scholarly journals Seismic Analysis of Commercial Building with Grid/Waffle slab using ETABS

Author(s):  
Anurag Kumar Pandey

Abstract: In This I have studied the seismic response of various types of slab in commercial buildings and their seismic behavior is studied. As we know every year uncountable number of earthquakes occur at different places, that means, small movements of tectonic plates occur all the time causing earthquakes. A seismic resistant designed building can provide safety for more people. slabs and roofs needed more columns if we design seismic resistant design but at some places like airport, shopping mall, commercial building more column can create some problem. To overcome this problem seismic design of grid slab or waffle slabs was comes out. Grid /Waffle slab consists of Concrete beams spaced at uniform intervals in perpendicular directions which are monolithically casted with slab and they are more safe in earthquake situation as comparison of to normal conventional slab. Keywords: Grid Slab, Earthquake Load , Response Spectrum , Storey Drift, Storey Displacement , E-Tab 2018 , Base Shear, Time Period , Mode Shapes.

2012 ◽  
Vol 39 (8) ◽  
pp. 867-877 ◽  
Author(s):  
Damien Gilles ◽  
Ghyslaine McClure

Structural engineers routinely use rational dynamic analysis methods for the seismic analysis of buildings. In linear analysis based on modal superposition or response spectrum approaches, the overall response of a structure (for instance, base shear or inter-storey drift) is obtained by combining the responses in several vibration modes. These modal responses depend on the input load, but also on the dynamic characteristics of the building, such as its natural periods, mode shapes, and damping. At the design stage, engineers can only predict the natural periods using eigenvalue analysis of structural models or empirical equations provided in building codes. However, once a building is constructed, it is possible to measure more precisely its dynamic properties using a variety of in situ dynamic tests. In this paper, we use ambient motions recorded in 27 reinforced concrete shear wall (RCSW) buildings in Montréal to examine how various empirical models to predict the natural periods of RCSW buildings compare to the periods measured in actual buildings under ambient loading conditions. We show that a model in which the fundamental period of RCSW buildings varies linearly with building height would be a significant improvement over the period equation proposed in the 2010 National Building Code of Canada. Models to predict the natural periods of the first two torsion modes and second sway modes are also presented, along with their uncertainty.


2018 ◽  
Vol 13 (2) ◽  
Author(s):  
Dian Yuristia ◽  
Ririt Aprilin S ◽  
R. Eka Murtinugraha

The purpose of this research was to analyze soft second  story bulding behavior due to the earthquake load by applying column height variation. The building case has a vertical irregularity soft story on the second level so the behavior during the earthquake was analyzed by heighten the columns at the second level of the building. The behavior of building structure results the response such as internal forces in columns and beams, base shear, fundamental period, displacement and story drift. The seismic analysis is using dynamic analysis response spectrum based on SNI 1726:2012 and carried out using software ETABS version 9.7.4. The results of this research indicates that the increase of column height in soft second  story building reduces the building stiffness. So it decreases the building forces, extending the fundamental period, decreasing the base shear, increasing the displacement and the story drift. It can be concluded that the soft second  story building reduces the building resistance of earthquake load by produces the behavior approaches the collapse.


2019 ◽  
Vol 8 (4) ◽  
pp. 3633-3637

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.


Author(s):  
Harsh Joshi

Abstract: Due to sloping land and high seismically active zones, designing and construction of multistory buildings in hilly regions is always a challenge for structural engineers. This review paper focuses to establish a review study on the Possible Types of building frame configuration in the hilly region and he behavior of Such building frames under seismic loading conditions, and (3) The recent research and developments to make such frames less vulnerable to earthquakes. This paper concludes that the dynamics characteristics of such buildings are significantly different in both horizontal and vertical directions, resulting in the center of mass and center of stiffness having eccentricity at point of action and not vertically aligned for different floors. When such frames are subjected to lateral loads, due to eccentricity it generates torsion in the frame. Most of the studies agree that the buildings resting on slanting ground have higher displacement and base shear compared to buildings resting on plain ground and the shorter column attracts more forces and undergoes damage when subjected to earthquake. Keywords: Building frame configuration, Seismic behavior, Dynamic characteristics, Response spectrum analysis, time history analysis.


2020 ◽  
Vol 184 ◽  
pp. 01107
Author(s):  
Y. Kamala Raju ◽  
G.V.V. Satyanarayana ◽  
G. Arun Sai

The present decade, high rise multi-storey buildings are subjected to many external effects such as earthquake, wind loads, tidal loads, etc., in most cases high rise buildings have more vulnerable to earthquake and wind loads. Most of the reinforced concrete multi-storeyed frame buildings were heavily damaged and many of them completely collapsed during due earthquakes. RC frame buildings were severely damaged due to various deficiencies when proper codal provisions are not designed. A study is need to study the behaviour of the RC framed structure under earthquake load to reduce the damage caused by earthquake forces In this investigation a RC framed building of G+20 storeyed is considered in several seismic zones under different soils as per Indian Standard code IS 1893(part1):2016, using STAAD. Pro V8i as software tool. Finally evaluate the ultimate Base shear using Equivalent static method and Response spectrum method addressing under design forces.


