Structural Design Of Tall Buildings Research Articles

Integrating embodied greenhouse gas emissions assessment into the structural design of tall buildings: A framework and software tool for design decision-making

Integrating embodied greenhouse gas emissions assessment into the structural design of tall buildings: A framework and software tool for design decision-making

Structural performance of superframed conjoined towers

SummaryTall buildings have generally been developed as solo towers. As tall buildings become ever taller, how to produce reasonably increased structural depths against lateral wind loads and maintain desirable lease depths simultaneously are critical design considerations. Conjoined towers have great potential to resolve these structural and architectural design issues holistically. While many different structural configurations are possible for conjoined towers, the concept of superframed conjoined towers is a viable option for superior performance. In the superframed conjoined towers studied in this paper, multiple braced tube towers are connected also with horizontal braced tube link structures. Various parameters of the link structures, such as stiffness, numbers, and locations, impact the structural performance of the superframed conjoined towers. As the structural design of tall buildings is generally governed by lateral stiffness, this paper investigates the lateral performance of superframed conjoined towers with variously configured link structures. While emphasis is placed on static responses in relation to architectural design, basic dynamic properties are also studied.

A Structural Grammar Approach for the Generative Design of Diagrid-Like Structures

An innovative generative design strategy, based on shape grammar, is proposed for the minimum-weight design of diagrid tall buildings. By considering the building as a three-dimensional vertical cantilever beam with a tubular section under horizontal load, it is evident that bending and shear stiffness demands vary along the width and elevation of the building. Further, while the structural design of tall buildings is usually governed by stiffness, the predominant design criterion for diagrids could be the local strength demand, especially for low slenderness values, thanks to the inherent rigidity of the triangular pattern. Starting from these considerations, in this paper, a generative design strategy is proposed, able to find diagrid patterns that accommodate the differentiated stiffness demand along width/elevation and satisfy the predominant design criterion, stiffness or strength. The design strategy is applied to tall building models characterised by different slenderness values. The comparison to diagrid patterns analysed in previous literature works in terms of structural weight and performance parameters highlights the effectiveness of the design strategy and the efficiency of the generated patterns.

Stress lines inspired structural patterns for tall buildings

In this paper, an innovative diagrid-like pattern for tall building structures is proposed. Based on the concept of principal stress trajectories, the pattern is characterized by triangular units with angle varying along width and elevation, and, being the expression of forces flow arising in the building façades, it is expected to be highly efficient and visually appealing. The idea is to model the building as a three-dimensional vertical cantilever beam with tubular section under horizontal load, and to derive the relevant principal stress lines. Then, the stress analysis results are processed, and geometrical rules are derived for generating structural grids that also satisfy constructability constraints. For this purpose, a framework for implementing and managing the stress lines concept in the preliminary structural design of tall buildings is proposed. The efficacy of the generation procedure and the efficiency of the obtained structural patterns are then verified by means of the application to tall building models characterised by different slenderness ratios, and by means of comparisons with the performance and steel weight of conventional diagrid structures.

The influence of life cycle inventory approaches on the choice of structural systems to reduce the embodied greenhouse gas emissions of tall buildings

The construction of tall buildings generates a high spatial and temporal concentration of greenhouse gas (GHG) emissions. Research has shown that as building height increases, more resources per floor area are required to withstand the increasing effects of wind and earthquake loads. This has major implications for the environmental performance of tall buildings since the embodied GHG emissions (EGHGE) of structural systems tend to represent the greatest portion of the life cycle GHG emissions of tall buildings. In mitigating the effects of climate change, life cycle assessment (LCA) has been proposed as an early stage design tool to facilitate the choice of structural systems for tall buildings. However, international standards on LCA do not specify which of the three main life cycle inventory (LCI) approaches to use - process analysis, environmentally-extended input-output analysis or hybrid analysis. The aim of this paper is to evaluate the influence of LCI approaches on the choice of structural systems for tall buildings to minimise their embodied GHG emissions.The effects of LCI approaches on the choice of structural systems for tall buildings are evaluated using 10 tall buildings, ranging in height from 10 to 50 storeys, parametrically designed using finite element modelling. Two alternative structural systems are proposed and various LCI approaches are used to compare their EGHGE. The paper demonstrates that varying the LCI approach can significantly influence the values of EGHGE of structural systems for tall buildings by up to 116%. Notably, the paper demonstrates that, in minimising EGHGE, the adopted LCI approach can influence the choice of structural systems for tall buildings. The findings of this study confirm the need for clarity, transparency and comprehensiveness in the use of LCI approaches for comparative LCA studies, particularly in the structural design of tall buildings.

