COMPARATIVE ANALYSIS OF DIAGRID STRUCTURE WITH VARIOUS INDIAN SEISMIC ZONE

Volume: 09 Issue: 06 | Jun 2022 www.irjet.net p ISSN: 2395 0072

COMPARATIVE ANALYSIS OF DIAGRID STRUCTURE WITH VARIOUS INDIAN SEISMIC ZONE

2

1MTech student L.J University, Ahmedabad, India.

2Aakash Suthar, Assistant Professor, civil engineering department, L.J University, Ahmedabad, India. ***

Abstract Diagrid systems are emerging as one of the most structurally efficient and visually appealing tall building alternatives. Such systems are increasingly being employed in modern construction. The present literature lacks extensive information on their structural behaviour and seismic design criteria to assure optimal performance under various earthquake seismic zones. This research aims to evaluate the seismic dependability of diagrid structural systems and create more efficient performance based approaches.

A total of seven models with varying sizes, angles, storey heights, and density with a regular floor plan are studied in E tabs software for the study of diagrid structural system for tall steel structure subjected to lateral loading for seismic zones II, III, IV, and V. The reaction spectrum analysis for earthquake loading and the gust factor technique for dynamic along wind response are investigated for structure analysis. A comparison of the results with various Indian seismic zones using IS 1893 part 1 2016 is conducted in terms of time duration, base shear, storey displacement, storey shear, and storey drift.

Key Words: Diagrid, Seismic zone II,III,IV,V, Storey drift, Storey displacement, base shear, IS 4506:2000, IS 1893:2016, IS 800:2007, Seismic analysis, ETAB.

1.INTRODUCTION

Over the last several decades, high rise structures have shown to be the best solution to the difficulties of land scarcity and rising rates of urbanisation in all areas. Controllingchallengesinhigh risebuildingdesigninclude earthquakeandwindlateralstress,aswellasgravitational loads.Asstructuresdevelopedtallerandthinner,structural engineers were challenged to meet the needed drift standards while reducing the architectural impact of the structure. Engineers have devised and deployed various uniquelateralloadresistingstructuralstructuresduringthe last half century to minimize(bundled tube, diagrid, outriggersystems,etc.) inmanyhigh risestructurestofulfill safety, serviceability, and aesthetic standards while minimizing material consumption. Previously, structural form modifications were implemented to accommodate changingaesthetictrendsinhigh risebuildingdesign.The diagridstructuralsystemhasrecentlyacquiredfavorfortall steel buildingsduetothestructural efficacyandaesthetic prospects provided by the system's unusual geometric pattern. In terms of design, (pre)fabrication, and erection operations, it is heavily reliant on steel's capabilities as a

structural system. A diagrid project's success is also contingent on the architect, engineer, and steel fabricator/erectorworkingwelltogether.

1.1 WHY USE OF DIAGRID STRUCUTURE?

Inlast10years,diagridstructureshaveestablishedtobe highlyadaptableinstructuringanextensiverangeofbuilding types, spans and forms. Diagrid is a specific form of space trussasshowninFig..1.1,whichcontainmultiplediagonal elements that form a diagonal grid on the fringe of the structureAllconventionalverticalcolumnsareeliminatedin diagridstructuralsystem.Diagridstructuralsystembalance gravityaswellaslateralloadwiththehelpofdiagridgridon perimeter. With the help of connection of diagonal and horizontalmemberdiagridstructureismodeled.

The structure prepared by this system contain unique aestheticappearanceandcanberecognizedfromtheoutside. Due to its unique formation and efficiency of structure a diagrid system reduces the number of structural elements necessary on the perimeter of the buildings. Hence, the exteriorviewfromthebuildinghaslesshindrancecompared to the conventional design of structures. The structural efficiencyof diagridsystemalsohelpsin escapinginternal and corner columns, thus, permitting important flexibility with the floor plan. In addition, perimeter diagrid system savesnearly20percentofthestructuralsteelweightwhen equatedtoaconventionalmoment framestructure.

