Design of Tall Buildings

The main objective of the study is to achieve the seismic response of the complex shape structures i.e. (Plus/ cross shape, L-shape, T-shape, I-shape, and U-shape) having same surface area for G+10 storey building and compare them by their seismic parameters. All the buildings have been analyzed by using ETABS 2016 software to conclude the most suitable and most vulnerable configuration among all these complex shape structures. Linear static analysis method has been adopted in this study. Seismic parameters such as displacement, story drift, modal time period and frequency have been compared to find out the most suitable shape among. The result shows that cross shape building is more stable comparing to all other shape of the building and L shape building is the most vulnerable among them. The study also shows that irregular shape building produces more deformation and displacement. The study also shows L shape building is more flexible and plus shape building is more rigid than other types of buildings.

The main objective of the study is to achieve the seismic response of the complex shape structures i.e. (Plus/ cross shape, L-shape, T-shape, I-shape, and U-shape) having same surface area for G+10 storey building and compare them by their seismic parameters. All the buildings have been analyzed by using ETABS 2016 software to conclude the most suitable and most vulnerable configuration among all these complex shape structures. Linear static analysis method has been adopted in this study. Seismic parameters such as displacement, story drift, modal time period and frequency have been compared to find out the most suitable shape among. The result shows that cross shape building is more stable comparing to all other shape of the building and L shape building is the most vulnerable among them. The study also shows that irregular shape building produces more deformation and displacement. The study also shows L shape building is more flexible and plus shape building is more rigid than oth...

This paper argues for sustainability as a necessity in the evolution of tall architecture. It provides a different mode for dealing with sustainability in tall architecture, taking into consideration the speciality of its typology. To this end, the article develops a Biomimetic Structural Form as a paradigm to attain Vital Sustainability. A Biomimetic Structural Form, which is derived from the amalgamation of biomimicry as an approach for sustainability defining nature as source of knowledge and inspiration in solving humans' problems and a Structural Form as a catalyst for evolving tall architecture, is a dynamic paradigm emerging from a conceptualizing and morphological process. A Biomimetic Structural Form is a flow system whose different forces and functions tend to be "better", more "fit", to "survive", and to be efficient. Through geometry and function—the two aspects of knowledge extracted from nature—the attributes of the Biomimetic Structur...

Since the construction sector ranks among the world's most dangerous industries, the Health and Safety Management Plan (HSMP) has been introduced as a strategic framework designed to outline systematic procedures for identifying potential hazards, assessing risks, and implementing control measures. It also encompasses safety training, supervision, and the establishment of emergency response protocols. When HSMPs are effectively implemented, they are expected to reduce the incidence rates prevalent in the industry. This study evaluates the level of awareness regarding HSMPs among stakeholders on high-rise building projects in Abuja, Nigeria, with a view to bridging the gap between awareness and implementation. The study adopted a mixedmethods approach to analyse the opinions of construction professionals and workers engaged in high-rise projects within the Central Area of Abuja, Federal Capital Territory (F.C.T). Twenty-nine (29) sites, collectively employing an estimated 1,015 workers (based on an average workforce of 35 personnel per site), were surveyed. Through the use of structured questionnaires, the findings reveal that respondents demonstrate a moderately high to high awareness of HSMPs across the construction industry in Abuja. This suggests that while the general concept and purpose of HSMPs are well understood, stakeholders are less knowledgeable about specific regulatory requirements and technical documentation unique to Abuja. Consequently, it is recommended that the government and regulatory authorities strengthen targeted awareness and enforcement of HSMP protocols.

Experimental study was carried out on rigid model of a square plan tall building made of Perspex sheet in a closed circuit wind tunnel under boundary layer flow. Wind pressure coefficients are calculated from wind pressure values measured at many pressure points on all 4-wall surfaces of the model. Purpose of the study is to generate large amount of data for the designers to be able to design structural frame as well as wall claddings safely under wind loads. The results of the experimental study are presented in the form of pressure contours.

