Culvert Repair Best Practices, Specifications and Special Provisions Best Practices Guidelines Bruce Wagener, PE Eric Leagjeld, PE 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 Focus Trenchless rehabilitation or repair of CMP and RCP culverts from 24 to 72 inches in diameter Outline • Overview of rehabilitation, repair, and replacement • Describe project tasks • Walk through the Guidelines document • Special Provisions and Standard Details prepared 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 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 • Best Practices Guidelines • Special Provisions • Standard Details Best Practices Guidelines 1. 2. 3. 4. 5. 6. 7. Introduction Culvert Repair Process Preparation for Rehabilitation or Repair Culvert Rehabilitation Methods Culvert Repair Methods Replacement using Open Cut Replacement using Trenchless Methods 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 • • • • • 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) Repair, Rehabilitation, and Replacement Options • • • • Inspect Repair Rehabilitate Replace 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 HydInfra Suggested Repair Methods 3. Preparation for Repair or Rehabilitation • • • • • • • Environmental protection Flow diversion Infiltration control Cleaning Checking culvert clearance Other preparatory work Safety 4. Rehabilitation Methods Paved invert Cured-in-place pipe liner (CIPP) Sliplining Centrifugally cast concrete mortar liner • Spirally wound liners • Close-fit liners • Shotcrete • • • • Paved Invert • Use in CMP or RCP • Cast-in-place concrete • Welded wire fabric (WWF) or rebar reinforcing • Anchored to existing culvert 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 • • • • Sliplining 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 Spirally Wound Liners Close Fit Liners Shotcrete Liners Placement of invert Completed liner 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 Spall Repair • Repair spalls of concrete due to movement, freeze/thaw, structural distress, deicing materials, etc • Personnel entry required • Similar to paved inverts 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 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 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 Other Important Features and Repairs • • • • Energy dissipators Trash rack maintenance Inlet and outlet protection Aprons/cutoff walls 6. Replacement of Culvert Using Open Cut Methods • Drainage Manual • Standard Specifications and Special Provisions • Standard Plates • Other MnDOT manuals 7. Replacement of Culvert Using Trenchless Methods • Conventional tunneling • Pipe jacking – Microtunneling – Auger boring • Pipe ramming • Pipe bursting Rehabilitation Special Provisions and Standard Details Method Paved invert Special Provision Name Paving Culvert Invert Standard Detail Name 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 Sliplining Culvert Pipe 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 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 Filling Voids Outside of the culvert Culverts 3X08 Culvert Void filling Detail - CSP and RCP Culverts Special Provisions and Standard Details Available by request from: Lisa Sayler MnDOT Bridge Office Hydraulics 3485 Hadley Ave Oakdale, MN 55128 Phone: 651-366-4468 Email: [email protected] Questions?