses a number of challenges for the architect and the engineer. Such design warrants a multidisciplinary approach and integration of architectural function, structural system, vertical transportation, fire safety, energy conservation, and communication systems. It also demands consideration of environmental effects, constructability, and conformity with the urban setting and civic infrastructure. Effective collaboration and a symbiosis of ideas are needed among professionals throughout a tall building project. This is more so for tall buildings because of their enormous scale. It is concluded that integration not only makes the building more reliable and efficient, it is in fact cost-effective to entwine the various systems together. Illustrative examples are included to shed light on well-integrated tall buildings and their impact on communities.

Protective Design Of Concrete Buildings Under Blast Loading

Designing buildings to resist failure due to blast loads is an extremely complex procedure. His a process that has been investigated for many years, yet it warrants tluther research. Several issues related to the design of concrete structures to survive blast loads are discussed in this paper. General design issues of “terroristproof’ buildings show how the threat of harrnfil blasts is affecting the thought process in designing government and public buildings as well as international and high-visibility organizations. Understanding the loads produced by explosions is an integral part of dealing with blast-resistant design. Case studies of buildings subjected to blasts reveal how actual structures have handled the dynamic loads. Current research on the subject is also reviewed.

Mycobacterium KansasII empyema

Abstract Two cases of empyema attributed to M. kansasii infection are described. Both patients died, despite chemotherapy.

The Role of Systems Integration in the Design of Sustainable Skyscrapers

This paper examines the process of integration of tall building systems with special emphasis on sustainable tall buildings. The design of such buildings warrants a multidisciplinary approach and requires the integration of architectural components, structure, vertical transportation, fire safety, energy conservation, and communication systems. “Technology transfer” is a concept that suggests that technical developments in one industry can be applied to another. Sustainable design of high-rise buildings has benefitted from technology transfers, which contribute new materials, systems, methods, and techniques. Developments in materials, systems, and design integration in the aerospace and automotive industries and lessons learned also can be applied to tall building systems. A major component of the paper entails case studies of buildings, which represent a new generation of sustainable high-rise buildings that are challenging conventional high-rise building practices and setting trends for such future pro...

Preliminary Design of a Special Monumental Structure

In late 1970s internationally renowned artists Christo and Jeanne-Claude deigned a Mastaba for the United Arab Emirates (UAE). A mastaba (Arabic word for a bench) resembles a truncated pyramid with two vertical walls and two inclined walls. The proposed structure measures 150 meters in height and is 300 meters by 225 meters at the base. It is large enough to house the largest Egyptian pyramid in Giza inside it. The artists designed the proposed monument as an enclosure only with no utilization of the space inside at any time. The Mastaba of UAE is to be located in a seismic zone covered on all four sides as well as the roof with about 400,000 horizontally placed 55-gallon steel oil barrels of varying brilliant colors acting as facade. Given that the entire Mastaba is a work of art, the patterns of barrel colors are established by the artists. The proposed monument is to stand alone with no facilities within the vicinity of the structure.

The role of tall buildings in sustainable cities

Tall buildings make up the urban fabric and cannot be viewed in isolation from the city. They also bring up ethical, social, and cultural issues, and they impact the local community – their social needs and what the neighborhoods can gain from creating a new tall building. As with the buildings themselves, the urban context in which tall buildings have evolved has changed dramatically since their Chicago origins, reflecting both social and technological developments. A tall building has been variously called a “city within a city,” “a vertical city,” and a “city in the sky.” Thus it is apparent that a tall building is a microcosm of a large city. It is an integral part of the urban habitat having a close relationship with it. In a way it is a vertical progression of a horizontal city. The two are interactive and connected by the transportation, power grid, water supply, and waste production and disposal systems. The tall building can therefore play a vital role in defining livable and sustainable cities. Both cities and skyscrapers must use fewer natural resources; create less waste; and impact less on the natural world. Technology will continue to improve the physical systems of the skyscraper and the city; however, their future will be defined by human interests and values.