2016 UNDERWATER BRIDGE INSPECTION REPORT. CSAH 10 over POMME DE TERRE RIVER. Date of Inspection: Equipment Used: 06/18/2016. County Highway Agency

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1 2016 UNDERWATER BRIDGE INSPECTION REPORT BRIDGE # CSAH 10 over POMME DE TERRE RIVER DISTRICT: District 4 COUNTY: Stevens CITY/TOWNSHIP: DARNEN STATE: Minnesota Date of Inspection: Equipment Used: 06/18/2016 Owner: County Highway Agency Inspected By: Forsyth, Roy Report Written By: Roy Forsyth Report Reviewed By: Final Report Date:

2 TABLE OF CONTENTS PAGE NUMBER UNDERWATER SUMMARY 3 UNDERWATER INSPECTION 4 UNDERWATER INSPECTION PROCEDURES 6 STRUCTURE INVENTORY 7 ELEMENTS 8 PICTURES 11 DRAWINGS 14

3 UNDERWATER INSPECTION REPORT SUMMARY The substructure units inspected at Bridge No , Piers 1 through 3, and East and West Abutments, were found to be generally in good to satisfactory condition with no defects of structural significance observed. All of the timber piles were generally solid and in good condition with only light weathering allowing up to 1/8 inch awl penetration. Minor outer shell delaminations with up to 1/2 inch thickness were noted on all piles, between 1 foot above and 1 foot below the waterline. Several of the pile braces exhibited splits through the fastener, up to 2 inches wide and 5 feet long, at the pile to brace connection. Overall, the channel bottom configuration consisted of 2 feet diameter rocks, random cobbles, and sandy gravel.. INSPECTION FINDINGS (A) All of the timber piles of the inspected substructure units were solid with light weathering allowing up to 1/8 inch awl penetration. Additionally, between 1 foot below and 1 foot above the waterline, the timber piles exhibited minor outer shell delaminations with 1/4 inch to 1/2 inch thickness. (B) There was an up to 2 inch wide gap in wall planking of the West Abutment backwall, located near the waterline. (C) Splits through the brace-to-pile fastener, up to 2 inches wide and 5 feet long, were noted on several braces of Piers 1 through 3. (D) Channel bottom material around Piers 1 and 3 consisted of up to 2 foot diameter rock with randomly scattered cobbles allowing no probe rod penetration. (E) The channel bottom material around Pier 2 consisted of sandy gravel with 6 inch diameter and smaller cobbles allowing negligible probe rod penetration. RECOMMENDATIONS (A) The deficient cross bracing connections should be restored/repaired during routine bridge maintenance. Until corrected, monitor the cross bracing deterioration and cracking, and if found to be progressing to a more detrimental condition that would threaten the lateral stability of the bridge, corrective measures would be warranted at that time. (B) Reinspect the submerged substructure units at the normal maximum recommended (NBIS) interval of sixty (60) months. Contractor: Contractor Job Number: Collins Engineers, Inc Page 3 of 15

4 UNDERWATER INSPECTION 1. BRIDGE DATA Bridge #: Feature Intersected: Facility Carried: District: County: POMME DE TERRE RIVER CSAH 10 District Stevens Bridge Description: The superstructure consists of four spans of timber beams supported by two timber abutments and three timber pile bent piers. The substructure units are designated as West Abutment, Piers 1 through 3 and East Abutment. 2. INSPECTION DATA Professional Engineer/Team Leader: Inspection Diver: Date of Underwater Inspection: Weather Conditions: Underwater Visibility (feet): Waterway Velocity (ft/sec): Roy A. Forsyth Marc Stern 06/18/2016 Sunny, 80 F 6 in. None/Negligible 3. SUBSTRUCTURE INSPECTION DATA Substructure(s) Inspected: West and East Abutments and Piers 1 through 3 General Shape: Each pier consists of a timber cap supported by ten driven timber piles with timber cross bracing. Each abutment has bulkhead timber wall planking and is supported by nine driven timber piles. Maximum Water Depth at Substructure(s) Inspected (feet): WATERLINE DATUM Water Level Reference: Waterline Elevation (feet): Description: The top of bent cap at the upstream end of Pier 1. Assumed Elevation of feet The waterline was approximately 5.6 feet below reference. 5. NBIS CODING INFORMATION (Minnesota specific codes are used for 92B and 113) Item 60: Substructure: Item 61: Channel and Channel Protection: Item 62: Culvert: Item 92B: Underwater Inspection: Code: Code: Code: Code: 6 8 Y 48 06/2016 Page 4 of 15

