Title: Instrumentation of the Maumee River Crossing
Description: This project has focused on the instrumentation, monitoring and testing of the main span unit of the VGCS, one of Ohio's first long-span, cable-stayed  bridges and one of only a few dozen such bridges in service in the nation. This effort looked at five main areas: (1) health monitoring; assessment of  the changes in force distribution and bridge condition during erection and early service, (2) verification of design assumptions during erection, (3)  investigation of the unique design features which have been incorporated into the VGCS, (4) investigation into the unique erection features and  sequencing which will be used during its construction, and (5) investigation of stay cable vibration which is a general, unresolved issue for bridges of  this type.  The purpose of this and associated documents is to outline the completed scientific study, which happened to consist primarily of two phases. The  first phase (Nims, 2002), contracted at the District level, included the initial structural analysis, modeling, instrumentation package design for the  monitor, and casting into the segments of the embedded sensors. The goal of this first phase was to capture the critical instrumentation issues  associated with this construction project and to develop a detailed instrumentation and testing in close consultation with ODOT officials, bridge  designers, and construction contractors.  The second phase (Helmicki, 2003), contracted through Central Office, included permanent instrumentation operated through a computer controlled,  digital data acquisition system located on-site and accessible tele-remotely via direct fiber optic internet connection, field calibration of a main span  finite element model using truckload and modal field tests; verification of various design assumptions and erection load conditions; creation of a  database of measurements for use as a supplement to the designer's maintenance manual to provide guidance for conducting future maintenance,  and determination of vibration performance of stay cable damping system under wind and rain-induced excitation.  The goal of the second phase was to finish the monitor installation begun in the first phase, establish a baseline concept of structural behavior and  performance by utilizing a combination of field tests and ambient monitoring, capturing the overall structural concept by calibration of the finite element  models, and finally benchmarking the condition of the structure by comparison of the above with its design values.
Subjects: Cable-stayed bridges, Design and construction, Testing
Places: Ohio, Toledo