| Millbrae Avenue
Millbrae, California
Transit Home >
Millbrae Avenue
 |
The Millbrae grade separation project
used both cast-in-place post-tensioned concrete box girders
and PPC inverted T-girders. |
The newly completed Millbrae Avenue overpass is an 1180-foot (360-m)
long structure that connects Rollins Road and El Camino Real, a
major regional street beginning in San Francisco. The grade separation
structure, crossing Caltrain’s commuter rail tracks, provides
a more effective transportation system by reducing train and street
traffic travel times, decreasing traffic congestion, and assuring
safe passage for all commuters by separating pedestrian, vehicular,
and train traffic.
Since daily traffic approaches 45,000 vehicles and more than 60
trains, the road had to remain open to traffic during construction.
The solution was to accommodate four lanes of traffic at the existing
grade crossing while building half the bridge structure, and then
diverting traffic on the bridge while the other half was built.
The finished bridge is six lanes wide, with five spans totaling
416 feet (127 m): four spans of cast-in-place, post-tensioned concrete
box girders (two on either side of the track corridor) and one span
of 92-ft (28-m) long precast, prestressed concrete inverted T-girders
over the tracks.
Careful attention was paid to maintaining uniformity in concrete
color, creating interesting surface textures and shadow lines, floodlighting
columns, and providing maintainable landscaping. The bridge itself
features a brick median, wide sidewalks with protective railings
and concrete barriers, anti-debris fencing immediately over the
tracks, and vintage cast iron light fixtures.
The project cost $9 million to construct, and was on schedule and
$1 million under budget.
Project Credits
Owner: City of Millbrae, CA
Engineer: Nolte & Associates, San Jose, CA
Construction Manager: O’Brien-Kreitzberg, San Francisco, CA
Contractor: RGW Construction, Inc., Fremont, CA |
 |
|