Seismic Performance Of Multistorey Building With Soft .
International Journal of Current Engineering and TechnologyE-ISSN 2277 – 4106, P-ISSN 2347 - 5161 2014 INPRESSCO , All Rights ReservedAvailable at http://inpressco.com/category/ijcetResearch ArticleSeismic Performance of Multistorey Building with Soft Storey at Different Levelwith RC Shear WallSuchita HirdeȦ and Ganga TepugadeȦ*ȦApplied Mechanics Department, Govt. College of Engineering, Karad, Dist-Satara (M.S.) IndiaAccepted 30 May 2014, Available online 01 June 2014, Vol.4, No.3 (June 2014)AbstractDue to increasing population since the past few years car parking space for residential apartments in populated cities isa matter of major concern. Hence the trend has been to utilize the ground storey of the building itself for parking. Alsofor offices or for any other purpose such as communication hall etc. soft storeys at different levels of structure areconstructed. Experience in the past earthquake has shown that a building with discontinuity in the stiffness and masssubjected to concentration of forces and deformations at the point of discontinuity which may leads to the failure ofmembers at the junction and collapse of building. Hence in this paper attempt has been made to study performance of abuilding with soft storey at different level along with at GL. The nonlinear static pushover analysis is carried out. Thehinges formed in the basic models are seen at performance point and to increase the performance, it is retrofitted withshear walls. Then the result obtained for basic models and retrofitted models are compared in the form of performancepoint and hinge formation pattern at performance point.Keywords: Nonlinear static pushover analysis, performance point, performance level, plastic hinges, shear wall, softstorey.1. Introduction1Many urban multistory buildings in India today have openfirst storey as an unavoidable feature. This is primarilybeing adopted to accommodate parking or receptionlobbies in the first stories. Also for offices or for any otherpurpose such as communication hall etc. soft storeys atdifferent levels of structure are constructed. IS 1893(Part1): 2002 classifies a soft storey as one in which thelateral stiffness is less than 70 percent of that in the storeyabove or less than 80 percent of the average lateralstiffness of the three storeys above. Hence in multistorybuilding with no infill walls in the first storey or anyintermediate storey is known as soft storey.Infill panels are generally not considered in the designprocess and treated as architectural (non-structural)components. The presence of masonry walls has asignificant impact on the seismic response of an RC framebuilding, increasing structural strength and stiffness(relative to a bare RC frame), but, at the same time,introducing brittle failure mechanisms associated with thewall failure and wall-frame interaction. The seismic forcedistribution is dependent on the distribution of stiffnessand mass along the height. The essential characteristics ofsoft storey consist of discontinuity of strength or stiffnesswhich occurs at the second floor column connection(Rahiman G. Khan et al, 2013).This discontinuity is*Corresponding author Ganga Tepugade is a PG (Civil-Structures)Scholar and Dr. Suchita Hirdeworking as Professorcaused because of lesser strength or increased flexibility inthe first floor vertical structure results in extremedeflection in the first floor. Fig. 1 and 2 shows thebehavior of soft storey due to discontinuity in mass andstiffness.Fig.1 Behavior of soft storey at GL.(Hugo Bachmann,2003)Fig.2 Behavior of soft storey at intermediate level. (HugoBachmann, 2003)2019 International Journal of Current Engineering and Technology, Vol.4, No.3 (June 2014)
