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 Behavioural Study of Shear Wall with Correlational to Bracing under Seismic Loading

2018 ◽  
Vol 65 ◽  
pp. 08008
Author(s):  
Syed Muhammad Bilal Haider ◽  
Zafarullah Nizamani ◽  
Chun Chieh Yip
Keyword(s):  
Reinforced Concrete ◽  
Lateral Displacement ◽  
Limit State ◽  
Shear Wall ◽  
Design Tool ◽  
Base Shear ◽  
Building Model ◽  
High Rise ◽  
Finite Element Software ◽  
Seismic Vibrations

The reinforced concrete structures, not designed for seismic conditions, amid the past earthquakes have shown us the significance of assessment of the seismic limit state of the current structures. During seismic vibrations, every structure encountered seismic loads. Seismic vibrations in high rise building structure subjects horizontal and torsional deflections which consequently develop extensive reactions in the buildings. Subsequently, horizontal stiffness can produce firmness in the high rise structures and it resists all the horizontal and torsional movements of the building. Therefore, bracing and shear wall are the mainstream strategies for reinforcing the structures against their poor seismic behaviours. It is seen before that shear wall gives higher horizontal firmness to the structure when coupled with bracing however it will be another finding that in building model, which location is most suitable for shear wall and bracing to get better horizontal stability. In this study, a 15 story residential reinforced concrete building is assessed and analyzed using building code ACI 318-14 for bracing and shear wall placed at several different locations of the building model. The technique used for analysis is Equivalent Static Method by utilizing a design tool, finite element software named ETABS. The significant parameters examined are lateral displacement, base shear, story drift, and overturning moment.

scholarly journals Seismic Behavior of Mid-Rise Precast Reinforced Concrete Building with Effect of Joints and Supports

2019 ◽  
Vol 8 (4) ◽  
pp. 3633-3637
Keyword(s):  
Reinforced Concrete ◽  
Response Spectrum ◽  
Precast Concrete ◽  
Mode Shapes ◽  
Base Shear ◽  
Reinforced Concrete Building ◽  
Axial Forces ◽  
Building Models ◽  
Precast Buildings ◽  
Concrete Building

Precast concrete structures are widely used in construction. It consists of prefabricated elements casted in industry and connected to each other to form a homogeneous structure. Connections function is to transfer moments and axial forces. Many engineers assume precast connection as pinned, but in reality, they are semi-rigid connections that transfer forces to other members. Lack of design and detailing of connection leads to improper behaviour of the structure, which then leads to the collapse of the building. Past earthquake studies show that many precast buildings performed poorly, and the main reasons were connections. This paper mainly focuses on understanding the seismic behaviour of mid-rise i.e seven-storey precast reinforced concrete buildings with various beam-column joints i.e rigid, semi-rigid, pinned and column-base supports i.e, fixed and hinged supports. Building is modelled and analyzed using ETABS v17 software. Rotational stiffness of precast billet connection is adopted for modelling of semi-rigid beam-column connections. Response spectrum and modal analysis are carried out. Results of displacements, storey drift, storey shear, storey stiffness, base shear, time periods and first mode shapes of models are discussed. It is observed, precast reinforced concrete building models with semi rigid connection performs better than building models with pinned connections and building models with fixed supports reduces the structural response to a great extent.

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.

Seismic Evaluation of Buildings with Plan Irregularity

2016 ◽  
Vol 857 ◽  
pp. 225-230 ◽  
Author(s):  
Ann Thomas Jereen ◽  
Soumya Anand ◽  
Binu M. Issac
Keyword(s):  
Lateral Stiffness ◽  
Lateral Loads ◽  
Base Shear ◽  
Seismic Evaluation ◽  
Maximum Displacement ◽  
Engineering Construction ◽  
High Rise ◽  
Story Drift ◽  
Modern Technologies ◽  
Plan Configuration

With the application of modern technologies in Civil Engineering, construction of high rise buildings with irregular plan configuration is increasing very quickly. Multi-story buildings are prone to lateral loads from wind or earthquake, which necessitates the need of seismic studies. Buildings can be designed to reduce these lateral loads by many methods; which is why the action of structural diaphragms have to be studied. Several studies have shown the effect of plan configuration on base shear, displacement and story drift, torsional buckling. The lateral stiffness of the building frame affects the maximum displacement of the structure due to earthquake. Study is done on various plan configuration buildings and the action of structural diaphragm on its performance during earthquake is studied.

scholarly journals Backstay Effect of Diaphragm in Tall Building

2020 ◽  
Vol 9 (3) ◽  
pp. 1578-1587
Keyword(s):  
Seismic Analysis ◽  
Response Spectrum ◽  
Retaining Wall ◽  
Tall Building ◽  
Structural Systems ◽  
Base Shear ◽  
High Rise ◽  
Structural Engineer ◽  
Structural Responses ◽  
Seismic Forces

Seismic analysis of structural systems with floor diaphragms has been a requisite in the recent past. The duty of a structural engineer is to be prudent about the behavior of every structural system adopted. Amongst the structural systems that are adopted world over, diaphragm with rigid and semi-rigid floor plate are adopted widely in the analysis. This research focuses on the backstay effect i.e. podium structural interaction with the tower area and consideration of retaining wall as increment of lateral stiffness as specified in latest tall building code IS6700:2016 for low and high rise structures. In the current study models were prepared with low to high rise storeys with rigid and flexible diaphragms considering backstay diaphragm placing tower at center and corner. The models were subjected to seismic forces; response spectrum along with the combination of the gravity loads. The structural responses like natural periods, base shear, displacement and inter storey drift were also studied.

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

An investigation on determining optimum wall ratio–cost relationship of shear walled reinforced concrete buildings

2020 ◽  
Vol 6 (1) ◽  
pp. 1
Author(s):  
İbrahim Hakkı Erkan ◽  
Talha Polat Doğan ◽  
Musa Hakan Arslan
Keyword(s):  
Reinforced Concrete ◽  
Response Spectrum ◽  
Construction Cost ◽  
Frame Structures ◽  
Structural Systems ◽  
Analysis Method ◽  
Base Shear ◽  
Shear Forces ◽  
Concrete Wall ◽  
Wall Structures

Reinforced concrete walls are very efficient structural elements in terms of carrying the lateral loads that are expected to affect the structures during the service of the buildings. These elements, which are not used for economic reasons in buildings designed in areas with low seismic hazard, can actually provide a significant increase in performance with a very small increase in construction cost. In this study, a total of 9 building models have been created and the relationship between optimum reinforced concrete wall ratio and cost on these buildings has been investigated. The design and analysis of the models were carried out according to the criteria specified in TSC 2018. Three different structural systems specified in TSC 2018 were used in the designed models. These structural systems used; RC frame structures, RC wall-frame structures and RC wall structures. These structures were analyzed by Response Spectrum Method which is linear analysis method and base shear forces were obtained. Then, push-over analysis, which is a nonlinear analysis method, was applied to obtain the base shear forces that the structure can actually carry. After the analysis, the quantities of materials to be used for the construction of the structural systems of the models were calculated and current manufacturing prices and rough costs were calculated. In order to compare the obtained costs with the structural performances, nonlinear shear forces and linear shear forces ratios were calculated and the over strength factors were calculated for each model. In the light of the data obtained from the studies in the literature, when the over strength factors and cost values are examined together, it is concluded that the optimum design for the conditions specified in TSC 2018 will be provided with the RC wall ratio between 0.001 - 0.0016. It is concluded that lateral load carrying capacity of construction increases up to 650% by increasing the construction cost by 17% for the designed models.

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