• International Journal of High-Rise Buildings
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• v.8 no.1
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• pp.29-36
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• 2019

Tall buildings are one of the most viable solutions to deal with the global phenomenon of rapid population increase and urbanization. While tall buildings are an essential building type to accommodate ever-growing urban population, as buildings become very tall they also produce many critical design challenges related to social interactions, emergency egress, structural systems, etc. While many different design solutions can be sought to resolve these challenging issues of tall buildings, this paper investigates potential of conjoined towers in producing more livable and sustainable megatall building complexes with an emphasis on their capability in efficiently providing exceedingly tall building structures.

• Journal of the Korea Academia-Industrial cooperation Society
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• v.18 no.2
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• pp.737-742
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• 2017

Recently, unconventional high-rise building shapes have attracted attention as a landmark of metropolitan cities and the search for innovative building forms in architecture is ongoing. In this study, $Isotruss^{(R)}$ grid(ITG) used in smaller scale structures was applied to building structural systems and its structural performance was examined. The structural behavior of an ITG was compared with that of a diagrid structure as a reference structure. The stiffness-based design method of the diagrid system was used for the preliminary design stage of member sizing in an ITG. The structural design of 16, 32, and 48-story buildings was carried out for the two systems with the same size. The angle of the inclined columns for ITG and diagrid was $59^{\circ}$ and $68.2^{\circ}$, respectively. The lateral stiffness, steel tonnage of the exterior frame, axial strength ratio, story drift ratio, and natural frequency of the two systems were compared. Based on the analysis result of 6 buildings, the two systems had similar structural capacity; 93.3% and 88.7% of the lateral load was carried by the perimeter frame in the ITG system and diagrid system, respectively. This suggests that the ITG system is better in arranging core columns. Therefore, the proposed ITG system has not only a unique façade, but also substantial structural capacity equivalent to the existing system.

• Wind and Structures
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• v.11 no.1
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• pp.51-70
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• 2008

CFD is applied to evaluate pedestrian wind comfort at outdoor platforms in a high-rise apartment building. Model validation is focused on generic building sub-configurations that are obtained by decomposition of the actual complex building geometry. The comfort study is performed during the design stage, which allows structural design changes to be made for wind comfort improvement. Preliminary simulations are performed to determine the effect of different design modifications. A full wind comfort assessment study is conducted for the final design. Structural remedial measures for this building, aimed at reducing pressure short-circuiting, appear to be successful in bringing the discomfort probability estimates down to acceptable levels. Finally, the importance of one of the main sources of uncertainty in this type of wind comfort studies is illustrated. It is shown that the uncertainty about the terrain roughness classification can strongly influence the outcome of wind comfort studies and can lead to wrong decisions. This problem is present to the same extent in both wind tunnel and CFD wind comfort studies when applying the same particular procedure for terrain relation contributions as used in this paper.

• Earthquakes and Structures
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• v.11 no.6
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• pp.983-1000
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• 2016

To date the engineering community has seen facade systems as non-structural elements with high aesthetic value and a barrier between the outdoor and indoor environments. The role of facades in energy use in a building has also been recognized and the industry is also witnessing the emergence of many energy efficient facade systems. This paper will focus on using exterior skin of the double skin facade system as a dissipative movable element during earthquake excitation. The main aim of this study is to investigate the potential of the facade system to act as a damper system to reduce earthquake-induced vibration of the primary structure. Unlike traditional mass dampers, which are usually placed at the top level of structures, the movable/smart double skin facade systems are distributed throughout the entire height of building structures. The outer skin is moveable and can act as a multi tuned mass dampers (MTMDs) that move and dissipate energy during strong earthquake motions. In this paper, using a three dimensional 10-storey building structure as the example, it is shown that with optimal choice of materials for stiffness and damping of brackets connecting the two skins, a substantial portion of earthquake induced vibration energy can be dissipated which leads to avoiding expensive ductile seismic designs. It is shown that the engineering demand parameters (EDPs) for a low-rise building structures subjected to moderate to severe earthquakes can be substantially reduced by introduction of a smart designed double skin system.

