SeismicProvisionsofASCE7-05Part3

2007 ASCE/SEI Structures Congress2007 ASCE/SEI Structures CongressLong Beach, California

Seismic Design Provisionsof ASCE/SEI 7 2005of ASCE/SEI 7-2005

Part 3

Robert BachmanChair, ASCE 7 Seismic Task Committee 2000-2005

h l i l iR. E. Bachman, Consulting Structural EngineerLaguna Niguel, California

May 16 2007May 16, 2007

OverviewOverview• Introduction to Earthquake Engineering• Revised Organization for ASCE 7 – 2005• Seismic Design per ASCE 7 – 2005g

– Basic Criteria– Structural Design for Buildings– Nonstructural Components in Buildings (Chptr 13)- Nonbuilding Structures (Chapter 15)

R f t M t i l D i St d d (Ch t 14)- References to Material Design Standards (Chptr 14)– Brief Discussion on Chapters 16-23– Modifications of ASCE 7-05 in the 2006 IBC

2007 Structures Congress Seismic Provisions of ASCE/SEI 7-05 2

– Modifications of ASCE 7-05 in the 2006 IBC

Nonstructural ComponentsNonstructural Components

• Architectural, Mechanical and Electrical Components supported , p ppby or located within buildings or other structures.

• In 1997 UBC Requirements Located in:

Section 1632 Lateral Force on Elements, Nonstructural Components and Equipment

Section 1633.2.4.2 Exterior ElementsSection 1633.2.8 Anchorage of Concrete and Masonry Walls

• In 2006 IBC – Refers to ASCE 7-05 including Supplement 1:

Ch t 13 S i i D i R i t f N t t lChapter 13 – Seismic Design Requirements for Nonstructural Components

Section 12.11.2 Anchorage of Concrete and Masonry Structural Walls


Structural Walls

Nonstructural Limits of ApplicabilityNonstructural Limits of Applicability

• 1997 UBC – Wherever UBC Adopted (Western States)1997 UBC Wherever UBC Adopted (Western States)

1. Requirements for the following items apply only in Seismic Zones 2, 3 and 4:

2. Ceilings, light fixtures, connections for prefabricated l t th th ll t i l telements other than walls, exterior elements,

anchorage of concrete or masonry walls.

• 2006 IBC – Applies throughout the US with following exceptions:1. Mechanical and Electrical Components in SDC A and B1. Mechanical and Electrical Components in SDC A and B2. Mechanical and Electrical in SDC if Ip = 1.03. Architectural in SDC A 4. Architectural in SDC B if Ip = 1.0 except certain parapets

• Other exceptions for light items, piping and ductwork in bothNOTE : there is a major errata in ASCE 7 – mechanical and electrical

are not exempt if all you do is attached flexible lines to them.


Nonstructural DemandsNonstructural Demands

Demands similar in both 1997 UBC and 2006 IBC• Demands similar in both 1997 UBC and 2006 IBC

• Equivalent Static Forces – Fp Equation – Independent of building structural propertiesbuilding structural properties

1. Strength Level Forces in both codes2. 2006 IBC provides building dependent option of

determining.

• Relative Displacements for Selected Components1 Anticipated Relative Displacements at Design1. Anticipated Relative Displacements at Design

Earthquake Level in both codes (Δm or Dp).2. 2006 IBC provides explicit equations and option of

determining using building structural properties.


