CalTrans spokesman Greg Bayol said Tuesday that road repairs are beginning to wind down. Bayol said construction crews expect to reopen the highway in time for the full Fourth of July weekend.
"We're shooting for June 30," Bayol said.
Highway 1 has been closed between Montara and Pacifica since Jan. 22 when it began to slip due to heavy rains. It eventually dropped more than five feet.
Wyatt Kaelin, resident engineer for CalTrans on the repair project, said during a visit to the slide last week that everything has been done to keep the road from slipping again in future rains. CalTrans still maintains the repairs are only a Band-Aid to keep Highway 1 open until the Martini Creek Bypass is built.
On Thursday, crews with Jensen Drilling Co. completed drilling 80 holes 100 feet into the side of the mountain below the road. Steel "rock bolts" were then inserted in the holes, which were then sealed to help hold the mountain in place. In addition, another 300 holes were drilled in the roadway itself and steel rods inserted in an interwoven pattern for support.
"It's going good," said John Jensen, co-owner of the Eugene, Ore.-based company, as one of two 40-ton cranes that were brought to the site for the cliffside drilling was driven away, its work completed. "We've enjoyed working seven days a week," he added jokingly.
After completing the drilling, the company began testing the bolts to ensure they are secure. That was to be completed Tuesday. After that, "shotcrete," a liquid mixture of sand and concrete to help hold the rock bolts in place, is to be sprayed four inches thick across the side of the mountain. That job is expected to be completed by Saturday, according to Jensen.
New drainage systems are also being installed in the mountainside above the road. Workers are drilling four-inch-wide horizontal holes 250 feet into the side of the mountain and then inserting piping. Workers with Jensen Drilling didn't know the total number that will be drilled, but said 15 had already gone into the south side of the slide.
Water that would otherwise remain in the hillside, weighing it down and possibly causing the road to slip again, is supposed to drain out into new drainpipes installed just below the surface along the east side of the highway.
Other parts of the job still to be completed include the installation of concrete guard rails along both sides of the road and final grading and paving.
There will be a few small areas on the side of the road for cars to pull off in the event of a flat tire, or emergency, but no room for sightseeing. There will also be areas to the side of the highway for CalTrans to move rocks and debris to since the concrete railing will prevent trucks from pushing debris off to the side of the road.
One final part of the contract is the installation of stop lights at both ends of the slide and electricity to power them. Bayol said they probably will not be installed by the targeted June 30 reopening, but will go in soon after. The lights will not be used, however, except for one-way emergency traffic control in the event of future problems with the road, such as removing boulders or repaving.
How long the highway remains open, however, is largely dependent upon nature, Kaelin stressed.
"It's up to the mountain," he said. "To predict what it's going to do is something modern science hasn't yet figured out."
Pointing to the large cranes, steel bars, work crews and other heavy construction equipment at the repair site--totalling upwards of 500,000 pounds--a CalTrans employee said they were the reason why CalTrans waited until after March to begin repairs. He said the fact that the road has held up under all that weight should reassure people about the road's safety.
Bayol said the roadbed slipped two inches about three weeks ago during the drilling and installation of steel bars into the roadway, but it did not pose a problem.
Bayol said incentives for early completion were not included in the Devil's Slide repair contract, as they were with highway repairs in Southern California following the Northridge earthquake, for safety reasons.
"We didn't want anybody to compromise safety for time," Bayol said.
The Highway 1 contract originally called for completion of the job by June 24, but rain delays and additional work orders have pushed it out to July 3, Bayol said. The company will not be fined up to $18,000 a day if it finishes the job by then.