Tall Concrete Buildings Research Articles

The Impact of End Shear Walls on the Behavior of Reinforced Concrete Tall Buildings with Helipad for Personal Transportation

The Impact of End Shear Walls on the Behavior of Reinforced Concrete Tall Buildings with Helipad for Personal Transportation

Effects of Fluid Viscous Damper on Reinforced Concrete Tall Building under Lateral Loading in Lagos, Nigeria

The rapid construction of tall buildings in unconventional areas of Lagos, driven by high land cost necessitates meticulous analysis and design to withstand lateral loads such as wind and seismic forces. Typically, enhancing structural rigidity is the conventional approach to counteracting horizontal loads. This study examines the effectiveness of fluid viscous damping (FVD) in reducing gravity, wind and seismic loads in a 24 – story suspended floor frame structure. Using ETABS 2019 software, the building’s modeling and analysis demonstrate that integrating FVDs at each floor level significantly reduces displacement, drift and overturning moments by 20%, 24%, and 29%, respectively, thus enhancing structural stability. Analyzing structural response in Nigeria, despite low seismic intensity, is crucial for risk management and resilience. It informs building practices, improves building codes, and prepares for potential seismic events, ensuring safer infrastructure. This research provides a computational framework for dampening vibrations in tall buildings through FVD technology.

The Effect of Core Eccentricity on the Structural Behavior of Concrete Tall Buildings

The Effect of Core Eccentricity on the Structural Behavior of Concrete Tall Buildings

Ensuring Structural Integrity: An Evaluation of Vertical Shortening in Tall Concrete Buildings

Vertical shortening, a phenomenon inherent to concrete structures, plays a key role in the quality and safety of construction, particularly in tall reinforced concrete buildings. This behavior is intrinsically linked to the time-dependent properties of concrete, encompassing both creep and shrinkage. Neglecting these aspects, especially when non-uniformly distributed, can give rise to various structural issues, including partition distress, overloading, and potential cracking in horizontal elements. This paper delves into the principal factors influencing vertical shortening and presents a rigorous approach to their evaluation, treating creep and shrinkage as critical parameters. The investigation employs two illustrative case studies: the first revolves around a 15-story reinforced concrete building with single columns supporting tributary areas at various levels, acting as a calibration case; the second encompasses a 30-story reinforced concrete structure employing a dual system, providing a broader perspective applicable to three-dimensional structures. A diverse array of analyses is conducted, incorporating considerations for concrete’s linear and nonlinear behavior as well as the impact of construction stages. Our findings reveal that vertical shortening is directly proportional to the building’s height and inversely related to concrete strength, longitudinal reinforcement ratios, member dimensions, volume-to-surface ratios, age of the structure upon load application, and relative humidity. Consequently, precise assessments of differential shortening effects are paramount. The utilization of staged construction analysis and time-dependent effects is recommended as the most suitable approach for evaluating vertical shortening effects.

Seismic Assessment of RC Frame Building using Gross and Cracked Section as per IS 1893: 2016 and IS 16700: 2017

The primary objective of this research is to investigate the behaviour of tall concrete buildings featuring structural walls combined with Special Moment Resisting Frames (SMRF) when subjected to seismic loads, as defined by the IS 1893:2016 and IS 16700:2017 codes. To achieve this, a comprehensive seismic analysis was conducted using the Linear Dynamic Response Spectrum Method in ETABS 2020 software.

Evaluation of Reinforced Concrete Tall Buildings with End Shear Walls Subjected to Sequences Far from the Fault

Evaluation of Reinforced Concrete Tall Buildings with End Shear Walls Subjected to Sequences Far from the Fault

Seismic performance of concrete coupling beams subjected to prior nonlinear wind demands

