, Former Researcher, Civil, Environmental and Geo-Engineering
Arturo Schultz, Former Professor, Civil, Environmental and Geo-Engineering
Many of the bridges in Minnesota and throughout the United States are being used beyond their initial design intentions, classified as structurally deficient, and are in need of rehabilitation or replacement. According to MnDOT records, as of July 2010, 270 highway bridges in Minnesota are classified as structurally deficient or obsolete. Of those, 99 are structurally deficient signifying that one or more members or connections of the bridge should be repaired or replaced in the near future. The majority of these bridges were built in the 1950s and 60s and are at or near the end of their intended design life. This situation prompts one to pose the following questions: (1) How can bridge owners extend the life of these bridges while funds are allocated for bridge replacement? (2) What options are both safe and affordable?
This research project refined a previously-developed response modification framework which combines technological developments in the fields of control systems, health monitoring, and bridge engineering to increase bridge safety. To enhance the modification framework, the numerical bridge model was refined and additional modification apparatuses were added to the numerical model to further develop and confirm the advantages of the response modification approach. A parameter study of the modification apparatus characteristics was carried out to optimize member sizes and modification device characteristics. Finally, a frequency response analysis was carried out to investigate the use of a semi-active system within the scope of the response modification framework.