International Research Journal of Engineering and Technology (IRJET) e-ISSN: 2395-0056
Volume: 12 Issue: 12 | Dec 2025 www.irjet.net p-ISSN: 2395-0072
Review Paper on Analysis of Isolated Lead Rubber Bearing
Mr. Kaushik Waghmare1
,
Dr. A. P. Patil2
1Post Graduate Student, Dept. of Civil Engineering, Datta Meghe College of Engineering, Airoli, Navi-Mumbai 400708, Maharashtra, India
2 Assistant Professor, Dept. of Civil Engineering, Datta Meghe College of Engineering, Airoli, Navi-Mumbai 400708, Maharashtra, India
Abstract –Earthquakes are among the most destructive natural hazards, primarily triggered by the movement of tectonic plates within the Earth’s crust. Such seismic events can causeseverestructuraldamageandsignificantlossoflife.Base isolationis anadvancedseismicprotectiontechniquedesigned todecouplea structurefromgroundmotion,therebyabsorbing and dissipating earthquake forces. This system effectively reduces floor accelerations and inter-storey drifts, enhancing structural safety and improving post-earthquake operability.
The present review synthesizes relevant literature and theoreticaldevelopmentsonseismicisolationtechnologies.The main objective of this paper is to evaluate and present the effectiveness of various isolator systems used to mitigate earthquake-induced impacts.
Key Words: Seismic isolation, Base isolation system, Earthquake engineering, Tectonic plates, Structural safety, Seismic mitigation, Inter-storey drift, Floor acceleration,Isolatoreffectiveness,Structuraldynamics etc.
1. INTRODUCTION
Inrecentyears,theriseoftallandslenderhigh-risebuildings hasmadethemincreasinglyvulnerabletolateralforcessuch as wind and earthquakes, requiring modern structural designstofocusonbothstrengthandstabilityunderthese loads. Seismic design now emphasizes understanding inelastic structural behavior to ensure life safety and controlled energy dissipation during earthquakes. Among various seismic protection methods, base isolation has proven highly effective in minimizing earthquake damage. Originating in the early 20th century and widely adopted since the 1980s in countries like Japan, the USA, and New Zealand,baseisolationhasalsobeenimplementedinIndia firstafterthe1993KillariearthquakeandnotablyintheBhuj CivilHospitalfollowingthe2001Bhuj earthquake.Seismic baseisolationisthemostpopularresponse-controlstructure technique, a device having some damping properties and sufficientbearingstrengthisusedinthestructure.
1.1 General Description of Base Isolation Systems
This study aims to evaluate how base isolators improve structuralperformanceduringearthquakesandtoidentify thetypesofstructuresforwhichleadrubberbearings(LRBs)
aremosteffective.Toachievethis,an8-storeysteelandRCC building with a fixed base is compared to an identical structure equipped with base isolation. Their seismic responses are analyzed to understand the improvements offeredbyisolationsystems.
Theresearchhighlightshowbuildingsofvaryingheightsand flexibilitybehaveunderdifferentseismiczoneswhenbase isolationisapplied. The findingscan help buildingowners andindustryprofessionalsbetterunderstandtheadvantages of adopting base isolation in a broader range of projects, promotingwideruseofthistechnology.
2. LITERATURE REVIEW
Todistinguishbetweentheresponsesofthefixedbaseand theisolatedbasestructureandtoknowtheeffectivenessof isolators,reviewofsomepapersisgiven:
StefnoSorace,GloriaTerenzi(2014) Inthispaper,Stefano andGloriadiscussthedesignandanalysisofabase-isolated building located in Italy. The building consists of 26 residentialflats.BoththeRCCstructureandthebaseisolation system were designed by practicing engineers. Double FrictionPendulum(DFP)sliderswereusedastheisolation devices Based on the structural analysis and construction details,thestudyconcludesthatthebuildingachievesvery highperformancelevels.Itwasalsoobservedthattheoverall construction cost is significantly lower compared to a conventional fixed-base design. In addition, the reinforcementdetailingwassimplified,makingthestructure moreefficientandeconomical.
The primary purpose of base isolation is to minimize structural damage during strong ground motions by increasingthefundamentaltimeperiodofthestructureand providing adequate damping. In this project, a low-rise building isanalyzedusingETABSsoftware.Thestudyalso includesanoverviewofearthquakeengineeringprinciples and base isolation techniques, which helps in improving understandinginthisfield.Bothfixed-baseandbase-isolated modelswereanalyzedusingtheresponsespectrummethod, with lead rubber bearings (LRB) providedas the isolation system. The results show that the use of LRB significantly
Tejas Jitendra Chordiya and Vaishnavi Yogesh Totla (2018)
International Research Journal of Engineering and Technology (IRJET) e-ISSN: 2395-0056
Volume: 12 Issue: 12 | Dec 2025 www.irjet.net p-ISSN: 2395-0072
improves the structural stability and performance of the buildingduringearthquakes.
