Comparative study on seismic performance of specially shaped RC columns with that of rectangular columns in high-rise structures

2019 ◽  
Vol 11 (2) ◽  
pp. 202-215
Author(s):  
Shanmukha Shetty ◽  
Subrahmanya R.M. ◽  
Sushanth Bhandary ◽  
Thushar Shetty
Keyword(s):  
Pushover Analysis ◽  
Geometrical Shape ◽  
Structural Elements ◽  
Base Shear ◽  
Percent Reduction ◽  
Rc Columns ◽  
Content Type ◽  
High Rise ◽  
Rc Frames ◽  
Rectangular Columns

Purpose Columns are structural elements that are predominantly subjected to compressive forces and moments that are to be transferred from the super-structure to the sub-structure. The geometrical shape of a column is a significant factor to be considered. The paper aims to discuss this issue. Design/methodology/approach Pushover analysis is carried out, to study the behavior of RC frames with rectangular and specially shaped columns for the same building layout. Findings Reduction of 27.3 percent in base shear, 67.4 percent in spectral displacement, 66.5 percent reduction in storey displacement, 70.22 percent in storey drift and 0.315 percent reduction in storey shear is observed. Practical implications Special shaped RC columns can effectively enhance the structural behavior of high rise structures under seismic excitation in comparison to those with regular shaped RC columns. Originality/value Applications of special shaped columns in structures have showed a great deal of reduction in displacement and shear forces developed due to seismic activity, for the same area of concrete and steel as in rectangular columns.

Analysis of Seismic Performance of RC Frames with Centrally Reinforced Columns

2013 ◽  
Vol 671-674 ◽  
pp. 1319-1323
Author(s):  
Zi Xue Lei ◽  
Yu Hang Han ◽  
San Sheng Dong ◽  
Jun Qing Guo
Keyword(s):  
Seismic Performance ◽  
Cross Sections ◽  
Carrying Capacity ◽  
Pushover Analysis ◽  
Seismic Load ◽  
Load Carrying Capacity ◽  
Rc Columns ◽  
Rc Column ◽  
Rc Frames ◽  
Load Carrying

A centrally reinforced column is a new type of RC columns, formed by providing a reinforcement skeleton at the central part of the cross section of an ordinary RC column. Tests have shown that as compared with an ordinary RC column, this type of columns has a higher load carrying capacity and ductility. From the pushover analysis of a frame composed of ordinary RC columns and one consisting of centrally reinforced columns, their seismic performance under seismic load of 9-degree intensity was studied according to Chinese code, including target displacements, story-level displacements, interstory drifts, appearance and development of plastic hinges. The results indicate that although the dimensions of cross sections of columns in the frame with centrally reinforced columns are smaller than those of the ordinary frame, the former still has a higher overall load carrying capacity and seismic performance than the latter.

scholarly journals SEISMIC EVALUATION OF HIGH RISE BUILDING WITH VERTICAL IRREGULARITIES BY PUSHOVER ANALYSIS

2021 ◽  
Vol 6 (2) ◽  
Author(s):  
Syed Shoaib ◽  
Syed Shoaib ◽  
Dr M L Waiker
Keyword(s):  
Structural Damage ◽  
Pushover Analysis ◽  
Vertical Plane ◽  
Base Shear ◽  
Seismic Evaluation ◽  
High Rise ◽  
Performance Point ◽  
Structural Irregularities ◽  
And Behavior ◽  
Static Pushover Analysis

During earthquake motion. The seismic behavior depends upon the strength, mass, and stiffness are distributed in both horizontal and vertical planes. the buildings structural damage was severe the frame is caused due to the discontinuity in the stiffness mass and strength between the alongside stories. The same type of discontinuity is vertical geometric irregularity which is due to the irregular building configuration in vertical plane so there is to know the seismic response of building modals in different structural irregularities. Non-linear static (pushover analysis) which is used for Investigation. The purpose of study doing nonlinear static (pushover analysis) by conventional design methodology G+12 High rise buildings this work shows seismic performance and behavior of building frame with and without vertical irregularity in terms of base shear, story shear, story displacement the performance point of all models are considered also found that irregularity in assessment of the structure decreases the performance level of building there is also reduces in deformation or displacement of the structure. all the models analyzed by using ETABS and design as per IS 456:200 and 1893:2016

scholarly journals Nonlinear Static Pushover Analysis of Medium Rise and High-Rise Building