5 Item 113: Scour Critical Bridge: Code: I Bridge is scour critical because abutment or pier foundation is rated as unstable due to observed scour at bridge site. Yes X No (Mark your selection with an X) 6. STRUCTURAL ELEMENT CONDITION RATING Conditions ELEM # Element Description Quantity Unit CS1 CS2 CS3 CS4 216 Timber Abutment 95 LF Timber Piling 48 EA Scour 1 EA 1 Page 5 of 15

6 UNDERWATER INSPECTION INSPECTION PROCEDURES The routine underwater inspection of Bridge (CSAH 10 over the Pomme de Terre River) was completed on June 18, 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, a backup diver and a dive tender. The inspection utilized commercial dive equipment and techniques (SSA and/or SCUBA) 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 2 timber abutments with 9 timber piles each and 3 timber piers consisting of 10 timpber piles each. According to the bridge inventory or design drawings, West and East Abutments and Piers 1 through 3 were founded on timber pilings. Inspection procedures followed FHWA guidance and the MnDOT Bridge and Structure Inspection Program Manual with channel bottom probing to search for bottom of 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. Page 6 of 15

7 Bridge ID: Minnesota Structure Inventory Report CSAH 10 over POMME DE TERRE RIVER Date: 07/28/ G E N E R A L + + R O A D W A Y + + I N S P E C T I O N + Agency Br. No. Crew Bridge Match ID (TIS) 0 Userkey 115 District 04 County Stevens Route Sys 04 - CSAH Number 10 Functionally Obsolete City Sect., Twp., Range Main Span Type 7 - Timber Median Width On Bridge Main Span Design Main Span Detail Appr. Span Type Appr. Span Design Appr. Span Detail Skew 0 Culvert Type Barrel Length Cantilever ID MAIN: 4 Main Span Length Structure Length 09 - Slab Span Number of Spans APPR: 0 TOTAL: 26.0 Deck Width (Out-to-Out) 29.6 Deck Material Wear Surf Type Wear Surf Install Year 2002 Wear Course/Fill Depth Deck Membrane Deck Rebars Deck Rebars Install Year Structure Area (Out-to-Out) 2605 sq. Roadway Area (Curb-to-Curb) Sidewalk Width 50A. Lt 0.00 Curb Height 0.7 MI E OF JCT TH9 Level of Service 1 - MAINLINE N - 42W Roadway Type Latitude ' '' Control Section (TH Only) Status Lt 8 - Wood or Timber 6 - Bituminous None + M I S C. Structure Flared Parallel Structure Field Conn. ID Abutment Foundation (Material/Type) Pier Foundation (Material/Type) Historic Status 4 - PILE BENT 2 - TIMBER 4 - PILE BENT Underwater 60 Pinned Asbly. Spec. Feat Navigation Control Year Painted 2540 sq. Traffic 50B. Rt Rt Painted Area Primer Type Posted Load B R I D G E D A T A No flare 5 - Not eligible + P A I N T + Bridge Railing 1 - MEETS STANDARDS N - No parallel structure GR Transition Appr. Guardrail GR Termini 2 - TIMBER Frac. Critical 2 - Vehicle & Semi (Type R12-5) 0 - Not Required Horizontal 1 - Object Markers 0.00 Vertical Unsound Paint % Finish Type 0 - None + B R I D G E 2-2-way traffic Longitude ' 5.73 '' Reference Point Custodian Owner 02 - County Highway Agency 02 - County Highway Agency Roadway Name or Description Township DARNEN CSAH 10 Desc. Loc. BMU Agreement Year Built 1967 MN Year Reconstructed FHWA Year Reconstructed MN Temporary Status Bridge Plan Location Date Opened to Traffic Maint. Area Roadway O/U Key Detour Length 6.0 mi. Lanes Route On Structure On - Off System 1 - ON Roadway Width Legislative District 11A Vertical Clearance Potential ABC 2 - N/A Max. Vert. Clear. Service On 5 - Highway-pedestrian Appr. Surface Width Service Under 3 - COUNTY + S T R U C T U R E + HCADT Functional Class If Divided + R D W Y Horizontal Clear. Lateral Clearance ON 2 UNDER ADT 5 - Waterway Bridge Roadway Width YEAR 2008 N - Not Applicable + I N + W A T E R W A Y + Drainage Area (sq. mi.) Waterway Opening (sf.) 1000 Pier Protection Posting Rating Date 07/27/ SUBSTANDARD 0 - SUBSTANDARD 0 - SUBSTANDARD D E P T H I N S P. + Y/N Freq Date 06/18/ No nav. control on VEH: 34 SEMI: 40 DBL: 40 Overweight Permit Codes Rail Type Lt 01 Rt 01 A N - N/A B N - N/A C N - N/A sq. ADTT 07 - Rural - Major Collector 28.0 S I G N S + Structurally Deficient Sufficiency Rating 89.3 Routine Inspection Date 11/24/2015 Routine Inspection Frequency 24 Inspector Name + N B I Nav. Clr. () Nav. Vert. Lift Bridge Clear. () MN Scour Code Design Load Operating Rating Forsyth, Roy P - Posted for Load C O N D I T I O N Deck 6 Unsound Superstructure 6 Deck % Underclearances Waterway Adequacy Approach Alignment 8 0 D I M E N S I O N S + NB-EB % SB-WB Substructure Channel 8 Culvert + N B I Structure Evaluation 6 Deck Geometry In place and functioning Vert. 0.0 Horiz. 0.0 I - LOW RISK Year C A P A C I T Y R A T I N G S Other/Unknown 2 - HS TRUCK R A T I N G S Inventory Rating 2 - HS TRUCK N N N A P P R A I S A L R A T I N G S + N + S A F E T Y F E A T U R E S + Page 7 of 15

