Selected New Provisions of ASCE 7-05

2007 Structures Congress

Selected New Provisionsof ASCE/SEI 7-2005:

Jim Harris

J. R. Harris & Company

Denver, Colorado

May 18, 2007

John HooperMagnusson Klemencic Associates

Seattle, Washington

2007 Structures Congress Seismic Design Under ASCE 7-2005 2

Overview• Reorganization• New maps; Long period map• New systems, revised R factors and limitations• Diaphragm assumptions• Redundancy factor• Dynamic analysis triggers• Near fault spectral shape applicability• Modal response spectrum analysis• Simplified design method


ASCE 7-05 ReorganizationGoals of Seismic Section Reorganization

1. To improve clarity and use2. Reduce depth of section numbering from 6 max

typical to 4 max typical(i.e. Sec. 9.5.2.5.2.2 is now Sec. 12.5.3)

3. Simplify table and figure numbering(i.e. Table 9.5.2.5.1 is now Table 12.6-1)

4. Create logical sequence of provisions aim at the structural engineering community

5. Improve headings and clarify ambiguous provisions


ASCE 7-05 Reorganization

1. Changed major subjects to Chapters rather than Sections (similar to the IBC)

2. Replaced Section 9 with Chapters 11-23

3. Incorporated the material appendices

4. Put the Chapters into a logical sequence

5. Rewrote ambiguous headings

6. Examined and rewrote sections to eliminate ambiguity

7. Provided Cross Reference Table C-11-1…02 to 05


Comparison of ContentsASCE 7-2002 Sections

1. General

2. Combinations of Loads

3. Dead Loads

4. Live Loads

5. Soil and Hydrostatic …and Flood Loads

ASCE 7-2005 Chapters

1. General

2. Combinations of Loads

3. Dead Loads, Soil … and Hydrostatic

4. Live Loads

5. Flood Loads


Comparison, continued

ASCE 7-2002 Sections

6. Wind Loads7. Snow Loads8. Rain Loads9. Earthquake Loads10. Ice LoadsA. Supplemental (QA)B. Serviceability

ASCE 7-2005 Chapters

6. Wind Loads7. Snow Loads8. Rain Loads9. (not used)10. Ice Loads11. - 23. SeismicA & B. QA & Existing


Seismic ContentsASCE 7-2002

9.1 General Provisions

9.2 Definitions/ Symbols

9.3 (not used)

9.4 Ground Motion

9.5 Structural Design Criteria, Analysis, and Procedures

ASCE 7-2005

11. Seismic Design Criteria

12. Seismic Design Requirements for Building Structures

13. Seismic Design Requirements for Nonstructural Comp.


Seismic Contents, continuedASCE 7-2002

9.6 Arch, Mech, Elect Comp and Sys

9.7 Foundations9.8 Steel9.9 Concrete9.10 Composite Struct.9.11 Masonry

ASCE 7-2005

14. Material Specific15. Nonbuilding

Structures16. Response Hist Anal17. Seismic Isolation18. Damping Systems19. Soil-Struct. Interact.


Seismic Contents, continued

ASCE 7-2002

9.12 Wood

9.13 Seismic Isolation

9.14 Nonbuilding Structures

A9. Quality Assurance

ASCE 7-2005

20. Site Classification21. Site-Specific

Ground Motions22. Maps23. Reference Docs11A. Quality Assurance11B. Existing Buildings


11 Seismic Design Criteria

11.1 General

11.2 Definitions

11.3 Notation

11.4 Seismic Ground Motion Values

11.5 Importance Factor

11.6 Seismic Design Category

11.7 Design Req’ts for Category A

11.8 Geologic Hazards & Geotechnical Invest.


11.1 Purpose

“…specified earthquake loads are based upon post-elastic energy dissipation in the structure, and because of this fact, the requirements for design, detailing, and construction shall be satisfied even for structures and members for which load combos w/o EQ exceed those with EQ…”


11.4 Seismic Ground Motions

1 Determine basic values from maps for bedrock conditions

2, 3 Classify soil conditions at site and determine site coefficients

4 Determine site-adjusted values

5 Take two-thirds for use in design

6 Construct design response spectrum

7 Site-specific studies permitted/required


Mapped Acceleration Parameters

• Two updated sets of basic maps for the response spectrum accelerations– SS for spectral response acceleration at 0.2 secs

