Part 17: Inspection and prediction of structural performance

Abstract

Adequate description of deterioration of structures and their elements is very important for the effective use of the BMS. In the course of exploitation of Moscow BMS, deterioration processes have been studied using the results of standard inspections of 1,059 facilities. The analysis shows that for structural SE, deterioration of strength properties virtually does not occur or is of accidental character. In most cases, deterioration is attributable primarily to the wear of materials, which depends to a large degree on the quality of their manufacturing and protection. Also, lifespan prediction for a set of SE should take into account their mutual effects on each other. The methodological sequence of adjustment of deterioration models for different SE, initially adopted on the basis of experts’ judgments, is suggested. The main objective of a bridge management system (BMS) is to ensure optimal planning of repair and rehabilitation activities and to establish a budget for it. Within most BMS, this objective is attained on the basis of deterioration models, which describe wear of structures and their elements in the course of time in quantitative terms, using both probabilistic (Thompson & Shepard, 1993) and deterministic (Kuznetsov et al., 2003) prediction methods. As a rule, most systems consider only one type of deterioration model for all structural elements. In the BMS of the city of Moscow, deterioration of each SE is described as an exponential relationship of wear in the course of time: I = e λt – 1 (1) where t is the time and λ = the rating coefficient determined for each SE on the basis of the boundary condition: Ln2