bridge # us 2 wb off ramp over i 35 ramp & lake 69101 … · the current load rating on the...
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2015 FRACTURE CRITICAL
BRIDGE INSPECTION REPORT
MnDOT Bridge Office
3485 Hadley Avenue North
Oakdale, MN 55128
BRIDGE #
DISTRICT: COUNTY: CITY/TOWNSHIP:
Date(s) of Inspection:
Equipment Used:
Inspected By:
Report Written By:
Report Reviewed By:
Final Report Date:
69101
US 2 WB OFF RAMP over I 35 RAMP & LAKE
District 1 St. Louis Duluth
- 05/04/2015
Carter, Rodney; Nelson, Bill; Potter, Farrell; Theisen, Scott
Bill Nelson
Jennifer Zink
10/28/2015
State Highway AgencyOwner:
I. FINDINGS SUMMARY 1
II. INSPECTION LOGISTICS 2
III. FRACTURE CRITICAL MEMBERS/FATIGUE PRONE DETAILS 3
IV. INSPECTION FIELD NOTES 7
V. PICTURES 9
APPENDIX A: SI&A 15
APPENDIX B: 7 DAY FC REPORT 17
APPENDIX C: STRUCTURAL ASSESSMENT REPORT - FC 20
APPENDIX D: 1997 LOAD RATING 23
SECTION PAGETable of Contents
This report documents the findings of the fracture critical inspection on MnDOT Bridge No. 69101 (USTH 2 Westboundoff Ramp over ISTH 35 Ramp and Lake). The fracture critical members were the steel pier caps at Piers 10 and 11.These pier caps were the only members inspected on the bridge. The inspection was completed on May 4, 2015.
I. Findings Summary
1. The current load rating on the bridge that was completed in 1997 did not take into consideration the load-carryingcapacity of the steel pier caps (Appendix D). In the 2011 fracture critical report, it was recommended that a new loadrating be completed taking into account the steel pier caps. As of the writing of this report, no new load rating has beencompleted.
Recommendation: Perform a new load rating taking into account the strength of the steel pier caps.
2. There is corrosion and minor flaking rust throughout the steel pier caps, but no significant section loss.
Recommendation: Continue to monitor the pier caps for advanced corrosion and section loss.
Significant Findings
Comments
The NBI ratings are the same as reported in 2013.
Suggested
NBI Condition Ratings
Item Current
NBI Condition Summary
Deck 7 (Good Condition) 7 (Good Condition)
Superstructure 7 (Good Condition) 7 (Good Condition)
Substructure 7 (Good Condition) 7 (Good Condition)
Channel 8 (Banks are protected) 8 (Banks are protected)
There are no inventory updates.
Inventory Updates
MnDOT Bridge No. 69101
2015 Fracture Critical Bridge Inspection Report
1
II. Inspection LogisticsThis report documents the fracture critical inspection on the steel pier caps located on Piers 10 and 11 on Bridge69101. The inspection was completed on May 4, 2015 by Bill Nelson, Farrell Potter, Rodney Carter and Scott Theisen.The 2015 Fracture Critical Bridge Inspection Report was written by Bill Nelson.
MnDOT Bridge No. 69101
2015 Fracture Critical Bridge Inspection Report
Bridge Description
Bridge 69101 is a flyover ramp from westbound USTH 2 to northbound I 35 and is considered an approach to Bridge69100 (Bong Bridge). Bridge 69101 crosses over a lake, a trail, Oneota Street, and an off ramp from northbound I-35.The bridge was constructed in 1983.
Steel pier caps are located at Piers 10 and 11, which are considered to be fracture critical. Piers 10 and 11 are“integral” caps that consist of welded steel I-girders anchored to a tapered concrete pier wall with four 2.50" diametersteel anchor bolts. There is a line of load path redundant diaphragms located on each side of the integral steel piercaps. The steel cap web plates are 1” thick and taper down in depth on the cantilever end sections. The flanges are20” wide and 1.50” thick. There are four welded web stiffeners on each face of the pier cap located near the center ofthe cap above the bearings. There is a 3” thick horizontal anchor rod bracket welded between each pair of webstiffeners approximately halfway up the web of the steel cap.
The design loading is HS 20, using 1977 and interim (1978-1981) AASHTO design specifications. The last load ratingwas performed in 1997. The operating rating is HS 45.2 and the inventory rating is HS 27.1. The bridge is not posted(open to legal loads). There have been no significant structural modifications since the bridge was constructed. TheMn/DOT Bridge Office has plans on file and are available on EDMS.