– S1 for spectral response acceleration at 1.0 secs

• New map for long period transition: TL in seconds


SS and S1 are themapped 2% in 50 yearspectral accelerationsfor firm rock

SDS and SD1 are thedesign level spectralaccelerations (modifiedfor site and “expectedgood performance”)

Ground Motion Parameters & Seismic Hazard

Mapped Contours of SS


General Comparison of Maps

With ASCE 7-02• Changes everywhere,

but mostly minor• Deterministic area

around New Madrid

With UBC 97• Lots of change• Lower in most areas• Higher in high hazard

areas, except near fault in California

• Three maps, not one


Long Period Transition Maps (Fig 22.15)


Site Specific Studies

• Clarification of two types:– Basic ground motion hazard at a point in rock– Site amplification in overburden soil

• First type never required, but permitted; limits placed upon results

• Second type encouraged; required in some instances


Cumulative Nature of Provisionsby Seismic Design Category

A B C D E F


Seismic Design Category A

• 11.7 is a self-contained section; defines E

• Horizontal force = 1% of dead load

• Load path for horizontal forces– connections = 5% of weight of smaller part

• Beam, truss connections = 5% D + L

• Anchor concrete and masonry walls– 280 pounds per foot


Geologic Hazards andGeotechnical Investigations

• SD Category E and F:– Do not locate on active fault

• SD Category C:– Evaluate slope instability, liquefaction,

differential settlement, surface displacement

• SD Category D, E, F:– More detail than C plus lateral pressures on

basement walls and retaining walls




12 Seismic Design of Building Structures

1 Design Basis

2 Structural Systems

3 Diaphragm Flexibility; Configuration; & Redundancy

4 Load Effects & Combinations of Loads

5 Direction of Loading

6 Selection of Analysis

7 Modeling Criteria

8 ELF Method

9 Modal RS Method

10 Diaphragms, Chords Collectors

11 Structural Walls (out-of-plane)

12 Drift and Deformation

13 Foundation Design

14 Simplified Alternate


12.1.1 Basic Requirements

• Strength, Stiffness, Energy Dissipation

• Design Motion in Any Horizontal Direction

• Construct Mathematical Model

• Evaluate Model for Effects– Limitations on methods of evaluation

– Modifications to internal forces (R, 0)

– Modifications to deformations (Cd)

• Alternate Procedures Must Be Consistent


Minimum Connection Forces

• Very Similar to 11.7 for SD Category A

• Continuous Load Path: “…from point of application to final point of resistance…”– 0.133 SDS WP 0.05 WP

– Does not apply to overall design of SFRS (Seismic Force Resisting System)

• Beams, Trusses to Support 5% of D + L


12.2 Structural System Requirements

1. System identification and limitations

2. Combos of systems: different direction

3. Combos of systems: same direction

4. Combos of systems: detailing

5. Specific system requirements


System Identification

• “Basic lateral and vertical SFRS shall conform to one (or a permitted combo) of the systems from Table 12.2-1…”

• “Selected SFRS shall be designed and detailed per referenced requirements…”

• SFRS not from table permitted only if analytical and test data establish basis


Basic system parameters

Obtain from table and use in seismic design:• R Response Modification Factor

- measure of system inelastic capabilities• Cd Deflection Amplification Factor

- increase elastic to total o System Overstrength Factor

- accounts for actual strength greater than design strength; used to protect vulnerable items.


R factor comparisonsSystem 97 02 05

Special RC Shear Wall (bearing) 4.5 5 5

Ordinary RC Shear Wall (bearing) 4.5 4 4

Special RC Shear Wall (bldg frm) 5.5 6 6

Ordinary RC Shear Wall (bldg frm) 5.5 5 5

Intermed Precast Shear Wall (b f) -- -- 5

Ord Precast Shear Wall (b f) -- -- 4



Special RM Shear Wall (bearing) 4.5 5 5

Intermed RM Shear Wall (bearing) 4.5 3.5 3.5

Ord RM Shear Wall (bearing) 4.5 2 2

Special RM Shear Wall (bldg frm) 5.5 5.5 5.5

Intermed RM Shear Wall (bldg frm) 5.5 4 4

Ord RM Shear Wall (bldg frm) 5.5 2.5 2.5



Special Steel Concentric BF 6.4 6 6

Ordinary Steel Concentric BR 5.6 6 3.25

Special RC Shear Wall (bldg frm) 5.5 6 6

Ordinary RC Shear Wall (bldg frm) 5.5 5 5

Eccentrically Braced Frame (with) 7 8 8

Eccentrically Bracked Frame (w/out) 7 7 7



Light Frame with SWP (bearing) 5.5 6 6.5

Light Frame with other (bearing) 4.5 2 2

Light Frame with SWP (bldg frm) 6.5 6.5 7

Light Frame with other (bldg frm) 5 2.5 2.5

Light Frame with straps (bearing) 2.8 4 4


Height Limits• Most shear wall and braced frame systems

limited to 160 feet high in SD Categories D and E, and to 100 feet in SD Category F

