Seismic Code Requirements

1 CE 243A Behavior & design of RC Elements Prof. J. W. WallaceFall 041CE243A 1 Seismic code RequirementsSeismic code RequirementsJohn W. Wallace, , W. Wallace, , ProfessorAssociate ProfessorUniversity of California, Los AngelesUniversity of California, Los AngelesCE243A 21971 San Fernando, CaliforniaEarthquakeCE 243A Behavior & design of RC Elements Prof.

2 J. W. WallaceFall 042CE243A 31971 San Fernando EarthquakeOlive View Hospital ComplexCE243A 41971 San Fernando EarthquakeSoft-storyCE 243A Behavior & design of RC Elements Prof. J. W. WallaceFall 043CE243A 51971 San Fernando EarthquakeCE243A 61971 San Fernando EarthquakeCE 243A Behavior & design of RC Elements Prof.

3 J. W. WallaceFall 044CE243A 71971 San Fernando EarthquakeTies @ 18 Spiral @ 3 81994 Northridge EarthquakeCal State NorthridgeCE 243A Behavior & design of RC Elements Prof. J. W. WallaceFall 045CE243A 91994 Northridge EarthquakeCal State NorthridgeCE243A 101994 Northridge EarthquakeNorthridge Fashion MallCE 243A Behavior & design of RC Elements Prof.

4 J. W. WallaceFall 046CE243A 111994 Northridge EarthquakeBarrington BuildingCE243A 121994 Northridge EarthquakeBarrington BuildingHoliday Inn Van NuysCE 243A Behavior & design of RC Elements Prof. J. W. WallaceFall 047CE243A 131994 Northridge Earthquake1994 Northridge EarthquakezzMajor failures:Major failures.

5 Steel momentSteel moment--resisting framesresisting frames PrecastPrecastconcrete parking structuresconcrete parking structures TiltupTiltup& masonry buildings with wood & masonry buildings with wood roofsroofszzMajor successesMajor successes retrofitted retrofitted unreinforcedunreinforcedmasonry masonry structuresstructures retrofitted bridge structuresretrofitted bridge structuresCE243A 141994 Northridge Earthquake1994 Northridge Earthquakezz1997 UBC & NEHRP 1997 UBC & NEHRP changes:changes.

6 Removal of preremoval of pre--qualified steel qualified steel connection detailsconnection details addition of nearaddition of near--fault factor to base fault factor to base shear equationshear equation prohibition on prohibition on highly irregular highly irregular structures in nearstructures in near--fault regionsfault regions stricter detailing for stricter detailing for nonnon--participating participating elementselements deformation deformation compatibility compatibility requirementsrequirements chords & collectors chords & collectors designed for real designed for real forcesforces redundancy factor redundancy factor added to design added to design forcesforcesCE 243A Behavior & design of RC Elements Prof.

7 J. W. WallaceFall 048CE243A 15 SummarySummaryzzObservation of the behavior of real buildings in Observation of the behavior of real buildings in real earthquakes have been the single largest real earthquakes have been the single largest influence on the development of our building influence on the development of our building codescodeszzThe lull in earthquakes in populated areas The lull in earthquakes in populated areas between approximately 1940 and

8 1970 gave a between approximately 1940 and 1970 gave a false since of security at a time when the false since of security at a time when the population of California was expanding rapidlypopulation of California was expanding rapidlyzzPerformance of newer buildings and bridges has Performance of newer buildings and bridges has generally been good in recent earthquakes; generally been good in recent earthquakes; however, older buildings pose a substantial however, older buildings pose a substantial hazard. hazard. CE243A 16 Seismic Codes and Source DocumentsSeismic Codes and Source DocumentsSEAOCASCE 7 NEHRPS tandardStandardBuilding CodeBuilding CodeUniformUniformBuilding CodeBuilding CodeBOCA NationalBOCA NationalBuilding CodeBuilding CodeStandardStandardBuilding CodeBuilding CodeUniformUniformBuilding CodeBuilding CodeBOCA NationalBOCA NationalBuilding CodeBuilding CodeInternational Building CodeInternational Building CodeCE 243A Behavior & design of RC

9 Elements Prof. J. W. WallaceFall 049CE243A 17 IBC 2000, 2003 IBC 2000, 2003zzInternational code International code Council (ICC), Council (ICC), established in 1994established in 1994zzSeismic provisionsSeismic provisions ASCE 7 ASCE 7--0202zzModelingModelingzzForcesForces Material codesMaterial codeszzACI, ASCEACI, ASCEzzIBC 2003 (ASCE 7 IBC 2003 (ASCE 7--02, 02, ACI 318 ACI 318--02)02)CE243A 18 Material CodesMaterial CodesInternational Building CodeInternational Building CodeACI 318-02 ACI 318R-02 Building code Requirements forStructural Concrete (ACI 318-02)and Commentary (ACI 318R-02)

10 American concrete BOX 9094 FARMINGTON HILLS, MI 48333aciMANUALOF STEELCONSTRUCTIONLOAD &RESISTANCEFACTORDESIGNV olume IStructural Members,Specifications,& CodesSecond EditionAISCAn ACI StandardReported by ACI Committee 318CE 243A Behavior & design of RC Elements Prof. J. W. WallaceFall 0410CE243A 19 Shake Table Test Shake Table Test Flat PlateFlat PlateCE243A 20 Earthquake Building ResponseEarthquake Building ResponseTimeTimeShakingShakingF4= m4a4(t)F3= m3a3(t)F2= m2a2(t)F1= m1a1(t)V(t) = miai(t)i=1,4 Note: Forces generally Increase with heightCE 243A Behavior & design of RC Elements Prof.