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The Others; New spans, several retrofit projects outpace

November 29, 2004 Reposted from the Oakland Tribune
  By Sean Holstege

THE TOWERING red cranes lining the eastern span of the Bay Bridge tell but half the story of the region's multibillion-dollar bridge-building bonanza.

With only two exceptions, every bridge in the region is getting or has gotten a makeover. The $10.4 billion investment -- and likely more -- will strengthen bridges against future earthquakes. Some will be widened and three new spans will go up. The reconstruction of the Bay Bridge between Oakland and Yerba Buena Island accounts for $5.1 billion -- for now.

The scope and cost of bridge work is staggering. It's more than the combined amount spent on highway improvements in a year by all 13 Western state transportation departments.

Untouched are the quarter-century-old Dumbarton and Antioch bridges, but recent speculation is that these, too, may need some seismic touch-ups.

Caltrans and the autonomous Golden Gate Bridge District parceled out the work into 42 separate contracts. Hundreds of companies and tens of thousands of skilled workers, from Hayward to Udine, Italy, and from Livermore to Nagoya, Japan, are cashing in.

Contract by contract, bridge by bridge, Caltrans has set and shattered a quick string of successive records for the biggest jobs in its history.

Before the bridge work, the $121 million Century Freeway in Los Angeles was the biggest-ever Caltrans contract. The $238 million contract to build the new Zampa Bridge over the Carquinez Strait broke that record in January 2000. The records tumbled like dominoes over the subsequent four years when bids came in to build the new Benicia Bridge, fix the San Rafael Bridge, build the Bay Bridge skyway and build a foundation for the Bay Bridge.

As impressive as is the scope of this latest gold rush, the details are even more so. Almost all of the bridge jobs involve unique challenges, never-attempted construction methods or one-of-a-kind machinery.

Golden Gate challenge

Under the Golden Gate Bridge, workers for Hayward-based Shimmick Construction Co. and its Japanese partner, Obayashi Corp., perform a delicate tap dance around the tourists. They have to strengthen the southern span and archway while preserving or avoiding the historic monuments and protecting one of the world's most appealing terrorist targets.

It's a bit like repainting the Sistine Chapel with original pigments, while the doors are open to gawking tourists during a Code Orange terror alert.

High above the Civil War-era Fort Point gunnery, workers have constructed an ingenious triple-deck corrugated aluminum work platform, which can only be reached by a clanky industrial elevator. The whole thing, where dozens of ironworkers are bolting braces to steel crossmembers, is suspended from the bridge by steel cables.

The work platform has its own climate and ecosystem. Almost ever-present fog drifts through the rigging, condenses and drips into pools. The place almost never sees direct sunlight, so algae grows on the damp surfaces.

The guts of the work involve sleeving the concrete walls of the support towers and cable anchorage in steel jackets. On the exposed concrete surfaces, workers embossed a pattern that mimics that left behind from the original wood-slat forms from the 1930s.

The $161 million contract is the second phase in a $392 million retrofit plan.

The first phase, to strengthen the most vulnerable structures on the north bank of the strait, was completed for $71 million by Balfour Beatty Construction Inc. in 2002. The Golden Gate Bridge district does not yet know how to pay for the final phase to strengthen the landmark steel towers, which is on hold until money is found.

Benicia's hex

At the Bay's other periphery, over the Carquinez Strait, the trick with the new Benicia Bridge wasn't fog or tourists, but fish and bedrock. The two conspired to make what was supposed to be a simple $385 million concrete viaduct bridge a $1.06 billion nightmare.

Kiewit Pacific, part of the same firm building the first stage of the new Bay Bridge, is building a new bridge to carry northbound traffic on Interstate 680 over the water. Built to ease traffic congestion, it was supposed to open a year ago. Instead, motorists will have to wait until December 2006.

That's because contractors found that driving piles into the bedrock proved more difficult than expected.

In some places, the rock crumbled. Contractors tried the painstaking technique of pouring cement grout down the steel pipes and then drilling through that. The concrete serves as substitute for bedrock.

In other places the rock proved too hard. Not only was pile-driving slow, but the clanging noise from enormous hammers reverberated through the water. The shock waves killed endangered Delta smelt and threatened to wipe out salmon. Caltrans developed a system to buffer the noise with a curtain of air bubbles and ended up getting a patent for the device.

Carquinez ease

Not every project has proven so difficult.

At the nearby mouth of the Carquinez Strait, the new Al Zampa Memorial Bridge sprang up close to schedule and budget. For $252 million, the public got a slender new suspension bridge, often admired by new visitors for its simple beauty. It opened a year ago, carrying westbound Interstate 80 traffic.

Caltrans called for the new span because it deemed the original 1927 bridge too old and fragile. It will be torn down in 2006.

Eastbound I-80 traffic will continue to travel over the parallel bridge, built in 1958. It was retrofitted with relatively little fuss as was the existing Benicia Bridge.

Similarly, strengthening the San Mateo Bridge went smoothly, a harbinger for the next job there: widening the flat section to six lanes in 2002. At one point, Caltrans contractor Balfour Beatty was constructing the trestle at the healthy clip of 290 feet a week.

While politicians like to focus on the jobs created by big bridge work, the Bay Area's economy benefits in more subtle ways too. Regionwide, every minute of traffic congestion sucks $1 million out of the Bay Area economy due to lost productivity and wasted fuel.

