..undoubtedly by the low-bidder. Think about that on your morning commute, stuck under a flyway/overpass in the gridlock...
sacbee.com 'Problem bridge' was fixed in '05 The local span over the Sacramento River had more than 700 cracks. By Tony Bizjak - Bee Staff Writer Published 12:00 am PDT Wednesday, August 8, 2007 The shocking collapse of a major downtown Minneapolis bridge last week opened eyes nationwide with the realization: It can happen anywhere. In Sacramento, a handful of Caltrans engineers already knew that. In the years leading up to 2004, state inspectors with flashlights counted more than 700 stress cracks in the belly of the Bryte Bend Bridge -- also known as the Caltrans Maintenance Worker Memorial Bridge -- which carries 80,000 vehicles daily on Interstate 80 over the Sacramento River between Yolo and Sacramento counties. Adding to the engineers' concern, the Bryte Bend Bridge design is what is known as "fracture critical," meaning the span has no secondary support to hold it up should one section fail. The collapsed I-35W Bridge in Minneapolis also was a fracture critical design. "This is a problem bridge," consultant David Prine of Northwestern University said at the time of the Bryte Bend Bridge. "The scary thing is, if you were to get a crack that was unstable and there is nothing to stop it, it could sever the girder, and the bridge would fall down." State Transportation Department officials say they never felt the bridge was in danger of falling. Nevertheless, they fixed the bridge two years ago at a cost of $11 million. Subsequent acoustic tests, measuring molecular movement or "pops" in the steel, indicate the repairs have worked, Caltrans officials say. "We detected the problems, realized it could be a serious problem if left unchecked, analyzed and tested solutions, and selected the one that gave us the best results," a pleased Caltrans bridge engineer Erol Kaslan said Tuesday. Ironically, a review of Caltrans' list of structurally deficient state highway bridges this week finds, on line 272, the 36-year-old Bryte Bend Bridge. The Minneapolis bridge was on the national deficiency list too, along with 74,000 bridges nationally, 3,000 of them in California. Oklahoma tops the list with 6,300. A Caltrans-provided partial list of deficient bridges in the Sacramento four-county area contains 117 spans, both large and small. While politicians and transportation officials take heat this week for not doing enough to keep bridges off the list of deficient spans, Caltrans officials and others nationwide repeatedly have said they believe almost all bridges on the list are safe. The list, in fact, includes bridges with oftentimes minor problems like worn road pavement or peeling paint. The Bryte Bend Bridge carries the notation "deck" as its deficiency. Crews replaced the worn road deck two years ago with a polyester concrete overlay to smooth out the ride and give the bridge more strength, engineer Kaslan said. But, he said, inspectors continue to note in their reports the old water stains and non-structural cracks from moisture that had previously seeped under the roadbed, and that is enough to keep the bridge classified as structurally deficient. Of the 117 local spans on the state highway bridge list, a Bee review shows 110 are listed because of unspecified "deck" problems. Several small bridges are listed because of unspecified problems with the superstructure -- the underbelly-- or the substructure -- the support columns. Among those on the list with deck problems: the Yolo Causeway, the Rocklin Road undercrossing of I-80, Watt Avenue over Highway 50, and the Missouri Flat Road overcrossing on Highway 50. Two Highway 160 bridges in the Delta were listed as having superstructure problems: the Paintersville and Three Mile Slough bridges. Caltrans officials were unable Tuesday afternoon to provide explanations of why those bridges are on the list. Officials said they have been busy finishing urgency bridge inspections mandated by federal officials after the Minneapolis collapse. University of California, Berkeley, civil engineering professor Abolhassan Astaneh-Asl warned Tuesday that simple road deck problems -- especially on heavy-load urban freeway bridges like the Bryte Bend and Minneapolis bridges -- can lead to dangerous structural stress. "When you have lanes of truck traffic mixed with local commuter traffic, that is a dangerous situation," Astaneh-Asl said. Expansion joints on bridges create bumps. "Any truck hits those bumps, the truck may not feel it, but the bridge will feel it. It's like hammers hitting the bridge," he said. "If you want to replace the deck, you have to be very careful." Caltrans officials say they are very aware of those "impact stresses" and how they can increase over time. That is one of several reasons, engineer Kaslan said, that Caltrans engineers aren't letting down their guard at the Bryte Bend Bridge. While most state bridges are inspected every two years, this one is on a one-year cycle, and inspections are conducted by a special unit with expertise on fracture critical bridges, Kaslan said. --30--