DhavalVShankhpal,AnkitPal(2013) DhavalV.Shankhpal and Ankit Pal carried out the design and analysis of an elevatedwatertankusingSAP2000software.Intheirstudy, they reviewed various research works related to base isolation systems for buildings as well as elevated water tanks. Based on the response spectrum analysis, they concluded that the use of a base isolation system is an effectivemethodforimprovingearthquakeresistance.The resultsshowedthatbaseisolationsignificantlyreducesbase shear and earthquake-induced displacements in the structure.
Shameena Khannavar and M H Kolhar (2016) In this research paper, a 10-storey RC building was modeled and analyzedusingETABSsoftware.Twotypesofmodelswere developed: one with a fixed base and the other with base isolation. The study considered two vertically irregular models and two plan-irregular models. Structural analysis wascarriedoutusingboththeequivalentstaticmethodand theresponsespectrummethod.Leadrubberbearings(LRB) weredesignedaccordingtotheUBC97codeandusedasthe base isolation system. Key response parameters such as storeydisplacement,storeyshear,storeyacceleration,and inter-storeydriftwereobtainedfromtheanalysis.Theresults indicate that base isolation is highly effective in reducing seismic responses in both plan-irregular and vertically irregularbuildingswhencomparedtofixed-basestructures.
Michael Dsymans Symansinvestigatedtheeffectivenessof anadaptiveseismicisolationsysteminprotectingstructures subjected to different earthquake ground motions. The proposedsystemcombinesslidingisolationbearingswithan adaptive hydraulic damper. The damping capacity of the hydraulicdampercanbeadjustedinrealtimetorespondto the characteristics of the earthquake motion. The results showthat,forearthquakesofvaryingintensities,thesliding base isolation system effectively controls the response of boththeisolationsystemandthestructure.
Sarvesh K Jain and Sashi K Thakkar (2004) This study focuses on the application of base isolation in flexible buildings. For the analytical investigation, three building modelswereconsidered:aten-storey,afourteen-storey,and atwenty-storeystructure.Theperformanceofbase-isolated buildings was evaluated by comparing them with correspondingfixed-basebuildings.Thestudyclearlystates thattheeffectivenessofbaseisolationisassessedusingthe EffectivenessRatio(ER),definedastheratiooftheresponse ofafixed-basebuildingtothatofabase-isolatedbuilding.
N Murali Krishna et al (2016) The study focused on the nonlineartimehistoryanalysisofbuildingsequippedwith seismic control systems. Asymmetric buildings were considered to evaluate how seismic responses can be effectivelycontrolled.Theanalysisexaminedtheinfluenceof
shearwallsandbaseisolationsystemsusingnonlineartime history analysis (NLTHA) on RCC moment-resisting frame structures. Key response parameters such as storey drift, baseshear,torsionalmoment,andstoreydisplacementwere evaluated. The results showed that base isolation has a significant impact in reducing storey drift, storey shear, storey displacement, and torsional effects in low-rise asymmetricbuildings.Incontrast,shearwallswerefoundto bemoreeffectiveinimprovingthesameresponsesinhighriseasymmetricbuildings.
MinalAshokSomwanshi(2015) etal.conductedastudyon theseismicanalysisoffixed-baseandbase-isolatedbuilding structures.Thestudyinvolvedmodelingandanalyzinga13storey rigid jointed plane frame under two conditions: a fixed-basesystemandabase-isolatedsystem.Themodeling and analysis were carried out using ETABS software, consideringtheBhujearthquakegroundmotionrecords.The maximumverticalreactionswereobtainedfromtheETABS analysis,andbasedonthesereactionsandthetotalmassof thestructure,leadrubberbearingsweremanuallydesigned. Time-historyanalysiswasthenperformedtoevaluatefloor responses, accelerations, and displacements during earthquake loading. The objective of the study was to demonstrate the effectiveness of the isolation system by examining reductions in key structural responses such as maximum shear force, maximum bending moment, base shear,storeydrift,andstoreydisplacement.Theanalytical results showed that base isolation significantly reduces seismic responses in both symmetric and asymmetric buildingswhencomparedtofixed-basestructures,thereby helpingtocontrolstructuraldamageduringstrongground shaking.
Yangetal(2006), Inthispaper,twohybridaseismiccontrol systems are proposed to protect building structures from strong earthquakes. Each hybrid system combines a base isolation system with either a passive or an active mass damper. The base isolation system, such as elastomeric bearings, helps reduce the transfer of horizontal ground motion to the building, while the mass damper whether passiveoractive enhancesthesafetyandreliabilityofthe base isolation system. The performance of these hybrid control systems was studied and compared with that of a conventional active control system. The theoretical and numericalresultsshowthattheproposedhybridsystemsare highly effective in reducing the seismic response of tall buildings during strong earthquakes. In addition, these hybridsystemsareeasiertoimplementinpracticecompared tousinganactivecontrolsystemalone.