Suchita Hirde et alSeismic Performance of Multistorey Building with Soft Storey at Different Level with RC Shear Wall1.1 Pushover analysisThe structural engineering community has developed anew generation of design and seismic procedures thatincorporate performance based structures and are movingaway from simplified linear elastic methods and towards amore non-linear technique. Recent interests in thedevelopment of performance based codes for the design orrehabilitation of buildings in seismic active areas showthat an inelastic procedure commonly referred to as thepushover analysis is a viable method to assess damagevulnerability of buildings. Basically, a pushover analysis isa series of incremental static analysis carried out todevelop a capacity curve for the building. Based on thecapacity curve, a target displacement which is an estimateof the displacement that the design earthquake willproduce on the building is determined. The extent ofdamage experienced by the structure at this targetdisplacement is considered representative of the damageexperienced by the building when subjected to designlevel ground shaking. Many methods were presented toapply the nonlinear static pushover (NSP) to structures.These methods can be listed as:(1) Capacity Spectrum Method (CSM)(2) Displacement Coefficient Method (DCM)(3) Modal Pushover Analysis (MPA). The approach hasbeen developed by many researchers with minor variationin computation procedure methods. Since the behavior ofreinforced concrete structures may be highly inelasticunder seismic loads, the global inelastic performance ofRC structures will be dominated by plastic yielding effectsand consequently the accuracy of the pushover analysiswill be influenced by the ability of the analytical models tocapture these effects. (S. I. Khan et al, 2013).4. Floor to floor height: 3.2 m5. Plinth height above foundation: 2 m6. Parapet height: 1 m7. Slab thickness: 150 mm8. Wall thickness: 230 mm9. Size of columnsExternal: 300 mm x 600 mm,Internal: 300 mm x 1200 mm (below 5 th floor) andInternal: 300 mm x 900 mm (above 5 th floor)10. Size of beam: 300 mm x 500 mm11. Live load on floor: 5 kN/m 212. Floor finishes: 2 kN/m 213. Roof treatment: 1.5 kN/m 214. Seismic zone: V15. Soil condition: Medium16. Importance factor: 117. Density of concrete: 25 kN/m 318. Density of masonry: 20 kN/m 3Fig. 3 Plan of building2.2 Seismic response of soft storey building2. Modeling and Analysis of BuildingIn this paper, for analytical study multistory building isconsidered with soft storey at different level along withground level. The building is modeled with shear wall atcore as shown in fig. 3 using finite element softwareSAP2000 version 14.4.2 and non-linear static pushoveranalysis is performed on all building models. To improvethe seismic performance of such buildings lateral loadresisting element i.e. shear walls are used. Shear walls areprovided at corner of building in L shaped to improveseismic performance of building.2.1 Building descriptionThe study is carried out on reinforced concrete momentresisting G 20 storey buildings with soft storey atdifferent levels. The plan of building is same for allmodels. Height of each storey is 3.2 m. The building hasplan dimensions 28 m x 20 m as shown in fig.3. In theanalysis special RC moment-resisting frames (SMRF) isconsidered. Other relevant data is given as below.1.2.3.Size of Building: 28 m X 20 mGrade of concrete: M 30Grade of steel: Fe 415Four models with soft storey at different levels areconsidered along with soft storey at ground level and thesemodels with incorporation of shear walls are considered.Various models under consideration are:Model I: G 20/G & 5 building- G 20 storeys buildingwith soft storey at GL and 5th floor without retrofitted withshear walls as shown in fig.4Model II: G 20/G & 10 building- G 20 storeys buildingwith soft storey at GL and 10th floor without retrofittedwith shear walls as shown in fig.5Model III: G 20/G & 15 building- G 20 storeys buildingwith soft storey at GL and 15th floor without retrofittedwith shear walls as shown in fig.6Model IV: G 20/G & 20 building- G 20 storeys buildingwith soft storey at GL and 20th floor without retrofittedwith shear walls as shown in fig.7Model V: G 20/G & 5/SW building- G 20 storeysbuilding with soft storey at GL and 5th floor retrofittedwith shear walls as shown in fig.8Model VI: G 20/G & 10/SW building- G 20 storeysbuilding with soft storey at GL and 10th floor retrofittedwith shear walls as shown in fig.9Model VII: G 20/G & 15/SW building- G 20 storeysbuilding with soft storey at GL and 15th floor retrofittedwith shear walls as shown in fig.102020 International Journal of Current Engineering and Technology, Vol.4, No.3 (June 2014)
