ASCE 7-05 Seismic Provisions

Earthquake Protective Design Philosophical Issues High probability of “Failure” “Failure” redefined to permit behavior (yielding) that ...

Earthquake Protective Design Philosophical Issues

  • High probability of “Failure”

  • “Failure” redefined to permit behavior (yielding) that would be considered failure under other loads.

  • High Uncertainty

  • Importance of Details

In dealing with earthquakes we must contend with appreciable probabilities that failure will occur in the near future.  Otherwise, all the wealth of the world would prove insufficient… We must also face uncertainty on a large scale… In a way, earthquake engineering is a cartoon… Earthquakes systematically bring out the mistakes made in design and construction, even the minutest mistakes.  Newmark & Rosenblueth

Performance Levels

  • Incipient Collapse

  • Life Safety

  • Immediate Reoccupancy

  • Fully Operational

Hazard Levels

  • Occasional

  • 50% in 50 years

  • Rare

  • 10% in 50 years

  • Very Rare

  • 5% in 50 years

  • Max Considered

  • 2% in 50 years

Design Objective Defined

  • A specific performance level given a specific earthquake hazard level

  • Stated basis of current codes:

  • Life safety (+some damage control) at 10% in 50 year event (nominally)

Purpose of the Provisions

FEMA 302 Section 1.1
The design earthquake ground motion levels specified herein could result in both structural and nonstructural damage.  For most structures designed and constructed according to these Provisions, structural damage from the design earthquake ground motion would be repairable although perhaps not economically so.  For essential facilities, it is expected that the damage from the design earthquake ground motion would not be so severe as to preclude continued occupancy and function of the facility.

For ground motions larger than the design levels, the intent of these Provisions is that there be a low likelihood of structural collapse.





This example uses an old version of both the NEHRP and the ASCE 7 Wind Load Criteria.  It is used for illustrative purposes only.


How to deal with huge seismic force?




  • Isolate structure from ground (Base isolation)


  • Increae damping (Passive energy dissipation)


  • Allow inelastic response

Interim Conclusion (The Good News)

The frame, designed for a wind force which is 15% of the ELASTIC earthquake force, can survive the earthquake if:

  • It has the capability to undergo numerous cycles of INELASIC deformation

  • It has the capability to deform at least 5 to 6 times the yield deformation

  • It suffers no appreciable loss of strength

Interim Conclusion (The Bad News)

As a result of the large displacements associated with the inelastic deformations, the structure will suffer considerable structural and nonstructural damage.

  • This damage must be controlled by adequate detailing and by limiting structural deformations (drift)

