Construction Of Tall Buildings Research Articles

Do high-rise buildings influence melanoma? Tall buildings as positive externalities

Population growth, urban densification and shortage of available land make the construction of tall buildings increasingly prevalent. Given the world population growth, the volume of high-rise construction is steadily rising. Previous literature identifies skyscrapers as a potential source of negative externalities due to their high carbon footprints, and negative environmental features (reduction of sun light and wind-tunnel effects). The current study is the first to provide evidence supporting the notion that skyscrapers may also be considered a source of a positive externality. Based on data from 50 US states over a 19-year period (1999–2017), we demonstrate projected connection between the prevalence of melanoma and high-rise construction per state. This result might be attributed to the shadier environment created by these structures. Findings suggest that the annual projected increase in melanoma cases may be offset by approximately 53 additional high-rise buildings per state. Research findings may be of assistance to city planner. Potential saving associated with reduction of melanoma prevalence in terms of lost productivity and life lost should be considered. In addition, Caucasians with above 50 nevi as well as those with a personal or family history of melanoma should be encouraged to live in urban environments with tall buildings.

Vibration Analysis and Human Comfort Assessment of Building Subjected to Wind Dynamic Loads

AbstractIn the last few decades, Brazilian cities have presented a substantial increasing associated to the design and construction of tall and slender buildings. However, this architectural trend has produced flexible structural systems, with low natural frequency values and, therefore, more susceptible to excessive vibrations problems, when subjected to the nondeterministic wind loadings. Having these ideas in mind, this research work aims to study the dynamic structural response and evaluate the human comfort of a 40‐storey reinforced concrete building with 150 m high and floor dimensions of 30 m by 60 m. In this research work the Spectral Representation Method (SRM) was adopted to generate the wind nondeterministic dynamic loadings, based on the use of pressure coefficients calculated through the use of different strategies such as the HFPI‐TPU and DEDM‐HRP databases, CFD modelling and the Brazilian design standard NBR 6123. The numerical model developed for the reinforced concrete building dynamic analysis, adopted the usual mesh refinement techniques present in finite element method simulations and implemented in the ANSYS program. The main conclusions obtained in this work aim to alert the civil engineers to the relevant modifications associated with the dynamic response, when different strategies are used to calculate the wind pressure coefficients on the building's facade.

Effect of Axial Shortening of Column in Building with and without Soft Storey

The construction of tall concrete building became popular. As a result, we can see the problem of shortening of column due to huge loads carry by column .During construction of a tall building, the vertical elements would be subjected to a number of load increments. Each load increment would cause elastic shortening of columns. It will lead to long term creep and shrinkage shortening of such elements. Shortening of column cause effect on horizontal elements such as beams and slabs seriously. The slabs may not be truly horizontal after some time. Beams could be subjected to higher bending moments when connected to outer columns and inner shear walls. These could have certain structural effects and also could affect the nonstructural elements like damage to floor finishes, services etc.so it became important to study column shortening. In this paper we are going to study the influence of column shortening in case of building with and without soft storey once without considering construction stage analysis and once with considering it and also creep and shrinkage effect include in construction stage by using ETABS Software and comparing the effect.

Effect of Column Shortening in Tall Structure

In our country population growth increses day by day, increase in the land costs to satisfy large population specially in urban cities have made a door for construction of tall buildings. To economize land area, building height increased & the construction of reinforced cement concrete structure increases, during which shortening of column is reported which is become more significant with increase in height and impact the strength design and serviceability of the building. If column shortening is not addressed properly, it can impact the serviceability of the building as it impact on structural and non structural elements. So study of shortening of column in tall structure is importanat. In this paper the effect of column shortening in tall structure, in post construction stage analysis in which all loads applied in a single step, construction stage analysis and construction stage with time dependent effect analysis in which dead load, live load are released on building gradually as the construction progresses is carried on different strucutural system like frame, frame-shear wall and tube in tube system using ETABS software. In the analysis dead load, live load, lateral load due to wind load, earthquake load should be considered. The result obtained from this study gives idea about effect of column shortening in different method of analysis with different structural system and varying height of the structure.

