INFLUENCE ANALYSIS OF BRIDGE INSPECTION EFFICIENCY IMPROVEMENT ON BRIDGE HEALTH DISTRIBUTION – IN THE CASE OF NIIGATA CITY –

Abstract

 While the bridge inspection in Japan is expected to be greatly improved in efficiency by future technological innovation, it is not clear how the efficiency improvement will influence on repair cost of bridges and will change the future bridge health distribution. In order to clarify this point, this study first analyzed actual tendencies of natural health deterioration due to the ages of the bridges, and tendency of increase of repair costs due to a decrease in health condition, using actual repair cost data of Niigata City. We also defined the probability that health condition is correctly determined according to the inspection accuracy, and made a management simulation model that outputs the distribution of the health conditions, with the inspection accuracy, inspection frequency, and repair budget as design variables. As a result of scenario analysis, under the current repair budget, inspection accuracy improvement does not lead to decrease in bridges with low health conditions, and expansion of repair budget and efficiency of inspection frequency may increase proportion of high health condition bridges.