g g g p p

Nonstructural Force DemandNonstructural Force Demand

1997 UBC Based on 1994 NEHRP• 1997 UBC – Based on 1994 NEHRP

Fp = ap Ca Ip ( 1 + 3 hx ) WpRp hrp r

Fp (min) = 0.7 Ca Ip Wp for Ca = 0.40, Fp = 0.28 IpWp

Fp (max) = 4 Ca Ip Wp for Ca = 0.40, Fp = 1.60 IpWp

• 2006 IBC – Based on 1997 NEHRP

Fp = 0.4 ap SDS ( 1 + 2 z ) Wp(R / I ) h(Rp / Ip ) h

Fp (min) = 0.3 SDS Ip Wp for SDS = 1.00, Fp = 0.30 IpWp

F (max) = 1 6 SDS I W for S S = 1 00 F = 1 60 I W


Fp (max) = 1.6 SDS Ip Wp for SDS 1.00, Fp 1.60 IpWp

N l I F INonstructural Importance Factor - Ip

Both the 1997 UBC and 2006 IBC ha e assigned Nonstr ct ral• Both the 1997 UBC and 2006 IBC have assigned Nonstructural Component Importance Factors, Ip

• In both codes the values of Ip are either 1.0 or 1.5

• In the 1997 UBC, the value of Ip is based on the Occupancy Category of the structure or facility

• In the 2006 IBC, the value of Ip is based

1. Requirements of the component to function after a DBE or 2 Occupancy Category of the structure or facility2. Occupancy Category of the structure or facility

• In the 2006 IBC, nonstructural components/systems which are assigned an Ip = 1.5 are called Designated Seismic Systems.


Nonstructural Component ap and Rp Factors

• Both 1997 UBC and 2006 IBC have ap and Rp factors assigned in tables that are used in Fp equation.

• The values of ap range from 1.0 to 2.5 in both codes and values p gof ap can be taken as less than 2.5 based on dynamic analysis.

• In the 1997 UBC, Rp values range from 1.0 to 4.0.

• In the 2000 IBC, Rp values range from 1.0 to 12.0.

• In both codes, the values of Rp can be assigned based on the ductility and deformability capacity.y y p y

• In the 1997 UBC there are 19 footnotes to the ap and Rp table.

• In the 2006 IBC there only 2 footnotes to the ap and Rp tables.


p p

Comparison of ap and Rp values for Selected Architectural ComponentsSelected Architectural Components

Architectural Component 1997 UBCa R

2006 IBCa Rap Rp ap Rp

Cantilever Parapets 2.5 3.0 2.5 2.5

E t i W ll * ( i id di h ) 1 0 3 0 1 0 2 5Exterior Walls* (rigid diaph.) 1.0 3.0 1.0 2.5

