Bridge Maintenance Strategies -...
Transcript of Bridge Maintenance Strategies -...
Bridge Maintenance Strategies Peter Weykamp, P.E.
Bridge Maintenance Program EngineerNew York State Department of Transportation
•Definitions•Conditions•Needs•Support•Bridge Elements
BACKGROUND
DEFINITIONS• Maintenance: a network
level, long-term strategy that enhances bridge performance by using an integrated, cost-effective set of practices that extend bridge service life, improve safety, and meet motorist expectations.
– Or anything done to a bridge short of a deck replacement.
PREVENTIVEPREVENTIVEMAINTENANCEMAINTENANCE
CORRECTIVE CORRECTIVE REPAIRSREPAIRS
CYCLICAL CYCLICAL MAINTENANCEMAINTENANCE
DEFICIENTFHWA - A bridge is “structurally deficient”if either the superstructure, substructure, or deck is rated less than 5 on a 9 point scale.
NYSDOT CONDITION RATING
• “Deficient”– Weighed average
condition < 5.0
• Rating Scale– 1 – Failed condition– 3 – Serious deterioration– 5 – Functioning as
designed– 7 – New condition
• Weights– Primary member 10– Abutments 8– Piers 8– Structural Deck 8– Bridge Seats 6– Bearings 6– Wing & Backwalls 5 – Secondary member 5– Joints 4– Wearing surface 4– Sidewalks 2– Curbs 1
Number and Status of Bridges in the US(12% SD, 13% FO)
0
20,000
40,000
60,000
80,000
100,000
120,000
Pre1910
1910s 1920s 1930s 1940s 1950s 1960s 1970s 1980s 1990s 2000s
Decade Built
Num
ber o
f Brid
ges
0%
10%
20%
30%
40%
50%
60%
70%
80%
% o
f Def
icie
nt B
ridge
s
Number of Bridges % of Deficient Bridges
Source: 2007 NBI
State and Local Highway Bridge Condition Trends
40
45
50
55
60
65
70
75
80
1999 2000 2001 2002 2003 2004 2005 2006 2007 2008
% Goo
d an
d Excellent by N
umbe
r
Year
Local Bridges State Bridges
Deficient Bridge Wave
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100
200
300
400
500
600
700
800
900
<3 3.1 3.3 3.5 3.7 3.9 4.1 4.3 4.5 4.7 4.9 5.1 5.3 5.5 5.7 5.9 6.1 6.3 6.5 6.7 6.9
New York State Rating
Num
ber o
f Brid
ges
Local Bridges State Bridges
1450 bridges become deficient in next 5 years
1500 additional bridges become deficient in next 6-10 years
ASSESSING NEEDS• Inspection data
– Focus on safety
• Models focus on rehab/replace
• Maintenance candidates – Real vs. ideal needs
• Decision support systems– Domestic scan of lead States
MAINTENANCE NEEDS
0%
100%
Time
BR
IDG
E C
ON
DIT
ION
• Bad– Rehab/Replace
• Good– Preventive/Cyclical
• Fair– What has to get done?– What are the
consequences of deferred action?