2019 ◽  
pp. 255-561
Author(s):  
M Keshava Murthy ◽  
Ashwini L K
Keyword(s):  
Pushover Analysis ◽  
Performance Level ◽  
Base Shear ◽  
High Rise ◽  
High Rise Building ◽  
Non Linear ◽  
Nonlinear Static ◽  
Static Pushover Analysis ◽  
Different Levels ◽  
Nonlinear Static Pushover Analysis

Pushover analysis is an elegant tool to visualise the performance level of a building under a given earthquake. The purpose of the paper is to summarize the Non Linear static Pushover analysis of medium rise RC bare frame and high rise RC infilled structure with soft stories at different levels using ETABS software. Results concluded that due to the introduction of soft stories in the higher level the intensity of hinge formation becomes lower and lower and at the same time displacement and base shear increases

scholarly journals Assessment of plastic hinge in RC structures with and without shear walls applying pushover analysis

2020 ◽  
Vol 1 (1) ◽  
pp. 11-18
Author(s):  
Jean Pierre Lukongo Ngenge ◽  
Abdallah M. S. Wafi
Keyword(s):  
Plastic Hinge ◽  
Pushover Analysis ◽  
Computer Software ◽  
Shear Walls ◽  
Span Length ◽  
Base Shear ◽  
Rc Structures ◽  
High Rise ◽  
Moment Resisting Frames ◽  
Moment Resisting

This paper gives a brief presentation about different types of analysis, plastic hinge, moment-resisting frames (MRFs) and shear walls (SWs) in reinforced concrete (RC) Structures. ETABS computer software is employed to model and analyse the structures applying the pushover. The performances of the modelled structures are also evaluated considering different parameters such as the number of stories, spans length, shear walls, reinforcement yield strength and characteristic strength of concrete. The study includes two cases, which are moment-resisting frames with and without shear walls (i.e. MRFs and MRF-SWs, respectively). Each case covers low-, mid- and high-rise buildings. In this regard, a comparative study has been performed for the results obtained from all models. It was observed that the stiffness of MRFs compared to MRF-SWs was less and also the stiffness of low-rise frames was higher than that of mid-rise and high-rise frames. Technically this means that a low-rise building is stiffer than a mid-rise building and a mid-rise building is stiffer than a high-rise building. Additionally, when the span length increases, the stiffness of the building decreases. Therefore, it can be concluded that the span length is inversely proportional to the stiffness. Finally, all stiffness values were calculated taking into consideration the displacement and base shear at the first hinge formation on the pushover curve of each model.

Investigation on Applicability of Pushover Analysis on High-Rise Diagonal Grid Structural System

2010 ◽  
Vol 163-167 ◽  
pp. 3918-3924
Author(s):  
Jun Teng ◽  
Hu Bing Tu ◽  
Huan Lin Mao ◽  
Ying Liang Qiu
Keyword(s):  
Seismic Analysis ◽  
Pushover Analysis ◽  
Incremental Dynamic Analysis ◽  
Analysis Method ◽  
Structural System ◽  
Base Shear ◽  
High Rise ◽  
Story Drift ◽  
Load Pattern ◽  
Global And Local

As an important seismic analysis method, Pushover is widely used in high-rise buildings, while there is still lack of investigation on applicability of Pushover analysis on diagonal grid structural system. Two structures with height 144 and 288 meters are respectively built, and then Pushover analysis and Incremental dynamic analysis are conducted. Results calculated by two different methods are compared, including top displacement vs. base shear curve, inter-story drift vs. inter-story shear curve, distribution of inter-story drift angle along the building height and plastic developing sequence of structural weak positions. Meanwhile, influence of three lateral load patterns (uniform pattern，inverted triangle pattern and SRSS pattern) on the results is investigated. Analysis results demonstrate that Pushover analysis can in some extent reflect seismic performance of structures and SRSS load pattern can better capture global and local information of structures compared with other two patterns.