Author(s):  
Kapil Shankar Soni

Abstract: Infill walls are inevitable components of any structure to create dispassion between interior space and external condition. In general, there are some prevalent openings inside the infill walls because of practical needs, architectural observations or aesthetic inspections. In current design practice, strength and inflexibility contribution of infill walls aren't thought of. However, the presence of infill walls may impact the seismic reaction of structures exposed to earthquake loads and cause a conduct which is not the same as that estimated for a bare frame. Additionally, partial openings inside infill walls are significant parameter prompting the seismic behaviour of infilled frames in this manner retreating lateral stiffness and strength. In this study is proposed to compare various models of buildings considering the openings (10% of surface area) at different locations in the infill walls for the seismic behaviour. A G+13 residential building is considered in Zone III with soil type II and analysis is carried out by Response Spectrum Method. Various parameters are considered such as Natural Time period, Base shear, Storey displacement, Storey drift and Storey stiffness were studied. The comparative study could simplify designers and code developers in selecting and recommending appropriate analytical models for estimating strength, stiffness, failure modes and other properties of infill frames with openings. Keywords: Residential Building, Openings Infill Wall, ETAB Software, Natural Time Period, Base Shear, Storey Shear, Storey Displacement, Storey Drift, Storey Stiffness.


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.


2021 ◽  
Vol 18 (1) ◽  
pp. 88-99
Author(s):  
Azis Wicaksana ◽  
Anis Rosyidah

Indonesia has a code for designing a seismic-resistant building, which has always improved year after year. Start from Peraturan Perencanaan Tahan Gempa Indonesia Untuk Gedung (PPTI-UG) 1983, SNI 1726:2002, SNI 1726:2012, and the latest one is SNI 1726:2019. SNI 1726:2019 experienced some renewal on designing a seismic-resistant building. This research aims to compare spectrum response design and the structural behavior between seismic-resistant building design using SNI 1726:2012 and SNI 1726:2019. The reviewed structure behaviors are base shear force (V), drift (δmax), and story drift (Δ). The study compares the detail of the structural components as well as using SNI 2847:2013 and SNI 2847:2019. The research uses a 10-story building modeling that serves as an apartment building and located in the city of Banda Aceh. Seismic analysis using a spectrum response analysis with Special Moment Resisting Frame (SMRF) structure. The result showed that the peak acceleration (Sa) for the class sites of Medium Land (SD) and Hard Land (SC) were 11% and 26%, respectively, while for Soft Land (SE), there was no increase. The shear force in SNI 1726: 2019 has increased by 19.75% for the X direction and 19.97% for the Y direction. The increase in the shear force is directly proportional to the increase in drift and story drift. In the beam detailing and beam-column connection, there were no significant changes. While in the column detailing, there are additional provisions that cause the transverse reinforcement to be tighter.


The offshore jacket platforms are primarily installed in the large oceans mainly for drilling the crude oil, carbohydrates and production of electricity. The current studies emphasize on the structural performance of offshore deck jacket platform with different bracing systems. Earthquake analysis has been performed to calculate the seismic responses, with the help of bracings to control the seismic induced vibrations of the jacket platforms. For this study, a jacket platform made up of steel members has been modeled and then analyzed under earthquake and wave loadings. This paper mainly deals to compute and compare the seismic behavior of offshore steel deck platform using SAP 2000 v20 software with bracing in the horizontal plane and bracing in both horizontal and vertical planes. The total number of 8 models has been analyzed in the SAP2000 software with bracing i.e. X, V, Inverted V and K in the vertical plane and bracing i.e. X, V, Inverted V and K in both horizontal and vertical plane. A relative study has been carried out in Time period, deck displacement and base shear. Seismic analysis using linear static, i.e. Equivalent static method (ESA) and linear dynamic, i.e. Response spectrum method (RSA) has been performed. Further deck displacement, time period and base shear are determined by Equivalent static method and Response spectrum method for various types of bracing models in both horizontal and vertical planes. Among the all various types of bracing models, Inverted V bracing in the vertical plane is found to be the optimum model among all other models.


2021 ◽  
Vol 7 (2) ◽  
pp. 71
Author(s):  
Yılmaz Keleş ◽  
Hüseyin Kasap ◽  
Zeynep Yaman

In this study, the effect of different types of slabs on dynamic characteristics of structures under the lateral loading was investigated. For this purpose, four different types of slabs namely, beamed slab, flat slab, one way ribbed (hollow core) slab and waffle slab have been modeled in buildings having 3, 4 and 5 storeys with the same geometric dimensions, in accordance to design and construction requirements (TS 500) and Turkish building seismic codes (TBDY, 2018). Seismic analysis calculations of the modeled buildings were done using the equivalent seismic load method. The assumed local soil class was taken from the geotechnical report as ZD. As a result of the analysis, natural periods, base shear forces, maximum horizontal displacements and relative storey drifts of the buildings were compared. Seismic analysis and calculations of the buildings were completed using SAP2000 finite element software.


Sign in / Sign up

Export Citation Format

Share Document