MnDOT District 1 was contacted prior to the inspection of the bridge to allow for coordination of necessary laneclosures and traffic protection. This inspection included an in-depth visual inspection of the steel pier caps located atPiers 10 and 11. No other portions of the bridge were inspected. The steel pier caps were accessed from below usinga 16 foot extension ladder. Access equipment was provided by MnDOT District 1.
Inspection Access
No special requirements were needed for this inspection.
Special Requirements
FRACTURE CRITICAL MEMBERS:Integral Steel Pier Caps1. Visual “hands-on” inspection concentrating on tack welds.2. Visual “hands-on” inspection concentrating of “tight fit” detail at web stiffener/top flange connection.
FATIGUE PRONE DETAILS:1. Check all welded and bolted connections for integrity.2. Check all fracture critical members for tack welds.
OTHER MISCELLANEOUS INSPECTION DETAILS:1. Visual inspection of Piers 10 and 11 and bearings.
Inspection Procedures
2
MnDOT Bridge No. 69101
2015 Fracture Critical Bridge Inspection Report
Fracture Critical MembersThe National Bridge Inspection Standards (NBIS) defines a “Fracture Critical Member” (FCM) as “A steel member intension, or with a tension element, whose failure would likely cause a portion of or the entire bridge to collapse.” Theonly fracture critical members on the bridge are the integral steel pier caps located at Piers 10 and 11.
Fatigue Prone DetailsThis section identifies fatigue prone details present on the primary structural steel members of this bridge. Steelstructural members subjected to tension or reversal stresses can develop fatigue cracks. The three primary parametersaffecting fatigue crack propagation are stress range, the number of stress cycles, and the type of detail. Other factors,such as out-of-plane bending, heat straightening, or field-welded repairs can increase the likelihood of fatigue cracking.
For the purpose of designing bridges for fatigue caused by in-plane bending stress, AASHTO describes weld detailsand connections using an alphabetical designation ranging from stress category “A” (best fatigue resistance) to stresscategory “F” (most susceptible to fatigue crack growth). Fatigue detail categories are defined in Table 6.6.1.2.3-1 of the2009 AASHTO LRFD Bridge Design Specifications. Refer to the table below for the applicable fatigue prone details.
III. Fracture Critical Members/Fatigue Prone Details
3
Fatigue Prone Details Member & Location Detail Description & Photo Reference
AASHTO Stress
Category
AASHTO Detail
Number Potential Crack Initiation Point
Steel Pier Caps
“Tight fit” detail at web stiffener/top flange connection. - NA In adjacent welds
and base metal Steel Cap (Pier #11)
Tack welds at web stiffener/top flange connection. D NA In tack weld and
adjacent base metal
MnDOT Bridge No. 69101 2015 Fracture Critical Bridge Inspection Report
4
IV. Inspection Field Notes
MnDOT Bridge No. 69101
2015 Fracture Critical Bridge Inspection Report
Inspection field notes reference photos in Section V.
7
MnDOT Bridge #69101 2015 Fracture Critical Inspection Report
Pier #10 Location Notes
Concrete Pier Wall
[2015] No significant change (Photo 1). [2013] There are two delaminated and spalled areas of concrete on the south face of the pier wall, approximately six square feet. [2009] 4 SF of spalling and delamination at the base adjacent to the off ramp guardrail.
Steel Pier Cap
[2015] No significant change (Photos 2-4). [2013] Complete paint system failure with areas of surface and flaking corrosion along the top and edges of the top flange and the edges of the bottom flange. [2009] paint failure and corrosion, mainly along the flanges. There is isolated flaking rust, but there is little or no section loss.
Bearings [2015] Paint failure and surface rust (Photo 5).
Pier #11 Location Notes
Concrete Pier Wall
[2013-2015] Same as previously reported (Photo 6). [2009] No notable damage or deterioration.
Steel Pier Cap
[2015] No significant change (Photos 7-10). [2013] Complete paint system failure with areas of surface and flaking corrosion along the top and edges of the top flange. There are tack welds at every stiffener against the top flange. None of the tack welds were cracked. [2009] paint failure and corrosion, mainly along the flanges. There is isolated flaking rust, but there is little or no section loss. On the N face there are 3 tack welds between the bearing stiffeners and the top flange. The plans designate this as a “tight-fit” connection. No tack welds shown on plans.
Bearings
[2015] Paint failure and surface rust (Photo 11).