8 09/14/2016 Inspector: CO Bridge MINNESOTA BRIDGE INSPECTION REPORT BRIDGE County: City: Township: Section: 12 Township: 124N Range: 42W Maint. Area: Span Type: 7 - Wood or Timber 1 - Slab List: Stevens DARNEN NBI Deck: 6 Super: 6 Sub: 6 Chan: 8 Culv: N Appraisal Ratings - Approach: Required Bridge Signs - Load Posting: CSAH 10 OVER POMME DE TERRE RIVER 8 Waterway: 8 Horizntal: Location: Route: Control Section: 2 - Vehicle & Semi (Type R12-5) 1 - Object Markers 0.7 MI E OF JCT TH CSAH 10 Ref. Pt.: Local Agency Bridge Nbr.: Open, Posted, Closed: MN Scour Code: Traffic: Vertical: P - Posted for Load I - LOW RISK 0 - Not Required N - Not Applicable Length: Deck Width: Rdwy. Area/ Pct. Unsnd: 2540 sq. / % Paint Area/ Pct. Unsnd: Culvert: N/A sq. / % Postings: Unofficial Structurally Deficient Unofficial Functionally Obsolete Unofficial Sufficiency Rating 89.3 N N ELEM NBR ELEMENT NAME REPORT TYPE INSP. DATE QUANTITY CS 1 CS 2 CS 3 CS 4 Timber Slab 07/28/ SF Underwater Notes: [2016] Migrator assumed CS SF Wearing Surfaces Underwater 07/28/ SF Notes: Added 3" overlay to deck. [2015] Moderate cracking SF Timber Stringer 07/28/ LF Underwater Notes: [2015] Minor splitting and decay. 505 LF Timber Floor Beam 07/28/ LF Underwater Notes: prevoiusly quantity 1, measured 4 beams at 31 feet. [2015] Minor splitting and decay. 124 LF Timber Abutment 07/28/ LF Underwater 135 LF Notes: [2016] Migrator added 40 LF to abutment quantity to account for wingwalls (CS1:0 CS2:40 CS3:0 CS4:0) East abutment has not moved. [2015] Minor splitting and decay. [2016] Underwater Inspection - There was a 2 inch wide by 6 feet long horizontal gap in the West Abutment bulkhead timber planking, located at the waterline. Wingwall notes: Small amount of erosion at NE wingwall Needs fill at the NE wingwall Filled behind NE wingwall. Need some fill behind NW wingwall NW wingwall needs to be stabilized on backside, is scheduled for this summer Possibilities for fill behind NW wingwall still being considered Work order to add riprap in front of NW wingwall. Timber Pile 07/28/ EA Underwater 60 EA Notes: 2006? - Northernmost column on west line had been pushed out by ice or debris from under pier cap. Maintenance crew pulled column back into place. No major structural damage noticed. [2015] Minor splitting and decay. [2016] Underwater Inspection - Splits through the brace-to-pile fastener, up to 2 inches wide and 5 feet long, were noted on several braces of Piers 1 through 3. Page 8 of 15

