After an over-height vehicle struck the US 34 E-S Ramp B, the Iowa DOT immediately closed the ramp after discovering the south girder was severely damaged. WHKS was contacted to provide an evaluation, analysis, and repair design for replacement of the damaged section.
While WHKS was working on analysis and repair options, the Iowa DOT realized that the Ramp B Bridge was the main point of entry for Burlington Steamboat Days, a major local festival. In order to have the ramp open in time for the event, the Iowa DOT and WHKS decided to complete the project in two phases. Phase 1 included temporary support design and the construction necessary to open the ramp in time for Steamboat Days. Phase 2 would be completed after the festival and would cover the replacement of damaged girder section.
WHKS devised a plan to use a strong back beam under a two phase placement method. In Phase 1, the temporary beam was placed directly over and connected to the damaged girder to allow ample room for vehicles while supporting necessary bridge weight and live loads from bridge traffic. The second phase involved moving the strong back a few feet off-center of the girder to allow for the replacement of the damaged girder and reconstruction of the deck/barrier.