Extending the life-time of existing bridges through load testing

Abstract

Load testing of bridges (in one of 3 possibilities: soft, diagnostic and proof load test ) may discover higher strength capacities than predicted by standard analytical assessment methods based on numerical models. This is due to hidden resisting mechanisms than in many cases analytical tools are not able to deal with. As a consequence, load testing can make a more accurate assessment of the bridge response and therefore predict longer life-time than predicted by simple calculations. At the end, this leads to an extended service life for bridges that may be posted or declared as unsafe after some years in operation due to increasing damage or traffic loading. An accurate life-cycle analysis requires an accurate estimation of the remaining service life of the bridge. In this sense, the paper shows how load testing can be used directly in the correct capacity assessment of existing bridges and how the results of the test can be included in a life-cycle cost analysis of the prospective decisions (repair, strengthening, replacement,…).