Published: April 21, 2021

Abrasion

The wearing a way of conduit material by the erosive action of bedload carried in the stream.

Abrasion Level

There are six Abrasion Levels. Abrasion Level 1 is defined as non-abrasive. As the size of abrasive material, sand and rock, increases so does the Abrasion Level.

Abutment

A substructure unit located at the ends of a bridge or slab top culvert.

Broken-Back

A conduit that has more than one slope. A broken-back conduit is one method of dissipating energy caused by conveying stormwater down a large elevation drop.

Buckling

A bend, warp, or crumpling of a plastic pipe.

Cardinal Direction

Compass direction by which roadways are inventoried in Ohio: South to North and West to East.

Culvert

A culvert is defined as a Type A Conduit located under pavement that forms a passageway or conveys water through an embankment. A culvert has open ends.

Corrosion

The deterioration of metal due to electrochemical or chemical reactions.

Conduit

A conduit, per this manual, will represent both a culvert and a storm drain or storm sewer. Recall that a culvert is a Type A Conduit located under pavement with open ends and a storm drain or storm sewer is a Type B Conduit located under pavement with a closed end inlet or closed end outlet or both.

Conduit File Number (CFN)

A unique number that identifies the conduit.

Damage Inspection

An unscheduled inspection to assess structural damage.

Deflection

A deviation from the original design shape of a flexible conduit without the formation of sharp peaks or valleys.

Differential Settlement

One section of the footing settles more than the rest of the footing

Dimpling

Applies to plastic pipe. Describes the wavy or waffling pattern that occurs in the inner wall of the pipe due to local instability.

Flexible Pipe

A conduit made of corrugated or spiral rib steel, aluminum, or plastic.

Granular Material

Material the size of pea gravel or larger.

Hinging

Applies to flexible pipe. Describes the yielding of the material due to excessive bending movement in the pipe wall.

Interim Inspections

An inspection scheduled at the discretion of the individual responsible for conduit inspection activity.

Inventory Inspection

The first inspection of a conduit when it becomes a part of the inventory.

Invert

The lowest point on the conduit cross section.

Masonry Conduit

A conduit made of stone, brick, or other rigid block units.

Rigid Pipe

A conduit made of concrete, clay, brick, or stone.

Rotational Settlement

The footing starts to tip in either direction due to lateral forces of undermining.

Scour

The removal of a streambed or bank area by stream flow.

Skew

Angle measured between the centerline of the conduit and a line perpendicular to the centerline of the roadway.

Span

Measurement taken between inside faces of the barrel walls perpendicular to the centerline of the conduit.

Springline

A line connecting the outermost points on the sides of a conduit.

Storm Drain or Storm Sewer

A storm drain or storm sewer is defined as a Type B Conduit located under pavement that conveys storm water, subsurface water or similar discharge. A storm drain or storm sewer has a closed end inlet or closed end outlet or both. Examples: Catch basin, inlet, or manhole.

Uniform Settlement

The whole footing settles. This will not ordinarily affect flexible conduit.

Wall Crushing

Applies to plastic pipe. Describes yielding in the wall produced by excessive compressive stresses.