Multi-level decision-making strategy for preparation of proof load and failure tests

Load testing and in some cases failure (or collapse) testing of bridges is a method to learn more about the behaviour of full-scale bridges in site conditions. Since such experiments, especially failure tests, are expensive, an extensive preparation of these tests is important. This paper addresses the question of when a bridge is a good candidate for a load test or a failure test. To answer this question, a multi-level assessment methodology is developed. The proposed method includes a decision tree that helps users decide which method should be used to reach the desired level of accuracy. These procedures are followed to carry out an assessment based on the load and resistance models and factors from the code, as well as to estimate the maximum required load in a collapse test based on average values and a single tandem. The procedures are illustrated with the case of the Nieuwklap Bridge in the province Groningen, the Netherlands. The multi-level analysis showed that testing the Nieuwklap bridge would most likely not result in a shear failure, and thus the test would not meet the goals of a collapse test in shear, which would provide valuable research insights. On a more abstract level, the result of this research is the development of a multi-level decision-making procedure that can be used to evaluate if a field test should be planned and can meet the identified goals.