Partitions* (rigid diaph.) 1.0 3.0 1.0 2.5

Ceilings 1.0 3.0 1.0 2.5

Penthouses (not an extension) 2.5 4.0 2.5 3.5

Signs and Billboards 2.5 3.0 2.5 2.5

Access Floors* (special) 1.0 3.0 1.0 2.5

2007 Structures Congress Seismic Provisions of ASCE/SEI 7-05 9Storage Cabinets 1.0 3.0 1.0 2.5

Comparison of Fp/Wp values for Architectural Components for Ca = 0.40,

SDS = 1.0, Ip = 1.0Architectural Component 1997 UBC

h = 0 h = h2006 IBC

z = 0 z = hhx 0 hx hr z 0 z h


E t i W ll 0 28 0 53 0 30 0 48Exterior Walls 0.28 0.53 0.30 0.48

Partitions 0.28 0.53 0.30 0.48

Ceilings 0.28 0.53 0.30 0.48



Access Floors (special) 0.28 0.53 0.30 0.48


Storage Cabinets 0.28 0.53 0.30 0.48

Comparison of ap and Rp values for Selected Mechanical and Electrical

ComponentsMech./Elect. Component 1997 UBC

a R2006 IBC

a Rap Rp ap Rp

Tanks and Vessels w/o skirts 1.0 3.0 1.0 2.5

Ai id i t 1 0 3 0 2 5 6 0Air side equipment 1.0 3.0 2.5 6.0

Wet side equipment 1.0 3.0 1.0 2.5

Emergency Battery Racks 1.0 3.0 1.0 2.5

Stacks, towers braced below cg 2.5 3.0 2.5 3.0

Vibration Isolated Equipment* 2.5 1.5 2.5 2.0 – 2.5

Piping – ASME Welded 1.0 3.0 2.5 12.0


Piping – threaded joints 1.0 3.0 2.5 4.5

Comparison of Fp/Wp values for Mech./Elect. Components for Ca = 0.40,

SDS = 1.0, Ip = 1.0Mech./Elect. Component 1997 UBC

h = 0 h = h2006 IBC

z = 0 z = hhx 0 hx hr z 0 z h




Emergency Batteries/Tanks 0.28 0.53 0.30 0.48


Vibration Isolated Equipment* 0.67 1.60 0.40-0.50 1.20-1.50





Architectural Component ASCE 7-02ap Rp

ASCE 7-05ap Rp


Exterior Walls* (rigid diaph.) 1.0 2.5 1.0 2.5


Ceilings 1 0 2 5 1 0 2 5Ceilings 1.0 2.5 1.0 2.5


Si d Billb d 2 5 2 5 2 5 2 5Signs and Billboards 2.5 2.5 2.5 2.5





Architectural Component ASCE 7-02ap Rp

ASCE 7-05ap Rp


Exterior Walls* (rigid diaph.) 1.0 2.5 1.0 2.5


Ceilings 1 0 2 5 1 0 2 5Ceilings 1.0 2.5 1.0 2.5


Si d Billb d 2 5 2 5 2 5 2 5Signs and Billboards 2.5 2.5 2.5 2.5




Comparison of Fp/Wp values for Architectural Components for Ca = 0.40,

SDS = 1.0, Ip = 1.0Architectural Component ASCE 7-05

z = 0 z = hASCE 7-05

z = 0 z = hz 0 z h z 0 z h


E t i W ll 0 30 0 48 0 30 0 48Exterior Walls 0.30 0.48 0.30 0.48

Partitions 0.30 0.48 0.30 0.48

Ceilings 0.30 0.48 0.30 0.48



Access Floors (special) 0.30 0.48 0.30 0.48



Comparison of ap and Rp values for Selected Mechanical and Electrical

ComponentsMech./Elect. Component ASCE 7-02

a RASCE 7-05

a Rap Rp ap Rp




Emergency Battery Racks 1.0 2.5 1.0 2.5


Vibration Isolated Equipment* 2.5 2.5 2.5 2.0 – 2.5




Comparison of Fp/Wp values for Mech./Elect. Components for Ca = 0.40,

SDS = 1.0, Ip = 1.0Mech./Elect. Component ASCE 7-02

z = 0 z = hASCE 7-05

z = 0 z = hz 0 z h z 0 z h




Emergency Batteries/Tanks 0.30 0.48 0.30 0.48


Vibration Isolated Equipment* 0.40 1.20 0.40-0.50 1.20-1.50




Nonstructural Relative Displacement Demand

• ASCE 7-05 – Maximum Relative Displacements for DBE level motions are to be considered

• In ASCE 7-05Required for Architectural Components which pose a life

safety hazard including exterior wall elements and glazingRequired for Mech/Elect components and systems where Ipq p y p

greater than 1.0.

• Except for glazing – no specific acceptance criteria is providedN i i hi l i li i ll blNo requirement to stay within elastic limits or allowables


Nonstructural Relative Displacement Demand

• In both 1997 UBC and 2006 IBC – Maximum Relative Di l f DBE l l i b id dDisplacements for DBE level motions are to be considered

• In 1997 UBCRequired to be considered for equipment attachments forRequired to be considered for equipment attachments for

Essential and Hazardous FacilitiesDeformation Compatibility in Exterior Elements

I 2006 IBC• In 2006 IBCRequired for Architectural Components which pose a life

safety hazard including exterior wall elements and glazingRequired for Mech/Elect components and systems where IRequired for Mech/Elect components and systems where Ip

greater than 1.0.

• Except for glazing – no specific acceptance criteria is provided


No requirement to stay within elastic limits or allowables

Load Combinations

• In both codes, strength, ASD and alternate ASD load combinations are provided.