scholarly journals Seismic Evaluation of Mixed Steel and RC Columns in Hybrid High-Rise Buildings

2019 ◽  
Vol 65 (2) ◽  
pp. 3-17
Author(s):  
D.-P. N. Kontoni ◽  
A. A. Farghaly
Keyword(s):  
Reinforced Concrete ◽  
Reinforced Concrete Beams ◽  
Structural Systems ◽  
Base Shear ◽  
Seismic Evaluation ◽  
Earthquake Excitation ◽  
Rc Columns ◽  
Steel Columns ◽  
High Rise ◽  
Building Models

AbstractThe growth in high-rise building construction has increased the need for hybrid reinforced concrete and steel structural systems. Columns in buildings are the most important elements because of their seismic resistance. Reinforced concrete (RC) columns and steel columns were used herein to form hybrid structural systems combining their distinct advantages. Eleven 3D building models subjected to earthquake excitation with reinforced concrete beams and slabs of 12 floors in height and with different distributions of mixed columns were analyzed by the SAP2000 software in order to investigate the most suitable distributions of a combination of reinforced concrete and steel columns. Top displacements and accelerations, base normal forces, base shear forces, and base bending moments were computed to evaluate the selected hybrid structural systems. The findings are helpful in evaluating the efficiency of the examined hybrid high-rise buildings in resisting earthquakes.

scholarly journals Advanced Composite Retrofit of RC Columns and Frames with Prior Damages—Pseudodynamic Finite Element Analyses and Design Approaches

Fibers ◽  
2021 ◽  
Vol 9 (9) ◽  
pp. 56
Author(s):  
Theodoros Rousakis ◽  
Evgenia Anagnostou ◽  
Theodora Fanaradelli
Keyword(s):  
Finite Element ◽  
Brick Wall ◽  
Rc Frame ◽  
Base Shear ◽  
Infill Wall ◽  
Rc Columns ◽  
Premature Failure ◽  
Displacement Ductility ◽  
Lap Splices ◽  
Rc Frames

This study develops three-dimensional (3D) finite element (FE) models of composite retrofits in deficient reinforced concrete (RC) columns and frames. The aim is to investigate critical cases of RC columns with inadequate lap splices of bars or corroded steel reinforcements and the beneficial effects of external FRP jacketing to avoid their premature failure and structural collapse. Similarly, the RC-frame FE models explore the effects of an innovative intervention that includes an orthoblock brick infill wall and an advanced seismic joint made of highly deformable polymer at the boundary interface with the RC frame. The experimental validation of the technique in RC frames is presented in earlier published papers by the authors (as well as for a four-column structure), revealing the potential to extend the contribution of the infills at high displacement ductility levels of the frames, while exhibiting limited infill damages. The analytical results of the advanced FE models of RC columns and frames compare well with the available experimental results. Therefore, this study’s research extends to critical cases of FE models of RC frames with inadequate lap splices or corroded steel reinforcements, without or with brick wall infills with seismic joints. The advanced pseudodynamic analyses reveal that for different reinforcement detailing of RC columns, the effects of inadequate lap-spliced bars may be more detrimental in isolated RC columns than in RC frames. It seems that in RC frames, additional critical regions without lap splices are engaged and redistribution of damage is observed. The detrimental effects of corroded steel bars are somewhat greater in bare RC frames than in isolated RC columns, as all reinforcements in the frame are considered corroded. Further, all critical cases of RC frames with prior damages at risk of collapse may receive the innovative composite retrofit and achieve higher base shear load than the original RC frame without corroded or lap-spliced bars, at comparable top displacement ductility. Finally, the FE analyses are utilized to propose modified design equations for the shear strength and chord rotation in cases of failure of columns with deficiencies or prior damages in RC structures.