The wind different forms i.e. cyclones, hurricanes, storms, tornados, etc., loads various structures which come in their way. To minimize the wind effects, different techniques have been used and geometrical modification is one of them. In this study, the pressure variation on a geometrically modified high-rise corner-cut building having interference has been evaluated. The study is carried out using ANSYS FLUENT in which CFD simulation is carried out for the different models at different wind incidence angles viz. 0°, 45°, and 90°. Two building models are used in this study, one is high rise Corner-cut building, which is called the principal or primary building. The other is a high-rise rectangular building, which is called interfering or secondary building. The results obtained in case of interference are then compared to that of an isolated corner-cut building. In general, from the present investigation, it is noticed that the suction effect increases due to the interference effect. When wind strikes obliquely the effect of interference is relatively lower.

The purpose of the study was to explore the interference effects on the wind-induced moment caused by two nearby high-rise structures. In order to use computational fluid dynamics (CFD), a stiff full-scale model of the buildings was created. Numerous wind incidence angles and two alternative model cross sections were used in the investigation. Additionally, it was looked at how building heights and aspect ratios affected interference effects. The findings showed that when there was a close proximity between the structures, the interference effects on the wind-induced moment were most noticeable. The study also showed that interference effects were more evident for structures with greater aspect ratios. The degree of interference effects was also greatly influenced by the angle of wind incidence, with perpendicular wind directions having the greatest effects. These results underline how crucial it is to carefully examine the positioning and orientation of high-rise structures when ma...

Roof shape and slope are both important parameters for the safety of a structure, especially when facing wind loads. The present study demonstrates the pressure variations due to wind load on the pyramidal roof of a square plan low-rise building with 15% wall openings through CFD (Computational Fluid Dynamics) simulation. Many studies on roofed structures have been performed in the past; however, a detailed review of the literature indicates that the majority of these studies focused on flat, hip, gable and spherical roofs only. There is a lack of research that analyses these effects on pyramidal roof buildings. ANSYS (Analysis System) ICEM (Integrated Computer Engineering and Manufacturing)-CFD and ANSYS Fluent commercial packages have been used for modelling and simulation, respectively, and ANSYS CFD Post was used to obtain the results. A realizable k-ε turbulent model was used for the pressure distribution on the roof of the building model. In the present study, twenty-four models with different roof slopes (α), i.e. 0°, 10°, 20°, and 30°, with various wind incidence angles (ϴ), i.e. 0°, 15°, 30°, 45°, 60° and 75° were investigated. The influence of roof slope and wind incidence angle are analysed in this study. Results have been represented through pressure coefficient (Cp) contours on the roof surface and velocity streamlines of the flow field of the different cases. The optimization of the roof slope may be achieved by considering different wind incidence angles for buildings so that they may better withstand wind force in a specific area. When wind pressure coefficients from building models with openings were compared with pressure coefficients from building models without openings, it was found that the pressure coefficients for building models without openings are almost twice or three times that of the pressure coefficients for models with openings. Wind pressure • Roof slope • Pyramidal roof • Wall openings • k-ε Turbulence model • Pressure coefficients • Wind incidence angle * Jagbir Singh

Elevators and escalators are the crucial element that makes it practical to live and work several floors above ground – more than 4,3 million units are installed in Europe. Due to ageing of the European population the installation of elevators in sin-gle family houses is experiencing a significant growth, as well as equipping existing buildings. Elevators use about 4% of the electricity in tertiary sector buildings. High untapped saving potentials exist with respect to energy-efficient technologies, investment decisions and behavioural approaches, in these sectors. This paper presents preliminary results from the IEE project E4, whose overall objective is the improvement of the energy performance of elevators and escalators, in tertiary sec-tor buildings and in multi family residential buildings. The project is characterizing people conveyors electricity consumption in the tertiary sector and in residential buildings in the EU. The installed park is characterised by a survey among e...

