What’s Happening
to the Richmond-San Rafael Bridge?
If you commute across that bridge, you must be even more
concerned!
![](August%20Richmond%20RSR%20Bridge%20from%20water.jpg) |
The East
Channel of the bridge. Photo by Wes Starratt
|
By Wes Starratt, Senior Editor
Your morning ferry from Larkspur or
Vallejo gives you an inspiring view of that most beautiful
and magnificent of all bridges, the Golden Gate, before you
dock near the workhorse of our bridges, the Bay Bridge, with
its dramatic and graceful spans. If you’re coming from
Vallejo, you pass under, and if you are traveling from
Larkspur, you pass alongside, another bridge: the Richmond
San Rafael Bridge (a.k.a. the RSR Bridge).
![](August%20Richmond%20RSR%20East%20Approach.jpg) |
The
seismically strengthened east approach of the
bridge. Photo by Wes Starratt |
You certainly can’t call the RSR Bridge
beautiful, magnificent, dramatic, or even graceful, and
certainly no architect had anything to do with it. The
bridge appears to sag in the middle, resembling a camel with
two humps. But why does it sag? Well, the bridge had to be
sufficiently high to cross two shipping channels, but one of
the bridge designers must have thought a significant amount
of steel could be saved by lowering the height of the bridge
between the two channels. Obviously, nobody cared much about
what it would look like when it was completed. Of course,
there were some folks who were so concerned that it was
sinking in the middle that they wouldn’t use the bridge. My
dear mother was one of them! But, as an engineer, I was even
more mystified at the diversity of structural steel shapes
used in the bridge: It appeared as if the bridge builders
used whatever steel shapes they could find off the shelf! In
fact, the bridge reminds me of structures that could be
built with the “Erector Set” that I played with as a kid!
In any case, there it is. The RSR Bridge
was completed in 1956 and replaced ferry service that had
operated since the early part of the 20th century. The
bridge became the only link across the northern reaches of
San Francisco Bay and not only permits residents to commute
to work, but also connects Highway 101 in Marin County with
Interstate 80 in Richmond, thus providing a vital
north-south trucking route, bypassing the City of San
Francisco.
![](August%20Richmond%20RSR%20East.jpg) |
Richmond–San Rafael Bridge from Richmond,
showing Red Rock and Mt. Tam. Photo by Wes
Starratt |
Nevertheless, the bridge really does
represent a major engineering achievement because it crosses
two heavily used shipping channels with water depths up to
65 ft, with difficult underwater soil conditions, and with
swift tides and currents that comprise the full volume of
water draining from the Central Valley into San Francisco
Bay.
This four-mile long bridge is indeed a
complex structure. It is made up of four distinct segments:
• On the Marin side, two
side-by-side 3,000-ft long concrete trestles, not far above
the high tide water level, each carrying two lanes of
traffic.
•
The curved western structural-steel approach
where the two roadways become stacked vertically and rise to
the height of the channel crossing.
l• The
central segment of the bridge with stacked roadways and two,
1,070-ft long cantilever steel trusses spanning the two
shipping channels with vertical clearances of 188 ft and 138
ft, and connected to each other by lower trusses with spans
of 289 ft.
•
The eastern approach that drops both
roadways to ground level and separates them so that they are
once again side by side at the toll plaza on the Richmond
end of the bridge.
Earthquake Problems and More
The RSR Bridge has another problem: it lies between the San
Andreas and Hayward Faults and is vulnerable to earthquakes
on either one of them. The Bay Bridge also lies between the
two faults, and its vulnerability was demonstrated in the
quake of 1989 with damage that put that bridge out of
service for almost one year. As a result, Caltrans began a
program to rebuild the western span of the Bay Bridge and
strengthen its six other Bay Area bridges through a major
construction program that was to be financed, in part, by an
increase in bridge tolls.
A joint-venture, headed by the venerable
Bay Area engineering firm Ben C. Gerwick, Inc., was selected
by Catrans to design the complex RSR Bridge seismic
retrofitting project. But as the work progressed, it became
evident that the bridge required far more than seismic
retrofitting. More and more problems were encountered,
especially on the long concrete causeway on the Marin side,
which, it turns out, would have to be almost completely
rebuilt after 48 years of salt water corrosion. Similar
deterioration was also encountered in the expansion joints
and the roadway of the steel bridge, requiring complete
replacement.
