Nonlinear Deterioration Model for the Estimation of Bridge Design Life

摘要

A comprehensive literature review was conducted and a questionnaire was circulated on the subjects of bridge deterioration and bridge life. Several relevant studies were identified, and selected methods were applied to Pennsylvania data. In general, the findings of the investigators were confirmed in the context of the Pennsylvania data. However, these studies were deficient in two significant ways: first, deterioration was assumed to occur linearly with time; second, no systematic effort was made to incorporate the effects of rehabilitation. A nonlinear deterioration model was developed that expresses condition rating as a function of age using an exponential decay function coupled with a rehabilitation 'spike' to provide the sudden increase in rating that accompanies bridge rehabilitation. The model was applied to substructures, superstructures, and decks of steel girder-type, prestressed concrete, and reinforced concrete bridges. The resulting deterioration models were assessed, limited conclusions were drawn regarding their applicability, and selected versions were applied to the problem of predicting bridge life.