Bridge Type
Main Span(s): Masonry [8] Arch - Deck [11]
Approach Span(s): Other [00]
Deck: Not applicable [N] with Wearing Surface: Not applicable (applies only to structures with no deck) [N]
Bridge Dimensions
Length: 53.9 m = 176.8 ft
Main Spans: 3 at 15.2 m = 49.9 ft
Approach Spans: 0
Skew: 0
Width, Roadway: 5.6 m = 18.4 ft (2 Lanes) and Out-To-Out: 6.6 m = 21.7 ft for a 6.4 m = 21.0 ft approaching roadway.
Vertical Clearance: 99.99 m = 328.1 ft and Navigational Clearance: 0 = N/A
Location
Saint Helena [64140]: Napa County [055], California [06]
Owned by City or Municipal Highway Agency [04], DOT District: 4
SILVERADO TRAIL
Condition
Deck: Not Applicable [N]
Superstructure: Fair [5]
Substructure: Good [7]
Loading
Design:
Operating: 27.2 metric ton = 29.9 tons ()
Inventory: 16.2 metric ton = 17.8 tons ()
Appraisal
Structural: Meets minimum tolerable limits to be left in place as is [4]
Deck Geometry: Basically intolerable requiring high priority of replacement [2]
Road Alignment: Basically intolerable requiring high priority of replacement [2]
Waterway: Equal to present desirable criteria [8] and "Bridge with ""unknown"" foundation that has not been evaluated for scour. [U]"
Inspections
Date: August 1999 [899] and Frequency: 24
Future Work
Work Needed:
Bridge Detour: 0.5 km = 0.3 mi
Traffic
ADT: 2790 (2005) and Trucks: 10%
Future ADT: 4356 (In 2041
)