Suchita Hirde et alSeismic Performance of Multistorey Building with Soft Storey at Different Level with RC Shear WallModel VIII: G 20/G & 20/SW building- G 20 storeysbuilding with soft storey at GL and 20th floor retrofittedwith shear walls as shown in fig.113. Result and DiscussionIn the present study, non-linear response of RC frame highrise building with soft storey at different levels in additionto one at ground floor using SAP2000 under the loadinghas been carried out and the result are presented in termsof performance point and roof displacement.3.1 Comparison of performance of various framesFig.4 G 20/G & 5buildingFig.5 G 20/G & 10buildingPushover analyses of models with and without shear wallsare carried out. Comparison between the performancepoint in terms of base shear and roof displacementobtained from the nonlinear static analysis and hingeformation pattern of the models without shear walls andwith shear walls are done. Table 1 shows the performancepoint and roof displacement of models with and withoutshear walls.Table 1: Performance point and performance level formodel without shear walls and model with shear walls.Model withoutshear wallsDescriptionModel with shearwallsSoft storey at GL & 5th floorFig.6 G 20/G & 15buildingFig.7 G 20/G & 20buildingPerformancepoint in XdirectionPerformancepoint in YdirectionPerformance 9;189B-IOBthSoft storey at GL & 10 floorPerformancepoint in XdirectionPerformancepoint in YdirectionPerformance 5;183.4B-IOBthSoft storey at GL & 15 floorFig.8 G 20/G & 5/SWbuildingFig.9 G 20/G & 10/SWbuildingPerformancepoint in XdirectionPerformancepoint in YdirectionPerformance 7;181.04B-IOBthSoft storey at GL & 20 floorPerformancepoint in XdirectionPerformancepoint in YdirectionPerformance levelFig.10 G 20/G & 15/SWbuildingFig.11 G 20/G & 1518897.3;181B-IOBFrom table 1 it is clear that the performance level for themodels without shear walls is within B-IO range. Thoughthe performance level is within B-IO range, it is observed2021 International Journal of Current Engineering and Technology, Vol.4, No.3 (June 2014)
Suchita Hirde et alSeismic Performance of Multistorey Building with Soft Storey at Different Level with RC Shear Wallthat hinges are formed in columns of ground level softstorey. Hence retrofitting is carried out with shear walls. Itis observed that the performance level for the models withshear walls is linear (B) and the roof displacement ofretrofitted models is less as compared to models withoutshear walls. Also it is observed that hinges are not formedin columns for buildings with shear walls. Hence shearwalls improves the seismic performance of the building.clear that no hinges are formed in bottom storey columnsand the performance of the soft storey is improved.3.2 Hinge formation patternFig. 12 to fig. 15 show the hinge formation pattern inmodels without shear walls. From this it is clear that, dueto the high shear forces at ground level soft storey; thehinges are formed in columns of ground soft storey.However it is observed that no hinges are formed incolumns of ground soft storey, when retrofitted with shearwalls.Fig.12 Hinge formations at performance point for G 20/G& 5 building in X and Y directionFig.15 Hinge formations at performance point for G 20/G& 20 building in X and Y directionFig.16 Hinge formation at performance point for G 20/G& 5/SW building in X and Y directionFig.13 Hinge formations at performance point for G 20/G& 10 building in X and Y directionFig.17 Hinge formation at performance point for G 20/G& 10/SW building in X and Y directionFig.14 Hinge formations at performance point for G 20/G& 15 building in X and Y directionFig. 16 to fig. 19 show the hinge formation pattern inretrofitted models. From this hinges formation pattern, it isFig.18 Hinge formation at performance point for G 20/G& 15/SW building in X and Y direction2022 International Journal of Current Engineering and Technology, Vol.4, No.3 (June 2014)