Juan C. Ramallo, et al (2008). In this paper, the authors investigated the use of controllable semi-active dampers, such as magneto-rheological (MR) fluid dampers, in baseisolated building systems. A simplified two-degree-offreedom(2DOF)modelofabase-isolatedbuildingwasused for the study. The main idea behind base isolation is to decouplethestructurefromgroundmotion,particularlyin
International Research Journal of Engineering and Technology (IRJET) e-ISSN: 2395-0056
Volume: 12 Issue: 12 | Dec 2025 www.irjet.net p-ISSN: 2395-0072
thefrequencyrangewherethebuildingismostvulnerable. Theprimaryobjectiveofthestudywastoreduceinter-storey drifts and floor accelerations in a cost-effective manner, thereby limiting damage to both the structure and its contents. The research examined the potential benefits of replacingconventionallinearviscousdampersusedinbase isolation with semi-active dampers. A linear lumped-mass 2DOF model was adopted, where the superstructure was represented by a single-degree-of-freedom system characterizedbyitsmass,natural frequency,anddamping ratio. The performance of passive linear viscous dampers, active dampers, and semi-active dampers was evaluated. Both generalized semi-active dampers and magnetorheological fluid dampers were considered for seismic protection. The results showed that semi-active dampers achieved performance levels close to those of fully active dampers.Comparedtopassivelineardampers,semi-active dampers significantly reduced peak base drifts. The study concludes that semi-active dampers, particularly MR fluid dampers,offerapromisingandenergy-efficientalternative forbaseisolationsystems,requiringmuchlesspowerthan fullyactivecontrolsystems.
3. CONCLUSIONS
Afterreviewingnumerousstudies,itbecomesevidentthat protectingstructures fromunpredictableseismic eventsis challenging when using conventional methods such as structural strengthening. Although these traditional approachescanenhancebuildingsafety,theyoftenlead to increasedflooraccelerationsandlargerinter-storeydrifts, whichnegativelyimpactstructuralperformance.Incontrast, theimplementationofdampingdevicescapableofabsorbing earthquake-induced vibrations has proven more effective. Thisconceptformsthebasisofseismicbaseisolation.
AdvantagesofBase-IsolatedStructuresComparedtoFixedBase Structures: Reduction in seismic energy transfer: Baseisolationdecouplesthestructurefromgroundmotion, significantly limiting the amount of earthquake energy enteringthebuilding.Thisresultsinlowerductilitydemands andreducedinter-storeydrift.
Lower natural frequency and minimized resonance: Astructure’snaturalfrequencydependsonparameterssuch as mass, stiffness, and height. When the natural frequency alignswithpredominantearthquakefrequencies,thebuilding may experience large oscillations. By decreasing the structure’s stiffness, base isolators reduce the natural frequency, thereby limiting resonance and minimizing seismic vibrations. Reduced need for additional structural strengthening: Since base isolation decreases the seismic forces transmitted to the superstructure, extensive strengtheningelementssuchasshearwalls,bracedframes, oradditionalreinforcementbecomelessnecessary.
REFERENCES
[1] R.S.Jangid‘’StochasticresponseofbuildingwithLead rubberbearings.
[2] ALiteratureStudytoSeismicIsolationinBuildingand Water Tank by Dhaval V. Shankhpal and Ankit Pal (International Journal of Current Engineering and Technology)
[3] A Review Paper on Base Isolation Technique by Miss.Sushma.G. Sawadatkar and Mr. Mandar.M. Joshi (IJRASET)
[4] Analysis, Design, and Construction of a Base-Isolated Multiple Building Structure by Stefano Sorace1 and GloriaTerenzi(Hindawi)
[5] Applicationof BaseIsolationforFlexibleBuildings by Sarvesh K. Jain1 And Shashi K. Thakkar (13th World ConferenceonEarthquakeEngineeringVancouver,B.C., Canada)
[6] TanwerM.T.,KaziT.A.andDesaiM.,2019,Astudyon differenttypesofbaseisolationsystemoverfixedbased, InformationandCommunicationTechnology
[7] MoniriH.,2017,Evaluation ofseismicperformanceof reinforced concrete (RC) buildings under near-field earthquakes, International Journal of Advanced StructuralEngineering,9(1),pp.13-25
[8] IslamA.S.,AhmadS.I.,JameelM.andZaminM.J.,2012, SeismicBaseIsolationforbuildingsinregionsoflowto moderate seismicity: practical alternative design, Practice Periodical on Structural Design and Construction,17(1),pp.13-20.
[9] Carlos Miguel Cabeçadas Calado (2014), Seismic responseofbase-isolatedstructuresduringimpactwith adjacentstructuresInternationalJournalofSciencesand Engineering,October2014,Volume04,PP.716-719
[10] Dr Manjunath N Hegde et al (2016), Comparison of Seismic Behavior of Building with Fixed Base, Base IsolatorandShearWall,InternationalResearchJournal ofEngineeringandTechnology(IRJET)e-ISSN:23950056Volume:03Issue:10|Oct-2016