FAIRFAIR
BAD
GOOD
FUNDING• Federal formula
– Based on deficiency – Rewards poor stewardship– Some flexibility
• Organized to build the interstate system• Few advocates for bridge maintenance • “Follow the Money”
BRIDGE PARTS
CEU QUESTIONS
Current Practices in Bridge Maintenance
PART 1
EXPANSION JOINTS• All Joints Leak• Armored Joints
– Constructability– Repair-ability– Safety hazard– Deterioration
ARMOR-LESS JOINTS• Elastomeric Concrete
– Polymer based– “Maintenance friendly”– Rapid setting– EXPENSIVE
• Seals– Repairable
• Liquid
• Pre-formed
INTEGRAL ABUTMENTS
INTEGRAL ABUTMENTS• Simple joint• Minimal substructure• Low Maintenance• Design Hierarchy
– Integral– Joint-less– Joint expansion end– Joints on both ends
• Large skews• Unbalanced spans, etc
PROTECTIVE COATINGS
• Lead-Based Primers– Safety concerns
• Moisture-cured Urethane– Over-coating– Total Removal– Moisture tolerant
CONCERNS
• Surface Preparation • Health & Safety
– Containment• Cost
– Service Life– Performance
• New Primer– Zinc
ALTERNATIVES• Weathering Steel• Concrete• Timber• New Coating Systems
WEATHERING STEEL
• Self-protecting– Patina
• Aesthetics• Environment
– Health & Safety• Needs Wet/Dry
Cycles
P/S ADJACENT BOX BEAMS
• Plant Q/C• No Painting• Rapid Construction• Low Initial Cost• Freeboard
– Pressure flow• Debris
CONCERNS• Longitudinal
Cracking of Decks– Working Cracks
• Limited treatments
• Deck Deteriorates• Unknown Beam
Condition
OPEN GRATED BRIDGE DECKS
• Super and substructure deterioration
• Eliminated
REINFORCING STEEL
• Bare Bars – Premature full-depth
cracking
– SIP forms• Corrosion evident
• Epoxy Bars– Proven success– Min. increase in $
• Stainless– Justifiable
UNCOATED REBAR
HP CONCRETE
• Pozzolans – Fly Ash & Silica Fume
• High Strengths• Low Permeability• Shrinkage Cracking
– Increased permeability
BRIDGE BEARINGS• Steel Bearings
– Lubrication Required– Can’t meet 4 year cycle
• Jack & Clean• Often “Freeze”
– Thermal Stresses• Replacement Program
– Elastomeric Bearings– “Maintenance Friendly”
CONTEXT SENSITIVE DESIGN
PREVENTIVE MAINTENANCE
TASK CODE DESCRIPTION CYCLEH11 Clean Substructure 2 yrs H13 Seal Substructure 6 yrs
H29 Lubricate Bearings 4 yrs
H38 Clean Superstructure & Deck 2 yrs
H58 Remove Wearing Surface 12 yrs H59 Place Wearing Surface 12 yrs H60 Place Waterproof Membrane 12 yrs H69 Seal Deck 4 yrs H73 Fill Cracks & Joints 4 yrs
H75 Clean Drainage Systems 2 yrs
H89 Bridge Painting 12 yrs
SPOT PAINTING
• Resume Program• Materials
– Calcium Sulfonate
• Needle Scalers• Vacuum Tools • Minimal
Containment Necessary
DECK TREATMENTS
• All Concrete Cracks– Transverse– Longitudinal– Map
• New & Old Concrete• Treatments
– Fill cracks or– Bridge cracks
RADAR Statistical Analysis• Inspector rating supported• GPR sees things the
inspector doesn’t• Rating alone cannot be
used for selecting deck treatment
• Deterioration is age related• Age and % delamination
are not correlated
FILLING CRACKS
BRIDGING CRACKS
PM & MINOR REPAIRS
4.4
5.8
$250K
$5K
2370 Good Bridges
4740 Fair Bridges
790 Poor
$3.7M
Treatment Costs / Bridge
Maintenance Candidates
Major Rehab or Replacement Candidates
MAINTENANCE DESIGN• Weathering Steel• Composite Design• Simple Span
– No pier in water• Integral Abutment
– No joints– No bearings
• Epoxy Bars • Bridge Railing
– No sidewalk
Best Practices in Bridge Management Decision Making
PART 2
Bridge Management Decision MakingDomestic Scan Tour
Discover and collect information on how DOTs manage maintenance of highway bridges and how maintenance impacts the overall bridge program
Focus on decision processes for maintenance programs;How Do Decisions Rely On:
• Bridge Conditions• Maintenance Needs• Effectiveness of Maintenance• Funding Availability
AASHTO
FHWA Consultant
Academia
Bruce JohnsonOregon DOT
Scot BeckerWisconsin DOT
Tod KimballFHWA Vermont
Narendra KhambhatiArora and Assoc., NJArt D’Andrea
Louisiana DOTKeith RamseyTexas DOT
George HearnUniv. of Colorado
Pete WeykampNew York DOT
WA
CA
MI
OH
FL
DE
VA
Washington DOT
California DOT & El Dorado/Placer County DOTs
Michigan DOT
Ohio DOT
Florida DOT & Turnpike
Delaware DOT
Virginia DOT
Inputs
.
