Risk Assessment and Update of Inspection Procedures for Culverts

A project funded by the Ohio Department of Transportation

Co-PI with G. F. Mitchell and T. Masada

Problem Statements

In the state of Ohio, all bridges with spans greater than 10 ft. are required to be inspected annually. In contrast, culverts less than 10 ft. in span are inspected sporadically under varying Ohio Department of Transportation (ODOT) district procedures. As the span decreases, the culverts become more difficult to inspect. No Federal or State requirements mandate frequent inspections of these short span culverts.

The 1982 ODOT inventory documented nearly eight thousand culverts, mostly constructed of steel and reinforced concrete, with service life ranging from a few months to over forty years. Since 1982, new coatings and materials have been utilized by ODOT for culverts. Many of the culverts associated with Ohio’s interstate and priority highway systems’ drainage infrastructures have reached their design service life.

A wide variety of pipe materials, treatments and structural designs are prevalent in the short span culverts, potentially leading to various failure mechanisms. Loss of culvert integrity could result in temporary roadway closure and considerable remediation costs. Total collapse of culverts could pose a major safety risk to motorists. Use of short span culverts has increased in many ODOT districts. The inventory of culverts less than 10 ft. in span needs to be updated, and comprehensive, statewide inspection plans and risk assessment procedures must be developed. Different inspection and risk assessment procedures should be established and applied to each culvert type.

Objectives

The primary objectives of this investigation will be to update the inventory and develop statewide inspection plans and risk assessment procedures for culverts with spans less than 10 ft. Specific tasks include:

• Task 1 - Update the inventory of culverts installed on the priority and general highway systems.
• Task 2 - Investigate other DOT’s culvert inspection policies and procedures.
• Task 3 - Evaluate the best remedial maintenance measures for high-risk culverts.
• Task 4 - Evaluate ODOT procedures for assessing culvert durability based on field data and maintenance records.
• Task 5 - Perform risk assessments of the culvert inventory based on culvert characteristics and data collected.
• Task 6 - Perform field inspections on statistically selected culverts in the updated inventory.