Transcript PPT

NEES and Earthquake Engineering Practice:
Getting the rubber to meet the road.
Craig D. Comartin
Questions
What do practitioners really do?
What motivates them with respect to research?
What do they think of NEES?
How can they get what they could really use?
What should researchers be doing?
The Players
Building official
Owner
Contractor
Architect
Cost estimator
Structural
Mechanical
Geotech
Electrical
others
The Products
Drawings
Architectural A
Structural S
Mechanical
M
Electrical
E
Etc.
The Products
Specifications
Division
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1 — General Requirements
2 — Site Construction
3 — Concrete
4 — Masonry
5 — Metals
6 — Wood and Plastics
7 —Thermal and Moisture Protection
8 — Doors and Windows
9 — Finishes
10 — Specialties
11 — Equipment
12 — Furnishing
13 — Special Construction
14 — Conveying Systems
15 — Mechanical
16 — Electrical
Structural engineer’s job
Meet minimum strength
requirements.
Conform to drift limits.
Implement required detailing.
STAMP THE DRAWINGS !
Current state of profession
• Clients view services as a commodity.
• Satisfy code for lowest possible
construction cost.
• Competition based primarily on fees.
• Offshore competition is a reality.
• Traditional business model outdated.
Role of Applied Research
Convert to Forms Needed by End Users
Calibrate / Validate / Consensus/ Test Applications
Design Innovation by
Industry Leaders
Basic Research by
NEES Grantees
Spanning the
Implementation
Gap
Technology Transfer
Mechanisms
• Codes and Standards – mandatory requirements
• Guidelines/Synthesis Reports – good practice
• Software – both an implementation and
technology transfer tool
• Innovative Practitioners – define problems and
incorporate new technology before codes and
guidelines are developed
Bay Area Rapid Transit System
(BART)
•
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•
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•
•
•
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100 miles double track
2200 aerial rail bents
22 miles subway
3.2 mile Berkeley Hills tunnel
Trans-Bay Tube and
ventilation structures
43 stations
4 train maintenance yards
Terminal and operations
facilities
Power, mechanical, train
control, and communications
equipment.
Various buildings
BART Aerial Railway
BART Pier test
BART Shear key test
BART Shear key test
Pier load tests



50 kip hammer
30 ft. max. drop
0 - 750() kip dynamic load
Pier load tests
D ate: 4-O c t -200 1
L oc ation :
U C B er k eley
B er k eley , C A
T es t S ha ft A 2-2 5:
24" O D
~25- ft P ene trat io n
T e s t P ie r A 2- 2 5 Un d e r D y na m ic a n d S t a ti c L o ad s
700
Dynamic
600
Load (kips)
500
Static
400
300
P LT - D y na m ic
S tatic
Conventional estimates
based on unconfined
compression strength
200
100
0
0 .0 0 0
0 .1 0 0
0 .2 0 0
0 .3 0 0
0 .4 0 0
D isp. (in )
0 .5 0 0
0 .6 0 0
0 .7 0 0
0 .8 0 0
Large plate bearing tests
Example building description
Height:
3 stories; 14 ft. floor
to floor; 42 ft total
above grade; no
basement
Area :
22,736 sq.ft. per
floor; 68,208 sq.ft.
total (actual building
slightly larger)
Occupancy :
General office space
(B2)
The example application uses the building shown above as a prototype. This building is located
in Berkeley, California, near the campus of the University of California. It is representative of
modern Class A office space in the Gre ater Bay Area of California. Construction was completed
in 2004. Some of the features of the actual building were modified and simplified for application
in this example.
Performance Groups
Name
Location
EDP
SH12
between levels 1 and 2
d1-2
SH23
between levels 2 and 3
d2-3
SH3R
between levels 3 and R
d3-R
EXTD12
between levels 1 and 2
d1-2
EXTD23
between levels 2 and 3
d2-3
EXTD3R
between levels 3 and R
d3-R
INTD12
between levels 1 and 2
d1-2
INTD23
between levels 2 and 3
d1-2
INTD3R
between levels 3 and R
d3-R
INTA2
below level 2
a1
INTA3
below level 3
a2
INTAR
below level R
a3
CONT1
at level 1
a1
CONT2
at level 2
a2
CONT3
at level 3
a3
EQUIPR
at level R
aR
Components
Structural lateral: lateral load
resisting system; damage oriented
fragility (direct loss calculations)
Exterior enclosure: panels, glass,
etc.
