Framework for inspection, maintenance, and replacement of corrugated steel culvert pipes

A framework for inspection, rehabilitation, and replacement of corrugated steel culvert pipes (CSCP) is developed. It is expected to lead to developing a culvert information management system (CIMS), wherein justification and need are based on recent Governmental Accounting Standards Board (GASB) requirements. The CIMS will assist in evaluating infrastructure assets and facilitate comparing present costs of preserving infrastructure. Benefits include long-term savings from adopting optimized preventive maintenance strategies. CSCP condition states are used to express the extent of deterioration. Rehabilitation options and recommendations are given for deteriorated CSCPs. These options will be incorporated into the proposed CIMS, which uses survival probabilities based on the CSCP condition state during the previous year. Survival probabilities within Condition States 1,2, and 3 are computed on the basis of corrosion research data. However, implementing the proposed CIMS requires field data for CSCPs or laboratory tests that mimic field conditions. The proposed CIMS can analyze decisions to inspect, rehabilitate and replace, or do nothing at both project and network levels. At the project level, inspection or rehabilitation and replacement costs are compared with failure risks and costs. At the network level, associated costs are optimized to meet the annual maintenance budget by prioritizing CSCPs needing inspection and rehabilitation and replacement. The proposed CIMS can also be used to estimate the required annual budgetary allocation for a stipulated planning horizon and to maintain or improve the aggregate condition state of the CSCP network or to maintain or improve the total highway CSCP network asset value, thereby meeting GASB 34 requirements. The optimum sequential path in the annual decision-making process may then be determined using a combination of operations research tools.