University Bridge is back in business

The University Bridge reopened to traffic Thursday afternoon, after workers filled a huge sinkhole beneath the south approach with a sand-and-concrete slurry.

Next, workers today will cut away and begin replacing the broken water pipe that poured 3 million gallons into the Lake Washington Ship Canal after it split open Wednesday morning.

The gushing water had scoured away soil and threatened to undermine a concrete abutment supporting the bridge's entrance on busy Eastlake Avenue East. The hole swallowed two cars parked on a side street under the bridge.

Inspections Thursday confirmed there was no shifting or damage to Eastlake Avenue and the bridge was never at risk.

Engineers closed the street for 1-½ days, fearing that traffic weight and vibration could make the abutment sink into gaps in the soil. But after filling the gap with the quick-drying slurry, the Seattle Department of Transportation allowed cars back onto the bridge at 3 p.m.

Bus service almost immediately returned to normal across the bridge, after six routes were detoured.

Reopening the bridge, which carries 31,400 vehicles a day, was more urgent than fixing the water main, because Seattle Public Utilities has rerouted water flow through other mains in the city.

Work around the water pipe stopped Thursday afternoon, and crews would likely take the weekend off to avoid interfering with the neighbors, including houseboat dwellers, as they celebrate the start of boating season, said Joe Mickelson, water-operations director for Seattle Public Utilities. The break in the water main, still unexplained, ran lengthwise along the bottom of a 10-foot-long segment installed in 1917.

"It cracked just like the seam of your pants," Mickelson said.

Sand and concrete also were pumped into the hillside next to the ship canal on Thursday, to firm up the area so water crews can work without fear of a soil collapse.

The broken pipe section should be replaced by early next week, he said. A bigger, 95-year-old water main, a few feet away, is intact.

Cyclists and pedestrians were allowed onto the bridge all day Thursday, to enjoy an odd, traffic-free crossing between the University District and Eastlake neighborhoods.

"I love it. You don't feel like you're going to get killed today. It's easy to relax," said Cindy Swazo, riding her mountain bike for exercise Thursday. The bridge, with its own bike lane and sidewalk in each direction, already was among Seattle's easiest bike routes. The bridge closure hurt businesses nearby, though customers began to trickle back into the area by midday.

Red Robin, which gave food and water to the road and water crews Wednesday, reaped good karma Thursday as workers in orange sat down for lunch. Customers returned to The Flower Lady once they could walk across from the U District.

Romio's had closed Wednesday because traffic jams on nearby streets thwarted deliveries, and employees had trouble getting to work. Angela Mokate, a waitress, said the day off was nice, but she lost a double shift of pay. Thursday wasn't much busier, with only three patrons at noon.

Mike Lindblom: 206-515-5631 or mlindblom@seattletimes.com