New tools for inspection of gusset plates

After the collapse of the I-35 W Bridge in Minneapolis, Minnesota, gusset cplate connections now must be evaluated by transportation agencies. Connection evaluations require accurate as-built drawings. A new methodology has been developed that permits rapid collection of accurate field measurements of connection plate geometry. The method uses close-range photogrammetry techniques to rectify field-collected digital images. Consumer-grade cameras are used to produce scaled orthographic photographs (orthophotos) of the bridge connections. The approach enables rapid and accurate collection of field measurements and allows for direct assessment of the connection using the high fidelity results. Implementation of the techniques does not require specialized knowledge and it has been practicably employed under field conditions using current technology and personnel.