Sunday, March 23, 2008

I-5 Update

Water was problem from the start.

I-5 stretch due for repairs was a bust from the beginning
By Tony Bizjak -
Published 12:00 am PDT Sunday, March 23, 2008

Some freeways age well. Others require a little extra care. Then there's the "boat section" of Interstate 5 in downtown Sacramento.

Built amid controversy in the 1960s, the stretch of sunken freeway has been trouble since it opened.

Concrete cracks appeared immediately. Drain pipes have since clogged, and the pavement is crumbling fast.

Fearing a freeway flood, state officials announced plans last week for an unprecedented project this summer to save the worrisome mile of interstate.

"With the potential for flooding, we feel we need to go in now," state Department of Transportation project manager Ken Solak said. "The wearing surface is in dire need."

They will partially close I-5 for weeks at a time – risking massive traffic jams – to rip out and rebuild much of the freeway.

The project is scheduled to start the last week of May.

The project area runs from Richards Boulevard on the north to the Highway 50 interchange on the south.

But the trickiest task lies below ground, where the freeway dips under Capitol Mall and P Street.

Engineers call it the "boat section," where the concrete-encased freeway is pressed in on three sides by muddy groundwater, below the level of the Sacramento River. The lowest portion of the boat section is anchored in the mud by numerous 80-foot-long piles.

Pressure from water pushing upward over the years has caused extensive pavement cracking. An underground drainage system designed to suction away water is failing. Pipes are packed so tightly with silt "it's almost as hard as concrete," Caltrans engineer Erol Kaslan said.

Maintenance crews and engineers have applied patchwork fixes for decades, but most have not taken, Caltrans reports show.

Crews will close the freeway's northbound lanes in downtown for an estimated two weeks, likely after the Memorial Day weekend and Jazz Jubilee in Old Sacramento.