Karema - Rapid Visual Screening of Critical Facilities Seismic ......Rapid Visual Screening...
Transcript of Karema - Rapid Visual Screening of Critical Facilities Seismic ......Rapid Visual Screening...
RAPID VISUAL SCREENING OF CRITICAL FACILITIES:
AN OVERVIEW OF THE FEMA METHODOLOGY AND ITS APPLICATION TO SELECTED CRITICAL FACILITIES IN
KINGSTON & ST ANDREW
SEISMIC RISK FORUMJANUARY 8‐9, 2014
Jamaica Conference Center
Outline of Presentation
Rapid Visual Screening (RVS-FEMA 154 Methodology) Purpose Overview of methodology Overview of RVS process
Application of RVS to Critical Facilities in KSA - Results of Survey
Implications for Earthquake Response Conclusion and Recommendations
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CONTEXT
Critical Facilities- The primary physical structures,technical facilities and systems which are socially,economically or operationally essential to the functioningof a society or community, both in routine circumstancesand in the extreme circumstances of an emergency(UNISDR 2009).
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CONTEXT
Populations at their most vulnerable immediately afterearthquake due to collapsed structures fires resulting ininjury.
Ability of critical facilities and first responders to servicethis need is paramount to saving lives and property.
RVS (FEMA 154)METHODOLOGY4
RVS-FEMA 154 techniquefirst proposed 1988 andfurther modified in 2002considered ideal forexecuting initial assessmentof critical facilities
Widely adapted and usedworldwide after suitablemodifications
developed for a broadaudience, including buildingofficials and inspectors,government agencies andpublic and private-sectorbuilding owners
Rapid Visual Screening (RVS-FEMA 154 Methodology
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PURPOSE: to provide preliminary estimation of the seismic vulnerability of buildings and categorizing them as: those that are expected to
have acceptable seismic performance – “Pass”
those that may be seismically hazardous and should therefore undergo detailed structural engineering assessment –“Fail”
Overview of Methodology
RVS uses a method based on a “sidewalk survey” to effect the visual inspection of the building from the exterior and, if possible from the interior without conducting any structural calculations.
It utilizes a damageability grading system that requires the evaluator to: Identify the primary lateral load resisting system
(Building type) Structural and non-structural characteristics that may
negatively impact seismic performance.
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Overview of Methodology7
Final performance score “S” is analyzed against a predetermined cut‐off score and determines if a building “Pass” or “Fail” the RVS.
This score is modified by adding or subtracting the assigned values of structural and nonstructural characteristics that applies to the particular building
MODIFIERS
Overview of Methodology8
Basic Hazard Score(By Building Type)
Structural Characteristics
No. of Stories Building Layout
Non‐Structural Characteristics
Soil Type Seismic code Adoption Dates
Number of Stories Medium rise ‐ (4‐7 stories) High rise (>7 stories
Plan and Vertical Irregularity design configuration that negatively affect the response mechanism and transfer of load throughout the structure
Overview of Methodology9
Basic Hazard Score(By Building Type)
Structural Characteristics
No. of Stories Building Layout
Non‐Structural Characteristics
Soil Type Seismic code Adoption Dates
Building Type
Model Building Seismic Design Provisions
BOCA SBCC UBC NEHRPW1 1992 1993 1976 1985
W2 1992 1993 1976 1985
S1 * * 1994 *
S2 1992 1993 1998 1991
S3 * * * *
S4 1992 1993 1976 1985
S5 * * * *
C1 1992 1993 1976 1985
C2 1992 1993 1976 1985
C3 * * * *
PC1 * * 1997 *
PC2 * * * *
RM1 * * 1997 *
RM2 1992 1993 1976 1985
URM * * 1991 *
Soil Type Related Parameters
Type A (hard rock)
Measured shear wave velocity (vs) > 5000 ft/sec.
Type B (rock) vs between 2500 and 5000 ft/sec.
Type C (soft rock and very dense soil)
vs between 1200 and 2500 ft/sec, or standard blow count( N) > 50, or undrainedshear strength (su) > 2000 psf.
Type D (stiff soil)
vs between 600 and 1200 ft/sec, or standard blow count (N) between 15 and 50, or undrained shear strength (su) between 1000 and 2000 psf.
Type E (soft soil)
More than 100 feet of soft soil with plasticity index (PI) > 20, water content (w) > 40%, and su < 500 psf; or a soil with vs ≤ 600 ft/sec.