Site Visit
Scan Team
Document Review
Bridge Management Process
Preventive Maintenance
Agency Support
KEY FINDINGS
•Maintenance Needs•Prioritization•Performance Measures•Verification
Bridge Management
Statewide -- State Owned
0
5000000
10000000
15000000
20000000
25000000
30000000
35000000
40000000
45000000
50000000
1998 1999 2000 2001 2002 2003 2004 2005 2006 2007 2008
Calendar Year Data
Squa
re A
rea
of B
ridge
s
Non Deficient Total deficient
New York
0
200
400
600
800
1000
1200
1400
Num
ber o
f Brid
ges
1 2 3 4 5 6 7 8 9
NBI Rating55
GoodFairPoorSerious or Critical
Michigan
Identified at the element level Uniform, specific, and repeatable Stated as standard work actionsAccessible throughout the agency
Maintenance Needs
NBI CONDITION ASSESSMENT Ohio
TYPESModified NBI Commonly Recognized (CoRe) Bridge ElementsOwn system
SUPPORTSDetailed reportsMaintenance decisionsTreatment options Early interventionMinimize repair costs
Element Level Inspection
INSPECTION FORM OHIO
Uniform, Specific, & Repeatable
METHODSInspectors recommend actionDrop-down menuActions prioritizedCosts per actionStored in database Draft work order
Needs Database New York
Needs Database Oregon
Inspector Recommendations Washington
Integrate objectives for deficiencies, preventive maintenance, network performance, and risk.
Engage both central and regional DOT.
Advance from network‐level rankings to selection of specific projects.
Prioritization
Prioritization Formulas• Sufficiency Rating (NBI) Structural Adequacy and Safety (55% maximum);
Serviceability and Functional Obsolescence (30% maximum);
Essentiality for Public Use (15% maximum); Special Reductions
• Health Index (Pontis)Health Index (HI) = (∑ CEV ÷ ∑ TEV) × 100
TEV = Total element quantity × Failure cost of element (FC)
CEV = (∑ [Quantity in condition state i × WF(i)]) × FC
Health 80-89 Health 70-79 Health below 70
Deficiency Form
ula
Del
awar
e
Maintenance Accountability Program Washington
Match objectives in bridge maintenance
Identify work to advance maintenance objectives
Provide simple indications of status of bridge networks
Virginia
Performance Measures
4A2 Structural Bridge Repair
2007-09 M Program Budget: $9.2 million
Bridge inspections result in the “to‐do list” of smaller‐scale structural repairs for the Maintenance Program to complete. Examples of these repairs include: Bridge Cap Repair
Bridge Column RepairDebris RemovalScour RepairExpansion Joint Repair
Washington
4A2 Performance Measurement
A: 90 -100% completedB: 80 - 89% completedC: 65 - 79% completedD: 50 – 64% completedF: Less than 50% completed
The performance measurement for this activity focuses on Priority 1 repairs. The of repairs for is compiled annually.
The Level of Service is based on the percentage of Priority 1 repairs completed.
Level of Service target is a C
2008 Level of Service delivered is a D
The 2009-11 proposed budget includes an additional $1.5 million to catch up with this maintenance backlog and achieve the target.