The ability to assess the role of pre-existing damage on the residual (reserve) capacity and reparability of buildings following a damaging event or events is essential to achieving the goal of functional recovery. If performance-based wind design is applied, where limited nonlinear deformations in some elements are allowed under extreme wind events, or if a design earthquake occurs, there are likely to be a significant number of buildings with modest damage (in addition to some with more severe damage, that obviously need to be evaluated and repaired). For tall concrete buildings that utilize structural coupled (core) walls as the primary lateral force-resisting system, coupling beams are the main fuses that limit force demands on other elements and actions and provide a reliable mechanism for energy dissipation during extreme events, and thus, are most likely to impact building performance in future events and to require repair. Therefore, tests were conducted on eight coupling beams, seven reinforced concrete (RC) beams and one W-shaped steel-reinforced concrete (SRC) beam, subjected to simulated windstorm loading protocols that introduced modest nonlinear deformations followed by a standard seismic loading protocol to large inelastic deformations. The test variables included aspect ratio, presence of an RC floor slab, type of wind loading protocol, level of detailing, and type of concrete coupling beam (RC vs SRC). The findings indicated that the limited damage due to the prior wind demands did not impact strength, axial growth, rotation capacity, and failure mode of the beams under the seismic loading protocol; however, a significant reduction in the initial stiffness of all beams and a minor reduction in energy dissipation capacity of the conventionally reinforced beams were observed.

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.

COMPARATIVE STUDY OF MODIFIED CONSTRUCTION STAGE ANALYSIS AND CONSTRUCTION STAGE ANALYSIS FOR RC BUILDINGS

A significant difference is found in axial shortening of vertical members in tall concrete buildings when analyzed by Construction Stage Analysis considering the effect of creep and shrinkage as compared to the conventional One Step Analysis method. In Construction Stage Analysis the self-weight of structural members, and a load of brick walls along with floor finishing load, gets added sequentially as construction is carried out. In addition to the above loads, construction loads such as the weight of formwork, the weight of wet concrete, staking of materials, and other construction loads of men and machines get imposed on the structure during construction. Also, stagewise reduction of load due to removal of formwork, material staking, and other construction loads of men and machines should also be considered during the analysis with the Construction stage method. The axial shortening of vertical members of RC buildings was analyzed by the Conventional one-step method, Construction Stage method, considering self-weight along with brick wall and floor finishing load as sequential loads. Modified Construction Stage method-in which in addition to self-weight, brick wall, and floor finishing load, above mentioned all loads that appear during construction, were added, and removed sequentially in the analysis, by taking 20,30, and 40 floor RC building models. Modified CSA gives 2.068% to 20.56% lesser axial shortening in comparison to the CSA method. The study also concludes that the difference of axial shortening between Modified CSA & CSA increases from first to a certain floor, after that it reduces till top floor.

COMPARATIVE STUDY OF MODIFIED CONSTRUCTION STAGE ANALYSIS AND CONSTRUCTION STAGE ANALYSIS FOR RC BUILDINGS

A significant difference is found in axial shortening of vertical members in tall concrete buildings when analyzed by Construction Stage Analysis considering the effect of creep and shrinkage as compared to the conventional One Step Analysis method. In Construction Stage Analysis the self-weight of structural members, and a load of brick walls along with floor finishing load, gets added sequentially as construction is carried out. In addition to the above loads, construction loads such as the weight of formwork, the weight of wet concrete, staking of materials, and other construction loads of men and machines get imposed on the structure during construction. Also, stagewise reduction of load due to removal of formwork, material staking, and other construction loads of men and machines should also be considered during the analysis with the Construction stage method. The axial shortening of vertical members of RC buildings was analyzed by the Conventional one-step method, Construction Stage method, considering self-weight along with brick wall and floor finishing load as sequential loads. Modified Construction Stage method-in which in addition to self-weight, brick wall, and floor finishing load, above mentioned all loads that appear during construction, were added, and removed sequentially in the analysis, by taking 20,30, and 40 floor RC building models. Modified CSA gives 2.068% to 20.56% lesser axial shortening in comparison to the CSA method. The study also concludes that the difference of axial shortening between Modified CSA & CSA increases from first to a certain floor, after that it reduces till top floor.

