ROADS/BRIDGES: California S.R. 91 on-ramp to be demoed, rebuilt following collapse

Work will begin Nov. 2, after partial collapse on Oct. 9 left 10 injured

October 29, 2015

Concerns over the structural integrity of a 750-ton bridge spanning East Grand Boulevard in Corona, Ca., have led to the decision by state DOT officials to demolish and rebuild it.

The S.R. 91 on-ramp work is expected to cause traffic delays, but to not affect or delay completion of the S.R. 91 expansion project.

Though the new work isn’t expected to delay completion of the 91 expansion project, it will cause traffic delays starting next week, Riverside County officials say. It will be paid for by the contractor. Ten construction workers were injured Oct. 9, when the wooden supports and jacks they were using to lower the bridge gave way, causing the concrete slab to drop roughly 16 inches. At present, four workers remain hospitalized, one of whom is still in a coma

Deficiencies in the bridge’s temporary supports were noted by an assistant county engineer the day before the collapse. While the incident remains under investigation, spokespeople for the contractor have indicated that all deficiencies noted were corrected prior to the faulty lowering.

The day after the collapse, however, Atkinson Walsh employees punched through the vent holes of the bridge and released nearly 25 tons of water from the bridge, engineering reports show.

“[We] are worried about the long-term durability of the structure,” Riverside County Transportation Commission Deputy Director John Standiford said of the decision to replace the bridge. “It’s safe for now. Long-term, it suffered some sort of strain or stress (from the bridge collapse).”

The possible role of water in the collapse is still under investigation; additional holes have been drilled in the bridge as part of those investigations. Demolition will start Monday, Nov. 2. The bridge deck will be replaced over the next month.