8
Pictures
Photo 7 - Pier 11 Typical Pier Cap
Photo 8 - Pier 11 Corrosion on Bottom Flange Under G2
12
Pictures
Photo 9 - Pier 11Typical Corrosion Bottom Flange
Photo 10 - Pier 11 G2 to Pier Cap Connection
13
5 - Not eligible
1 - No Restriction
3 - FTG PILE
Posting
24
GENERAL
1A
AT THE JCT TH 2 & 35
01 - Beam Span
1426.2
45.2Operating Rating
134.7
Latitude
99999
GR Transition
Deck Geometry
Superstructure 7 - Good Condition
N
Parallel Structure
0 - Not Required
0 - Not Required
1983
29930 sq. ft.Painted Area
1 - CONC
1 - CONC
Deck Rebars
Appr. Span Detail
Service Under
County
City
1983
Appr. Span Type
Sect., Twp., Range 8
Duluth
District 1
MnDOT Structure Inventory ReportBridge ID: over
069 - St. Louis
Desc. Loc.
Township
District
Owner 01 - State Highway Agency
BMU Agreement
Main Span Type
4 - Steel Continuous
Agency Br. No.
Longitude
Custodian 01 - State Highway Agency
Crew
Year Built
MN Year Reconstructed
FHWA Year Reconstructed
MN Temporary Status
Bridge Plan Location 1 - CENTRAL
Main Span Detail
0 - NoneDeck Membrane
6 - Highway - waterway
Service On 1 - Highway
Skew 0
Culvert Type
Barrel Length
NUMBER OF SPANS
MAIN: 12 APPR: 0
Main Span Length
Structure Length
Deck Width (Out-to-Out) 25.8
Deck Material 1 - Concrete Cast-in-Place
Wear Surf Type 4 - Low Slump Concrete
Wear Surf Install Year 1983
Wear Course/Fill Depth 0.17 ft.
1 - Epoxy Coated Reinforcing
1983Deck Rebars Install Year
36796Structure Area (Out-to-Out)
36791Roadway Area (Curb-to-Curb)
Sidewalk Width 0.00 0.00
Curb Height 0.00 0.00
Rail Type 23 23
0 - No flareStructure Flared
N - No parallel structure
MISC. BRIDGE DATA
Field Conn. ID 4 - Bolted
Abutment Foundation
Pier Foundation
1 - ONOn-Off System
Year Painted
5Unsound Paint %
PAINT
D - Organic Zinc - 3309Primer Type
H - VinylFinish Type
Posted Load
Traffic
0 - Not RequiredHorizontal
BRIDGE SIGNS
0 - Not RequiredVertical
17Userkey
Unofficial Structurally Deficient
05/07/2015Routine Inspection Date
12Routine Inspection Frequency
Inspector Name Bridge Office FC Unit
Status A - Open
7 - Good ConditionDeck
Substructure
8 - Banks are protected
Culvert N - Not Applicable
1 - MEETS STANDARDSBridge Railing
1 - MEETS STANDARDS
1 - MEETS STANDARDSAppr. Guardrail
1 - MEETS STANDARDSGR Termini
SAFETY FEATURES
6
4
9 - Bridge Above Flood Water ElevationsWater Adequacy
9 - Superior to present desirable criteriaApproach Alignment
NBI APPRAISAL RATINGS
05/04/2015Frac. Critical
DateFreq
Underwater
Pinned Asbly.
Drainage Area (sq. mi.)
Waterway Opening
0 - No nav. control on waterwayNavigation Control
Pier Protection
Nav. Clr. (ft.)
Nav. Vert. Lift Bridge Clear. (ft.)
I - LOW RISKMN Scour Code 1995Year
WATERWAY
5 - HS 20Design Load
CAPACITY RATINGS
1 - LF (LF)
1 - LF (LF)Inventory Rating 27.1
Rating Date 4/1/1997
A: 1 - No Restriction
B: 1 - No Restriction
C:
- 049N 14W-
INSPECTION
Maint. Area
7 - RAMP, WYE, CONNECTOR
1
Route On Structure
SB-WBNB-EB
Bridge Match ID (TIS)
Roadway O/U Key
02 - USTHRoute Sys
Roadway Name or Description
Level of Service
1 - 1-way trafficRoadway Type
6937Control Section (TH Only)
Reference Point
10/1/1984Date Opened to Traffic
1.0Detour Length
1Lanes On 1Under
4500ADT
0HCADT
12 - Urban - Principal Arterial - Other Freeway or ExpresswayFunctional Class
If Divided
22.80
RDWY DIMENSIONS
Roadway Width
Vertical Clearance
ft.
ft.
Max. Vert. Clear. ft.
22.7Horizontal Clear. ft.