High-rise building subjected to excessive settlement of its foundation: a case study

2017 ◽  
Vol 8 (2) ◽  
pp. 210-221 ◽  
Author(s):  
Lan Lin ◽  
Adel Hanna ◽  
Anup Sinha ◽  
Lucia Tirca
Keyword(s):  
Pushover Analysis ◽  
Three Dimensional ◽  
Element Model ◽  
Differential Settlement ◽  
Design Stage ◽  
Content Type ◽  
High Rise ◽  
Dimensional Finite Element ◽  
Load Component ◽  
Three Dimensional Finite Element

Purpose Differential settlement between foundations’ elements induces additional stresses in the structural elements. In general, the amount of settlement that a structure can undergo without distress is large, provided that the structure settles uniformly. However, based on the fact that the soil under the foundation may not be uniform in nature and the loads transferred from the superstructure to the foundation are variable, differential settlements between the foundation elements are expected. The purpose of this paper is to evaluate the stresses induced in a typical ten-storey reinforced concrete building subjected to excessive differential settlement. Design/methodology/approach In this investigation, excessive differential settlement up to 75 mm is assigned to the center column on the ground floor that represents the most critical case. A three-dimensional finite element model is developed to perform structural analysis using the software SAP2000, and the nonlinear static pushover analysis is performed. Findings The results of this study show that the building behaves elastically up to 25 mm of differential settlement between its foundation elements, which agrees well with the recommendation given in design manuals. Beyond this value, significant inelastic response is observed in the lower floors and decreases gradually in the higher floors and accordingly, some members have consumed the factor of safety and are in the verge of failure. Originality/value Based on the results of this study, recommendations are made for better communication between the structure and the geotechnical engineers to either limit the differential settlements or incorporate these additional stresses during the design stage of the building. Furthermore, the results of the study can be used to recommend to building codes or design manuals to add a load component due to the anticipated differential settlements of the foundation.

scholarly journals Reinforced Concrete Buildings with Plane Frame, Shear Wall with and without Openings

2018 ◽  
Vol 65 ◽  
pp. 02007
Author(s):  
Zafarullah Nizamani ◽  
Wong Che Luk ◽  
Syed Muhammad Bilal Haider
Keyword(s):  
Reinforced Concrete ◽  
Pushover Analysis ◽  
Shear Wall ◽  
Seismic Action ◽  
Base Shear ◽  
Reinforced Concrete Buildings ◽  
Concrete Buildings ◽  
Frame Model ◽  
High Rise ◽  
Plane Frame

Malaysia is situated at Sunda plate which has geographic advantage in seismic zone. However, an earthquake occurred in Sabah, east of Malaysia without a warning in 2015. This scenario raised the question regarding the structural performance of high-rise buildings in Malaysia in response to seismic activity. This study is to analyze the effects of the shear wall on seven RC buildings by using pushover analysis. This pushover analysis is a simple approach where a building is subjected to increasing horizontal lateral loads until the building fails. SCIA Engineer software is used to model three different designs of seven storeys buildings are model in accordance with the Eurocode 8. The pushover analyses are carried out on three models, pushover curves (base shear vs. roof displacement) are plotted, and they are compared to explore both elastic and inelastic properties of the building response to the seismic action. The frame model without shear wall can resist less base shear. The plane frame model also approaches maximum allowable displacement of 60 mm earlier as compared to the other two models. Therefore, the high-rise buildings with shear wall design are highly recommended for the lifelong seismic resistance of reinforced concrete buildings.

scholarly journals Displacement Analysis of RC Frames and its Seismic Performance Appraisal

2020 ◽  
Vol 9 (3) ◽  
pp. 94-101
Keyword(s):  
Performance Appraisal ◽  
Seismic Performance ◽  
Design Method ◽  
Pushover Analysis ◽  
Lateral Force ◽  
Base Shear ◽  
Seismic Performance Evaluation ◽  
Analysis And Design ◽  
Direct Displacement Based Design ◽  
Rc Frames

In India when structure engineer’s analysis and design a structure like buildings, they are checking it for displacement because of safety and control of damages; so in this paper a set of frames with different height of reinforced moment resisting frames were analyzed by two popular methods of performance-based plastic design method and direct displacement-based design method. For calculation of base shear, the IS code has been used in both methods and ETABS software used for seismic performance evaluation by nonlinear static pushover analysis. The results of analysis with different methods compared by suitable parameters and graphs, such as: (a) story lateral force, (b) beam seismic moment, (c) displacement profile and (d) capacity curve. Results show acceptable performance in 2 methods in terms of capacity and deformation

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