• In both codes there are E and E loads• In both codes, there are Eh and Ev loads.

• In the 1997 UBC Ev may be taken as zero for the alternate ASD load combinations. In the 2006 IBC, Ev is used and not taken as

f t f f d ti i izero for except for foundation sizing.

• In both codes, the redundancy factor, ρ, is specified as 1.0 for nonstructural components.p

• In both codes, Ωo is not specified and load combinations with Ωoare not used with nonstructural components (including penthouses)


penthouses)

Anchorage of Nonstructural Components

• In the 1997 UBC1. Special Requirements for shallow anchors. Rp = 1.5p q p

Shallow anchors defined as embed/diameter less than 82. Special Requirement for expansion anchors for vibration

isolated equipment – 2 Fp SEAOC Bluebook only if gap > 0.25 in3. Section 1923 – Anchorage to concrete - Strength

2.0 factor if no special inspection – 1.3 with special insp.

• In the 2006 IBC1. All anchor forces based on Rp of 1.5 unless:

- Anchorage governed by ductile steel element or- Post installed for Seismic Applications per ACI 355.2 or- Anchors design in accordance with ACI 318-05, App. D

2. Additional 1.3 factor or maximum transferable force3. Special requirement – vib iso equipment – 2 Fp if gap > 0.25”4 L d th l i t i t t h ll b f d


4. Load path analysis to primary structure shall be performed.

Design and Detailing Requirements of Design and Detailing Requirements of Architectural Components

• In 1997 UBC

1. Specific demands exterior walls and connections2. UBC Standard 25-2, Part III for lay-in ceilings

• In 2006 IBC

1. Specific demands exterior walls and connections2. Suspending Ceilings – CISCA & ASTM standards3 Glazing Drift capacity AAMA 501 63. Glazing – Drift capacity AAMA 501.64. Access Floors – special access floor details5. Tall Partitions – independent bracing


Design and Detail Requirements forDesign and Detail Requirements forMechanical and Electrical Equipment

• In 1997 – No specific requirements

• In 2006 IBC1. Sprinkler systems – NFPA 13 with amendments2. Escalators and Elevators – ASME A17.13. Vessels – ASME B& PV3. Vessels ASME B& PV4. Piping – ASCE B 31.15. HVAC Ducting – (SMACNA not specifically referenced)6 Lighting fixtures – Prescriptive detail requirements6. Lighting fixtures Prescriptive detail requirements7. Many specific prescriptive details for Mechanical and

Electrical Equipment – Section 13.6.5.5


Special Certification Requirements for Certain Designated Seismic Systems Certain Designated Seismic Systems

(Ip=1.5)• In 1997 UBC – No specific requirement

• In 2006 IBC - Seismic qualification required for1 Active mechanical and electrical equipment that are1. Active mechanical and electrical equipment that are

required to function following a DBE2. Components containing hazardous contents

• Qualification to demonstrate functionality after being subject to a DBE to be determined by either:

1. Shake table testing – ICC-ES AC-156 , 20042. Experience Data 3. Analysis (extremely difficult for active equipment)

Certification required by supplier indicating compliance


• Certification required by supplier indicating compliance

Final Comments about Final Comments about Nonstructural Components

• Force levels and approaches similar between 1997 UBC and 2006 IBC. Terminology is similar.

• Much more implementation detail in the 2006 IBC

• Additional documentation requirements in the 2006 qIBC

• Much more QA requirements in the 2006 IBC. Note there are specific requirements for supports and attachments to be shown on the construction documents


documents.

Nonbuilding Structuresg

• Self supporting structures other than buildings that support gravity loads and resist overturning moments at their base.