Wind Design of Tall Buildings: The State of the Art

The construction of tall and slender buildings has seen recent growth in many cities around the world. Tall buildings are susceptible to dynamic excitation under wind effects which typically govern the structural design for strength, stability, and serviceability. This paper presents the state of the art in the analysis and design of tall buildings against wind effects. Structural design criteria are discussed in detail, with serviceability criteria relating to occupant comfort noted as being of particular importance. The latest in wind analysis tools and techniques is also presented. Wind tunnel testing remains the gold standard for determining wind loads on tall buildings, while the emerging use of computational fluid dynamics (CFD) is noted as being particularly useful for concept design stages. The paper aims to provide a valuable reference for engineers, architects, and designers involved in wind analysis and design of tall buildings.

Analysis of vertically irregular R.C structure using outrigger system

Tall building construction is quickly rising across the world, posing new issues that must be addressed by engineering judgement. The rigidity of a structure decreases as it becomes taller. As a result, in the current analysis of work, an outrigger system is recommended to increase the performance of the structure under seismic loading. The current effort includes a comparison study of regular and irregular buildings with and without outriggers, as well as a centrally stiff shear wall and steel bracings as outriggers. The construction is modelled with the "ETABS" application. To avoid causing harm to the structures, the limitations should be kept to a minimum. The outrigger is one of the maximum effective systems for efficiently controlling excessive lateral drift owing to lateral load, so that the danger of structural and non-structural damage may be avoided under minor or medium lateral loads due to either wind or seismic stress. This technique may be used to construct high-rise buildings, especially in seismically active areas. This research investigates the effective usage of outrigger systems in regular and irregular buildings with and without outrigger systems when exposed to earth quake loads.

Selection of the optimal diagrid patterns in tall buildings within a multi-response framework: Application of the desirability function

Diagrids are efficient structural systems for tall building design and construction due to their high lateral stiffness. Their structural response can be optimized by changing the geometrical pattern of external diagonals. This has usually been carried out by looking for the diagonal pattern that employs the minimum amount of structural material, while complying with strength and stiffness requirements. However, other responses can be significant for the selection of the optimal pattern, such as the torsional flexibility and construction complexity of the building. In this work, the desirability function approach has been used for selecting the optimal diagonal pattern for diagrid tall buildings in a multi-response framework. The most desirable diagonal layout has been selected based on its overall desirability to minimize: (i) the wind-induced lateral displacement, (ii) the torsional rotation, (iii) the diagrid structural weight, and (iv) the construction complexity. The application of this methodology straightforwardly provides the optimal diagrid pattern considering the four responses simultaneously. The method has been applied initially to a limited set of uniform-angle patterns, and afterwards to a wider population of varying-angle geometries. Four different floor plan shapes were also taken into account. The outcomes of the analysis revealed that the specific plan shape plays only a minor role in the definition of the optimal structure, whereas the diagonal layout affects greatly the efficiency of the solution. Uniform-angle diagrids are generally the most desirable, even for taller buildings, due to their higher performance in terms of torsional rigidity and construction complexity. Among these, the patterns in which the diagrid triangular module spans over two-three floors, corresponding to diagonal inclinations of about 55°–65°, have the highest desirability. Notably, because of the competition between the different responses, this optimal inclination is not found to increase as the building becomes taller.

Nonlinear Dynamic Structural Analysis of Buildings Considering the Wind Nondeterministic Actions

AbstractIn recent decades, the technological advances in civil construction have driven projects and construction of tall buildings in several countries. However, increasing the slenderness of the structural design has been crucial for reducing the natural frequencies values, generating, in some situations, excessive vibrations and human discomfort. This way, an aspect generally disregarded in day‐to‐day project practice is related to the geometric nonlinearity effect on the buildings structural response. Therefore, this work aims to assess the dynamic structural behaviour of a 48 floors and 172.8 m height steel‐concrete composite building, when subjected to nondeterministic wind actions. The results have indicated relevant differences when the geometric nonlinearity effect was included in the building dynamic analysis.

Towards understanding, estimating and mitigating higher-mode effects for more resilient tall buildings

Rapid urbanization has resulted in increased demand for tall buildings in many large and medium-sized cities around the world. Current code-based standards for seismic design are primarily aimed at minimizing life-safety risks under major earthquakes. While reinforced concrete (RC) high-rise buildings designed following current code requirements are expected to achieve collapse-prevention, the contribution of higher modes of vibrations to the dynamic response of these structures can produce seismic demands significantly larger than those obtained from prescriptive code-based procedures, causing unexpectedly higher structural and non-structural damage to these buildings. These imply considerable costs associated with the loss of residences and business operations as well as the post-earthquake recovery of cities. This paper presents a concise review of the current state-of-the-art and state of research pertaining to the understanding, estimation and mitigation of higher-mode effects on the seismic response of tall and slender RC structures. The paper is organized into four main foci: (1) analytical studies on understanding and quantifying higher-mode effects, (2) available experimental work on this topic, (3) advances in code practices in accounting for higher-mode effects in seismic design of RC tall buildings, and (4) recent developments in innovative systems intended to mitigate higher-mode effects in RC tall buildings. The paper concludes by briefly summarizing future challenges facing the construction of earthquake-resilient RC tall buildings that are essential in building resilient cities of the future.