• These limits can be increase to 240 feet and 160 feet, respectively for some structures– No line resists more than 60% of base shear– Torsional force < 20% of total force in the line

• Many exceptions, especially for nonbuilding


Concrete Shear Wall - Frame

• Limited to SD Category B

• Ordinary detailing for wall and frame

• Analyze for interaction and provide as a minimum– Walls strong enough for 0.75 Vx at each story

– Frames strong enough for 0.25 Vx at each story


12.3 Diaphragms, Configuration, and Redundancy

1. Diaphragm Flexibility in Analysis

2. Identification of Irregularities in System Configuration

3. Limitations on and Penalties for Irregularities

4. Redundancy– Significant changes from prior edition


Diaphragm Flexibility

Assume Flexible if• Wood or steel deck with

concrete or masonry walls

• 1 or 2 family residential if light frame

• Compute

ΔDia > 2 * δvert

Assume Rigid if• Concrete slab (or filled

deck) with span to depth < 3 and no horizontal irregularity

Otherwise:• Must analyze system

including actual stiffness of diaphragm!


Configuration: Basic Parameters

Size

ProportionShape


Plan Irregularities

1a Torsional irregularity corner > 1.2 center

1b Extreme torsional irregularity corner > 1.4 center

Note: torsional irregularity not checked for flexible diaphragms

2 Re-entrant corners Both projections > 15% of respective sides

3 Diaphragm discontinuity 50% change in a level or

from level to level

4 Out-of-plane offsets absolute

5 Nonparallel systems absolute

Type Measure


Vertical Irregularities

1a Stiffness-Soft Story Story stiffness < 70% above

1b Stiffness- Extreme Soft Story Story stiffness < 60% above

2 Weight (Mass) More than 150% adjacent story

Note: 1 and 2 dropped if no story drift exceeds 130% of story above

3 Vertical Geometric Length of SFRS >130% of that in adjacent story

4 In-Plane Discontinuity Offset > length of element or a reduction in stiffness below

5a Capacity-Weak Story Lat strength < 80% of above

5b Extreme Weak Story Lat strength < 65% of above

Type Measure


Configuration Limitations

• Horiz 1b not permitted in SD Cat E+

• Vert 1b, 5a not permitted in SD Cat E+

• Vert 5b not permitted in SD Cat D+

• Vert 5b limited to 2 stories or 30 feet in SD Cat B or C, unless weak story strength capable of 0 times design force


Configuration Penalties

• Horiz 4 and Vert 4 (column, slab, beam, or truss elements supporting discontinuous elements) to resist 0 force (all SD Categories)

• Horiz 1, 2, 3, 4 and Vert 4 have 25% increase in force for connection of diaphragm to vert element and collectors in SD Cat D+; also req’d for collectors except those already designed for 0 force




Redundancy factor

Reliability Factor

1.3or 1.0 ρ

1.0ρ

Seismic Design Category

B or C

D, E or F

is always 1.0 for drift and P-delta calcs and for design of:• Nonstructural components• Nonbuilding structures not similar to buildings• Members designed for 0 forces• Diaphragms• Structures with damping systems


Redundancy Factor = 1.3Unless following loss does not an extreme torsional irregularity and does not reduce story strength by more than 33%:

• Braced frame: removal of a single brace• Moment frame: loss of moment resistance

at both ends of a single beam (or at base of a single cantilever column)

• Shear walls: removal of any single pier with h/l > 1.0 (or collector to such a pier)


12.6 Analysis Method Selection

Methods Defined

• Equivalent (Static) Lateral Force: ELF

• Modal Response Spectrum: MRS

• Seismic Response History (Linear and Nonlinear): SRH (Defined in section 16)

Alternate classifications:

Static / Dynamic Max / Dynamic History

Linear / Nonlinear


What type of Analysis?