• Wind and Structures
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• v.21 no.5
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• pp.537-564
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• 2015

Excessive motions in buildings cause occupants to become uncomfortable and nervous. This is particularly detrimental to the tenants and ultimately the owner of the building, with respect to financial considerations. Serviceability issues, such as excessive accelerations and inter-story drifts, are more prevalent today due to advancements in the structural systems, strength of materials, and design practices. These factors allow buildings to be taller, lighter, and more flexible, thereby exacerbating the impact of dynamic responses. There is a growing need for innovative and effective techniques to reduce the serviceability responses of these tall buildings. The current study considers a case study of a real building to show the effectiveness and robustness of the TLD in reducing the coupled lateral-torsional motion of this high-rise building under wind loading. Three unique multi-modal TLD systems are designed specifically to mitigate the torsional response of the building. A procedure is developed to analyze a structure-TLD system using High Frequency Force Balance (HFFB) test data from the Boundary Layer Wind Tunnel Laboratory (BLWTL) at the University of Western Ontario. The effectiveness of the unique TLD systems is investigated. In addition, a parametric study is conducted to determine the robustness of the systems in reducing the serviceability responses. Three practical parameters are varied to investigate the robustness of the TLD system: the height of water inside the tanks, the amplitude modification factor, and the structural modal frequencies.

• Smart Structures and Systems
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• v.4 no.1
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• pp.85-98
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• 2008

In this paper, excitation systems using a linear mass shaker (LMS) and an active tuned mass damper (ATMD) are presented to simulate the wind induced responses of a building structure. The actuator force for the excitation systems is calculated by using the inverse transfer function of a target structural response to the actuator. Filter and envelop functions are used to prevent the actuator from exciting unexpected modal responses and an initial transient response and thus, to minimize the error between the wind and actuator induced responses. The analyses results from a 76-story benchmark building problem for which the wind load obtained by a wind tunnel test is given, indicate that the excitation system installed at a specific floor can approximately reproduce the structural responses induced by the wind load applied to each floor of the structure. The excitation system designed by the proposed method can be effectively used for evaluating the wind response characteristics of a practical building structure and for obtaining an accurate analytical model of the building under wind load.

• International Journal of High-Rise Buildings
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• v.10 no.4
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• pp.251-263
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• 2021

Fire safety engineering is a critical specialization to include in the design of a tall building yet is often excluded from the Building Information Model (BIM) and integrated design process. The design of fire safety systems is interdependent with building/structural geometry, HVAC, mechanical, and electrical systems. A BIM is a 3D visual representation that stores data on these kinds of systems. The compatibility between BIM and fire safety design seems obvious yet has received a dearth of attention in structural (fire) engineering literature. The authors herein have reviewed over 40 recent papers on utilizing BIM for fire safety engineering, focusing on contemporary literature to obtain a more up-to-date review of the state-of-the-art. The resulting trends, technologies, research gaps, and methodologies are presented in this paper. Adoption of BIM in fire safety engineering is slow and behind other disciplines which may be improved if research involved more industry partners. For BIM technology to reach its potential, industry manufacturers need to provide high LOD fire BIM objects, fire engineers and researchers need to collaborate on future advancements, and building owners/management need to be educated on how to use the benefits provided.

• International Journal of High-Rise Buildings
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• v.3 no.2
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• pp.89-98
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• 2014

Employing tilted forms in tall buildings is a relatively new architectural phenomenon, as are the cases with the Gate of Europe Towers in Madrid and the Veer Towers in Las Vegas. This paper studies structural system design options for tilted tall buildings and their performances. Tilted tall buildings are designed with various structural systems, such as braced tubes, diagrids and outrigger systems, and their structural performances are studied. Structural design of today's tall buildings built with higher strength materials is generally governed by lateral stiffness. Tilted towers are deformed laterally not only by lateral loads but also by dead and live loads due to their eccentricity. The impact of tilting tall buildings on the gravity and lateral load resisting systems is studied. Comparative evaluation of structural systems for tilted tall buildings is presented.

• International Journal of High-Rise Buildings
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• v.11 no.1
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• pp.31-39
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• 2022

The seamless integration of the architecture and structure of a tall building plays a key role in establishing a recognizable and iconic design. The structural system developed for Shenzhen Rural Commercial Bank Headquarters (SRCBH) utilizes enhanced structural innovations unique to the tower's geometry to improve structural and sustainability performance. SRCBH utilizes a steel diagrid system pulled outside of the enclosure line with diaphragm forces resolved primarily by corner diagonal beams. During the design process the structural systems underwent performance based design and optimization for wind and seismic loading. Resiliency was prioritized for structural design as well as fire resistance. More closely integrating the structure of a building with its architecture and sustainability goals can lead to unique and innovative towers with a timeless expression.

• Proceedings of the Computational Structural Engineering Institute Conference
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• 2006.04a
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• pp.711-718
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• 2006

This paper aims to introduce a concept of the integrated structural design for the tall building using STEP(Standard for the Exchange of Product Model Data). STEP(ISO 10303) is an international standard for the computer-interpretable representation and exchange of product data and it provides a consistent data exchange format and application interfaces between different application systems. The structural systems for tall buildings are often controlled by the need to restrict wind responses at serviceability levels. In this study. the STEP entities for serviceability evaluation are proposed.