Fire resistance of a fully concealed, moment-resisting new timber connection utilizing mechanically-fastened steel rods

One major hindrance to more utilization of timber in the construction of tall buildings is the limited fire resistance of the connections between its structural elements. In an experimental study that aimed to investigate the structural behaviour of a new connection configuration that utilizes fully concealed, mechanically fastened steel rods, eight (8) full-size glued-laminated timber beam-end connections were tested under the CAN/ULC-S101 standard time-temperature curve. Test variables investigated in this study included rod anchorage length (200 and 250 mm) and washer size (38.1 × 38.1 and 50.8 × 50.8 mm). Results show that using the smaller washer provided more wood side cover to protect the steel components from the effects of elevated temperatures. Also, utilizing longer rod anchorage length provided larger internal surface area of the wood prism to better resist shear stresses as well as longer length for the rods to bear against the wood at high rotation values of the connection. By combining the said two aspects (longer anchorage length and smaller washer) a fully concealed glulam beam-end connection that utilizes only two mechanically-fastened steel rods can be successfully designed to achieve a 1-h fire resistance without the application of additional fire protection.

Influence of the construction stages analysis on the distribution of displacement and forces in columns of reinforced columns tall buildings

The increasing construction of tall buildings in the world, as well as in Bulgaria, defines the desire for a more precise study of this type of structures. To satisfying this necessity, the possibility of carrying out nonlinear analysis of structures is included in many software packages. The question of the proper definition of material characteristics and the application of computational software in the design of structures with consideration of the stages of construction remains open. In addition to purely research, the problem has also a practical application related to the increasing number of tall buildings at different stages of design and construction. The issue of more accurate modeling of the behavior of tall buildings is discussed, with a focus on the distribution of forces and displacements in columns. A computational model of a tall building is considered. The distribution of forces and displacements in a computational model that accounts for the stages of construction is compared to one in which such consideration is not included. A comparison of the forces and displacements in representative sections of the columns in the two modeling options is presented as a result. Finally, general conclusions and recommendations for the research and design of tall buildings with reinforced concrete structure are given.

Effect of outrigger systems for tall buildings

The development of tall building construction is increasing worldwide today to meet the demands and challenges in construction industry. The intention of tall building construction is owing to population growth and lack of enough horizontal spaces. The rise in height of the tall building needs at most care on lateral stiffness of the structure where the introduction of outrigger trusses plays a vital role. In this paper, an investigation has been performed to study the behaviour of outrigger trusses on different locations of the building using response spectrum analysis. For this analysis, a three-dimensional building model is developed for G + 20, G + 26 and G + 30 storey RC building to find out the performance of outrigger trusses subjected to earthquake loading conditions. The performance analysis is evaluated by ETABS software and the analysis results were compared among lateral displacements, storey shear and storey drift to find out optimal position of outriggers and an efficient reduction of storey drift in a structure. It was observed that, the introduction of outrigger trusses at the bottom storey reduces considerable drift to enhance the stiffness of the structure.

On the Behavior of Coupled Shear Walls: Numerical Assessment of Reinforced Concrete Coupling Beam Parameters

