The Bump in the Road (and how to eliminate it)

Over the past several years the soil under the Loop 101 travel lanes, where it abuts the bridge over Camelback Road, has been slowly settling and creating a depression. When vehicles approach the bridge, they encounter a noticeable bump at the bridge deck. ADOT tried several methods to stabilize the roadway, including lifting it with a jack, but they only solved the issue temporarily.

To provide a permanent fix (and an overall smoother ride for motorists), ADOT contractors are using grout stabilization – a well-established construction technique that involves drilling shafts through the roadway and filling them with grout, a “soupy concrete” that fills the voids under the road. When the grout hardens, it creates a strong foundation for the finished road above.

In total, crews will drill and fill more than 400 shafts. The drill bit is nearly three inches in diameter and bores to an average depth of 30 feet.

ADOT was able to integrate the grout stabilization work at Camelback Road into the larger Loop 101 HOV lane project. The roadway stabilization phase of the project is anticipated to be complete by the end of May.