Before the San Mateo Bridge widening, which voters paid for by approving a toll increase, the bridge was the third-worst Bay Area commute. Now, the seven-mile bridge is the fastest in the region.

Complex approach

The most complicated retrofit work still remains. Sylmar-based Tutor-Saliba Corp. is tearing down and rebuilding lane by lane the western approach to the Bay Bridge through downtown San Francisco, for $178 million.

Without closing any lanes of traffic, Caltrans has to get 282,000 cars a day along the elevated freeway from the bridge to Fifth Street and funnel them through gaps that come within six inches of some buildings. In the next five years, drivers will have to adjust three times to detours, as Tutor-Saliba crews braid traffic side to side from an existing lane to a temporary lane and back to a permanent replacement lane.

Ramps and lanes will be built, then torn down. At one stage the westbound Fifth Street offramp will be divided so that eastbound and westbound traffic share the ramp. At another stage, eastbound traffic will be split into four separate freeways and fused into one as it reaches the lower deck.

Some westbound drivers coming off the upper deck will exit the main freeway on a temporary ramp. There will be no shoulder and no exits, just an isolated one-mile, one-lane freeway, earning the structure the nickname from Caltrans engineers "The Toboggan Run."

The complex work drags on until late 2009.

Commuters may have noticed fluorescent green paint markings overhead as they leave San Francisco on the lower deck. These highlight steel tendons that run through the concrete from one side of the bridge to the other. Workers have to drill holes to bolt plating here without touching those tendons. If they make a mistake, the structure becomes unbalanced when workers tear out lanes. Nothing like it has ever been attempted, project manager Raoul Maltez said.

Caltrans engineers call it the most complex project the state agency has ever undertaken.

The Beast

But another Tutor-Saliba job could claim that "most complex" bragging right: the reconstruction of the Richmond-San Rafael Bridge.

Engineers at Caltrans privately wanted to tear down and replace the much maligned ugly duckling, but chose to avoid what might have turned into another political circus.

The San Rafael Bridge retrofit was the costliest single contract in Caltrans history at the time it came in at $485 million, 20 percent over estimates. The job, still the biggest ever seismic retrofit, is now expected to cost $955 million by the time work ends in mid-2005. It is nicknamed "The Beast."

Part of the reason is holes. Years of wind and salt kept gouging holes in the deck, forcing a string of traffic-clogging emergency repairs. Caltrans decided to fix the holes at the same time it was already rebuilding the 1956 structure piece by piece.

The most dramatic part of that work, infuriating to drivers who are wearied by the resulting nightly lane closures, involves replacing entire sections of the flat deck.

Each new section weighs 1 million pounds. A barge with one of the biggest cranes on the West Coast, brought in from Germany just for this job, lifts the 100-foot hunks of concrete in place.

It sounds a lot easier than it is, or looks. The barge, floated down from the pre-fabrication plant in Petaluma, bounces around in high surf while a crew of about 90 workers helps the crane operator guide the new deck into place within half-inch precision.

Before that can happen, the German crane lifts two old sections and a connector piece off the bridge onto other barges in a careful choreography.

Tutor-Saliba crews have gotten good. They can get through the whole process in 90 minutes and replace 300 feet in an overnight shift. They have to be fast, because when they're done, they have to open the bridge for morning commuters. They've never been late.

Old Gray Lady facelift

Strengthening the western half of the Bay Bridge has proven the costliest in human terms. The $170 million retrofit work has claimed two lives and injured several other people. The hazards came from two sources: lead paint and difficult access.

To get access, workers with a joint venture of California Engineering/Modern Continental had to build a special work platform that traveled the length of the lower deck on running rails. The work platform buckled and killed one worker, and a plywood panel collapsed in a separate accident and crushed a passing truck, killing the driver.

On the top deck, workers built huge platforms around the four towers out of steel I-beams and massive timbers. These propped up the lattice of scaffolding that rose hundreds of feet as workers replaced rivets with bolts and stiffened the "Old Gray Lady" with new chunks of steel. Of course, not one bolt could fall on traffic, so the entire work site had to be shrouded in a web of fine mesh.

Invisible to the public, inside the hollow steel towers near the waterline, was arguably the grimmest job of the entire $10 billion bridge program. Workers had to clamber inside a catacomb of crawl-spaces and chambers through a series of child-sized hatches, dragging a steel pipe that weighed up to 100 pounds. Once inside this claustrophobic place, they hooked the pipe up to hoses and blasted away lead paint to prime the steel surfaces for bolts and welds. Several workers on the western side of the Bay Bridge reported the effects of lead poisoning.

Is it worth it?

After all the toil and money spent, Bay Area commuters will have bought an insurance policy against quakes and traffic.

The new San Mateo, Benicia and Zampa bridges will add lanes. The eastern span of the Bay Bridge and the reconstructed I-80 above downtown San Francisco will have wide shoulders where stranded cars can wait for help.

The Bay Bridge and Carquinez bridges are engineered to reopen within hours of the most violent Bay Area quake imaginable. The others should reopen within days. Before the work, engineers talked of catastrophic collapses at worst, and closures measured in months at best.

Ultimately, it's all a reinvestment.

The bridges of the mid-20th century gave the region its defining character and helped propel it into the economic juggernaut it became. The bridges of the early 21st century will give the Bay Area's economy, many of its engineering and construction firms and thousands of its skilled workers staying power for the years ahead.

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