Modern construction of high-rise and tall buildings depends on coupled shear walls system to resist the lateral loads induced by wind and earthquake hazards. The lateral behavior of this system depends on the structural behavior of its components including coupling beams and shear walls. Although many research studies in the literature investigated coupling beams and shear walls, these studies stopped short of investigating the coupled shear walls as a system. Therefore, in this research, the effect of the coupling beam parameters on the nonlinear behavior of the coupled shear walls system was investigated. The full behavior of a 10-story coupled shear wall system was modeled using a series of finite element analyses. The analysis comprised of testing several coupling beam parameters to capture the effect of each parameter on system response including load-deflection behavior, coupling ratio, crack pattern, and failure mechanism. The results indicated that a span-to-depth ratio equal to two is a turning point for the coupling beam behavior. Specifically, the behavior is dominated by ordinary flexure for a ratio of more than two and deep beam behavior for a ratio of less than two. This study showed that the coupling beam width does not have a significant effect on the coupled shear wall response. Additionally, it was concluded that the excessive coupling beam diagonal reinforcement could significantly affect the coupled shear walls behavior and therefore an upper limit for the diagonal reinforcement was provided. Moreover, limitations on the longitudinal and diagonal reinforcement and stirrups are presented herein. The analysis results presented in this paper can provide guidance for practitioners in terms of making decisions about the coupling ratio of the coupled shear walls.

Preliminary Design Proposals for Dovetail Wood Board Elements in Multi-Story Building Construction

Adhesives and metal fasteners play important roles in the composition and connections of engineered wood products (EWPs) such as cross-laminated timber and glue-laminated timber in the building construction industry. However, due to their petroleum-based nature, adhesives can cause toxic gas emissions, while metal fasteners compromise the end-of-life disposal and reusability of EWPs. These issues adversely affect the sustainable material properties of EWPs. Numerous studies have been conducted in the literature on the technological, ecological, social, and economic aspects of EWPs in construction with different construction solutions, but no studies have been conducted to evaluate the technical performance of dovetail wood board elements (DWBE) in multi-story or tall building construction. This study focuses on adhesive- and metal fastener-free DWBE as sustainable material alternatives for ecologically sensitive engineering solutions. Various preliminary design proposals are presented for DWBE using architectural modeling programs as an environmentally friendly approach intended for use in the timber construction industry. The research findings are based on a theoretical approach that has not yet been practically tested but is proposed considering existing construction practices that need further investigation, including technical performance tests. It is believed that this paper will contribute to the promotion and diffusion of DWBE for more diverse and innovative architectural and structural applications, particularly in multi-story timber building construction, as one of the key tools in tackling climate change challenges.

Twisted-wind effect on the flow field of tall building

Tall buildings in hilly terrain are very likely being attacked by topography-induced twisted wind. In this study, the effects of three wind profiles on second-generation benchmark building, i.e. conventional wind profile (CWP), two twisted wind profiles (TWP15 and TWP30) with maximum twisted angle (MTA) of 15°and 30°, are investigated by large eddy simulation. Wind tunnel tests under the same wind profiles are replicated to verify reliability of numerical results. Wind loads, flow motion, spatial correlation and mode patterns are comprehensively analyzed to elucidate underlying mechanism of TWP. The results show that with MTA increasing from 0° to 30°, mean lateral and torsional wind loads are significantly magnified while along-wind force is reduced, this variation is attributed to TWP-induced modification in flow field. Under TWP, fluctuating base moment are all weakened due to suppressed vortex shedding, moreover, fluctuating energy of DMD modes tend to accumulate toward low-frequency region, which could amplify background component of buffeting response. Notably, “twisted extensibility” is discovered in TWP, which magnifies vertical correlation and momentum exchange, thus generating larger torsional responses. These findings provide references for designing and constructing tall buildings in mountainous areas where twisted flows occur frequently.

DIALECTIC OF HIGH-RISE BUILDINGS AND SKYSCRAPERS AS GREEN SUSTAINABLE BUILDINGS

The low-rise development has always been compatible with Human nature, it has been the dominant trend and it is also compatible with the environment. At the same time, tall buildings, despite their rarity, constitutes an emblem of pride and a symbol of prestige and wealth .The process of constructing very tall buildings or skyscrapers is controversial in all fields. Very tall buildings are harmful to the environment and to their occupants, and from this standpoint there are those who reject them and see that they are an infringement on the environment. The truth is that there cannot be one simplified answer, because there are cases in which tall buildings are needed or justified, and in other cases the construction of tall buildings will become a problem.The balance between the two directions in the sense of when to build very tall buildings and when not to build, is what this research discusses .While there are places where tall buildings should be refrained from, such as areas of heritage value, nature reserves and areas where the sky line is affected, it has been shown that the use of skyscrapers or very tall buildings in some places may be logical and have positive economic and tourism effects, such as high-density city centers and waterfronts, which allows a large number of residents or users to benefit from the economic or visual advantages, also in high-density areas it gives a chance for the presence of open spaces, routes for car traffic and parking. Other places, especially where there is a conflict whether to construct tall building or prevent them, are studied on a case by case basis.Finally, if there is a necessity or a sovereign decision has been taken or a need for the construction of very tall buildings or skyscrapers, then building should be designed in a sustainable manner that reduces the negative and harmful impact on the residents and the surrounding environment, and set standards regulating this.