COMMENTS

Name

• compression couplers,1,• tension couplers,1,1997 UBC,1,56 days Concrete test,1,ADDICRETE,1,additives,1,administer computer networks,1,admixtures,1,Advises Subcontractors,1,alignment of the shafts,1,Allowable Stress Design,1,Anchor Bolts,1,Annual depreciation expense,1,approval of drawings,1,ASD,1,Assist in Quantity,1,Assist the Project Manager,1,Authority to Delegate,1,AutoCAD,2,AutoCAD to Etabs,1,bars,1,bars in a bundle,1,BASE ISOLATED DAMAGE,1,base plates,1,basement wall,1,Basic soil properties,1,basic wind speed,1,Beams Inspection Checklist,1,Bearing capacity,1,bell pile bottom,1,bent bars,1,Bitomeneous,1,Bowels,1,breaching spillway,1,BS 8007:1987,1,BS5400,1,BS6399,1,BS8007,1,BS8110-1997,1,buildings height,1,CALCULATION OF CRACK WIDTH,1,Canary Island Dates,1,cantilever footing,1,Carbon Equivalent,1,carbon test,1,cast in-situ,1,cast-in-place anchors,1,cast-in-place concrete pile,1,Cause-and-effect diagram,1,Chairs,1,Check sheets,1,Chemical Admixtures,1,Chute spillway,1,CIRIA,2,CIRIA Report 136,1,civil structures,1,Coal ash,1,collars,1,Collision Load,1,columns,3,columns and walls,1,Combination of combinations,1,combinations in Etabs,1,Company's Health,1,Compliant Towers platforms,1,compression test,1,compressive strength,1,concrete,4,concrete block buildings,1,CONCRETE IN HOT WEATHER,1,CONCRETE MOMENT FRAME,1,concrete pile,1,Concrete Rebound Hammer,1,Concrete Shrinkage,1,Concrete Slump Test,1,concrete walls,1,Construction and Stressing,1,construction drawings,1,Construction joints,1,Construction Manual,1,continuous external restraint,1,continuous slabs,1,contract planresponsibilities of QA/QC,1,Contracts Manager,1,cooling pipe system,1,Corner reinforcement,1,Cost Plus Award Fee,1,Cost-reimbursable,1,COUPLED SHEAR WALL,1,Couplers,1,couplers in columns,1,CP3,1,CRACK WIDTH,1,Creep,1,CURING,1,day to day work progress,1,Dead load and Self-weight,1,Deck,1,Deflection,1,Deflection discussion,1,Deflection in Prestressed,1,deformed bars,1,Demolition,1,Design Requirements,1,designing a tall building,1,Designs projects,1,detailed review,1,detailing and implementation,1,Development length,1,different codes in one structure,1,Differential elastic shortening,1,dimensions,1,DIRECT TENSION,1,Draftsman responsibilities,1,drawings and specifications,1,Drift Limitations,1,Drop beams,1,dust loads,1,dust on roof,1,Dynamic Pile Head,1,dynamic wind pressure,1,Early age Crackwidth,1,early strength cement,1,Earth pressure,1,Earthquake Design,1,earthquakes,1,EBT adhesive sealant,1,Elastic Shortening,1,electrical and manual,1,elevator requirement,1,Elevators,1,Encasement of pipes,1,end plate connection,1,Energy dissipater,1,engineering design,1,Environmental procedures,1,epoxy compound,1,Epoxy grout,1,equipment performance records,1,Error and warning free model,1,Errors in Etabs,1,establishment of construction,1,Estimating Flow Standard,1,Etabs,2,Etabs Design,1,ETABS to ROBOT,1,excavation,1,Excavation slopes,1,external concrete surfaces,1,Finishing of slip-forms,1,Fire,1,Firm Fixed Price,1,Fixed platforms,1,Fixed Price Incentive Fee,1,Fixed Price with Economic,1,Flexible Joints,1,Flexible pipes,1,floors,1,Flow charts,1,Fly ash,1,Foundation analysis,1,Foundations,1,framed openings,1,Free over fall spillway,1,FRP,1,FRP advantages,1,FRP disadvantages,1,FRP technology,1,full length bar,1,General Notes,1,Geophone sensor,1,Hammer Schmidt Type,1,HDP,1,Health and Safety procedures,1,High Early Strength Portland Cement,1,High quality additives,1,high rise / tower,1,highly effective,1,Histograms,1,hooked bars,1,Horizontal steel,1,Human Comfort,1,hydraulic,1,hydraulic jump,1,Hydraulic resistance,1,Hydro technical tunnels,1,IBC/ASCE,1,immediate reaction,1,importance of Plasticizers,1,Importing,1,IMS,1,Inspection Checklist,6,INSTRUMENT CALIBRATION,1,inter-story drift,1,interest payments,1,IT engineer responsibilities,1,Jack-up Platforms,1,Jacking Systems,1,Japanese code for escalators,1,Kicker,1,largest oil platform,1,lateral forces,1,lateral loads,1,LFD,1,lifting hooks,1,Load Factor Design,1,load resisting elements,1,load-bearing wall,1,Loading,1,Loads and Resistances,1,LRFD,1,Maintain contract database,1,Maintains close scrutiny,1,maintenance cost,1,Makes recommendations,1,manage,1,manufacturer,1,manufacturing process,1,Maximum allowable slopes,1,maximum deflection,1,maximum difference,1,maximum pressure,1,maximum reinforcement,1,maximum temperature,1,Mechanical couplers,1,Mechanical damage,1,membrane floors,1,Metal sleeves swaged,1,Method of dissipation,1,METHOD OF TESTING,1,Method statement,2,Mineral Admixtures,1,minimize the seepage,1,minimizing the cost,1,minimum eccentricity moment,1,Minimum reinforcement,1,mixing concrete,1,modelling in Etabs,1,Monitors performance,1,monthly invoice,1,Monthly Safety Report,1,multi-storey buildings,1,multistory buildings,1,Natural frequency,1,Necessity of tunnel lining,1,new structural systems,1,O&M,1,of concrete block buildings,1,office buildings,1,Office Tall Buildings,1,offshore platforms,1,oil platform,1,oil rigs,1,on beams from loaded slab can be achieved by defining the slab as a membrane,1,opening reinforcement,1,ordinary Portland cement,2,Other bars,1,Overlap,1,overlap locations,1,Oversee and review,1,palm trees weight,1,parallel threads,1,parapet,1,Perform data backups,1,Performance Bonds,1,Performs design drafting,1,physical properties,1,Pile Dynamic Test,1,Pile Head Preparation,1,Pile Integrity Testing,1,Pile Shaft Overbreak,1,Pindos,1,Pipe Classifications,1,PLACING,1,Placing boom,1,Plan and prioritize work,1,Planning Engineer,1,plant and equipment,1,Plant and Equipment Engineer,1,plaster walls,1,Platform types,1,pneumatic,1,Post-Tensioning Grouting,1,Pour strip,1,precast panel,1,Prepares monthly report,1,Pressure Ratings,1,Prestressed Concrete,1,prevent uplift,1,principal load resisting,1,procedure of fixing,1,Project Coordinator,1,Project manager assignment,1,project schedule,1,project's compliance,1,Provides technical expertise,1,provisional Sum,1,PT slabs,2,pump,1,PVC,1,QA,1,QA/QC Engineer,1,QC,1,Quality,1,raft foundations,1,Raft Slab Inspection Checklist,1,reaction as an engineer,1,rebound hammer,1,recommended tests,1,Recorded experience,1,Reinforced concrete columns,1,reinforcement,1,Reinforcement at openings,1,reinforcing bars,2,reinforcing-steel,1,Residential Tall Buildings,1,RESISTING SYSTEMS DAMAGE,1,Retaining Wall Inspection Checklist,1,Retaining walls,1,retarder,1,Review contract documents,1,review contracts,1,review expiring contracts,1,Reviews accidents,1,reviews contract drafts,1,Reviews shop drawings,1,Reviews the terms and conditions,1,Rice husk ash,1,rigid foundation,1,Rigid pipes,1,Road layers,1,Robot Millennium,1,Roles and Responsibilities,8,Roller bucket,1,Rough Order of Magnitude,1,round deformed bars,1,Rules of thumb,1,saddle beams,1,Safe 14,1,Safety Manager,1,sample letter,3,sand,1,SAP2000,1,Schmidt Hammer,1,Seismic Design Principle,1,SEISMIC RESISTING SYSTEMS,1,seismic zone factor,1,Semi-structural welding,1,Semi-submersible