9 BRIDGE CSAH 10 OVER POMME DE TERRE RIVER ELEM NBR ELEMENT NAME REPORT TYPE INSP. DATE QUANTITY CS 1 CS 2 CS 3 CS 4 Timber Pier Cap 07/28/ LF Underwater 230 LF Notes: Ice moved the middle upstream pier, timber was only supported by half straightened and repaired. [2015] Upstream end of center pier is split in half. Metal Bridge Railing 07/28/ LF Underwater Notes: [2016] Migrator assumed metal rail/timber post combination type rail. [2015] Moderate weathering, minor splitting Guard rail NE corner was damaged, no structural damage. 178 LF Steel Protective Coating Underwater 07/28/ SF Notes: [2016] Migrator assumed CS1 and a quantity of 999 SF. 999 SF Timber Bridge Railing 07/28/ LF Underwater Notes: [2015] Moderate weathering, minor splitting. 198 LF [2016] Migrator assumed metal rail/timber post combination type rail. Post spacing assumed to be 5LF, each post 1LF. [2015] Moderate weathering, minor splitting. Critical Deficiencies or Safety Hazards 07/28/ EA Underwater Notes: NO CRITICAL FINDINGS OBSERVED DURING THE LAST INSPECTION. 1 EA Bituminous Approach Roadway 07/28/ EA Underwater Notes: Added 3" overlay Bituminous approach was overlayed in summer. Filled pothole in bituminous roadway approach. [2015] NW and NE corners have settled, appears to be a drainage issue. 2 EA Scour 07/28/ EA Underwater 890 Load Posting or Vertical Clearance Underwater Signing Notes: [2016] Structure requires a vertical clearance sign or load posting sign. 07/28/ EA EA Other Bridge Signing 07/28/ EA Underwater 1 EA Slopes & Slope Protection 07/28/ EA Underwater 1 EA Deck & Approach Drainage 07/28/ EA Underwater Notes: Use this element to rate the condition, function, and adequacy of the drainage system. 1 EA Page 9 of 15

10 BRIDGE CSAH 10 OVER POMME DE TERRE RIVER ELEM NBR ELEMENT NAME REPORT TYPE INSP. DATE QUANTITY CS 1 CS 2 CS 3 CS 4 Sidewalk, Curb, & Median 07/28/ EA Underwater Notes: Curb was hit by snowplow, no damage of consequence. [2015] NE corner has impact damage from a plow truck, occurred in the winter of EA Protected Species 07/28/ EA Underwater Notes: Use this element to track the presence of protected species living on this structure. 1 EA General Notes: 58. Deck NBI: No new notes Same as previous Inspected via boat this year, water depth 7+' 9.5' deepest in channel. Bikepath was added in 1978 being the most northern part of bridge. The existing wingwalls were also extended at the same time. Some tie cross timbers need to be replaced, the work is scheduled. Need to schedule a load rating review All necessary repairs were completed in summer of 08. Underwater inspection was also completed. Load rating was reevaluated because of overlay in Conditions unchanged. noticed slight sagging in timber decking. 36A. Brdg Railings NBI: 36B. Transitions NBI: 36C. Appr Guardrail NBI: 36D. Appr Guardrail Terminal NBI: 59. Superstructure NBI: 60. Substructure NBI: Minor splitting and decay. Minor splitting and decay. 61. Channel NBI: 62. Culvert NBI: 71. Waterway Adeq NBI: 72. Appr Roadway Alignment NBI: Inventory Notes: Inspector's Signature Reviewer's Signature Page 10 of 15

11 Pictures Photo 2 - View of West Abutment, looking northwest. Photo 3 - View of East Abutment, looking east. Page 11 of 15

12 Pictures Photo 4 - View of Pier 1, looking northeast. Photo 5 - View of Pier 2, looking east. Page 12 of 15

13 Pictures Photo 6 - View of Pier 3, looking west. Page 13 of 15

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