In Case of Emergency
Donner Summit Bridge
Donner Bridge construction and rehabilitation involved the restoration and seismic upgrade of a historic cast-in-place arch bridge and the installation of 50-ton rock anchors into bedrock at each abutment.
To ensure the stability of the superstructure during construction, shoring was constructed from the canyon floor approximately ninety feet below, consisting of four 100 KIP per leg towers. This temporary support of the bridge was required to replace each column, one bent at a time. Reinforcement and seismic stabilization of all four arch bases was performed in addition to the conversion of column connections from moment resisting to pinned connection.
Hydro blasting of the main bridge deck was performed to remove deteriorated concrete and salvage the existing rebar. The bridge deck was widened to accommodate upgraded barrier rails. Extensive dental concrete repair involved hand chipping of deteriorated concrete and replacing with reinforced shotcrete.
This project was completed on time even though the site required the removal of twenty feet of snow in June of the second construction year to gain access to the project at 7000' elevation.
Project Photos
Click on a thumbnail to view slideshow