Moving load test-based rapid bridge capacity evaluation through actual influence line

Abstract

With increasing service times and performance deteriorations, the cost of inspecting and maintaining aged bridges increases dramatically, and becomes a massive challenge. There is an urgent need to explore a cost-effective and rapid evaluation method for determining the load capacities of large quantities of short/medium-span bridges. In this study, an influence line-based moving load test method was proposed for a rapid bridge capacity evaluation. The influence line of the bridge was initially extracted using the moving load test. The ratios of the maximum amplitude and total area between the actual and theoretical influence lines were defined as the capacity evaluation indices for the bridge. Based on numerical validations of three typical deterioration conditions, the proposed evaluation indices were proven to be equivalent to the conventional static evaluation index. In addition, in-situ static load and moving load tests were conducted to verify the effectiveness of the proposed method. The results show that relative to the static evaluation index, the proposed indices have a maximum difference of 1.5% in the numerical validations and 2.2% in the in-situ tests, indicating that the proposed method is accurate and more effective for future short/medium-span bridge capacity evaluation.