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2017 UNDERWATER
BRIDGE INSPECTION REPORT
BRIDGE #
DISTRICT: COUNTY: CITY/TOWNSHIP:
Date of Inspection:
Equipment Used:
Inspected By:
Report Written By:
Report Reviewed By:
Final Report Date:
33527
CSAH 11 over SNAKE RIVER
District 3 Kanabec GRASS LAKE
04/07/2017
Stuber, Cory
Cory Stuber
County Highway AgencyOwner:
MinnesotaSTATE:
UNDERWATER SUMMARY 3
UNDERWATER INSPECTION 4
UNDERWATER INSPECTION PROCEDURES 6
STRUCTURE INVENTORY 7
ELEMENTS 8
PICTURES 12
DRAWING 14
TABLE OF CONTENTS
PAGE NUMBER
Contractor:
(A) Reinspect the submerged substructure units at the normal maximum recommended (NBIS) interval of sixty (60) months.
Collins Engineers, Inc.
9687Contractor Job Number:
RECOMMENDATIONS
REPORT SUMMARY
UNDERWATER INSPECTION
The substructure units inspected at Bridge No. 33527, Piers 1 and 2, were found to be in good condition with no defects of structural significance observed. However, the protective coating/paint system has experienced a 10% loss of coverage throughout. A scour depression was observed around the upstream nose of Pier 1, with a 5 foot radius and a 3 foot depth. A large 24 inch diameter timber log has become wedged into the channel bottom extending up to the underside of the superstructure on the south side of Pier 1. Aside from localized scour around Pier 1, the channel bottom around the substructure units appeared stable, consisting of a sandy infill with random cobbles. This report represents the initial underwater inspection for this structure.
(A) The channel bottom consisted of sandy infill with random cobbles, up to 18 inches in diameter, starting 10 feet out from the shoreline.
(B) Typically, a 10% loss of coating was observed on the steel shells of the cast-in-place piles.
(C) A large timber log, with up to a 24 inch diameter, and other timber debris, up to 12 inch diameters, were observed accumulating on Pier 1 from the channel bottom extending up to the superstructure.
(D) Scour depression observed around the first pile on the upstream nose of Pier 1, with a 5 foot radius and a 3 foot depth.
INSPECTION FINDINGS
Page 3 of 15
The top of the pier cap of the downstream end of Pier 2. Water Level Reference:
WATERLINE DATUM
Waterline Elevation (feet):
The waterline was approximately 13.1 feet below reference.Description:
945.0
4.
Piers 1 and 2Substructure(s) Inspected:
SUBSTRUCTURE INSPECTION DATA
General Shape:
7.4Maximum Water Depth at Substructure(s) Inspected (feet):
The piers consist of a reinforced concrete pier cap with rounded ends supported by seven cast-in-place concrete piles with steel casings (shells).
Code:Item 62: Culvert:
8
Y 48 04/2017Code:Item 92B: Underwater Inspection:
Code:
(Minnesota specific codes are used for 92B and 113)
NBIS CODING INFORMATION5.
Item 60: Substructure:
Item 61: Channel and Channel Protection:
7Code:
District 3District:
CSAH 11
County:
The bridge superstructure consists of three spans. The superstructure is supported by two bent piers and two reinforced concrete abutments. Each pier is comprised of a reinforced concrete cap supported by seven steel encased cast-in-place piles. Substructure units were designated as follows: South Abutment, Piers 1 and 2, North Abutment.
Bridge Description:
033 - Kanabec
Facility Carried:
BRIDGE DATA1.
UNDERWATER INSPECTION
Bridge #:
SNAKE RIVERFeature Intersected:
33527
Underwater Visibility (feet):
Sunny, 45°FWeather Conditions:
3
3.
2.0Waterway Velocity (ft/sec):
04/07/2017
Professional Engineer/Team Leader:
INSPECTION DATA2.
Cory Stuber, P.E.
Date of Underwater Inspection:
Cory Stuber, P.E.Inspection Diver:
Page 4 of 15
885 Scour 1 1EA
STRUCTURAL ELEMENT CONDITION RATING
Conditions
6.
N
Bridge is scour critical because abutment or pier foundation is rated as unstable due to observed scour at bridge site.
Item 113: Scour Critical Bridge: Code:
No (Mark your selection with an X)Yes X
225
CS3 CS4
Steel Piling 1414 EA
CS2ELEM # Unit CS1Element Description Quantity
Page 5 of 15
The routine underwater inspection of Bridge 33527 (CSAH 11 over the Snake River) was completed on April 7, 2017. The underwater inspection was conducted from shore. The inspection was conducted by a team consisting of a PE-Diver with a valid MnDOT Team Leader certification and a dive tender. Due to waterway conditions at the time of inspection, the inspection could be accomplished by wading in accordance with OSHA regulations Profiles were taken along the upstream and downstream faces of the bridge and around the periphery of substructure units to determine the presence, location and area of scour.
