NAPA (BCN) — The Oakville Crossroad Bridge over the Napa River remains closed after Thursday’s magnitude 4.1 earthquake damaged the nearly 100-year-old span that was already scheduled to be replaced this summer.
The earthquake caused the west abutment that holds up the west side of the bridge located over the Napa River between state Highway 29 and Silverado Trail to sink two to four inches, Napa County public information officer Kristi Jourdan said.
The temblor also widened age-old cracks, exposing steel and creating a hazard for vehicle traffic, but bicycles and pedestrians can still use the bridge, Jourdan said.
It is unclear how the structure would behave in a subsequent seismic event, Jourdan said.
Caltrans recommended the bridge closure Friday after an inspection.
The bridge was to be replaced in phases over two construction seasons by demolishing half of the old bridge and building half of the new bridge while maintaining one lane of traffic on the old bridge during the first season.
During the second season, one lane of the new bridge would be open while the second half of the old bridge was demolished and construction of the second half of the new bridge occurred, Jourdan said.
Bridge design engineers are evaluating the construction plan, but one lane access during construction is no longer feasible, Jourdan said.
The county believes it can accelerate the two-year schedule and reduce costs by demolishing the old bridge in full and building the new bridge in one sequence, Jourdan said.
More details about the project are expected in two or three weeks, Jourdan said. Ghilotti Brothers Inc. is the projects contractor.
Properties east of the bride can be accessed from Silverado Trail and those to the west from state Highway 29. Alternative routes include Yountville Crossroad to the south or Rutherford Road (state Highway 128) to the north.
More information is available at www.countyofnapa.org.