• In 1997 UBC Requirements located in:

Section 1634 Nonbuilding Structures

Section 1629 Criteria Selection

Section 1630 Minimum Design Lateral Forces…

• In 2006 IBC – Refers to ASCE 7-05 including Supplement 1Chapter 15 - Seismic Design Requirements for Nonbuilding

StructuresStructures Chapter 12 - Seismic Design Requirements for Building

StructuresChapter 13 - Seismic Design Requirements for


p g qNonstructural Components

Two Types of Nonbuilding Structures

• In both 1997 UBC and 2006 IBC there are two types of nonbuilding structures

1. Those that have seismic force resisting systems that are similar to buildings (e.g. pipe racks)

2. Those that do not have seismic force resisting systems that are similar to a building (e.g. flat bottom tanks)bottom tanks)


Example of a “Similar” Systemp y


Example of a “Not Similar” System


Nonbuilding Structures Limits of Applicability

• 1997 UBC – Wherever UBC Adopted (Western States)1997 UBC Wherever UBC Adopted (Western States)

1. Not required in Seismic Zone 0 but everywhere else2. For structures similar to building – same restrictions as for

b ildi t t ith i il tbuilding structures with similar systems.3. For structures not similar to buildings – no restrictions.

C S f• 2006 IBC – applies throughout the US with following exceptions:

1. Not required for Seismic Design Category A except Sec11.72. For structures similar to building – same restrictions as for2. For structures similar to building same restrictions as for

building structures with similar systems but with additional options.

3. For structures not similar to buildings – some restrictions


Nonbuilding Structure Demands

• In both codes – same base shear equations used for building structures.

Basically the same equation in the 1997 UBC and 2006 IBC except for site ground motion terminology.

However, the R values, I values and minimum values are significantly different in the two codes.

2006 C f Ω CAlso the 2006 IBC specifies Ωo and Cd values, detailing requirements along with height limits and restrictions for all systems while the 1997 UBC only specifies R and Ωovalues


values.

Equivalent Lateral Force Equations for Structures with Systems Similar to Structures with Systems Similar to

Buildings1997 UBC 2006 IBC

( Ts = Cv / 2.5 Ca ) ( Ts = SD1 / SDS )

T < Ts V = Ca I W V = SDS W R (R / I)R (R / I)

T > Ts V = Cv I W V = SD1 WR T (R / I ) T

T > TL V = SD1TL W(R / I ) T2

Min V V = 0.11 CaI W V = 0.01 W

Min Zone 4 V = 0.8 Z NV I W V = 0.5 S1 W


(S1 > 0.6) R (R / I )

Equivalent Lateral Force Equations for Structures with Systems Not Similar to Structures with Systems Not Similar to

Buildings1997 UBC 2006 IBC( Ts = Cv / 2.5 Ca ) ( Ts = SD1 / SDS )

T < Ts V = Ca I W V = SDS W R (R / I)R (R / I)

T > Ts V = Cv I W V = SD1 WR T (R / I ) T

T > TL V = SD1TL W(R / I ) T2

Min V V = 0.56 CaI W V = 0.03 W (or 0.01 W)

Min Zone 4 V = 1.6 Z NV I W V = 0.8 S1 W (or 0.5 S1 W )


(S1 > 0.6) R (R / I ) (R / I )

Comparison of Minimum ValuesComparison of Minimum ValuesFor Structures Not Similar to Buildings

• To Compare – assume a rock site with I =1.0

1997 UBC Z = 0.4, Ca = 0.40, Nv = 1.0, Cv = 0.4 and

2006 IBC SDS = 1.0, S1 = 0.60, SD1 = 0.40

1997 UBC 2006 IBCR=2.2 R=3.6 R= 2.2* R=3.6*

V min 0.22 W 0.22 W 0.03 W 0.03 W(or 0.01W) (or 0.01W)

Zone 4 V min 0.29 W 0.17 W 0.22 W 0.13 W(or 0.14W) (or 0.08W)


*For Comparison Only

Nonbuilding Structure Importance Factor INonbuilding Structure Importance Factor I

B th th 1997 UBC d 2006 IBC h i d• Both the 1997 UBC and 2006 IBC have assigned Seismic Importance Factors, I.

