Chapter 5 CULVERT MAINTENANCE, REPAIR, RENEWAL AND REPLACEMENT

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Chapter 5 - CULVERT MAINTENANCE, REPAIR, RENEWAL
AND REPLACEMENT

• Culvert Maintenance
• Reduces risk of having future problems related to
  the structural, hydraulic and durability aspects
• Inspecting the culverts for current performance
• Removing debris, sedimentation and dirt from the
  culverts
• Identifying the probable problems which might
  occur in the future

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Culvert Repair

• Routine maintenance is not enough to solve the
  problems
• Rehabilitation is not feasible.
• For Concrete Culverts

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Culvert Repair (Contd)

• For Metal Culverts

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Culvert Repair (Contd)

• Flowchart summarizing culvert repair methods.

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Culvert Renewal

• Partially or fully deteriorated pipe is used as
  the host pipe
• New pipe is formed within this host pipe
• Sliplining
• Inserting a new pipeline into an existing culvert
  and grouting the annular space.
• Cured-in-Place Pipe (CIPP)
• a continuous lining composed of a liquid
  thermoset resin-saturated material is cured by
  heat

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Culvert Renewal (Contd)

• Cement Mortar Lining
• Thin Lining used to prevent culverts against
  corrosion
• Spiral Wound Pipe
• new lining pipe is obtained by spirally winding a
  polyvinyl chloride strip.
• Close-fit Pipe
• generated by modifying the cross sectional area
  of polyethylene pipes, inserting them to the host
  pipe and applying pressure

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Culvert Renewal (Contd)

• Panel Lining
• May be used to renew large diameter noncircular
  culverts.
• Can be designed either as a self supporting pipe
  or as a pipe which depends on the strength of the
  existing pipe and the concrete fill in the
  annular space.
• Thermoformed Pipe
• polyvinyl chloride or polyethylene pipes are
  thermoformed inside the host pipes to provide a
  tightly fitting chemical and abrasion resistant
  pipe

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Culvert Renewal (Contd)

• Reasons for replacement
• Current condition of the culvert does not allow
  forming a new pipe within the existing culvert.
• Hydraulic capacity would not be adequate after
  rehabilitation
• Replacement options
• Open-cut replacement
• Trenchless replacement

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Culvert Replacement

• Open- cut Replacement
• Performed by opening a trench, replacing the
  culvert and filling the trench.
• Most commonly used method.
• Closing the road or some of the lanes during
  construction
• Detour or bypass should be designed or the
  construction has to be staged

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Culvert Replacement (Contd)

• Trenchless Replacement
• Eliminates open trenches
• Providing safer working environment for public
  and workers
• Might be costly in some cases and may not be
  suitable for every site due to the space
  requirements and/or surrounding terrain

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Culvert Replacement (Contd)

• Trenchless Replacement Options
• Pipe Bursting
• inserting and pushing a bursting head to the
  existing pipe, and thereby fracturing the pipe
  and pushing its parts into the surrounding soil
• Pipe Removal
• The existing pipe is removed from the system
  after being excavated.
• Resembles a new trenchless construction of a pipe