Seismic Analysis

EVALUATION OF SEPERATION GAP BETWEEN MULTISTOREY BUILDINGS SUBJECTED TO propulsive SEISMIC LOADDr. G Sridevi1*(0000-0002-5922-3132), Mr. Umesh Biradar 2(0000-0003-0087-9433), Mr. G Sudarshan 3(0000-0002-5129-5465) and , Mr. A Shivaraj 4(0000-0002-7437-1256) 1234 B V Raju Institute of Technology, Narsapur, India Abstract When mental synthesiss ar below earthquake forces, side by side(predicate) structure may collide with each other callable to dissimilar high-voltage characteristics. When expression vibrates out of phase and separated hatchway between buildings be not sufficient to accommodate their relative consummations, this can apparent motion severe damage to the structures and it is known as unstable buffeting. close to of the time it is not possible to maintain sufficient punt gap between adjacent buildings. bear witness work evaluate the minimum interval gap required between high-rise building shams considered. dickens high-rise building of 10 narrative and 15 storey are modelled and analysed for dynamic time storey abbreviation for the EI Centro ground motions and minimum hammer gap between buildings has been discussed.Keywords Seismic Pounding, RC Building, ETABS, Time History abbreviation.INTRODUCTIONBecause of expanding state and land esteems, structures are being built to close to each other. During a quake it is expected that, they leave behind pound against each other. This repeated smasher activity is referred as seismic pounding. Pounding of structures could have cause severe damage, as neighbouring structures with various dynamic attributes vibrate out of phase and there is inadequate breakup gap to accommodate the relative movements of adjacent structures.This highly congested construction system in the metropolitan cities is the major concern for the seismic pounding. The most simple and viable method for controlling the issue and belittle the harm caused by it is to give enough insularism gap between the ad jacent structures.LITERATUREShehata (2006) examined structure pounding response and proper seismic hazard dissipation technique. Three categories of recorded earthquake excitation are used for input. The return of impact is studied using analogue and nonlinear contact force model for different insularism distances and compared with nominal model without pounding consideration. And it is concluded that, an increasing gap width is seeming to be effective to minimize the effect of seismic pounding.Mizam Dogan et.al (2009) carried stress examinations on outline models for various effect focuses and investigation on pounding. It is concluded that pounding forces are not totally absorbable on bill of their high esteems but rather their consequences for structure can be decreased by setting versatile materials between adjacent structures or by strengthening basic frameworks.Pushover is a static nonlinear analysis method to estimate seismic structural deformations. It gives force displ acement relationship of a structure or structural element. Horizontal load is applied in a specified pattern in increments and for a given applied soak force, associated displacement is found until it reaches its maximum capacity of deformation.As the storey mould increases the columns are subjected to additional moment leading to the failure of the structure. A B Kawade et.al studied the minimum gap to be provided between the adjacent buildings using push over analysis. Response spectrum analysis was carried out by taking the data of EI Centro earthquake on different models. The results indicated that the acceleration and shear force produced because of pounding varies with the storey height and peak storey drift depends on the ground excitation characteristics.The effect of pounding is sight to be more predominate when floor levels of adjacent building are different constructing separate buildings with disturb floor heights is mavin of viable solutions to prevent seismic stru ctural pounding. It was also detect that the separation distance to be maintained increases with the increase in peak ground acceleration values.Jeng-Hsiang Lin et.al (2002) investigated the seismic pounding hazard of buildings in the Taipei metropolitan area.Detailed procedures of the analytical method are presented. And concludes that pounding probability of adjacent buildings is found to be significantly affected by the natural pointedness of individual buildings and the period ratio of the adjacent buildings. Due to the lack of proper treatment of the vibration phases of adjacent buildings, it is found that the method used in the current Taiwan Building Code (TBC97) provides poor estimates for the required building separation distance and produces a non-uniform risk for all the cases investigated in this study.MOTIVATION AND OBJECTIVES OF STUDYTo Study the participating Behaviour of Tall twists.To valuate Seismic Pounding Effect of conterminous Buildings with Consideratio n of Vertical Geometrical Irregularity.To Study the Influence of shear Walls on Seismic Pounding Effect.MODEL DESCRIPTIONIn Present Study Total 3 modellings have been mannikinled to Evaluate Dynamic Behaviour of High Rise Buildings by Considering Vertical Geometrical Irregularities. object lesson 1 A Plan which consists adjacent multi storey buildings one is 10 Storey and the other one is 15 Storey with a separation of 100mm with Masonry infill walls.Model 2 A Plan which consists adjacent multi storey buildings one is 10 Storey and the other one is 15 Storey with a separation of 100mm in this particular model all infill walls are modelled and knowing as shear walls.