Research and Application of Fire Safety in Super Tall Building Construction

Research and Application of Fire Safety in Super Tall Building Construction

The effect of soil–structure interaction on the along-wind response of high-rise buildings

Rapid population growth tends to lead to the construction of tall buildings. It is thus necessary to study the influential parameters on the behaviour of tall structures due to wind action. Soil deformability is one parameter that can affect the aerodynamic behaviour of tall structures. In this work, the impact of wind on the standard tall building of the Commonwealth Advisory Aeronautical Research Council, placed on a raft footing, was numerically modelled using Abaqus software. The wind was defined by a power function in the boundary layer of the atmosphere. Stream turbulence was modelled using the implicit large eddy simulation technique and a co-simulation was used to exchange non-uniform loads from the fluid domain to the structural domain. The mechanical reaction of the footing–soil framework was modelled using a direct strategy. Infinite boundary conditions were added to the numerical model for simulation of free boundaries and appropriate contact elements for sliding and separation between subsurface components were considered. The fluid and structural solutions were compared with the mean and root mean square values of experimental estimations for an extensive range of reduced speeds. Numerical results for the framework with soil–structure interaction (SSI) were compared with those without SSI. The dynamic properties and reactions of the building subjected to wind loading were affected by the SSI and therefore engineers should consider these parameters to guarantee practical designs.

Analyzing shear strength of steel-concrete composite beam with angle connectors at elevated temperature using finite element method

Steel- concrete composite beams are widely used in the construction of tall building with steel floors. In these floors, the bearing capacity of beams in which the performance of concrete and steel is composite is more than 30% of the same beams with non-composite performance. Fire, especially in buildings, has a devastating effect on the components of the structure including the columns, beams, floors, etc. Also, fire indirectly affects the shear connectors buried in floor concrete and reduces their strength, thus reducing the overall strength of the floor. In this research, the behavior of angle shear connectors as a type of shear connectors used in the steel-concrete composite floor due to temperature increase was investigated numerically. Thermo-mechanical finite element modeling was performed using Abaqus software on push-out samples, and the results have been compared with the results obtained from the laboratory tests. Similar to the laboratory conditions, samples with different dimensions of angle shear connectors were modeled at different temperatures including 25, 550, 700 and 850 degrees Celsius. According to the laboratory process, 24 samples were modeled in Abaqus software thermally. The research results showed that the models made in the software were able to accurately predict the laboratory results including shear strength and slip. It was found that the maximum shear force error between analytical and laboratory results is 21.6% and the minimum shear force error in some samples is near to zero. As the temperature increases, the error rate between the laboratory and analytical results increases. Also, shear connector dimensions, concrete strength and temperature value have direct effect on the final strength of steel-concrete composite floors and load slip diagrams. It was also concluded that increasing the angle height to a certain extent could increase the final shear strength of the steel-concrete floor and increasing the angle height after a certain limit had no effect on increasing the shear strength and results in material loss and uneconomical design. Moreover, results indicated that increasing the temperature up to 850C leads to reducing the shear strength of the samples by approximately 56%.

Measurements of Local Sources of Particulates with a Portable Monitor along the Coast of an Insular City

The air quality of modern cities is considered an important factor for the quality of life of humans and therefore is being safeguarded by various international organizations, concentrating on the mass concentration of particulate matter (PM) with an aerodynamic diameter less than 10, 2.5 and 1 μm. However, the different physical and anthropogenic processes and activities within the city contribute to the rise of fine (<1 μm) and coarse (>1 μm) particles, directly impacting human health and the environment. In order to monitor certain natural and anthropogenic events, suspecting their significant contribution to PM concentrations, seven different events taking place on the coastal front of the city of Limassol (Cyprus) were on-site monitored using a portable PM instrument; these included both natural (e.g., dust event) and anthropogenic (e.g., cement factory, meat festival, tall building construction, tire factory, traffic jam, dust road) emissions taking place in spring and summer periods. The violations of the limits that were noticed were attributed mainly to the various anthropogenic activities taking place on-site, revealing once more the need for further research and continuous monitoring of air quality.