1. Bruce Wagener, PE Eric Leagjeld, PE
Culvert Repair Best Practices, Specifications and Special Provisions Best Practices Guidelines
Bruce Wagener, PE
Eric Leagjeld, PE

2. Goals
Provide guidance to MnDOT engineers in making better decisions on culvert repairs
Provide guidelines, Special Provisions and Standard Details that will standardize practices and increase effectiveness and longevity of repairs

3. Focus
Trenchless rehabilitation or repair of CMP and RCP culverts from 24 to 72 inches in diameter

4. Outline Overview of rehabilitation, repair, and replacement
Describe project tasks
Walk through the Guidelines document
Special Provisions and Standard Details prepared

5. Definitions
Trenchless: Repair or rehabilitation that does not involve excavating the roadway
Rehabilitation: The existing culvert pipe is returned to its initial condition or better
Repair: A maintenance activity that keeps the existing culvert in a uniformly good safe condition
Replace: Removal or abandonment of the existing culvert by open cut or trenchless methods

6. Project Tasks Task A—Survey MnDOT, cities, counties, and contractors
Task B—Survey of other state’s DOT’s
Task C—Research Synthesis: Literature review of information provided in SP&R Work Plan, Tasks A and B, and other sources
Task D—Best Practices Guidelines, Special Provisions, and Standard Details
Task E—Feasibility Study: Recommendations for evaluating culvert rehabilitation and repair methods

7. Best Practices Guidelines
Special Provisions
Standard Details

8. Best Practices Guidelines
Introduction
Culvert Repair Process
Preparation for Rehabilitation or Repair
Culvert Rehabilitation Methods
Culvert Repair Methods
Replacement using Open Cut
Replacement using Trenchless Methods

9. 2. Culvert Repair Process
Identify the Problem
Determine the Cause(s) of Deterioration
Evaluate the Structural Condition
Evaluate the Hydraulic Condition
Evaluate Repair, Rehabilitation, and Replacement Options
Implement the Design
Maintain the Repairs

10. Rigid vs. Flexible Pipes
Rigid Pipe: Substantially self-supporting and relies on the surrounding soil for only a small fraction of its overall strength. (RCP)
Flexible Pipe: Designed using soil structure interaction, where the majority of the pipe’s strength is derived from the quality of the backfill soils and compaction. (CMP, PVC, HDPE and fiberglass)

11. Repair, Rehabilitation, and Replacement Options
Inspect
Repair
Rehabilitate
Replace

12. Repair and Rehabilitation Method Guidance
Recommendations from suppliers, fabricators, or specialists
HydInfra suggested repairs reports and flow charts
FHWA Culvert Assessment and Decision-Making Procedures Manual
FHWA Hydraulics Toolbox
Caltrans Supplement to FHWA Culvert Repair Practices Manual

13. HydInfra Suggested Repair Methods

14. 3. Preparation for Repair or Rehabilitation
Environmental protection
Flow diversion
Infiltration control
Cleaning
Checking culvert clearance
Other preparatory work
Safety

15. 4. Rehabilitation Methods
Paved invert
Cured-in-place pipe liner (CIPP)
Sliplining
Centrifugally cast concrete mortar liner
Spirally wound liners
Close-fit liners
Shotcrete

16. Paved Invert Use in CMP or RCP Cast-in-place concrete
Welded wire fabric (WWF) or rebar reinforcing
Anchored to existing culvert

17. Cured in Place Felt tube saturated with resin
Pull in place or inverted
Polyester or vinyl ester resins
Epoxy resins for special conditions
Generally not bonded to culvert

18. Sliplining

19. Centrifugally Cast Liner
Cementitious or other material applied by an electric or air-powered rotating head
Usually applied to CMP
Thickness controlled by speed that the machine is pulled through the culvert
Cementitious mortars discussed in Guidelines

20. Spirally Wound Liners

21. Close Fit Liners

22. Shotcrete Liners
Placement of invert
Completed liner

23. 5. Repair methods Spall repair Joint repair methods
Filling voids outside the culvert
Joint sealing with internal packers
CMP seam repair
Invert plating
Sprayed coatings and linings
Slab jacking
Compaction grouting

24. Spall Repair
Repair spalls of concrete due to movement, freeze/thaw, structural distress, deicing materials, etc
Personnel entry required
Similar to paved inverts

25. Joint Repair
Fix infiltration and exfiltration at joints to prevent ground loss and surface settlement
Infiltration can lead to culvert deformation if soil support is lost
Guidelines discuss personnel entry joint repairs
Remote repairs are also possible

26. Void Filling outside Culvert
Voids can develop due to piping, joint infiltration, and invert erosion
Special Provisions specify lightweight cellular or rigid foam hydrophobic urethane grout

27. Other Culvert Repair Methods
Joint sealing with internal packers
CMP seam repair
Invert plating
Sprayed coatings
Slab jacking
Compaction grouting
Resetting and retying end sections

28. Other Important Features and Repairs
Energy dissipators
Trash rack maintenance
Inlet and outlet protection
Aprons/cutoff walls

29. 6. Replacement of Culvert Using Open Cut Methods
Drainage Manual
Standard Specifications and Special Provisions
Standard Plates
Other MnDOT manuals

30. 7. Replacement of Culvert Using Trenchless Methods
Conventional tunneling
Pipe jacking
Microtunneling
Auger boring
Pipe ramming
Pipe bursting

31. Rehabilitation Special Provisions and Standard Details
Method
Special Provision Name
Standard Detail Name
Paved invert
Paving Culvert Invert
3X02 Paved Invert Repair - Corrugated Metal Pipe
3X03 Paved Invert Repair -
Reinforced Concrete Pipe
Cured-in-place pipe (CIPP)
Cured-in-Place Pipe Lining
3X06 Cured-in-Place pipe Liner - Corrugated Metal Pipe
3X07 Cured-in-Place Pipe Liner - Reinforced Concrete Pipe
Sliplining culvert pipe
Sliplining Culvert Pipe
Grout Culvert Liner
3X04 Sliplining Culvert - Corrugated Metal Pipe
3X04A Sliplining Culvert - Corrugated Metal Pipe
3X05 Sliplining Culvert - Reinforced Concrete Pipe
3X05A Sliplining Culvert - Reinforced Concrete Pipe
Centrifugally cast liner
Centrifugally Cast Culvert Lining

32. Repair Special Provisions and Standard Details
Method
Special Provision Name
Standard Detail Name
Spall repair
Culvert Patching
3X03 Paved Invert Repair
Joint repair
Repair Culvert Joint
3X01 Pipe Joint Sealing - Reinforced Concrete Pipe
Void filling outside the culvert
Filling Voids Outside of Culverts
3X08 Culvert Void filling Detail - CSP and RCP Culverts

33. Special Provisions and Standard Details
Available by request from: Lisa Sayler MnDOT Bridge Office Hydraulics 3485 Hadley Ave Oakdale, MN Phone:

34. Questions?