Evaluation of New Underground Infrastructure Maintenance Technologies

Abstract

Vast sums are spent for the upkeep of the nation's public facilities. The need to contain maintenance costs, which grow as the physical infrastructure ages, is driving the development and use of new technologies. For underground utilities, trenchless technologies offer practical alternatives to open-cut methods for replacing or fixing existing lines. However, data on costs and performance of these new technologies are scarce, and good data are required for effective infrastructure-management decisions. This paper presents an initial cost and performance evaluation of three new sewer spot-repair methods and explains how the approach to their evaluation applies to other mainenance technologies. All three spot-repair techniques evaluated were significantly less expensive than conventional open-cut repairs. In addition, the spot-repair techniques reduce indirect costs such as materials disposal and social costs such as traffic delays. However, total life-cycle costs are sensitive to the useful life of the repair for which very little data are available. Test results reported here indicate that material properties and repair performance differ significantly between the repair methods. Recommendations are made for further studies.