Elevators and escalators are the crucial element that makes it practical to live and work several floors above ground. In the EU-25 there are more than 4,8 million elevators and 75 thousand escalators and moving walks. Elevators use about 4% of the electricity in tertiary sector buildings. This paper presents a technical analysis to the final results of the audits performed in the scope of IEE project E4, whose overall objective is the improvement of the energy performance of elevators and escalators, in the tertiary sector and in the multifamily residential buildings. A total of 82 equipments have been measured, and a collection of load curves, including the characterization of standby consumption, is also presented. There is a high energy savings potential with respect to energy-efficient technologies, investment decisions and behavioral approaches, in these sectors. The E4 project characterized people conveyors electricity consumption in the tertiary sector and in residential buildings in the EU-27, according to a common developed methodology. Standby consumption of an elevator can represent up to 80% of the total energy consumed per year, and can be drastically reduced (more than 65% is possible), by reducing the standby consumption and using more energy efficient technologies.

Robust active controllers, designed to seismic excited building structure facing to parametric uncertainties (variations in mass, stiffness, damping coefficients…etc) were studied these last years with recent focus to non parametric ones (time delay, actuator saturation…etc). This study presents an evaluation of the robustness to variations in the model parameters of a three floors seismic exited structure (stiffness and damping coefficients) and modelling errors in the actuator dynamics of a robust controller designed on the base of the μ-synthesis approach chosen for its ability to directly incorporate performance and robustness objectives into multivariable control design. To further check the controller designed, we perform simulations using state feedback control and a seismic excitation source modelled by Kanai Tajimi filter attacked by a white noise. The resulting controller achieves closely similar performances (level of vibrations attenuation) in nominal and worst case of u...

Designing a high rise building has its challenges. Different structural systems have been developed to control the lateral displacement of high rise buildings. One of these systems is called the outrigger which decreases both the horizontal movement of the structure and the moment on the foundation of the structure. However the location of the outriggers has an immense influence on the efficiency of the structure. Outrigger optimization is a significant challenge. The objective of this thesis is to give a better understanding of outrigger location optimization and the efficiency of each outrigger when several outriggers are used in the structure. An optimization is also performed on a certain configuration of an outrigger to a concrete core. Finally a program has been developed that enables the user to analyze a structure with up to 10 outriggers.

The development of high-rise buildings in Nigeria has been experiencing drawbacks. The retarding growth translates to the very fewness of high-rise buildings in existence in Nigerian cities just as even most of the few in existence are poorly utilized due to some persistent factors. A current trend in modern cities all over the world is the development of high-rise buildings mainly to overcome the challenges of urban over population, for optimal use of scarce land resources, as status symbol, as tourist attractions and for beautiful skylines. From the existing literature, only few research were conducted in this very important aspect of real estate profession. The data used in this research was obtained through physical inspection and careful observations of the elevators (lifts) in some selected high-rise commercial buildings within the area of study.  Samples of 2500 tenants, 25 Property Management Companies and 70 visitors or clients were selected. The sampling procedure used inc...

In a windy morning of March 17, 2013, a warehouse belonged to Asiacell Telecom collapsed during construction. The structure was a relatively large 108m by 48m double-span steel portal frame designed by an Iranian engineering firm and constructed by a local construction company. This catastrophic structure collapse that killed three workers and injured few, was a sudden failure that triggered an intense investigation to determine the cause to avoid the occurrence of the same mistake in the future. This research paper is the product and outcome of the forensic structural analysis performed by the author for Asiacell that indicates the exact reasons behind the catastrophic failure. It provides the evidence to be a lesson-learned document for the future steel structure construction in Iraqi Kurdistan.