International Research Journal of Engineering and Technology (IRJET) e ISSN: 2395 0056

Volume: 09 Issue: 06 | Jun 2022 www.irjet.net p ISSN: 2395 0072

2. OBJECTIVE







Tobuildthe28modelofdiagridstructureinETABS 19.

Toanalysediagridstructuralsystemwithpertaining toangleandvariousseismiczone.

Tostudyonthevariationsinthestructuralresponse duetotheearthquakemotionswithdifferentIndian seismiczone.

4. Behaviors of diagrid structure with different loading condition



Todeterminethedifferentstoreysdiagridstructures behaviourwithallseismiczoneofIndia.

 Best configuration of diagrid system for various seismiczonewhichresultsintooptimalsolution.

 To determine the storey drift and storey displacementofdiagridstructure.

3. scope of work

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To perform parametric study of performance of diagrid for lateral loading with different angles, variousvertical&horizontaldensitieswithseismic zone Ⅱ , Ⅲ, Ⅳ, Ⅴ.

Fig 2: EffectofGravityLoadonDiagridModule

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Tocomeupwiththebestconfigurationfordiagrid systemthatreducesdisplacement,inter storeydrift, timeperiod,baseshear.

To realise scope of work, 28 models of different storey steel building is to be analysed in Etabs softwarefordynamicwindloadbyusinggustfactor method and non linear static earthquake load by performingresponsespectrumanalysisforseismic zone Ⅱ , Ⅲ, Ⅳ, Ⅴ

Fig 3: EffectofShearForceonDiagridModule

Chart 1:StructuralAnatomyof28Models

Fig 4: EffectofShearForceonDiagridModule

5.Modelling of diagrid structure

In this topic, analysis and design of various storey diagrid structuralsystemispresented.Modeling,analysisanddesign ofdiagridstructureiscarriedoutusingETABSsoftware.All structural members are designed using IS 800:2007 considering all load combinations. The static analysis is carried out considering earthquake and wind loads on structures.Importantanalysisresultsintermsoftimeperiod, topstoreydisplacementandinterstoreydriftarepresented forvariousseismiczoneandresultsarecompared.Further sizesofdiagonalmembersforallbuildingsarepresented.

International Research Journal of Engineering and Technology (IRJET) e ISSN: 2395 0056

5.2 Loading data

Followingloadingsareconsideredfortheanalysisanddesign ofstructure;

Dead Load: Deadloadofslab3.75kN/m2+Self weightof the structural members.

Live Load: 2.5kN/m2

Terrain category: III Class: C

Wind Load: Static wind loading is calculated as per IS: 875(III) 1987[24].Dynamicalongwindloadingiscalculated using gust factor method as per IS: 875(III) 1987[24]. Calculationofacrosswindequivalentstaticloadispresented inAppendixA.

Load Combinations: Loadcombinationsareconsideredas perIS:800 2007fordesignofstructure.combinationsforthe analysisanddesignofstructureasperIS:800 2007.

Earthquake Load: Run model with different seismiczone likeII,III,IV&V.

6. CONCLUSIONS

1. The following observations are made based on a comparisonoftheanalysisandresultsofa36 story diagrid structural system with a diagrid Angle of 74.75ºtoanalyzethebehaviorofdiagridstructural systemsinvariousseismiczones. 

Fromcomparisonofanalysisresultsseismic zone II to III to IV & V inter storey drift & Srorey displacement increases to 37.7%, 33.08%,&33.42%.

2. From the comparison of analysis and results of 60 storeydiagridstructuralsystemwithdiagridAngleof 71.57º to understand the behaviour of diagrid structural system, with various seismic zone followingobservationsaremade 

Fromcomparisonofanalysisresultsseismic zone II to III to IV & V inter storey drift & Srorey displacement increases to 36.42%, 31.12%,&33.33%.

3. From the comparison of analysis and results of 60 storeydiagridstructural systemwithShearwall at coreanddiagridAngleof71.57ºtounderstandthe behaviourofdiagridstructuralsystem,withvarious seismiczonefollowingobservationsaremade 

Fromcomparisonofanalysisresultsseismic zone II to III to IV & V inter storey drift &

International Research Journal of Engineering and Technology (IRJET) e ISSN: 2395 0056

Volume: 09 Issue: 06 | Jun 2022 www.irjet.net p ISSN: 2395 0072

Srorey displacement increases to 36.42%, 31.12%,&33.33%.