Type F (poor soil)
Soils requiring site-specific evaluations:
Process for Executing RVS10
STEP 3 -EXECUTION OF SCREENING (15 - 30 MINS FOR EACH BUILDING
STEP 2 - PRE-FIELD DATA
COLLECTION
STEP 1 PLANNING
STAGE
• Selecting study area• Training screeners• Developing budget
• Selecting Data Collection form
• Selecting cut‐off score• Review geo‐technical
data for soil type
• Obtain approximate square footage of building
• Complete a sketch of building layout (plan and one elevation)
• Take picture of building
Overview of Methodology Cont’d
Interpretation of Final Score Final score is derivative of the Basic Hazard score therefore,
it represents the estimated probability of that building collapsing at the MCE.
It is the final score expressed as a negative of the logarithm (Base 10) . Example a final score of 2.0 signifies a probability of 10(^-2), which equates to a 0.01 or 1% chance of collapse.
The least final score which would produce a meaningful interpretation is 0.0 as this equates to a probability of 1.0 or 100% chance of collapse.
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RESULTS – RVS OF Critical Facilities in KSA
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Results – RVS of Critical Facilities in Kingston & St Andrew
*11 Structures located on Soil Type F for which the RVS was inapplicable, site specific investigations required
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Facility Number Fail IndeterminatePolice Stations 37 23 6Health Centres 33 20 3
Fire Stations 7 4 2
TOTAL 77 47 11*
Percentage 100% 61.04 14.29
Results of RVS – Police Stations
19%
65%
16%
Overall Performance of Police Stations in KSA
Passed
Failed
Indeterminate
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16% 14%
54%
16%
0%
10%
20%
30%
40%
50%
60%
% Concentration of Police Stations across soil types
Soil Type B Soil Type C
Soil Type D Soil Type F
Results of RVS – Fire Stations
14%
57%
29%
Seismic Performance of Fire Stations within the KSA
PassedFailedIndeterminate
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14%
57%
29%
0%
10%
20%
30%
40%
50%
60%
% Concentration of Fire Stations across soil types
Soil Type B Soil Type D Soil Type F
Results- (Health Centers)
30%
61%
9%
Performance of Health Centresin KSA
Passed
Failed
Indeterminate
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33%
6%
52%
9%
0%
10%
20%
30%
40%
50%
60%
% Concentration of buildings across Soil types
Soil Type B Soil Type C Soil Type D Soil Type F
Location- Police Stations and Health Centers
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Composite Soil Map 18
Soil Type DefinitionsType A (hard rock)Type B (rock) – Limestone/WagwaterType C (soft rock and very dense soil) – August Town FormationType D (stiff soil) – Liguanea AlluviumType E (soft soil) – Mangrove/SalinaType F (poor soil) – Engineered Fill/Landfill
22%
9%
55%
14%
0%
10%
20%
30%
40%
50%
60%
B C D F
DistributionAcross Soil Types
Type B‐ 22%
Type C‐ 9%
Type D‐ 55%
Type F‐ 14%
Distribution- Critical Facilities Across Soil Type
Pictures- Modifiers
Eg. of Vertical Irregularity ‐Harbour View Police
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Eg. of Plan Irregularity –Lawrence Tavern Police Station
PICTURES OF DEFECTSYork Park Fire Station 20 Franklin Town Police Station‐Wall
System
Implications for Emergency Response
Results suggest that initial response capacity by critical facilities would likely be limited by internal response
Remaining functional facilities would become overwhelmed
Potential for increased casualties and property damage/loss depending on service area
Challenges to mounted a coordinated response
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Conclusion and Recommendation
Majority of critical failed facilities assessed located on Soil type D which happens to be most populous zone in the KMA
Urgent need to prioritize programme for detailed Structural Assessments of Critical Facilities in the KMA
Retrofitting of critical facilities with lower final scores
Extending use of RVS methodology to other facilities such as Schools (Shelters)
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Update on Other Applications of RVS and Seismic Research
Application of RVSmethodology and seismicmicrozonation studies toRisk Assessments:
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Seismic Retrofitting:Seismic retrofittingexploratory mission (EGIS,FRANCE)(ODPEM/Martinique MOU)
15 critical facilitiesexplored – dam,bridges, police and firestation, schools, healthcentre, central bank
Possible FutureInitiatives (World Bank)
Expansion of seismicnetwork, seismicretrofitting
Locations
Number of Buildings Assessed
Number of Critical Facilities TOTAL
Annotto Bay 1387 13 1400Falmouth 1483 17 1500Linstead 1447 5 1452TOTAL 4317 35 4352
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