Washington
Bridge Maintenance Contract Funding and Backlog
$94
$63
$63
$94
$94
$94
$13
$9$6$6$6
$94
$94
1645
2883
2922
2961
3000
3039
3078
3117
2844
1870 20
95 2320 25
44
$-
$20
$40
$60
$80
$100
$120
$140
$160
$180
$200
01/02 02/03 03/04 04/05 05/06 06/07 07/08 08/09 09/10 10/11 11/12 12/13 13/14Fiscal Year
Fun
ding
Lev
el (M
illio
n $)
0
500
1,000
1,500
2,000
2,500
3,000
3,500
4,000
# of
Bri
dges
Funding $ Backlog Bridges
Actual Projected
71
Bridge Maintenance Program 2001 - 2005
CalTrans
Bridge Maintenance Contract Funding and Backlog
$94
$63
$63
$94
$94
$94
$13
$9$6$6$6
$94
$94
1645
2647 28
35
2874
2913
2952
2991
3030
2507
1870 20
95 2320 25
44
$-
$20
$40
$60
$80
$100
$120
$140
$160
$180
$200
01/02 02/03 03/04 04/05 05/06 06/07 07/08 08/09 09/10 10/11 11/12 12/13 13/14Fiscal Year
Fun
ding
Lev
el (M
illio
n $)
0
500
1,000
1,500
2,000
2,500
3,000
3,500
4,000
# of
Brid
ges
Funding $ Backlog Bridges Reduce Backlog
2007 & 2009 Five Year Plan
Actual
72
CalTrans
Strategy is effectiveInvestment pays off
Needs are metLevel of Service indicatorsNeeds – Accomplishment = Gap
Work completed Report into BMS, MMS, Capital Program, …
Verification
74
1,333 BridgesCurrent - 11%
Goal – 5%
8,623 BridgesCurrent - 69%
Goal – 85%
2,544 BridgesCurrent - 20%
Goal 10%300 Bridges/Yr
Rehab. Program (SHOPP)
Maintenance Program Preservation Program(Major Maintenance)
40 Bridges/Yr
870 BridgesCurrent - 7%
Goal – 5%
9,122 BridgesCurrent - 71%
Goal – 85%
2,835 BridgesCurrent - 22%
Goal 10%560 Bridges/Yr
Rehab. Program (SHOPP)
Maintenance Program Preservation Program(Major Maintenance)
20 Bridges/Yr
CALTRANS
Preventive Maintenance
Significant part of programApplied before bridges become deficientImplements clear plans of actionFlexible allocation of resources
Washington
Tracking Trends Michigan
Deterioration RateStatewide Trunkline Bridges
0
50
100
150
200
1998 1999 2000 2001 2002 2003 2004 2005 2006 2007 2008
Year
Num
ber B
ridge
s G
oing
fro
m G
ood/
Fair
to P
oor Linear Fit
76
Bridge Deck Preservation Matrix Michigan
77
Cyclical Maintenance Virginia
78
Bridge Deck Washing (Concrete) – 1 YearBridge Deck Sweeping – 1 YearSeats & Beam Ends Washing – 2 YearsCutting & Removing Vegetation - 2 YearsRoutine Maintenance of Timber Structures - 2 YearsReplacement of Compression Seal Joints – 10 yearsScheduled Replacement of Pourable Joints – 6 yearsCleaning and Lubricating Bearing Devices – 4 yearsScheduled Beam Ends Painting – 10 YearsInstallation of Thin Epoxy Concrete Overlay – 15 YearsRemoving Debris from Culverts – 5 Years
Bearing Replacement Program New York
79
LEGISLATURE: gas tax, dedicated fund, MPOpercentage
DOT Executives: Maintenance is not a episodic.ODOT – “Fix it First”
DOT Central: Use quantitative performance measures, Recognize districts’ first‐hand knowledge
District Engineers: Evaluate needs and trends funds and projects
Inspectors: Identify needs, recommend actions
Crews: Execute work, take initiative
Agency Support
Funding Levels
Michigan– Fixed: 22% PM, 30% Rehab, 48% Replace
Ohio, Washington– 15% to MPOs (Fed. legislation @ 15% min.)
Virginia– Majority of $ maintenance - legislated
California– PM from $6M to $94M
State Gas Tax– NY 42.5; Ca 39.9; Wa 37.5; Fl 34.5; Mi 30.9
DIRECTION“Service-life Extension”
MobilityAdvances in Materials
Concrete repairs, CoatingsInnovative Designs for In-
service BridgesDeck replacement optionsRapid replacement
Culverts
Comparative MeasuresPartnerships
Industry, ConsultantsRegional GroupsCommunicationOwners, LegislaturesTriagePosted & Closed AssessmentTreatmentsHolistic
Management
CEU QUESTIONS
We, the bridge maintenance engineers of New York, hold these truths to be
self-evident: all joints leak, all concrete cracks, and rust never sleeps. We will
strive to capitalize our way out of maintenance and maintain our way out of capital. It is our endeavor to educate others that a bridge is as important to a
highway as a diamond is to a ring.