Widening an Artery
By K. Robert Wendel

Bad soils and heavy rains are making it tough for contractors reconstructing Interstate 40 in Albuquerque, but plans are still calling for a November completion on the 4-mi. rebuilding effort.

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The project entails the reconstruction of three lanes of westbound I-40 along with the construction of acceleration and deceleration lanes and a new interchange structure on Pennsylvania Avenue.

Albuquerque's A.S. Horner is the general contractor on both the freeway reconstruction and the $6 million renovation of the Pennsylvania Avenue interchange.

The project also includes under grounding an open floodway channel >> and detention basins for highway drainage.

Funded by Gov. Bill Richardson's G.R.I.P., or Gov. Richardson's Investment Partnership, the 4-mi. project is the second phase of an eight-phase plan to rebuild I-40 in just three years. The replacement of the Washington and San Mateo bridges crossing I-40 is included in this three-year plan.

Although work on the hard bid, $19 million road project started in January, with the record rains, it's been difficult for contractors to get rolling.

"The weather this year has just been the worst," said A.S. Horner project manager Patrick Shaw. "January and February were the wettest months in New Mexico since Abraham Lincoln was president. We just had 6-in. of snow."

The wet conditions haven't helped the existing road bed either. Constructed in the 1960s, the aging road is crumbling from below, with saturated soils undermining the freeway's integrity.

The route is a major east-west artery that sees more than 300,000 vehicles a day, including thousands of semi trucks.

"Anyone who has driven this stretch of I-40 knows how badly this is needed," said New Mexico transportation secretary Rhonda Faught during the project's groundbreaking. "The years of heavy traffic on this major trucking corridor have taken its toll. This highway is falling apart."

Crews from A.S. Horner are working on the first stage of the project, widening the three-lane road to include the acceleration and deceleration lanes and a wider shoulder. Plans call for that portion of the project to finish in May.

At that point, traffic will be flipped to the newly constructed road and crews will start demolishing and rebuilding the three lanes between Pennsylvania and Tramway Boulevard in east Albuquerque. Plans call for 13-in. of Portland cement concrete paving sitting on 4-in. of open-graded base course.

But the soils in the area are less than ideal.

"The soils are really kicking our butt. It's just tough to deal with such saturated conditions," said New Mexico Department of Transportation project manager Ted Barela. "It may seem ironic for the desert, but once moisture gets underneath there and gets trapped beneath the PCCP, there's no escape."

Engineers from the N.M.D.O.T., which designed the reconstruction project, are working with the general contractor to develop an inexpensive way to improve the soils. Over excavating and replacing the soil with engineered fill was one option, but costs and time were prohibitive. Geo grid was another expensive option, although it was less time consuming.

The team hopes that a cement treatment on the soils will solve the problems quickly and cheaply.

"We have a lot of clays and silts that either need to be treated chemically or mechanically with some kind of stabilizing system like geo grid," Barela said.

"To sub excavate something takes a lot of time and money, so right now we are shooting more for the chemical stabilization."