• The answer depends on:– what performance level you

are hoping to achieve

– the configuration of the structure

– how accurate you need to be

• A wide range of choices are available-


Superior Performance Levels

• Behavior will be essentially elastic– For regular structures with short periods, linear static

procedures are fine

– For regular structures with long periods and all irregular structures - linear dynamic procedures are better, response spectra accurate enough

J oe’s

Beer!Beer!Food!Food!


J oe’s


Poorer Performance Levels

• Inelastic behavior is significant (elastic analyses are the wrong approach!)– For structures dominated by first mode response,

pushover analysis may be adequate

– For structures with significant hire mode response, nonlinear time history necessary


J oe’s


Methods Permitted• SD Cat B and C: any defined method

• SD Cat D+: ELF permitted for– Occ Cat I/II < 3 stories– Occ Cat I/II of light frame < 4 stories

– Reg structures with T < 3.5 TS

– Reg structures of light frame any T

– Irreg structure with T < 3.5 TS limited to horiz types 2, 3, 4, or 5 and vert types 4, 5a, or 5b

• Other SD Cat D+ must use MRS or SRH


Design Response Spectrum

0.0

0.1

0.2

0.3

0.4

0.5

0.6

0.7

0 1 2 3 4 5 6 7TST0 Period, seconds

Spe

ctra

l Acc

eler

atio

n, g

0.4SDS

Sa = SD1 / T

Sa = SDS(0.4 + 0.6 T/T0)

Sa = SD1 TL / T2

Drawn for SS = 1.0, Fa = 1.0 S1 = 0.4, Fv = 1.5 TL = 4



0.0

0.1

0.2

0.3

0.4

0.5

0.6

0.7


Spe

ctra

l Acc

eler

atio

n, g

0.4SDS

Sa = SD1 / T

Sa = SDS(0.4 + 0.6 T/T0)

Sa = SD1 TL / T2


Sa = 0.5 S1


12.8 ELF Method of Analysis

1. Seismic Base Shear: V = CSW

2. Period Determination

3. Vertical Distribution of Seismic Forces

4. Horizontal Distribution of Forces

5. Overturning

6. Story Drift Determination

7. P-Delta Effects


Seismic Coefficient

Basic rules are the design spectrum adjusted for R and I:

Also, where S1 > 0.6:

minimum)new(01.0

2

11

s

LDDDSs

C

IR

T

TS

IR

T

S

IR

SC

IRS

Cs15.0


Adjustments to Base Shear

• Soil-Structure Interaction per Section 19 is permitted

• Low rise buildings in high ground motion areas:

If stories < 6 and T < 0.5 seconds

Can use SS = 1.5 max


12.8.2 Period of Vibration

• Follow modeling criteria in 12.7 to compute T

• Upper bound for forces:

auTCT

SD1 Cu

> 0.4 1.4

0.3 1.4

0.2 1.5

0.15 1.6

<0.1 1.7


Approximate Periodxnta hCT

Structure Ct x

100% Moment Frames:

Steel

Concrete

0.028

0.016

0.8

0.9

Eccentrically Braced 0.03 0.75

All others 0.02 0.75


What is hn? – Concept of Base

hn hn

Base

RC frame

RC wall

Masonrywall

RC wall

Base


Alternate Estimates for Ta

• 100% moment frames up to 12 stories with story heights at least 10 feet: , Ta = 0.1N

• Shear walls of concrete or masonry:

n

w

a hC

T0019.0

x

i

i

i

i

i

n

Bw

D

h

A

h

h

AC

12

2

83.01

100


Vertical Distribution of Force

Equivalent static force at level x: VCF vxx

n

i

kii

kxx

vx

hw

hwC

1

wherewi , wx: Portion of W assigned to level i or x

hi , hx: Height of level i or x above base

k sets the shape of distribution and depends on T

Story Shear:

n

xiix FV


Shape of Vertical Distribution1 ≤ k ≤ 2: Varies with T

For T ≤ 0.5, k = 1 (linear distribution)

For T ≥ 2.5, k = 2 (parabolic distribution;impact of higher modes)

For 0.5 < T < 2.5, k = 2 or k = 0.75 + T/2

(interpolation)


ELF - Story Shears

F V

n

xiix FV Sum the story forces from the top down

Distribution of story forces intended to give proper envelopeof maximum story shears for a regular building. It does not give envelope of maximum story forces.