I th 1997 UBC th l f I i ith 1 0 1 25• In the 1997 UBC, the value of I is either 1.0 or 1.25 and is based on the Occupancy Category.

In the 2006 IBC the value of I is either 1 0 1 25 or• In the 2006 IBC, the value of I is either 1.0, 1.25 or 1.5 and is based on largest value from:

1. Referenced standards for the structure type2. Occupancy Category (Table 11.5-1)3. Specified values in Chapter 15


Nonbuilding Structures Similar to Buildingsg gR Factors and Height Limits

• In the 1997 UBC, R, Ωo and height limits are the same as for , , o gbuilding structures with 2 exceptions:

1. Concrete IMRFs permitted to height of 50 feet rather than NP in Zones 3 and 4 if R is taken as 2 8 rather than 5 5NP in Zones 3 and 4 if R is taken as 2.8 rather than 5.5

2. Height limits may be increased by 50% if regular structures that are not occupied or accessible to general public

• In the 2006 IBC, the R, Ωo, Cd and height limits are same as for building structures with additional options:

1. Height limits of certain systems are permitted to higher1. Height limits of certain systems are permitted to higher levels if lower R values are used (see next slide)

2. SCBF and special shear wall height limits can be increased by 50 % if regular structures with multiple lines of


resistance – same as permitted for buildings

“Similar” Nonbuilding Structure OptionspOrdinary Steel Concentrically Braced

Frames

System Detailing R Height Limit (ft.)B C D E F

Steel OCBFs AISC 341 3.25 NL NL 35 35 NP

With Permitted AISC 341 2.5 NL NL 160 160 100Height Increase

With Unlimited AISC 360 1.5 NL NL NL NL NLHeight


“Similar” Nonbuilding Structure OptionsSimilar Nonbuilding Structure OptionsIntermediate Moment Frames of Steel


Steel IMFs AISC 341 4.5 NL NL 35 NP NP

With Permitted AISC 341 2.5 NL NL 160 160 100Height Increase



“Similar” Nonbuilding Structure OptionsSimilar Nonbuilding Structure OptionsOrdinary Moment Frames of Steel


Steel OMFs AISC 341 3.5 NL NL NP NP NP

With Permitted AISC 341 2.5 NL NL 100 100 NPHeight Increase



“Similar” Nonbuilding Structure OptionspIntermediate Reinforced Concrete

Moment Frames


Concrete IMFs ACI 318 5.0 NL NL NP NP NP with Chptr. 21

With Permitted ACI 318 3.0 NL NL 50 50 50Height Increase with Chptr. 21

With Unlimited ACI 318 0.8 NL NL NL NL NLHeight with Chptr. 21


“Similar” Nonbuilding Structure OptionspOrdinary Reinforced Concrete

Moment Frames

System Detailing R Height Limit (ft.)B C D E FB C D E F

Concrete OMFs ACI 318 NOT 3.0 NL NL NP NP NP ith Ch t 21with Chptr. 21

With Permitted ACI 318 NOT 0.8 NL NL 50 50 50Height Increase with Chptr. 21


Comparison of Selected “Not Similar” Comparison of Selected Not Similar Nonbuilding Structure R values

Structure Type R value1997 UBC 2006 IBC

Skirt Supported Vessels 2.9 2 or 3Cast in Place Silos 3.6 3.5 T k d P i d S h 2 2 2 3Tanks and Pressurized Spheres 2.2 2 or 3Cooling Towers 3.6 3.5Bins and Hoopers 2.9 3.0Signs and Bill Boards 3.6 3.5Amusement Structures/Monuments 2.2 2.0Trussed Towers 2 9 3 0


Trussed Towers 2.9 3.0

Nonstuructural Component orNonstuructural Component or Nonbuilding Structure?

• Sometimes its confusing whether one should use the nonbuilding structure or nonstructural component requirements.