-47625012700Fig 1 Plan View of the Buildings1219200176530Fig 2 Isometric View of ETABS Model1104900191770Fig 3 point of ETABS ModelMETHODOLOGYThe principle objective is to evaluate the effects of seismic pounding between two closely spaced multi-storey buildings, to understand the minimum seismic gap between th e buildings, modelling is done to study the response of buildings under pounding during EI Centro earthquake.In order to observe pounding effect between adjacent buildings, two RC buildings of 10 and 15 storey are considered. Both buildings have been modelled and analysed in ETABS 2015 software. Based on the analysis results the clear separation distance is provided. all 3 models have been analysed for nonlinear time history analysis to study dynamic behaviour of buildings.The output results were obtained.In Time History Analysis the ground motion records are given as input. The time history analysis has the ability to perform linear as well as non linear analysis . The ability of this method to account for bi complaintal effects by applying three components of ground motion helps in predicting the response more precisely. In a Linear analysis, it is assumed that the displacement of whole structure does not exceed live limit under the application of design forces. when the structur e deforms more than elastic limit, non linearity of the structure in terms of geometry or material are to be considered.Bureau of Indian Standards clearly gives in its code IS 4326, that a Separation distance is to be provided between buildings to avoid collision during an earthquake. The IS code provisions are mentioned in following tabular array.Fig 4 Gap Width for Adjoining Structure as per IS 4326 ( Table 1 )Table 1 Seismic ParametersSoil Type MediumResponse Reduction Factor, R 5Importance Factor, I 1.5Zone IVTable 2 Material PropertiesConcrete cube strength, fck30 N/mm2 (M30)Characteristics strength of reinforcing steel, fy415N/mm2(Fe 415)Modulus of elasticity of concrete, E 29.5 kN/mm2Unit weight of concrete 25 kN/m3Table 3 Sectional PropertiesName of the Element Size in mmBeam 1 three hundred * 400Beam 2 300 * 500Beam 3 350 * 600Column 1 300 * 300Column 2 300 * 400Column 3 300 * 500Column 4 300 * 600Column 5 300 * 700Slabs 125Exterior walls,w1 300Interior walls,w2 230 6 . RESULTS AND DISCUSSIONS Dynamic Time History Analysis of considered models have been performed in ETABS Software. EI Centro Ground Motions were considered as Input selective information for Analysis.Effect of Pounding is studied with a reference to storey displacement. The Storey Height Vs Storey shifting graph has been plotted to understand the dynamic behaviour of Structure.Fig 2 Storey Displacement Curve for Model 1Fig 2 Storey Displacement Curve for Model 2Fig 3 Storey Displacement Curve for Model 37. CONCLUSION Stiffness of building has got a great influence on displacements in respective directions.In Model I separation gap between adjacent buildings are 100 mm. Displacement observed was 509.883 mm in X direction and 31.881 mm in Y direction. When masonry wall are replaced with shear wall, lateral displacement has reduced in considerable amount to 36.74 % and 80.8 % in X and Y direction respectively.Effect of pounding can be reduced by providing safe separation gap. By the result of Model I we can conclude that minimum safe separation gap between building is 540 mm.Stiffness of building can be enhanced by adopting shear wall to reduce the pounding effectREFERENCESA.B. Kawade , Mr. Abhijeet A. Sahane Seismic pounding effect in building Amrutvahini college of engineering, Sangamner.Alireza M.Goltabar.R, Shamstabar Kami, A.Ebadi, (2008) Analyzing the effective parameters in Pounding Phenomenon between Adjacent Structure due to Earthquake,The 14th World Conference on Earthquake Engineering, pp. 12-17, Beijing, China.Diego Lopez Garcia, (2004)Separation between Adjacent nonlinear Structures for Prevention of Seismic Pounding, 13th World Conference on Earthquake Engineering Vancouver, B.C., Canada, account nary(prenominal) 478.Jeng-Hsiang Lin, Cheng-Chiang Weng, (2002)A Study on Seismic Pounding Probability of Buildings In Taipei metropolitan Area, Journal of the Chinese Institute of Engineers, Vol. 25, No. 2, pp. 123-135.K.Kasai, V.Jeng, P.C.Patel J.A.Munshi Seismic Pounding Effects Survey and Analysis Illinois Institute of Technology, Chicago,USA.Mizam Dogan and Ayten Gunaydin, (2009)Pounding of Adjacent RC Buildings During Seismic Loads, Journal of Engineering and Architecture, Vol XXII, No 1.Raja Rizwan Hussain et.al. (2013)Non-linear FEM Analysis of seismic Induced Pounding between Neighbouring Multi-Storey Structures, Latin American Journal of solids and structures, pp. 921-939.Shehata E. Abdel Raheem, (2006)Seismic Pounding between Adjacent Building Structures, Electronic Journal of Structural Engineering, Vol. 6, pp.66-74.Susendar Muthukumar and Reginald DesRoches, (2006)A Hertz contact model with non-linear damping for pounding make-believe, Earthquake Engineering and Structural Dynamics, Vol.35, pp.811-828.Weng Dagen, Li Tao Bashar Alfarah, Fransisco Lopez-Almansa (2017)Non linear time history analysis of a stern isolated RC building in shanghai founded on soft soil Tongji University, Technical university of catal onia, paper No. 2634.