Interior nonstructural drift
sensitive: partitions, doors,
glazing,etc
Interior nonstructural acceleration
sensitive: ceilings, lights, sprinkler
heads, etc
Contents: General office on first and
second floor, computer center on third
Equipment on roof
Loss distribution for a single intensity
or scenario
P capital loss  DV IM  10%/ 50yr
1
0.9
0.8
0.7
0.6
0.5
0.4
0.3
0.2
0.1
0
0
1
2
3
4
5
DV  capital loss in $M
6
P capital loss  DV IM  10%/ 50yr
1
0.9
0.8
0.7
0.6
0.5
Median loss
= $1.1M
0.4
0.3
0.2
0.1
0
0
1
2
3
4
5
DV  capital loss in $M
6
P capital loss  DV IM  10%/ 50yr
1
0.9
0.8
0.7
0.6
0.5
0.4
Loss for 90%
confidence
$1.9M
0.3
0.2
0.1
0
0
1
2
3
4
5
DV  capital loss in $M
6
P capital loss  DV IM  10%/ 50yr
1
0.9
0.8
0.7
80% chance
losses are
between $0.7M
and $1.9M
0.6
0.5
0.4
0.3
0.2
0.1
0
0
1
2
3
4
5
DV  capital loss in $M
6
P capital loss  DV IM  10%/ 50yr
1
0.9
0.8
0.7
60% Chance
that loss
exceeds $1M
0.6
0.5
0.4
0.3
0.2
0.1
0
0
1
2
3
4
5
DV  capital loss in $M
6
Distribution of losses
1
0.9
0.8
10%/5yr
10%/10yr
10%/50yr
10%/100yr
P(Total Repair Cost <= $C)
0.7
0.6
0.5
0.4
0.3
0.2
0.1
0
0
1
2
3
4
5
$C (dollar)
6
7
8
9
10
x 10
6
Aggregated loss function
annual rate of exceeding
capital loss repair cost
0.25
0.2
0.15
0.1
0.05
0
0
0.5
1
1.5
2
2.5
capital loss repair cost
3
3.5
4
x 106
Annual Probability of Exceedance
From hazard
Peak Ground Acceleration
To loss
annual rate of exceeding
capital loss repair cost
0.25
0.2
0.15
0.1
0.05
0
0
0.5
1
1.5
2
2.5
capital loss repair cost
3
3.5
4
x 106
Annualized loss
Annual probability of
being exceeded
0.25
0.2
0.15
Area represents expected losses
per year (annualized loss)
0.1
0.05
0
0.5
1
1.5
2
2.5
3
3.5
4
Capital losses ($M)
Benefit of retrofit
Annual probability of
being exceeded
0.25
0.2
0.15
Annualized loss before
retrofit= $100k
0.1
Annualized loss after
retrofit= $60k
0.05
0
0.5
1
1.5
2
2.5
3
3.5
4
Capital losses ($M)
Design decisions
Exterior envelope
41%
Contents (3rd flr. computer center)
25%
Interior nonstructural (drift sensitive)
12%
Interior nonstructural (accel. sensitive)
8%
5%
Contents (Ist and 2nd flr. offices)
Structure
4%
Roof top equipment
4%
0%
5%
10%
15%
20%
25%
30%
35%
40%
Portion of annualized capital loss
45%
Stanley Hall Replacement
UC Berkeley
Braced Frame Costs
$5.0
$1.2M
premium
$4.0
$4.4
$3.0
$2.0
• Footing difference
negligible
• Soft cost difference
negligible
$3.2
$1.0
$0.0
COST ($M)
SCBF
• Costs include:
Braces
Beams
Columns
20% OH
UBB
Annual losses
Present value of losses
$8.0
($,000)
$207
$113
$200
$100
$188
$143
$0
($,000,000)
$400
$300
$2.5M
reduction
$6.0
$3.8
$4.0
$2.0
$2.1
$3.4
$2.6
SCBF
UBB
$0.0
SCBF
Capital/Contents
UBB
Business Interruption
Equivalent to
~11% Return
on Investment
Capital/Contents
Business Interruption
5% Discount
50 year life
BCR = 2.1
First things first
 Repeat of San Francisco 1906 would
result in several thousand deaths.
 Over half of these would be
attributable to 5% of the building
inventory (e.g. URMS, nonductile
concrete, soft stories)
If you of dangerous buildings and fail
to speak out, that is malpractice.
Diane Feinstein
Concrete Coalition
• Initiative on the part of EERI, ATC,
and PEER to address nonductile
concrete buildings
• Partners include structural engineers,
building officials, building owners and
managers
• Technical and socio-economic focus
• Find and fix the real killers
Recent Losses in Earthquakes
Turkey (1999- Mw7.2)
India (2001- Mw7.9)
Iran (2003- Mw6.6)
Pakistan (2005- Mw7.7)
over 15,000 killed
over 20,000 killed
over 40,000 killed
over 73,000 killed
Chances of Dying if a Major
Earthquake Occurs
San Francisco
1 in 1000
Istanbul
1 in 50