Bridge Structures 6 (2010) 121–127 DOI:10.3233/BRS-2010-010 IOS Press 121 Cost, benefit, and value of bridge load testing S. Alampalli a,∗ and M. Ettouney b a New York State Department of Transportation, Albany, NY, USA b Weidlinger Associates, New York, NY, USA Abstract. Load testing is gaining popularity among bridge owners to take advantage of the actual load capacity that can not be estimated using conservative analyses. This paper provides an easy, generalized model for evaluating the value of load testing using costs and benefits of load tests. Both quantitative and qualitative benefits are included. Also explored are the effects of load tests on the life cycle analysis of bridges and quantification of extended life of bridges due to load testing. Keywords: Load testing, cost-benefit modeling, load testing value, bridge testing 1. Introduction Load testing has been an attractive method to bridge owners when conservative analyses cannot estimate the actual load capacity of a structure. They are typically used to extend the bridge life, evaluate the effect of new materials and construction practices on durabil- ity, and check design/assumptions [2, 3, 6, 7]. Hence, it will be of value to develop an objective method to evaluate the value of load testing. Value is defined in this paper as the relationship between costs and bene- fits of a given activity. This paper attempts to provide an easy, generalized model for evaluating the value of load testing and the effect of load testing on bridge life [5]. Methodology combines both quantifiable and qualita- tive benefits. Quantifiable benefits include operational decisions, maintenance and rehabilitation decisions, and validating design and analysis. A life cycle cost analysis and load test effects on it are also described. 2. Cost-benefit model for load tests 2.1. Costs There are numerous sources for costs associated with load testing. Generally speaking single span bridges ∗ Corresponding author. E-mail: salampalli@dot.state.ny.us. offer the simplest load test projects. This is due to the simplicity of placing sensors, ease of controlling traffic, and the relative short period of time that is required to load the bridge with trucks. As the geometry of bridges becomes more complex the operation becomes more complex and the costs increase accordingly. But as these costs are, in general, associated with a specific structure with defined objectives, load testing costs can be esti- mated with relatively high confidence. Sources of load testing costs are discussed below. 2.1.1. Traffic control costs Typically loaded trucks readily available to the owner are traversed along the bridge while monitoring the bridge response; the normal bridge traffic may have to be controlled during the loading operation. The costs of traffic control depend on the size and traffic volume of the bridge, length of time required to perform the test, and work zone control guidelines effective at the bridge location. We define the cost of controlling traffic as C T . 2.1.2. Sensors and other instruments Costs of sensors and instrumentation are another important source of costs. The main sensors used during most of the load tests are strain sensors. However, other types of sensors (LVDTs, accelerometers, etc.) might be used during the tests, depending on the test objectives. 1573-2487/10/$27.50 © 2010 – IOS Press and the authors. All rights reserved