Main features and issues in the design of tall buildings in Bulgaria

In recent years, construction of tall buildings has been flourishing in many places around the world. In a considerable number of cases it is very much a matter of demonstrating financial and technological capabilities. Bulgaria is not isolated from these processes, mainly designing and building office, residential and hotel buildings with reinforced concrete structures. This requires systematization of information and experience in the design of tall buildings, as well as discussing the basic features and problems in the structural design of tall buildings and making recommendations based on existing experience and trends observed in the development of analysis methods and design. Basic issues related to height, architectural solutions, structural systems and other aspects that affect design solutions and problems related to these issues are discussed. The regulations related to the design of structures of tall buildings were commented on, with the main issues discussed mainly based on structural Eurocodes. The most important aspects of computer modeling of tall building structures and numerical analysis are discussed. Common problems related to the dimensioning and detailing of basic structural elements are commented. Finally, general recommendations are made for the research and design of tall buildings with reinforced concrete construction.

Framework for Balancing Structural Efficiency and Operational Energy in Tall Buildings

Buildings are responsible for a third of worldwide energy demand as well as anthropogenic greenhouse gas emissions. Therefore, a holistic approach for energy-efficient design over the life cycle of buildings is necessary. In this work, the relationships between structural efficiency, energetic performance, and aesthetic design are explored in the context of tall buildings. The goal is to reduce the structural mass in order to reduce embodied energy while considering operational energy as well as the aesthetic expression of the structure. For this, we propose a framework that integrates code-based structural design of tall buildings with energy demand simulations, and perform a multiobjective optimization for a tall building in various climate zones. We show that structure can act as shading, that is, cooling savings are achieved with respect to a fully glazed building. Further, we illustrate the trade-offs between buildings with reduced mass, with comparatively little cooling savings, and heavier buildings, with increased cooling savings potential, for example, up to 50%. Finally, we discuss the impact of the column design in different climate zones. The resulting trade-offs allow the architect to make an informed decision between structural design and energy efficiency of the building without sacrificing the architectural intent.

Comparative Evaluation of Structural Systems for Tapered Tall Buildings

Structural efficiency of tapered tall buildings has been well recognized, and many tall buildings of tapered forms have been built throughout the world. Tall buildings are built with an enormous amount of building materials. As one of the most efficient structural forms for tall buildings, the contribution of tapered forms to saving structural materials coming from our limited natural resources could be significant. Structural design of tall buildings is generally governed by lateral stiffness rather than strength. This paper systematically studies the structural efficiency of tapered tall buildings in terms of lateral stiffness. Tall buildings of various heights and angles of taper are designed with different structural systems prevalently used for today’s tall buildings, such as diagrids, braced tubes, and core-outrigger systems. The heights of the studied buildings range from 60 to 100 stories, and the corresponding height-to-width aspect ratios in their non-tapered prismatic forms range from 6.5 to 10.8. The angles of taper studied are 1, 2, and 3 degrees. Gross floor area of each building of the same story height is maintained to be the same regardless of the different angles of taper. Based on design studies, comparative evaluation of the various structural systems for tapered tall buildings is presented.