Lateral Clearance ft. ft.
22.0Appr. Surface Width ft.
22.8Bridge Roadway Width ft.
Median Width On Bridge ft.
ROADWAY
1994
Date: 10/28/2015
sq. ft.
sq. ft.
ft.
ft.
ft.
STRUCTURE
Structure Evaluation 7
7 - Good Condition
Channel
Underclearances
VEH: SEMI: DBL:
Unsound Deck %
ft.
ft.
ft.
ft.
2
ft. ft.
ft.
ft.ft.
ft.
mi
3 - FTG PILE
Historic Status
MnDOT Permit Codes
NBI CONDITION RATINGS46Deg Min Sec44 30.46
Deg Min Sec92 9 12.09
ft.
0ADTT %
Spec. Feat.
Y
Y/N
Legislative District 07B
Cantilever ID F - Friction Hinge
Number
Year
NUnofficial Functionally Obsolete
Unofficial Sufficiency Rating 97.6
IN DEPTH INSP.
Vert. Horiz.
Lt
Lt
Lt
Rt
Rt
Rt
US 2 WB OFF RAMP69101 I 35 RAMP & LAKE
TOTAL: 12
mo.
sq. ft.
US 2 WB off ramp
HS
HS
(Material/Type)
(Material/Type)
16
MnDOT Bridge No. 69101
2015 Fracture Critical Bridge Inspection Report
7 Day Fracture Critical Report (Report Date: 06/04/2015 )
Disclaimer: The condition ratings in this report are only suggested. It is the responsibility of the Bridge Owner to approveinspection data in SIMS.
Bridge # 69101
Facility Carried: US 2 WB OFF RAMP
Bridge Owner: State Highway Agency
Inspection Date(s): - 05/04/2015
Primary Inspector: Nelson, Bill
Other Inspector(s): Carter, Rodney; Potter, Farrell; Theisen, Scott
Method of Access:
Traffic Control: Pier caps were accessed with a ladder from behind the guardrail - no traffic control required.
Fracture Critical Inspection of Steel Pier Caps ONLYScope of Inspection:
NoCritical Structural Deficiencies (Yes/No)
YesNew Load Rating Recommended (Yes/No)
NoTraffic Safety Hazard (Yes/No)
NoStructural Analysis Recommended (Yes/No)
Facility Intersected: I 35 RAMP & LAKE
The current load rating on the bridge does not takeinto consideration the load-carrying capacity of thesteel pier caps. In the 2011 fracture critical report, itwas recommended that a new load rating becompleted taking into account the strength of thesteel pier caps. No new rating has been completed(also recommended in 2013).
NBI Condition Ratings
CommentsSuggestedCurrentItem
Deck 7 7
Superstructure 7 7
Substructure 7 7
Channel 8 8
QuantityElement Condition Ratings
54321
Suggested Element Condition Rating Changes in RED
Element Description#
106 Weathering Steel Girder or Beam 2,517 LF 0 2,517 0 0
107 Painted Steel Girder or Beam 1,761 LF 0 1,409 352 0 0
210 Reinforced Concrete Pier Wall 246 LF 218 28 0 0
215 Reinforced Concrete Abutment 26 LF 25 1 0 0
300 Strip Seal Deck Joint 77 LF 77 0 0
301 Poured Deck Joint 258 LF 206 52 0
310 Elastomeric (Expansion) Bearing 24 EA 12 12 0
311 Expansion Bearing 15 EA 15 0 0
313 Fixed Bearing 21 EA 18 3 0
321 Concrete Approach Slab-Concrete Wearing Surface 1 EA 0 1 0 0
333 Masonry, Other or Combination Material Railing 2,852 LF 2,139 713 0
358 Concrete Deck Cracking Smart Flag 1 EA 0 1 0 0
359 Underside of Concrete Deck Smart Flag 1 EA 0 1 0 0 0
373 Steel Hinge Assembly 12 EA 12 0 0 0 0
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MnDOT Bridge No. 69101
2015 Fracture Critical Bridge Inspection Report
QuantityElement Condition Ratings
54321
Suggested Element Condition Rating Changes in RED
Element Description#
377 Low Slump O/L (Concrete Deck with Epoxy Rebar) 36,796 SF 36,796 0 0 0 0
380 Secondary Structural Elements 1 EA 1 0 0 0
387 Reinforced Concrete Wingwall 2 EA 2 0 0 0
410 Modular Deck Joint 77 LF 77 0 0
422 Painted Beam Ends 6 EA 0 3 3 0 0
427 Painted Steel Pier Cap 50 LF 0 0 50 0 0
964 Critical Finding Smart Flag 1 EA 1 0
966 Fracture Critical Smart Flag 1 EA 1 0 0
981 Signing 1 EA 1 0 0 0 0
982 Approach Guardrail 1 EA 0 1 0
984 Deck & Approach Drainage 1 EA 0 1 0
985 Slopes & Slope Protection 1 EA 0 1 0
988 Miscellaneous Items 1 EA 0 1 0
Element Rating Notes:
ELEMENT #427: [2015] The paint on Pier caps 10 and 11 continues to deteriorate, but there is no significantsection loss (Photos 1-3).[2013] On Pier Caps 10 and 11, the paint system on the top surface of the top flange has extensive deteriorationwith surface corrosion along the edge of the flange. There are scattered areas of failed paint and surface corrosionon the edges of the bottom flange on Pier Caps 10 and 11. On the north face of Pier Cap 11, there is one tack weld(four total) between the top flange of the pier cap and the vertical stiffeners. None of the tack welds were cracked.