• Particularly confusing are tanks, vessels, signs and bill b d h h i h ibill boards where the requirements show up in 2 places.Wh d li ti if it t i ll fit i• Where duplicative, if it can typically fit in or on a building (10 feet tall or less) suggest using nonstructural requirements


nonstructural requirements.

Load Combinations

• In both codes, strength, ASD and alternate ASD load combinations are provided.

• In both codes there are E and E loads• In both codes, there are Eh and Ev loads.

• In the 1997 UBC Ev may be taken as zero for the alternate ASD load combinations. In the 2006 IBC, Ev is used and not taken as

f t f f d ti i izero for except for foundation sizing.

• In both codes, redundancy factor, ρ, is specified as 1.0 for “not similar” nonbuilding structures. Same as buildings for “similar”.g g

• In both codes, Ωo is specified. However in the 1997 UBC not really explained how to use but its explained to a certain extent in the 2006 for some nonbuilding structures.


in the 2006 for some nonbuilding structures.

Fundamental Period DeterminationFundamental Period DeterminationFor Nonbuilding Structures

• In 1997 UBC – Requires that period be determined by rational methods such as Method B (Rayleigh approach).

• In 1999 SEAOC Bluebook states Method A should not apply to both “similar” and “not similar” nonbuilding structures. Suggests Rayleigh approach or dynamic analysis BB Section C 109 1 4Rayleigh approach or dynamic analysis. BB Section C 109.1.4

• In 2006 IBC – Fundamental Period to be determined by rational building type procedures or by the Rayleigh formula –building type procedures or by the Rayleigh formula Specifically excludes Method A type procedures to be used in determining the period of nonbuilding structures.


Design and Detailing Requirement forDesign and Detailing Requirement forStructures “Similar” to Buildings

• In 1997 UBC – No specific additional requirements provided

• In 2006 IBC• In 2006 IBC

1. Same requirements as for buildings except where noted2. Steel Storage Racks – RMI plus additional requirements2. Steel Storage Racks RMI plus additional requirements3. Towers supporting tanks and vessels – added requirements4. Piers and wharves – only for those accessible to the public


Design and Detailing Requirement forDesign and Detailing Requirement forStructures “Not Similar” to Buildings

• In 1997 UBC – Use approve national standards with limit that the that the total base shear overturning moment determined by them can not be less than 80 % of the UBC determined value.

• In 2006 IBC – Some requirements provided for the following

1. Earth Retaining Structures2. Secondary Containment Structures3. Flat Bottom Tanks - AWWA 100, API 650, ACI 3134. Elevated Tanks for Liquids and Granular Material5. Boilers and Pressure Vessels – ASME BPVC6. Liquid and Gas Spheres/ Refrigerated – ASME BPVC & API7. Horizontal Vessels


Final Comments AboutFinal Comments AboutNonbuilding Structures

• Approaches between 1997 UBC and 2006 IBC similar.

• Force levels, height limits and detailing requirements for structures “similar” to buildings very different between codes.

• Forces levels for structures “not similar” to buildings very similar except for I factors.

• More detailing requirements provided in the 2006 IBC.


Chapter 14 Material Specific Requirements

(Trumped by IBC Chapters 18-23)( p y p )

1. Steel: references plus light frame2. Concrete: reference plus selected details

and section on pilesp3. Composite steel and concrete: references4 Masonry: references plus selected details4. Masonry: references plus selected details5. Wood: references plus selected details


Chapter 16Chapter 16Response History Analysis

• Provides Requirements for Selection and Scaling of Ground Motion Time Histories – virtually the same as those found in the UBCsame as those found in the UBC

• Provides requirements for performing nonlinear response history analysisresponse history analysis

(Note: time history analysis = response history analysis)• Similar to the UBC requirements but with a few q

additional requirements.