Platforms,1,Senior Architect,1,Senior Contracts Engineer,1,Sequential Loading,1,Set work program,1,Seven Basic Quality Tools,1,shallow foundation,1,Shell,1,Ship-board Rigs platforms,1,shortening of columns,1,Shrinkage,1,Shrinkage and Temperature,1,Side channel spillway,1,simply supported,1,Site engineer responsibilities,1,site facilities,1,SK Gosh,1,Ski-jump,1,slab assignment,1,slabs,2,Slabs Inspection Checklist,1,slings,1,slip forms,1,Slip-form,1,Slip-form construction,1,slip-forming,1,smooth finish,1,soffit slabs,1,Soil classification,1,Soil Sloping Systems,1,speed of erection,1,Spring Force,1,standard size bolts,1,Static load,1,Static load multiplier,1,steel beam,1,Steel Columns,1,steel quantity,1,steel stress,1,Stiffness,1,stiffness and resistance,1,stilling basin,1,Strap footing,1,Strength and Stability,1,Stress on soil in etabs,1,Stressing sequence,1,Striking formworks,2,Strip footing,1,Strong Column,1,structural construction process,1,structural design spreadsheet,1,Structural Details,1,structural engineers,1,Structural Provisions,1,structural purposes pipes,1,strukts spreadsheets,1,Subcontract Agreement,1,Super-plasticizers,2,surfactants,1,Tack welding,1,Tall Building,1,tall buildings,1,Tallest buildings,1,taper-cut threads,1,Tdr Test Accuracy,1,Technical Engineer,1,technical submittals,1,test hammer,1,Test on Piles,1,Test specimens,1,TESTING,1,Thermal Expansion,1,threaded rods with nuts,1,time for completion,1,Top bars,1,torsion-load test,1,Total Shortening,1,tower cranes,1,Tower cranes installation,1,Transform AUTOCAD drawings,1,trough spillway,1,Trump Tower,1,Tunnel,1,tunnel lining,1,type of concrete,1,Types of contracts,1,types of foundation,1,Types of shallow foundation,1,Types of spillways,1,Types of waterproofing,1,Ultra Ever Dry,1,Uniform loads Safe 14,1,uniform thickness,1,Uplift Force,1,uplift test lateral-load test,1,vertical load resisting,1,Voided Biaxial Slabs,1,wall openings,1,walls,2,Warning,1,Water curing,1,Weak Beam Concept,1,Wedge locking sleeves,1,weekly and monthly program,1,weekly and monthly report,1,Welding of reinforcement,1,Welding procedures,1,What teachers never taught us,1,wind and seismic,1,Wind loads,1,Wind simulation,1,WOOD SHEAR WALL,1,workability,2,Workshop repair,1,
ltr
item
strukts: ASCE 7-05 Seismic Provisions
ASCE 7-05 Seismic Provisions
http://2.bp.blogspot.com/-uVtucGYXzyU/VRSu8d7Uu-I/AAAAAAAABts/WL5wvm5WTHo/s320/Untitled.jpg
http://2.bp.blogspot.com/-uVtucGYXzyU/VRSu8d7Uu-I/AAAAAAAABts/WL5wvm5WTHo/s72-c/Untitled.jpg
strukts
http://www.strukts.com/2012/05/asce-7-05-seismic-provisions_38.html
http://www.strukts.com/
http://www.strukts.com/
http://www.strukts.com/2012/05/asce-7-05-seismic-provisions_38.html
true
7606260228666216043
UTF-8
Loaded All Posts Not found any posts VIEW ALL Readmore Reply Cancel reply Delete By Home PAGES POSTS View All RECOMMENDED FOR YOU LABEL ARCHIVE SEARCH ALL POSTS Not found any post match with your request Back Home Sunday Monday Tuesday Wednesday Thursday Friday Saturday Sun Mon Tue Wed Thu Fri Sat January February March April May June July August September October November December Jan Feb Mar Apr May Jun Jul Aug Sep Oct Nov Dec just now 1 minute ago $$1$$ minutes ago 1 hour ago $$1$$ hours ago Yesterday $$1$$ days ago $$1$$ weeks ago more than 5 weeks ago Followers Follow THIS CONTENT IS PREMIUM Please share to unlock Copy All Code Select All Code All codes were copied to your clipboard Can not copy the codes / texts, please press [CTRL]+[C] (or CMD+C with Mac) to copy