Seismic performance of a high-rise building by using linear and nonlinear methods

In this paper, the seismic behavior of the existing reinforced concrete tall building is investigated by using the linear and nonlinear dynamic methods. The selected existing reinforced concrete structure was designed according to Turkey Seismic Code-2007. The performance analysis according to the Turkey Building Earthquake Code-2019 is realized in a 41-story reinforced concrete shear wall-framed structure in Istanbul where active fault lines are located. For high-rise building, firstly, spectrum analysis according to mode superposition methods of linear computational methods used within the scope of strength-based design is performed. Turkey Building Earthquake Code-2019 advises a nonlinear deformation-based design approach to determine more accurately the behavior of high-rise building, as in the earthquake regulations of other developed countries. In addition, the nonlinear time history analyses of building were performed. At the end of the study, torsional irregularity is seen on the normal floors and intermediate floor; stiffness irregularity was found on second floors. In addition, it has been observed in some of the oblique columns of the building that load bearing capacities were exceeded due to creep, axial compressive loads and severe damages occurred. According to the Turkey Building Earthquake Code-2019, the high-rise reinforced concrete shear wall building is not expected to satisfy life safety performance levels under design earthquake.

Effect of roof garden weight on the seismic fragility of relatively tall concrete wall buildings

Effect of roof garden weight on the seismic fragility of relatively tall concrete wall buildings

RC 고층건물 성능기반 내풍설계의 적용성 연구

In this research, a case study and research on performance-based wind design of reinforced concrete tall building was carried out. To introduce inelastic behavior, resonant component was reduced by half in initial design, and its inelastic performance was verified. Modeling methods for inelastic behavior were presented. For projects with frequent design changes, time history wind loads were generated from power spectral density functions presented in design codes. And considerations for time history generation for nonlinear analysis were presented. Although the building was designed by reducing resonant component, the inelastic behavior was shown only from horizontal members, and their plastic rotations satisfied the immediate occupancy performance level.

Seismic collapse risk of reinforced concrete tall buildings in Istanbul

Seismic collapse risk of reinforced concrete tall buildings in Istanbul

Concrete: Previous and Future Technologies

The analysis for development of both theoretical and applied research summarizing all the previous experience for application of the concrete as a construction material through the ages is presented herein. Current construction practice with application of high-efficient concretes as well as some new widely applied efficient binding substances, modifiers for binding substances and fillers, active mineral additives and fillers, as well as new technological techniques and methods for making construction composites of hydration hardening are considered in details. Low power-consuming processes, making of mixed and specialty cements and nanomodified concretes are demonstrated to be the main trends in development of the researches almost around the world. Therewith, the concrete properties are likely to be predicted with durability and operational reliability thereof being increased, and the outlook for improving concrete quality and technological advances, application of various technological wastes in the concrete making, in particular, for the Republic of Bashkortostan as the developed petrochemical cluster, of wastes, end products and by-products of different petrochemical industries. Some engineering concepts with application of high strength concrete grades in the Republic of Bashkortostan are given. The research results are applied in engineering and construction of reinforced concrete tall buildings both in Ufa and in the Republic of Bashkortostan.

Seismic performance of reinforced concrete tall buildings with conventional and non-conventional construction systems

Currently in the city of Lima there is a limited number of high-rise buildings. Therefore, there is not much literature on this type of building in Peru. Peruvian codes focus on medium and low-rise buildings. For this reason, studies are required to analyze and design these tall buildings more appropriately according to the reality of the country. In this article, a pushover modal analysis of 6 types of 35-Story reinforced concrete buildings in the city of Lima will be developed. Three building models with different structural systems and square and rectangular plan are proposed, being the areas of 29m × 29m and 52m × 26m respectively. These structural systems are rigid core and frames with an energy dissipation system (fluid viscous dampers and shear-link-bozzo dissipators SLB) in order to study their behavior against seismic stresses. These buildings were based on the criteria and requirements of the current codes in the country as well as the distribution of the floor plan of buildings commonly used for offices and homes. Natural periods (T) were found to range from 2.6 to 3.3 seconds for rigid core buildings. There is an increase for viscous damping buildings from 4.2 to 5.4 seconds and also for SLB devices to range from 3.7 to 4.6 seconds. In turn, modal static nonlinear analysis was performed to obtain the capacity curves for each type of building, which were compared with the seismic demands according to the design provisions of the Peruvian seismic standard E.030 and an average of design spectra. of acceleration records of severe seismic events in Peru and scaled in a range of 0.2T to 1.5T. The performance points for each building case were determined following the ATC-40 methodologies, finding that tall buildings with a rigid core have approximately twice the stiffness of buildings with SLB dampers, as well as low ductility, unlike buildings with dissipators, that have a high ductility.

