It won’t be long before motorists fill the tunnels at Devil’s Slide with
traffic as crews poured the last bit of concrete pavement yesterday to mark
another significant milestone for the nearly 5-year-old project.
Actually, it will be a while before cars can enter the tunnel but yesterday’s
completion of the two roads will now allow crews to jump to the next phase of
the project — connecting the two southern tunnel portals with Highway 1.
Caltrans is hoping to have the tunnels open to traffic by the end of this
year and be completely off the site by March 2013, said senior engineer Tom
Gray.
“We are looking for ways to improve the schedule,” Gray said.
The project is behind schedule and over budget as Caltrans had intended to
open the tunnels to traffic in early 2012 but tunnel soil movement required
months of reinforcement work, putting the project behind schedule by nearly a
year.
The original estimate for the work was about $350 million but Caltrans has
since allocated at least $439 million for its completion.
When opened, the project will officially be called the Tom Lantos Tunnels at
Devil’s Slide. Lantos, the late congressman, secured about $150 million in
federal funding to get the project off the ground. Lantos had worked for three
decades to bring the project to light and lived long enough to dedicate the two
tunnels before he died in early 2008 at the age of 80.
After the tunnels open, the current Devil’s Slide route that wraps around San
Pedro Mountain just south of Pacifica will be closed to traffic and opened up
for recreational use.
“There will be no more worries about the road closing due to heavy rains,”
said Caltrans’ spokesman Robert Haus.
Yesterday, about 15 construction workers floated the last bit of concrete,
about 9 inches thick, into the northbound tunnel as the southbound tunnel was
finished earlier this week.
Each of the two tunnels is about 4,200 feet long, 45 feet tall and just under
30 feet wide. The debris from the tunnels filled a disposal site equivalent the
size of a football field, 150 feet deep and Caltrans essentially constructed a
new mountain on the south side of the tunnels with all the debris where a
maintenance center will be hidden away from view.
The tunnels consist of a separated two-lane road that passes over twin
bridges on the north side of the project. The tunnels have nine cross passages,
an emergency vehicle cross passage and three equipment chambers with emergency
access to the main tunnels. The tunnels are vented by jet fans and have lighting
and fire protection.
The final lining in the tunnels is a cast-in-place reinforced concrete
lining, with a waterproofing membrane and drainage system placed between the
initial and the final linings.
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