Steel is starting to rust. Active corrosion bottom of bearings and anchor bolts. 2012- Both caps have activecorrosion.(2014) no change.
ELEMENT #966: [2015] The steel pier cap at Piers 10 and 11, as shown on the plans, are integral caps and areconsidered fracture critical. A fracture critical inspection was completed on the caps of Piers 10 and 11 on May 4,2015.From E. Piers #11 & 12 have "fracture critical" integral steel pier caps (anchored to the concrete pier shaft) - theseare welded I-girders which do not require internal inspection, but should have a close-up inspection with a snooperor manlift. blasting and painting would aid in inspection in FC areas. (2014)no change.
General Notes:
Inventory Item Notes:
58. Deck NBI:
36A. Brdg Railings NBI:
36B. Transitions NBI:
36C. Appr Guardrail NBI:
36D. Appr Guardrail Terminal NBI:
59. Superstructure NBI:
60. Substructure NBI:
61. Channel NBI:
62. Culvert NBI:
71. Waterway Adeq NBI:
72. Appr Roadway Alignment NBI:
19
BRIDGE OWNER:
DATE INSPECTED:
FACILITY CARRIED:
TYPE OF INSPECTION:
BRIDGE NO.:
STRUCTURE TYPE:
FEATURES INTERSECTED:
FRACTURE CRITICAL
SPECIAL:
State Highway Agency
05/04/2015
US 2 WB OFFRAMP
69101
Steel Continuous
Stringer/Multi-beam or Girder
I 35 RAMP & LAKE
PURPOSE:
This report is a structural assessment of the structure and its ability to carry loads based on conditionsidentified in the attached bridge inspection report. The assessment is only a cursory review intended toprovide guidance as to the relative hazards for structural conditions and deficiencies identified. This report ismandatory for all fracture critical bridges and is completed by the MnDOT Bridge Office upon receipt of the7 Day FC Report; however, it is an OPTIONAL tool for agencies to utilize at their discretion for all otherinspection types.
DAMAGE:
OTHER:Check all that apply:
Redundancy: Structural Load Path
Internal
RivetedConnectionType:
Welded
Other:
Bolted
PINNED ASSEMBLY:
ROUTINE
1. Was a critical finding identified during this inspection or upon
3. Does the condition of any bridge component indicate impaired
2. If a critical finding was identified, what is the current status?
Yes No
Pending Resolved
N/A
Yes No
Yes" above, state briefly the finding(s):a) If selected "
a) Briefly state actions taken:
structural review?
function? Examples of bridge components with impaired functioninclude elements that are: frozen or immoveable, out-of-plumb ormisaligned, distorted or structurally deformed, excessivelydeteriorated, cracked, broken, eroded or scoured.
21
4. Does the overall condition of the bridge, or any of its components Yes No
Continue monitoring the paint failure at the steel surface at the pier caps. Continue monitoring the cracked tack welds between the top flange of the pier cap and the verticalstiffeners.
mentioned in Question 3, suggest the need for detailed structuralanalysis and/or a revised load rating?
Bridge Office Reviewer Jihshya J. Lin5/25/2015
If selected "Yes" above, state briefly the component(s) and condition(s):a)
If selected "Yes", state the reason for this recommendation and indicate a proposed timeframe ina)
accordance with State of Minnesota Rule 8810.9500 (Subpart 2):
Explain recommended actions:
6. Other comments:
5. Based on the structural assessment of these findings, recommendations include:
Repair/Maintenance
Other Increased Inspection Frequency
Monitoring Plan
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