Influence of wind speed on a Reinforced Concrete tall building

This study is conducted to assess the influence of wind on a 17-storey multipurpose Reinforced Concrete Tall Building according to the revised wind code of IS 875 (Part 3): 2015 compared to its previous version i.e., IS 875 (Part 3): 1987. The study covers all basic wind speeds of 33, 39, 44, 47, 50 and 55m/s as specified in the Indian standards. Dynamic effects due to ‘Along wind’ and ‘across wind’ are considered in the analysis using ETABS evaluation software. The Lateral load, Lateral sway and Longitudinal Rebar Percentage (LRP) are found to be increased as per the revised version. The LRP in the Middle, Edge and Corner columns are also reported. An increase of total Rebar quantity by about 3.7% (beams and columns) in the entire structure for a basic wind speed of 50m/s is observed.

Seismic Fragility Curves for Tall Concrete Wall Building in Malaysia Subjected to Near-Field Earthquakes

Tall buildings have been widely constructed in Malaysia, and most of them have been designed only for gravity and wind loads. This study addresses the seismic vulnerability of two tall concrete wall buildings in Malaysia through the framework of seismic fragility curves. The studied buildings shared a similar plan, but the first building had five parking levels while the second building had three parking levels. The structural system of both buildings at the parking levels was an ordinary moment-resisting frame, and at the residential levels was a low-ductile concrete shear wall system. The reference structures were subjected to 15 near-field earthquake records. Fragility curves were obtained by relating the inter-story drift demands to the peak ground accelerations using a reliable statistical model. It was observed that in both buildings, the probability of exceeding minor damage to the exterior frame was larger than that of the interior frame. Besides, a decrease in the number of parking levels increased the probability of collapse. It was also found that only minor damage was expected for tall concrete wall buildings in Kuala Lumpur when subjected to near-field earthquakes.

Seismic Performance of Bracing, Diagrid and Outrigger System

In this paper bracing, diagrid and outrigger system have been analyzed for comparing the seismic performance of multistorey buildings. Bracing system is a very efficient system which can be used as a lateral load resisting system in concrete and steel buildings, in this system lateral loads are transferred through lateral bracing by undergoing in tension and compression .diagrid is another effective and efficient system that can be used as lateral load resisting system in steel and concrete tall buildings, in this system lateral loads are transferred by inclined members of the building. Another very effective system which commonly used for resisting lateral loads in concrete and steel high rise building is outrigger system, in this system lateral loads will be resisted by outrigger belt truss and core shear wall. Location and number of outrigger and type of bracing is very important which needs to be optimized in this system. In this paper comparison of bracing, diagrid and outrigger system have been studied on a 24 storey by using a standard package of ETABS 2017.

WIND ANALYSIS OF TALL BUILDING

Tall building is an emerging construction practice in Indian metropolitan cities due to large urbanization. The design criteria for tall buildings are different than low and mid-rise buildings. In tall buildings usually, the wind is the critical load that needs to be considered for the safety and serviceability of the structure. Any tall building can vibrate and oscillate in both the directions due to along-wind and across-wind. These oscillations may even cause discomfort to the occupants even if it is not in a threatening position for the structural damage. So, an accurate assessment of building motion is an essential prerequisite for serviceability. National building code and other Indian standard codes are not sufficient to adequately address various issues related to tall buildings. Recently, IS 16700: 2017 “Criteria for Structural Safety of Tall Concrete Buildings” is released by BIS for tall concrete buildings. This Work deals with the detailed wind analysis of 180m tall building as per IS 16700: 2017. In which wind tunnel studies will be carried out on a scaled-down model of a proposed tall building. This wind tunnel studies have also been compared with the responses computed analytically and also check and satisfy all the criteria as per this code.