The bridge elements inspected consisted of two steel pile bent piers. According to the bridge inventory or design drawings, Piers 1 and 2 were each founded on seven CIP piles. Inspection procedures followed FHWA guidance and the MnDOT Bridge and Structure Inspection Program Manual with channel bottom probing to search for foundations. The routine underwater inspection frequency is recommended to remain at a maximum of 60 months based on those findings and risk factors. Also, inspection procedures should continue to follow the above approach and standard guidance with 100% Level I and 10% Level II intensity efforts.
INSPECTION PROCEDURES
UNDERWATER INSPECTION
Page 6 of 15
Spec. Feat.Pier Foundation (Material/Type)
8 - CIPCantilever ID
+ W A T E R W A Y +Number of Spans Historic Status
4 - PILE BENT
UnderwaterCulvert Type 3 - FTG PILE
Pinned Asbly.
04/07/2017
Barrel Length
185.6 ft. Navigation Control
Waterway Opening (sf.) 1950Structure Length
ft. Year Painted
0 - No nav. control on waterwayDeck Width (Out-to-Out) 43.3
+ P A I N T +
APPR: 0 TOTAL:5 - Not eligible
MAIN: 3
Main Span Length 60.2 ft.Drainage Area (sq. mi.) 3988.0
B R I D G E D A T A +Main Span Detail
1 - MEETS STANDARDS+ M I S C.
Appr. Span Type Structure Flared
GR Termini 1 - MEETS STANDARDS
Appr. Guardrail
Main Span Type 5 - Prestress or Precast Median Width On Bridge
ft. Bridge Railing 1 - MEETS STANDARDS
1 - MEETS STANDARDS
Main Span Design 01 - Beam Span
ft. GR Transition
Skew 0
Y/N Freq Date
Abutment Foundation (Material/Type)
1 - CONC Frac. Critical
D E P T H I N S P. +Appr. Span Design
0 - No flare+ I N
Appr. Span Detail Field Conn. ID
Parallel Structure N - No parallel structure
Pier Protection
0 - Not Required
Rating Date 04/08/20157427 sq. ft. Traffic
ft. 50B. Rt 0.00Sidewalk Width 50A. Lt 0.00
Roadway Area (Curb-to-Curb)
Posted Load 0 - Not Required
PostingStructure Area (Out-to-Out) 8036 sq. ft.
40 DBL: 40VEH: 32 SEMI:
Rt 22 ARail Type Lt 22 C N - N/AN - N/A B N - N/A
N - Not Applicable Overweight Permit CodesCurb Height Lt
ft. Horizontal 0 - Not Required
0.00 ft. Vertical0.00 ft. Rt
Wear Surf Install Year
sq. ft. Nav. Vert. Lift Bridge Clear. (ft.)
N - STBL - LIM SCOUR
YearPrimer Type MN Scour Code
Painted Area
Unsound Paint % Nav. Clr. (ft.)Deck Material 1 - Concrete Cast-in-Place 0.0Wear Surf Type 1 - Monolithic Concrete
(concurrently placed with stru
Vert. 0.0 Horiz.
S I G N S +Operating Rating 2 - HS TRUCK
1 - Epoxy Coated Reinforcing + B R I D G E
Inventory Rating 2 - HS TRUCK 11.4
19.0Deck Rebars Install Year 1988
Deck Rebars
Finish TypeWear Course/Fill Depth 0.00 ft.
0 - None
Design Load 5 - HS 20
+ C A P A C I T Y R A T I N G S +Deck Membrane
45 ° 48
Inspector Name Stuber, Cory
Latitude Control Section (TH Only) Status' 41.76 ''
2 - 2-way traffic
Routine Inspection Frequency 24
Sect., Twp., Range
0.4 MI S OF JCT CSAH 17 Level of Service 1 - MAINLINE
- 23W Roadway Type6 - 038N
Detour Length 12.0 mi.R A T I N G S +
Custodian 02 - County Highway Agency
Owner 02 - County Highway AgencyDeck 7 Unsound
Deck %
C O N D I T I O N° 15 '
B - Open, Posting Required
Longitude -93+ N B I
57.35 '' Reference Point
Crew
+ I N S P E C T I O N +
Agency Br. No. 73
District 03
Bridge Match ID (TIS) 0 Userkey
CSAH 11 over SNAKE RIVER
Minnesota Structure Inventory Report
Bridge ID: 33527
+ G E N E R A L + + R O A D W A Y +
Date: 05/11/2017
Sufficiency Rating 81.3Roadway Name or Description
11
City
Routine Inspection Date 11/20/2015
Desc. Loc.