ELF - Horizontal Distribution

• Distribute story shear to vertical elements

per relative stiffness of vertical elements and

diaphragm

• Account for computed (inherent) torsion - eccentricity

between mass and resistance

• Add accidental torsion, except for flexible diaphragms

• Amplify torsion if torsionally irregular


Torsional Irregularity

For S.D. Category C, D, E or F accidental eccentricity must be multiplied by Ax

0.32.1

2

max

avgxAwhere

avgmaxmin

extreme

irregular

avg 4.1

2.1max


ELF - Overturning Moments

.

Story force times heightto level under consideration.

• Overestimate where higher modes are significant• Prior “codes” allowed up to a 20% reduction in tall buildings• Now require modal analysis for such structures, thus this

provision is now deleted• Moment can be reduced 25% at foundation, permitting

some rocking

F V M

xi

n

xiix hhFM


Definition of Drift

I

C xedx

Structural displacement,

where,

xe Elastic deflection calculatedfrom design forces

dC Deflection amplification factor

Importance factorI

No reduction for ASD,but, can ignore limit on T


Stability: P-Δ Effects

P

ΔDeflection introduces P-Δ momentwhich increases deflection, whichincreases moment …..

Structure must be designed to prevent collapse due to P-Δ effects


Stability: P-Δ Effects

• Determine stability coefficient, θ, for each story

dsxx

x

ChV

P

• If θ > 0.10 at any level, then all design forces andmoments must be increased by factor 1+ad

1dawhere

• Check 25.05.0

max dC


Derivation of Stability Factor θδf

h

V

P

kV

P

V

δUndeformed

ADeformed

BResponse

C

Equilibrium at B: 0 hkPVh ff

Define: 0, o

ffo

hVPVhthenVk

Rearranging terms:

11

o

o

of

VhP


P-Delta

• What if your analysis program “includes” P-Delta and you don’t want to make a second set of output?

max must still be checked

• Compute * from displacements that include P-Delta, then

max*1

*


12.9 Modal Response Spectrum Analysis Method

1. Minimum Number of Modes2. Adjustment of Response Parameters by

R/I (forces) and Cd/I (displacements)3. Combining Modes for Total Response4. Scaling of Design Values5. Horizontal Shear Distribution, Torsion6. P-Delta7. Soil Structure Interaction


M.R.S. Analysis• Include enough modes to obtain a combined

modal mass participation of at least 90% of the actual mass in each of the orthogonal directions of response

• Short period branch of spectrum is usable• Divide spectrum by (R/I) to obtain force

responses• Multiply each displacement by (Cd/I)


Combining Modal Results

• Basic rule is Square Root of Sum of Squares (SRSS)

• Complete Quadratic Combination (CQC) always permitted (see ASCE 4)

• CQC required where modal periods are closely spaced or where translational and torsional modes are cross correlated



0.0

0.1

0.2

0.3

0.4

0.5

0.6

0.7


Spe

ctra

l Acc

eler

atio

n, g

0.4SDS

Sa = SD1 / T

Sa = SDS(0.4 + 0.6 T/T0)

Sa = SD1 TL / T2



Scaling Modal Results

• Compute limiting base shear, V, by ELF; if T exceeds CuTa, then use T = CuTa

• Compare 85% of this force with combined modal base shear, Vt

• If Vt < 0.85V then multiply all combined response quantities from modal analysis by 0.85V / Vt


M.R.S. Analysis

• Critical direction of load applies (orthogonal

combinations)

• Inherent torsion automatically included

• Accidental torsion: two choices:

– Offset mass to achieve accidental eccentricity

- Include static torsion as a load case

• P-Delta applies as for ELF

• Soil Structure Interaction analysis permitted


12.12 Drift and Deformation

1. Story Drift– Satisfy limits per table; occupancy is factor– If irregular, include torsion effect in SD Cat C+– Divide allowable by for MF in SD Cat D+

2. Diaphragm Deflection

3. Building Separation

4. Compatibility for SD Category D+


Drift Ratio LimitsStructure Occupancy Category UBC

I or II III IV

4 stories, no masonry 0.025 0.020 0.015 0.025*

Masonry cantilever 0.010 0.010 0.010

Other masonry 0.007 0.007 0.007

All other 0.020 0.015 0.010 0.020*


Deformation Compatibility

Applies to

• SD Category D+

• All structural components not in SFRS

• Check capacity for gravity load combined with effects induced from design drift; rational analysis of restraint required