Chapters 17 - 19

• Chapter 17 – Seismic Isolation Requirements- basically the same as UBC excepts for:

* ground motions* RI values and height limits

• Chapter 18 – Brand new Chapter on Structures with Damping Systems – Based on NEHRPChapter 19 Soil Str ct re Interaction Reall• Chapter 19 – Soil Structure Interaction – Really developed for large structures with rigid bases (e.g. nuclear reactor containment structures)


( g )

Chapter 20Chapter 20Site Classification Procedure

• Intended primarily for Geotechnical Engineers• Provides Detailed Procedures for Determining Site

Class A – FSi il t h t i i th 1997 UBC• Similar to what is in the 1997 UBC

• Provides specific Details for how to deal with Site Cl F d h t d l ith f l if kClass F and how to deal with refusal if a rock layer is met at a depth of less than 100 feet.


Chapter 21Chapter 21Site Specific Ground Motion Procedures

• Specific Procedures Provided for both- Site Response Analysis

Ground Motion Hazard Analysis- Ground Motion Hazard Analysis• Limits provided on site specific determined spectra

- Can be greater than map determined spectra including soil lifi ti ff tamplification effects

- Can’t be less than 80% of map determined spectra including soil amplification effects.- Site Class F site specific spectra can’t be less than 80% of the map determined spectra including soil amplification effects if the site were classified Site Class E.


Chapter 22Chapter 22Ground Motion Maps

• Maps provided for Ss and S1 on soft rock and the long period transition TL

f h k d d f• Use for cursory checks, not recommended for design

• For design use the USGS web site (or CD which is• For design use the USGS web site (or CD which is coming) based on longitude and latitude of site (not zip code) determined to 3 digits beyond decimal.

http://earthquake.usgs.gov/research/hazmaps/design/index.php


Chapter 23Chapter 23Seismic Design References

• Same as Chapters 35 in IBC and UBC

Ch t 35 i IBC T IBC if th i diff F• Chapter 35 in IBC Trumps IBC if there is a difference. For example AISC 341 is referenced in Chapter 23 while in the IBC its AISC 341-05 including Supplement No. 1.

• The seismic forces specified in ASCE 7-05 are tied to the detailed reference documents. Not using the detailing

ifi d i th IBC i l di difi ti thspecified in the IBC including any modifications means the specified seismic forces may not be valid.


Appendix 11AAppendix 11AQuality Assurance Provisions

• Provides testing and inspection requirements for structures and nonstructural components

• Not adopted typically by jurisdictions. Instead use Chapter 17 of the IBC.

• Includes a description of a quality assurance plan that needs to be developed.


Appendix 11BAppendix 11BExisting Building Provisions

• Provides triggering requirements for structural independent and dependent additions, alterations and change of use

• Not adopted typically by jurisdictions. Instead use h f h l ll d dChapter 34 of the IBC or locally adopted

ordinances.


2006 IBC Modifications to ASCE 7-05

2006 IBC S ti 1613 6 P it C t i L R t i ti• 2006 IBC Section 1613.6 Permits Certain Less Restrictive Alternatives to be used than those found in ASCE 7-05

1. Assumption of flexible diaphragms – provides additional conditions when diaphragms may be considered flexible

2. Permits steel OMFs and OCBFs to be used with2. Permits steel OMFs and OCBFs to be used with seismic isolation for structures assigned SDC D, E and F if RI is taken as 1.0 (currently not permitted since isolation limits tied to R table).limits tied to R table).


Concluding Remarks

• Seismic Provisions of ASCE 7-05 represent our best current seismic design practiceC i i h ll h l i l d bi• Consistency with all the latest material codes – big improvement from the UBC

• Reorganization and reformat of seismic provisions shouldReorganization and reformat of seismic provisions should greatly improve usability

• Seismic forces in most cases will be similar or less than h ifi d i h 199 C b f hthose specified in the 1997 UBC because of the

convergence strategy that SEAOC used in developing the 1997 UBC seismic requirements.


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SeismicProvisionsofASCE7-05Part3

Documents

flat bottom

specific acceptance

billboards

permitted

rp values

seismic design

similar nonbuilding

ev loads codes