Assessment of earthquake-induced ground liquefaction susceptibility for Hanoi city using geological and geomorphologic characteristics

Assessment of earthquake-induced ground liquefaction susceptibility for Hanoi city using geological and geomorphologic characteristics

Comparison of Reduced-Order Models to Analyze the Dynamics of a Tall Building under the Effects of Along-Wind Loading Variability

Aeroelastic vibration, influenced by wind load effects, is relevant to the structural design of tall buildings. In the framework of performance-based design of wind load–sensitive structures, the effects induced by variability in the loading estimation, often relying on the results of a wind tunnel test, must be evaluated. This research is a continuation of a recent study by the author on the stochastic dynamics of tall buildings, contaminated by experimental errors, wind load uncertainty, and modeling simplifications. A number of reduced-order models are described and discussed. Among these models, a recently developed one that couples the along-wind dynamic response with intervention costs due to nonstructural damage on the external façade is considered. Even though the models assume a linear structural response dominated by the primary vibration modes and vortex shedding effects are not directly considered, they are sufficiently accurate for the purpose of evaluating, in a semianalytical form, the probability density function of the generalized dynamic response. The study examines the use of the reduced Fokker–Planck equation in high dimensions to derive the probability function of stationary wind response, depending on the mean wind speed and standard deviation of a parametric along-wind loading error term.

Sustainable structural design of tall buildings based on embodied energy

This paper deals with the environmental resources consumed to construct tall building structures; the consumption is measured by the energy required to obtain tall building structures and is expressed in terms of cradle-to-gate embodied energy.A reference structure composed of central core (made of reinforced concrete) and rigid frames (made of either reinforced concrete or steel) is considered. The reference structure is dimensioned and detailed for buildings from 20 to 70 stories; the embodied energy of each building is then estimated (total, of the components, per net rentable area).The results show that, if some design decisions are dictated by the embodied energy, the premium for height of the embodied energy is not substantial, which proves that tall building structures can be sustainable. However, a structure with the lowest weight does not imply the lowest embodied energy. The results also prove that the embodied energy depends mainly on the flooring system, and that steel consumes more embodied energy than Reinforced Concrete.Ultimately, the embodied energy is confirmed to be a viable tool to design sustainable tall buildings, and the results presented herein may address design toward minimizing the embodied energy, which means to save environmental resources.

Statistical extremes and peak factors in wind-induced vibration of tall buildings

In the structural design of tall buildings, peak factors have been widely used to predict mean extreme responses of tall buildings under wind excitations. Vanmarcke’s peak factor is directly related to an explicit measure of structural reliability against a Gaussian response process. We review the use of this factor for time-variant reliability design by comparing it to the conventional Davenport’s peak factor. Based on the asymptotic theory of statistical extremes, a new closed-form peak factor, the so-called Gamma peak factor, can be obtained for a non-Gaussian resultant response characterized by a Rayleigh distribution process. Using the Gamma peak factor, a combined peak factor method was developed for predicting the expected maximum resultant responses of a building undergoing lateral-torsional vibration. The effects of the standard deviation ratio of two sway components and the inter-component correlation on the evaluation of peak resultant response were also investigated. Utilizing wind tunnel data derived from synchronous multi-pressure measurements, we carried out a wind-induced time history response analysis of the Commonwealth Advisory Aeronautical Research Council (CAARC) standard tall building to validate the applicability of the Gamma peak factor to the prediction of the peak resultant acceleration. Results from the building example indicated that the use of the Gamma peak factor enables accurate predictions to be made of the mean extreme resultant acceleration responses for dynamic serviceability performance design of modern tall buildings.

A New Wind Vibration Control Strategy Based on Active Variable Stiffness

Based on the active variable stiffness, a new semi-active control method, whose principal content is using frequency control (FC), is presented. As a new semi-active algorithm, short time maximum entropy analysis is firstly proposed and the exact time and frequency signal at every control short time sequence also is given. The calculation results of a case of a 40-story building showed that the FC method is more effective than the results calculated by the method in the current structural design of tall buildings. The robustness of the algorithm is obtained and the displacement of the structure is reduced effectively.