Township 33006 - GRASS LAKE CSAH 11
Number
NRoadway O/U Key Route On StructureMaint. Area Structurally Deficient
Notes: [2016] Migrator added 40 LF to abutment quantity to account for wingwalls (CS1:40 CS2:0 CS3:0 CS4:0).5 Vert. hairline cracks N. abut. some Efforvecence. 3 Vert. hairline cracks S. abut.2015:Spall between girders 3 & 4 E. abut.
Wingwall notes: No change.
Steel Pile 04/07/2017 14 EA 14 0 0 0225 Underwater
14 EA 14 0 0 0Migrated Values
Notes: Piling need to be painted.2015: Several need paint.
515 - Steel Protective Coating 999 SF 999 0 0 0
Notes: [2016] Migrator assumed CS1 and a quantity of 999 SF.
Notes: NW bolt sheared off expansion plate. Numerous hairline cracks, both rails. Slight impact damage.2015: Expansion plate still needs repair. Graffiti on rails, the should be painted.
Critical Deficiencies or Safety Hazards 04/07/2017 1 EA 1 0 0 0800 Underwater
1 EA 1 0 0 0Migrated Values
Notes: NO CRITICAL FINDINGS OBSERVED DURING THE LAST INSPECTION. None.
Notes: Due to deep water unable to check for scour at piers.2015:Due to deep water unable to check for scour. Need to inspect for scour when water levels are low, use a boat.[2017] Underwater Inspection - Scour depression observed around the first pile on the upstream nose of Pier 1, with a 5 foot radius and a 3 footdepth.
Load Posting or Vertical ClearanceSigning
04/07/2017 1 EA 1 0 0 0890 Underwater
1 EA 1 0 0 0Migrated Values
Notes: [2016] Structure requires a vertical clearance sign or load posting sign.
Other Bridge Signing 04/07/2017 1 EA 1 0 0 0891 Underwater
1 EA 1 0 0 0Migrated Values
Notes: SE delin. has damaged face.04/08/2015: Load Posting Required: 32T/40T/40T. NBI 41: Status coded 'B - Open, Posting Required'. Agency to notify MnDOT BADMU whensigns are installed.2015: Load limit signs are inplace. Guardrail markers at ends.
Protected Species 04/07/2017 1 EA 1 0 0 0900 Underwater
1 EA 1 0 0 0Migrated Values
Notes: Use this element to track the presence of protected species living on this structure.
General Notes: PONTIS inspection comments -2001 inspection - structure remains in good condition. No problems noted during thisinspection. 2003 inspection - Structure is in good to very good condition. All concrete members of structure are sound.Superficial cracks in railing remain the same - no serious problems. Piers are in good condition; although there is a largeamount of debris to be removed from upstream end of south pier. Abutment slopes need riprap. Grafitti on beams andabutments should be covered with a coat of paint. 2005 All concrete in this pre-stressed concrete beam span structure is ingood condition. J-railing have minor expansion cracks in them. Bridge beams and abutments have grafitti painted on them thatshould be painted. All C-I-P pier piling are in good condition. Remove debris from upstream end of pier no. 1. Gland on northend of bridge has failed and should be repaired. Bituminous approaches and signs are in good condition. 2007 inspectionfound this structure to be in good condition. No change in overall condition. All concrete is sound. CIP pier piling are in goodcondition. Expansion cracks in conrete railings remains the same. Riprap needed on abutment slopes. Gland on expansionjoint on north end of bridge is leaking and should be replaced. Unable to inspect for scour at this time. Will complete inspectionin the spring and forward results to MN/DOT at that time. Signs and approaches are in good condition. 8-11-08 Found 3.0'deep scour on west end of south pier. Remoive debris and continue to monitor. 2009 - Strucutre is in good condition. Concreteslab has delamination oever pier joints. Debris on upstream end of pier 1 needs to be removed. J-railing has expansion cracksthroughout which remain the same. pier pilings are in good condition. All concrete members are sound.Abutment slopes stillneed riprap. Leaking gland on Norh end of bridge needs to be repaired.No change in scour since last inspection. ET-Plusguardrail is good. Signs okay.2011 - Structure is in good condition. Concrete deck has some minor delamination at joints over piers. Debris upstream andalong pier #1 needs to be removed. J-railing expansion cracks are the same as in 2009. Pier piling & piers are in goodcondition. Abutment slopes still need riprap. Guardrail is in good condition. Signs are all ok. Gland on north end still needsrepair.2013 - Structure is in good condition. North concrete diaphragm, 3 hairline cracks center & 3 east side. S. concretediaphragm, 1 hairline crack east side, and 1 W. side. Cracks w/ efforvesence deck underside over N. pier (W. side), also overS. pier. Debris in channel needs to be removed at W. end of S. pier. Bit. apps. have moderate dips at Br. ends, and patchesare breaking up.2015: Br. is in good cond., no changes since previous inspection. Due to high water unable to check for scour at piers.