In October of 2000, with funding in place
from a $1 hike in bridge tolls from the seven Bay Area
bridges (excluding the Golden Gate Bridge), a $484 million
construction contract was awarded to a joint venture of
Tutor-Saliba, Koch Skanska, and Tidewater Skanska (both
subsidiaries of the Swedish firm Skanska AB). Construction
started shortly thereafter, and, since then, commuting on
the bridge has indeed been an adventure, with delays and
lane closures, especially during night-time construction
work on the concrete trestle. The project has grown, and the
joint venture currently has between 700 and 800 construction
workers on the bridge with a $1-million-per-week payroll.
Caltrans Explains the Project
![](August%20Richmond%20RSR%20Usen.jpg) |
Caltrans
Resident Engineer, Usen Unyang. Photo by Wes
Starratt |
To learn more about what is going on, we contacted Caltrans’
District 4. Usen Inyang, who is originally from Nigeria, is
the resident engineer who manages a staff of some 100
engineers working on the project. He joined this project in
the Fall of 2001 as the construction manager and later
became the resident engineer.
A boat
ride provided an opportunity to see what was really
happening to the bridge, since you see little of the
construction work from the roadway, although a lot more from
the Vallejo Ferry. It was also a way to appreciate the
strong winds and currents that impact the bridge, which
looks far more imposing from the water below.
Inyang explained that the complex
underwater work has been completed, including the
installation of pre-cast concrete jackets around the
existing piers, along with pre-cast pile cap foundations,
cast-in-place piles at the bridge towers, and steel casings
at the existing bell foundations. “We are now moving into
the structural phase of the project. The underwater work has
been largely completed, and the below deck structural work
is going on during daylight hours,” he explained. Later,
there will be the above-deck structural work and the
replacement of those 696 expansion joints, largely at night
to avoid disrupting the 60,000 cars that cross the bridge
daily during commute hours.
The Concrete Trestles
Night work has been required for the reconstruction of the
two side-by-side concrete trestles, since Caltrans must keep
two lanes of traffic moving in each direction during
daylight hours, but can reduce that flow to a single lane in
each direction at night. Thus, one trestle can be completely
closed for construction work, and two-way traffic can be
transferred to the other trestle.
Inyang explained that the concrete segments of the trestle
are precast in Petaluma and barged down to the bridge. At
monthly intervals tugs position barges with one or two
100-foot long, 500-ton pre-cast concrete roadway segments
ready to be lifted into place by a 900-ton barge-mounted
crane. Earlier, either two or four of the corroded, 50-ft
concrete segments of the old roadway were removed by crane.
Then, a pile driver was moved into position for driving new
piles. After the new concrete road segment is in place,
steel plates are used to temporarily fill the gaps, and the
roadway is ready for the morning rush-hour traffic.
![](August%20Richmond%20RSR%20CRANE.jpg) |
The 900-ton
crane used for lifting concrete segments of the
trestle. Photo by Wes Starratt |
Completion Finally in Sight
The seismic construction work on the bridge was originally
scheduled for completion in September 2004, but as it became
apparent that more and more of the 48-year-old bridge needed
replacement, the project grew from seismic replacement to
major reconstruction, and the completion date kept sliding
while the budget grew to $600 million.
A recent infusion of $50 million from
current bridge tolls has meant that it will be possible to
replace the bridge deck while overhead structural work is
continuing, thus combining two phases of the project and
bringing the targeted completion date to 2005.
However, that is not the end! Caltrans is
already planning a separate contract for a polyester
concrete overlay for the roadway on both bridge approaches
and the main span. That contract will follow the completon
of the current retrofitting contract and is scheduled for
completion in 2006.
So, Vallejo ferry riders will still be able to enjoy
watching the bridge work for another couple of years.
Automobile commuters on the bridge will have to hold on for
a while. Unfortunately, things may get worse for them before
they get better. While the disruption caused by the
replacement of the concrete trestle may be almost over, it
will be matched by the structural work on the bridge, the
replacement of the bridge deck, and finally by an overlay on
the roadway on the structural steel segments of the bridge.
So, our suggestion is to try the ferry or stay home with
your computer. Some day, if all goes according to plan,
there will be more ferries on the Bay for you.