Flawed bridge part may need redesign 

A trouble-plagued repair to a cracked Bay Bridge support beam might be redesigned after the hurriedly drafted fix failed weekend safety tests, Caltrans announced Sunday.

The damaged piece still needs several rounds of approval before two independent agencies conduct inspections.

Caltrans had previously resisted calls for it to redesign the repair from scratch, with bridge spokesman Bart Ney telling reporters Wednesday that could create "tit-for-tat" disputes about the new design and could lead to a weeks-long bridge closure.

"For something like this, simple is often the best," Ney said Wednesday. "We have our best minds working on it."

But Sunday — five days after the bridge was closed to traffic — Ney gave the first vague indications to reporters that the agency is finally willing to consider overhauling the design if the latest round of testing fails.

"To replace the original eyebar is not in our plans at this point," Ney said Sunday evening, announcing that the bridge would not reopen in time for this morning’s commute because the repair had not passed safety tests. "We're considering other possibilities — it's possible that it'll be something new."

It is unclear how long it would take to draft and execute a new repair plan, but the flawed first plan took nearly three days to design, fabricate and implement.

The about-face came Sunday after crews were forced to temporarily abandon repair efforts because they ran into trouble while tensioning rods, Caltrans spokeswoman Lauren Wonder said.

Workers were sent home around midnight Saturday and resumed work at 7 a.m. Sunday after working around the clock for four days, according to Wonder.

"It was just a question of fatigue and taking a look at the adjustments to the tensioning project," Wonder said.

The epic repair snafu, which has led to the longest Bay Bridge closure since the aftermath of the 1989 Loma Prieta earthquake, began over Labor Day weekend when the bridge was closed to allow work to proceed on a replacement span. During the scheduled closure, Caltrans discovered a rusty crack in a load-bearing eyebar.

Caltrans engineers sketched makeshift repair plans to reinforce the area around the eyebar, but the steel components failed to fit together properly. That prompted an additional chunk of steel, called a spacer, to be incorporated into the design.
Because of the design flaw, the scheduled bridge closure was extended by several hours.

Adding to the debacle, the engineers failed to design the repair to withstand wind gusts, which are common on the Bay. After the fix was implemented, Caltrans discovered that it was vibrating in the wind.

The vibration problem was not addressed before it snapped a two-inch support rod Tuesday, causing massive pieces of steel from the repairs to fall onto evening rush-hour traffic.

jupton@sfexaminer.com
tbarak@sfexaminer.com

 

Bay Bridge timeline

Thursday, Sept. 3, evening: Bridge shuts down during Labor Day weekend to allow planned work on replacement span

Saturday, Sept. 5, afternoon: Caltrans discovers dangerous crack in load-bearing eyebar

Sunday, Sept. 6, afternoon: Steel parts for eyebar repairs arrive from Arizona

Monday, Sept. 7, morning: Caltrans discovers the parts don’t fit together properly and orders an additional part as a makeshift solution

Monday, Sept. 7, evening: New part arrives from Oakland and is placed in position

Tuesday, Sept. 8, morning: Bay Bridge reopens several hours behind schedule

Tuesday, Oct. 27, afternoon: Several steel repair parts fall onto bridge during peak traffic time, as strong winds cause vibrations that shake pieces loose

Wednesday, Oct. 28, morning:

Caltrans blames strong winds for fallen repair parts and says those parts will be put back in position and reinforced


Wednesday, Oct. 28, evening: Caltrans announces several repair enhancements to better protect against wind gusts

Thursday, Oct. 29, morning: Caltrans announces bridge will not reopen in time for Friday morning commute

Thursday, Oct. 29, evening: Caltrans announces repairs could be completed by 10 p.m., but tests will be performed before bridge reopens

Saturday, Oct. 31: Caltrans crews run into trouble while putting tension on the rods that will support the Bay Bridge fix, and decide to take an overnight break as more planning is done

Sunday, Nov. 1: Caltrans says repairs have failed internal testing and that the failed piece may need to be redesigned

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