• ACI 318 Chap 21 acceptable alternate




12.14 Simplified Alternate

1. General (Limitations/Eligibility)

2. Design Basis (& Load Combinations)

3. SFRS Identification (& Combinations)

4. Diaphragm Flexibility

5. Direction of Loading

6. Design & Detailing: Load path connections, collectors, wall anchorage

7. ELF Analysis


Limitations

• Occupancy Category I or II

• Site Class A, B, C, or D

• 1, 2, or 3 stories

• Bearing Wall or Building Frame System– Braced frames or shear walls– No unbraced (moment) frames

• “Regular”


Torsional Regularity

• Flexible diaphragms:– Overhang (cantilever) < depth / 5– Controls displacement at edge– Controls torsion in non-flexible

• Non-flexible diaphragm– Eccentricity < 15% width of diaphragm– Minimum torsional stiffness


Torsion

m

ii

n

jjj

m

iii kb

b

edkdk

11

21

1

1

1

222

1

211 )05.0(5.2

•k1i - lateral stiffness, wall “i” parallel to 1

•k2j - lateral stiffness, wall “j” parallel to 2

•d1i,- the distance from the wall “i” to the

center of rigidity, perpendicular to axis 1•d2j is the distance from the wall “j” to the

center of rigidity, perpendicular to axis 2•e1 is the distance perpendicular to axis 1

between the center of rigidity and the center of mass•b1 is the width of the diaphragm

perpendicular to axis 1•m is the number of walls in direction 1•n is the number of walls in direction 2


Regularity

• Limit skewed alignments to 15 degrees

• Use simplified method for design in both horizontal directions

• No in-plane or out-of-plane offsets– Exception: shear walls in 2 story light frame

– Must use Ω0 ( = 2.5 for all structures)

• No weak stories (80% rule)


Seismic Design Category

• Limited to Occupancy groups I and II

• Only use SDS, therefore

SDS < 0.33 gives Category B

SDS < 0.50 gives Category C

SDS > 0.50 gives Category D

• Can have Category E if S1 is high


Combined Effects

• Vertical Seismic Load =

• Combine positive vertical seismic load where gravity and effect of horizontal seismic add; combine negative vertical seismic load where gravity offsets effect of horizontal seismic

• Orthogonal combinations not required

0 2. S WD S


R Factor Table

• Includes wood shear walls, all concrete and masonry walls and all steel bracing systems – special, ordinary, intermediate, plain, detailed, etc – and composite steel/concrete walls

• Includes specific citations to reference standards for detailing the systems

• No Cd or Ω0 factors here


Detailed Rules

• Connections: 0.2SDSwi or 0.05wi

• Openings and corners in shear panels

• Collectors: Ω0 = 2.5 (except light frame)

• Diaphragms: – use the story force– provide continuous ties

• Anchor concrete/masonry walls (flexible)


Detailed Rules

• No orthogonal combinations

• Redundancy factor = 1.0

• Bearing walls: out of plane = 0.4SDSwc

• Nonstructural components – same as any other building


Simplified ESF Analysis

• Base Shear

• Story Force

• Story factor F =

1.0 for one story

1.1 for two stories

1.2 for three stories• Same acceleration at all

levels of building (very simple!)

• No I factor, No period T

VF S

RWD S

FF S

Rwi

D Si


Simplified Response Acceleration

• Use only SDS; don’t use S1S

• Equation

• Site response amplifier Fa =

1.0 for rock

1.4 for soil

S F SD S a S

2

3


Drift and Separation

• Do not have to check drift

• Use 1% drift for purposes of building separation, nonstructural component compatibility, etc, unless actually computed


Overview• Introduction to Earthquake Engineering• Basic Criteria in ASCE 7 – 2005

– Ground Motions

– Response Spectrum

– Occupancy and Seismic Design Categories

• Seismic Design for Buildings– Basic Requirements

– System Requirements

– Analysis

– Diaphragms, Walls, Foundations

– Simplified Method


Errata

• Go to the SEI website

www.seinstitute.org

• Go to the “Publications” in the bar at the top

• Click on the “Errata” tab

• Download pdf files for ASCE 7-05 (and any other structural standards you may need)

http://www.seinstitute.org/

Documents

Selected New Provisions of ASCE 7-05