Earthquake Resistant Design & Construction

1 ByProfessorAPPLIED MECHANICS DEPARTMENTL D COLLEGE of ENGINEERINGA hmedabadEarthquake Resistant Design & Construction (Gujarat Institute of Disaster Management)(28-07-2020). Earthquake Engineering PracticeConcept of EarthquakeResistantDesign of RC structures ActualConstruction PracticeConstruction practice -Beam, column, foundation, walls and roofsGeotechnicalconsiderations Earthquakesdonotkill,unsafebuildingsdo Earthquakeisamanmadedisaster Solutionliesin buildings &notin earthquakes Challenge : Understanding2005 NPEEE Earthquake Design Concept : Lecture 1: Impact of Earthquakes4/29 Destruction of Human Design LifeofStructures LoadsactingoncivilengineeringstructuresD esign Loads Dead Load Live Load Wind Load Earthquake Load Many other types of loadsStructural Design DesignforGravityLoads:(DL+LL) DesignforLateralLoad:(Wind+EQ) (Maxeffectivetime2minutes)Dead Load + Live Load +Wind or EQ Load DL + LL + WL or EQEarthquakeForceF=massxacceleration=maW indForceF=IntensityofwindxAreaofObstruct ionCyclone Resistant Design No damage conditionEarthquake Resistant Design -?

2 ?????? Design Philosophy for EarthquakeWhich Design philosophy should we follow? Earthquake Proof DesignOREarthquakeResistant DesignPhilosophy of Earthquake Resistant structure Duringanearthquake,lighterthebuildingand theroof, , ,duringacyclone,heaviertheroof, , Resistant Design No damage allowedEarthquake Resistant Design Damages allowed but no collapse We heavily rely on ductilityIS13920 2016 DuctileDesign&DetailingofRCStructuressub jectedtoSeismicForces CodeofPracticeDuctilityisdefinedastheabi lityofastructuretoundergoinelasticdeform ationsbeyondtheinitialyielddeformationwi thoutdecreaseinstrength&stiffnessElastic Response Vs Inelastic ResponseAdvantages of ,thereforegoodperformanceduring loadreversals, Impact IS DUCTILTY REQUIRED? TO PREVENT BRITTLE FAILURES. SHEAR FAILURE BOND FAILURE COMPRESSION FAILURES (OVER REINFORCED SECTIONS)VARIOUS CONVETIONAL LATERAL LOAD RESISTING SYSTEMS COLUMNS SHEAR WALLS BRACING SYSTEMS MOMENT RESISTING FRAME TUBES2005 NPEEE Earthquake Design Concept : Lecture 9: Overview of EQ Resistant Structural Systems22/232005 NPEEE Earthquake Design Concept : Lecture 9: Overview of EQ Resistant Structural Systems23/232005 NPEEE Earthquake Design Concept : Lecture 9: Overview of EQ Resistant Structural Systems24/232005 NPEEE Earthquake Design Concept : Lecture 9: Overview of EQ Resistant Structural Systems25/232005 NPEEE Earthquake Design Concept : Lecture 9: Overview of EQ Resistant Structural Systems26/232005 NPEEE Earthquake Design Concept : Lecture 9: Overview of EQ Resistant Structural Systems27/232005 NPEEE Earthquake Design Concept : Lecture 9: Overview of EQ Resistant Structural Systems28/232005 NPEEE Earthquake Design Concept : Lecture 9.

3 Overview of EQ Resistant Structural Systems29/232005 NPEEE Earthquake Design Concept : Lecture 9: Overview of EQ Resistant Structural Systems30/232005 NPEEE Earthquake Design Concept : Lecture 9: Overview of EQ Resistant Structural Systems31/23 Learning from failuresDEFICIENCIES IN BUILDINGS LOCAL DEFICIENCIES GLOBAL DEFICIENCIESLOCAL DEFICIENCIES IN BUILDINGSF ailures of Flexural Members2005 NPEEE Earthquake Design Concept : Lecture 14: Ductility of MRFs34/372005 NPEEE Earthquake Design Concept : Lecture 14: Ductility of MRFs35/37 Confinement & AnchorageConfinement to increase strengthContinuity & Anchorage for integral actionConfinement to increase strengthContinuity & Anchorage for integral actionAnchorage for integral action135 degree bendLOCAL DEFICIENCIES IN BUILDINGSF ailures of MEMBERS SUBJECTED TO BENDING & AXIAL LOADH ingesFAILURES DUE TO INADEQUATE LINKSFAILURES DUE TO INADEQUATE LINKSWhen a column terminates into a footing or mat2005 NPEEE Earthquake Design Concept : Lecture 14: Ductility of MRFs49/37 Thanks to well detailed confining reinforcement (Taiwan 1999)IS 13920 -2016 Design of Beam Column Joint Design of shear wallMITIGATING GEOLOGICAL HAZARDS Ground collapse Liquefaction Differential compaction Landslide Earthquake -induced floodASSESS THE POTENTIAL FOR SOIL LIQUEFACTIONThe building sank evenly about 1 m due to soil liquefaction.

4 The displaced soil caused a bulge in the inclined building sank unevenly and leans against a neighbouring buildingThe solid building tilted as a rigid body and the raft foundation rises above the ground. The building itself suffered only relatively minor tank is also tilted due to the liquefaction of the sandy artificial Liquefaction Foundation on bed rock Vibro-floatation Soil with stabilizing materials Provision of drainage to release pore pressureFactors for Good Seismic Performance Architectural configuration Simple and regular configuration Structural Design Adequate lateral strength Adequate stiffness Adequate ductility Integral Action Non-structural elements Quality of constructionCONCLUSIONF orsafetyinfutureearthquakes,allprovision softhecodesshouldbefollowedindesign& U All the BestCourtesy: Dr S K JainDr C V R M Murthy