Monitoring the Health of Structures for Quantifying and Achieving Resilience for Natural Hazards - PowerPoint PPT Presentation

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Monitoring the Health of Structures for Quantifying and Achieving Resilience for Natural Hazards

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October 22, 2014 Monitoring the Health of Structures for Quantifying and Achieving Resilience for Natural Hazards Bilal M. Ayyub and Yunfeng Zhang – PowerPoint PPT presentation

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Title: Monitoring the Health of Structures for Quantifying and Achieving Resilience for Natural Hazards


1
October 22, 2014
Monitoring the Health of Structures for
Quantifying and Achieving Resilience for Natural
Hazards
Bilal M. Ayyub and Yunfeng Zhang Department of
Civil Environmental Engineering University of
Maryland, College Park ba_at_umd.edu and
zyf_at_umd.edu
2
Motivation
  • After natural hazardous events, engineers are
    usually faced with many competing priorities in
    making safety and occupancy decisions about large
    inventories of building and bridge assets, which
    could be more effectively managed through
    automated inspection and computerized condition
    assessment.

Fractured EBF in Pacific Tower, from Bruneau et
al. 2012
Paint flaking of partially hidden EBF link
global view of EBF braces obstructed by various
utility runs. Photos by M. Bruneau and C
Clifton
2
3
EBF Building Damage in the 2011 M6.3
Christchurch, New Zealand Earthquake
  • Club Tower building, completed in 2009.
  • estimates of the peak inelastic demand in the
    active link were made through visible assessment
    of the active link yielded web metal.

Paint flaking of partially hidden EBF link
global view of EBF braces obstructed by various
utility runs. Photos by M. Bruneau and C
Clifton
4
CBF Building Damage in the 1994 M6.7 Northridge
Earthquake (California)
  • The building remained plumb following the
    earthquake.
  • The initial assessment of the structure by the
    owner's representative was that the structure had
    not sustained much damage (only one window had
    been broken).
  • Only after the dry wall was removed, the extent
    of damage was revealed.

Photos from Sabelli 2013 and Trembaly 1995
5
  • Clearly, ability of rapid structural condition
    assessment especially for many hidden locations
    after major hazardous events reduces the time to
    recovery and increases the resilience in disaster
    recovery

6
Resilience Metrics (Ayyub 2013)
Re gt 0
7
Measuring Performance (Ayyub 2013)
8
Resilience Metrics (Ayyub 2013)
Re lt 1
The failure-profile value (F) can be considered
as a measure of robustness and redundancy
whereas the recovery-profile value (R) can be
considered as a measure of resourcefulness and
rapidity.
9
Definition for resilience components
  • Measuring resilience based on its components
    (MCEER)
  • Robustness as the ability of the system and
    system elements to withstand external shocks
    without significant loss of performance
  • Redundancy as the extent to which the system and
    other elements satisfy and sustain functions in
    the event of disturbance
  • Resourcefulness as the ability to diagnose and
    prioritize problems and to initiate solutions by
    identifying and monitoring all resources,
    including economic, technical, and social
    information
  • Rapidity as the ability to recover and contain
    losses and avoid future disruptions

10
Resilience concept of functionality versus
recovery time
Qf1
Qf0
Qf2
tr1
tr2
11
  • Structural health monitoring system should
    generate an alarm signal whenever the strain
    exceeds the pre-specified limit state (e.g.,
    yielding, fracture or buckling).

12
Hybrid simulation test setup for system
validation of WSCA on truss structure
13
Component Validation Test
Brittle Bar Size Brittle Bar Size
H6W4 H9W2
Test 1 0.65 1.10
Test 2 0.61 1.02
Ave. of Test values 0.63 1.06
Design value 0.55 1.18
14
Alternative test plan
15
Experimental Validation Test
16
Concluding Remarks
  • Resilience metrics is defined
  • For such seismically resilient structures with
    fuse members, automated wireless scanning of fuse
    zone for possible damages suffered during
    earthquakes or strong winds could be performed in
    a very efficient way and this practice would
    greatly accelerate condition assessment and thus
    enhance resilience through shorter and more
    accurate inspection.

17

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