4. From the comparison of analysis and results of 6 storeydiagridstructuralsystemwithdiagridAngleof 74.50º to understand the behaviour of diagrid structural system, with various seismic zone followingobservationsaremade. 

Fromcomparisonofanalysisresultsseismic zone II to III to IV & V inter storey drift & Srorey displacement increases to 3720%, 33.25%,&33.66%.

5. From the comparison of analysis and results of 12 storey diagrid structural system with different vertical densityofdiagridAngleupto4thstoreyis 70º, 5th to 8th storey is 71º, 9th to 12th 72º to understand the behaviour of diagrid structural system, with various seismic zone following observationsaremade. 

Fromcomparisonofanalysisresultsseismic zone II to III to IV & V inter storey drift & Srorey displacement increases to 3738%, 33.40%,&33.33%.

6. From the comparison of analysis and results of 16 storey diagrid structural system with different vertical densityofdiagridAngleupto5thstoreyis 55º,6thto10thstoreyis65º,12thto16th73.47ºto understand the behaviour of diagrid structural system, with various seismic zone following observationsaremade. 

Fromcomparisonofanalysisresultsseismic zone II to III to IV & V inter storey drift & Srorey displacement increases to 37.72%, 33.33%,&33.13%.

7. From the comparison of analysis and results of 16 storey diagrid structural system with different vertical densityofdiagridAngleupto5thstoreyis 60º,6thto10thstoreyis65º,12thto16th71.20ºto understand the behaviour of diagrid structural system, with various seismic zone following observationsaremade. 

Fromcomparisonofanalysisresultsseismic zone II to III to IV & V inter storey drift & Srorey displacement increases to 3764%, 33.87%,&33.33%.

ACKNOWLEDGEMENT

Iwishtoexpressmysincereappreciationtomy sister,my parents, and guide, Prof. Aakash Suthar Asst. Prof. Civil Department,L.J.University,Ahmedabadforhisinspiration, encouragement, enthusiastic guidance and invaluable suggestions.Withouthiscontinuedsupportandinterest,this reportwouldnothavebeenthesameaspresentedhere.His constantsupportandinterestinthesubjecthelpedmewitha great understanding of different aspects of the required Planningfortheprojectwork.Hehasshownkeeninterestin thisreportworkrightfrombeginningandhasbeenagreat motivatingfactorinoutliningtheflowofmywork.

REFERENCES

[1] CharnishB.andMcDonnellT.,“Thebow:UniqueDiagrid Structural System for a Sustainable Tall Building”, CTBUH8thWorldCongress,Dubai,March2008.

[2] Soo k.J., Sik K.Y. and Hee L.S., “Structural Schematic Design of Tall Building in Asan using the Diagrid System”, CTBUH 8th World Congress, Dubai, March 2008.

[3] Rahimian A. and Eilon Y., “Hearst Headquarters: InnovationandHeritageinHarmony”,CTBUH8thWorld Congress,Dubai,March2008.

[4] MoonK.S.,“OptimalGridGeometryofDiagridStructures forTallBuildings”,ArchitecturalScienceReview,2008.

[5] TorenoM.,ArpinoR.,MeleE.,BrandonisioG.andLuca A., “An Overview on Diagrid Structures for Tall Buildings”

2022, IRJET | Impact Factor value: 7.529 | ISO 9001:2008 Certified Journal

International Research Journal of Engineering and Technology (IRJET) e ISSN: 2395 0056

Volume: 09 Issue: 06 | Jun 2022 www.irjet.net p ISSN: 2395 0072

BIOGRAPHIES

Arvishkumar Navneetbhai Panchal Student at L.J.University, Ahmedabad pursuing master degreeinstructuralengineering.

Mr. Aakash R. Suthar Faculty of civil structure department at L.J.University, Ahmedabad.

2022, IRJET | Impact Factor value: 7.529 | ISO 9001:2008 Certified Journal