The research by non-military research associations and assemblies on explosion have increased due to the growth in the death and damage rates resulting from explosion, particularly blasts induced by terroristic invasions which mostly occur on the ground. Most studies are conducted with a major focus on strengthening the structures against explosions. Further, scholars have focused on resistance and ductility criteria required for the design and control over structural elements. Now, the question is whether the health of a structure can represent its inhabitants' health. Few studies have been done on the convenience of inhabitants and response of non-structural elements, which are limited to impact of vibrations on high-rise structures caused by the loads imposed by wind and earthquake. The important factors relevant to the health and convenience of building inhabitants are as follows: speed, acceleration, and variations in the acceleration of floors. In this paper, the aforementioned parameters are measured, according to which the convenience and health of inhabitants were assessed. For this purpose, two 4-story and 8-story buildings were selected on which four selective explosions were applied. The results were then presented in two forms of maximum values and dynamic response by performing dynamic modal linear time history analysis. The building's response under typical forces such as dead and live and earthquake forces was remarkably desirable and the behavior remained linear, but the building's acceleration may cause serious injuries in terms of human comfort criteria. The obtained results indicated that the healthy state of the structure does not represent the health of the building inhabitants. Further, although the building was safe against the elective blasts, the lateral accelerations were capable of imposing significant damages to the building residents. This can be considered as a criterion for control and future designs from a passive defense point of view, as the explosions induced by terroristic attacks is increasing.

The determination of fundamental period of vibration for structures is essential to earthquake design. The current codes provide empirical formulas to estimate the approximated fundamental period and these formulas are dependent on building material, height of structure or number of stories. Such a formulation is excessively conservative and unable to account for other parameters such as: length to width ratios, vertical element size and floors area. This study investigated the fundamental periods of mid-rise reinforced concrete moment resisting frames. A total of 13 moment resisting frames were analyzed by ETABS 15.2.2, for gross and cracked eigenvalue analysis and Extreme Loading for Structures Software® or ELS, for non-linear dynamic analysis. The estimated periods of vibration were compared with empirical equations, including current code equations. As expected, the results show that building periods estimated based on simple equations provided by earthquake design codes in Europe (EC8) and America (UBC97 and ASCE 7-10) are significantly smaller than the periods computed using nonlinear dynamic analysis. Based on the results obtained from the analyzed models, equations for calculating period of vibration are proposed. These proposed equations will allow design engineers to quickly and accurately estimate the fundamental period of moment resisting frames with taking different length to width ratios, vertical element size, floors area and building height into account. The interaction between reduction factor and the reduced period of vibration is studied, and it is found that values of maximum period of vibration can be used as an alternative method to calculate the inelastic base shear value without taking reduction factors in consideration.

This paper examines the application of BRB in strengthening of reinforced concrete frame structures to meet seismic requirements according to Chinese seismic design code. Elastic response spectrum analysis and nonlinear time history analysis are performed by taking a real engineering example that suffers weak first floor irregularity due to added loads and addition of one floor. With the method of equivalent stiffness and displacement-based design method, buckling restrained brace parameters are deduced and are used to model BRB in ETABS using plastic wen model. Three configurations of buckling restrained braces are studied together with ordinary braces. Under elastic state, the relationship between the required cross section area of BRB and ordinary braces is deduced from the formula of calculating elastic bearing capacity where it is shown that the area of the ordinary braces must be 1.25 times that of BRB for ensuring the same performance. The results show that Inverted V brace configuration demonstrated better performance over single brace and V brace configurations and X brace configuration, although not recommended by Chinese code, is simulated and used in this paper and has demonstrated better performance over other configurations, and the further research on the practical use of this brace is recommended. Also, under action of strong earthquakes, by nonlinear time history analysis, buckling restrained braces demonstrated better performance of strengthening the structure and make it meet the requirement of code. Under this same condition, ordinary braces losses their bearing capacity due to excessive buckling.

Prestressing in structure increases ratio of load-bearing capacity to weight. Suspendomes are single-layer braced domes reinforced with cable and strut. Prestressing of cables alter value and distribution of stress in structure. In this study two configuration, diamatic and lamella domes is selected. Investigated domes have span of 100m with rise-to-span ratios of 0.1, 0.2, and 0.3. Single layer domes loaded under service load combinations according to ISO code. After geometric nonlinear analysis, models are designed with tubular and I-shaped sections then reinforced with cable and strut and converted to suspendomes. Displacements and stresses of some groups of nodes and elements in all of single-layer domes and suspendomes for three load combinations, symmetric snow, asymmetric snow and wind are compared. Variation due to suspending system is investigated. Suspendomes are redesigned and minimum possible weight after addition of cable and strut is obtained.