Suchita Hirde et alSeismic Performance of Multistorey Building with Soft Storey at Different Level with RC Shear Wall4. Provision of shear walls results in reduction in lateraldisplacement.5. Displacement reduces when the soft storey is providedat higher level.6. After retrofitting the base shear carrying capacity isincreased by 8.45% to 13.26%.ReferencesFig.19 Hinge formation at performance point for G 20/G& 20/SW building in X and Y directionConclusions1. This study highlights the poor seismic performance ofG 20 RCC building with soft storey at different levelalong with soft storey at ground level.2. It is observed that plastic hinges are developed incolumns of ground level soft storey which is notacceptable criteria for safe design.3. After retrofitting of all the models with shear wallshinges are not developed in any of the columns.Rahiman G. Khan and Prof. M. R. Vyawahare (2013),Pushover analysis of tall building with soft storey’s atdifferent levels, International Journal of EngineeringResearch and Application, ISSN: 2248-9622, Vol.3, pp.176-185.Hugo Bachmann, (2003), Seismic conceptual design ofbuildings – Basic principles for engineers, architects,building owners, and authorities, Federal Department oftheEnvironment,Transport,EnergyandCommunications (DETEC).S. I. Khan et al. (2013), Seismic evaluation and retrofittingof RC building by using energy dissipating devices,International Journal of Engineering Research andApplications, ISSN-2248-9622, Vol 3(3), pp. 15041514.2023 International Journal of Current Engineering and Technology, Vol.4, No.3 (June 2014)
SAP2000 version 14.4.2 and non-linear static pushover analysis is performed on all building models. To improve the seismic performance of such buildings lateral load resisting element i.e. shear walls are used. . formation pattern of the models without shear walls
The Seismic Tables defined in Pages 5 & 6 are for a seismic factor of 1.0g and can be used to determine brace location, sizes, and anchorage of pipe/duct/conduit and trapeze supports. The development of a new seismic table is required for seismic factors other than 1.0g and must be reviewed by OSHPD prior to seismic bracing. For OSHPD,
EXAMPLE 9 SEISMIC ZONE 1 DESIGN 1 2018 Design Example 9 Example 9: Seismic Zone 1 Design Example Problem Statement Most bridges in Colorado fall into the Seismic Zone 1 category. Per AASHTO, no seismic analysis is required for structures in Zone 1. However, seismic criteria must be addressed in this case.
SC2493 Seismic Technical Guide, Light Fixture Hanger Wire Requirements SC2494 Seismic Technical Guide, Specialty and Decorative Ceilings SC2495 Seismic Technical Guide, Suspended Drywall Ceiling Construction SC2496 Seismic Technical Guide, Seismic Expansion joints SC2497 Seismic
Peterson, M.D., and others, 2008, United States National Seismic Hazard Maps ․ Frankel, A. and others, Documentation for the 2002 Update of the National Seismic Hazard Maps ․ Frankel, A. and others, 1996, National Seismic Hazard Maps Evaluation of the Seismic Zoninig Method ․ Cornell, C.A., 1968, Engineering seismic risk analysis
To develop the seismic hazard and seismic risk maps of Taungoo. In developing the seismic hazard maps, probabilistic seismic hazard assessment (PSHA) method is used. We developed the seismic hazard maps for 10% probability of exceedance in 50 years (475 years return period) and 2 % probability in 50 years (2475 years return period). The seisic
This analysis complied with these provisions by using the USGS 2014 National Seismic Hazard Map seismic model as implemented for the EZ-FRISK seismic hazard analysis software from Fugro Consultants, Inc. For this analysis, we used a catalog of seismic sources similar to the one used to produce the 2014 National Seismic Hazard Maps developed by .
the seismic design of dams. KEYWORDS: Dam Foundation, Probabilistic Seismic Hazard Maps, Seismic Design 1. INTRODUCTION To perform seismic design or seismic diagnosis, it is very important to evaluate the earthquake hazard predicted for a dam site in order to predict earthquake damage and propose disaster prevention measures. There are two .
USING INQUIRY-BASED APPROACHES IN TRADITIONAL PRACTICAL ACTIVITIES Luca Szalay1, Zoltán Tóth2 1Eötvös LorándUniversity, Faculty of Science, Institute of Chemistry, Pázmány Pétersétány1/A, H-1117 Budapest, Hungary, luca@chem.elte.hu 2University of Debrecen, Faculty of Science and Technology, Department of Inorganic and Analytical Chemistry,, Egyetem tér1., H-4010 Debrecen, Hungary,