An integrated design technique of advanced linear-mode-shape method and serviceability drift optimization for tall buildings with lateral–torsional modes

The advance to ever-taller and complex-shaped buildings requires a more accurate determination of dynamic wind loads for structural design purposes through wind tunnel tests. The three-dimensional (3D) mode shapes found in complex tall buildings complicate the use of the high frequency base balance (HFBB) technique for predicting wind-induced loads and effects. The linear-mode-shape (LMS) method was recently proposed to address some of the complications in the calculation of the generalised wind forces, which serve as the input to modal analysis for predicting wind-induced dynamic responses of tall buildings. The advanced linear-mode-shape (ALMS) method, a modification of the LMS method, is developed in this paper by introducing torsional mode shape corrections to take into account the partial correlation of torques over building height. The ALMS method is then incorporated into the accurate complete quadratic combination (ACQC) method to form a comprehensive framework to predict the equivalent static wind loads (ESWLs) for structural design of tall buildings. Then, an automated stiffness optimization technique integrated with the ESWL framework is developed for serviceability drift design of complex tall buildings with 3D mode shapes. A 60-storey building with an asymmetric structural system tested in a wind tunnel is used as an illustrative example. Encouraging results demonstrate that the integrated design optimization technique is able to produce a more economical element stiffness distribution of the example building, satisfying multiple serviceability wind drift design criteria while allowing for an accurate update and determination of the equivalent static wind loads under multiple wind angle conditions.

ON INTER-STOREY DRIFT LIMITATION OF STEEL–CONCRETE HYBRID STRUCTURES FOR TALL BUILDINGS

The inter-storey drift limitation is an important index for the structural design of tall buildings. The inter-storey drift limitation of steel-hybrid structures for tall buildings is studied in this paper. It is found that it is more reasonable to divide the inter-storey drift of steel–concrete hybrid structures into harmless part and harmful part. It is meaningful to limit the harmful drift for preventing the crack of concrete walls in hybrid structures. A formula to calculate the allowable harmful inter-storey drift with no cracks of concrete walls is deduced for hybrid structures for tall buildings. The effectiveness of the formula is verified through the FEM analysis of a typical tall building hybrid structure.

The effect of amplitude-dependent damping on wind-induced vibrations of a super tall building

Full-scale measurements of wind effects on a 70 storey tall building have been conducted. The tall building that has a height of 367 m is the second tallest structure in Hong Kong. The amplitude-dependent characteristics of damping have been obtained by using the random decrement technique from the field measurements of acceleration responses. The objective of this study is to present detailed investigations into the effects of amplitude-dependent damping on the wind-induced responses of the super tall building based on the measured non-linear damping and wind action characteristics. An efficient and less time consuming digital simulation technique is developed to generate time series of turbulent wind loads acting on the tall building based on the measured wind speed records. The predicted dynamic responses of the building using the actual amplitude-dependent damping characteristics are compared with those computed by using constant damping parameters assumed by the structural designers or estimated from the field measurements in order to evaluate the adequacy of current design practices and to apply that knowledge to structural design of tall buildings. It is observed from this study that the effect of amplitude-dependent damping on the dynamic responses of such a super tall building is significant and knowledge of actual damping characteristics is very important in the accurate prediction of wind-induced vibrations of a tall building.

An Innovative Approach to Structural Design of Tall Buildings

Structural design of a tall building involves several rather complex processes, or design activities, including data capture and modeling, conceptual design, structural analysis, structural detaili...

Distributed Multi-Reasoning Mechanism to Support Conceptual Structural Design

The conceptual phase of structural design involves selecting preliminary materials, selecting the overall structural form of the building, producing a rough dimensional layout, and considering technological possibilities. Decisions are made on the basis of such information as height of the building, building use, typical live load, wind velocity, earthquake loading, design fundamental period, design acceleration, maximum lateral deflection, spans, story height, and other client requirements. More detailed information about the task itself, constraints, possible solution principles, and known solutions for similar problems is extremely useful in the process of defining and finding a solution to the design problem. This paper presents the M-RAM, which is intended to assist engineers in the conceptual phase of the structural design of tall buildings by providing designers with adapted past design solutions generated by a distributed multi-reasoning mechanism. The objective of the M-RAM (Multi-Reasoning Model...