Caltrans Nearing Completion of Big Lagoon Repair Project

Sat February 14, 2009 - West Edition

Caltrans announced Jan. 23 that the project to repair Route 101 just south of Kane Road near Big Lagoon in northern Humboldt County is nearing completion. This project was necessary due to ground movement which created chronic maintenance and safety concerns.

Prior to the project, Caltrans maintenance crews had been patching the roadway with asphalt one to two times a week. When the road movement increased to beyond what could be maintained by patching, it prompted closure of the southbound lane. This emergency repair project was then initiated to stabilize and fully reopen the highway.

To stabilize the roadway, the project utilized a micropile buttress wall. Steel micropiles, or mini piles (small diameter long steel rods or pipes), were drilled and grouted into the ground to provide a deep, stable foundation. Improved drainage, another feature of the project, also will help stabilize the highway. This design was selected to minimize the project footprint through this ecologically sensitive and geologically active area.

The project realigned Route 101 slightly to the east to channel traffic away from the slide. This also allowed the highway to stay open to traffic during construction. Preexisting turnouts, used during construction as staging areas by the contractor, will remain after project completion.

Remaining work for this project includes erosion control, removal of the construction access road, backfilling along the western side of the micropile buttress wall, and revegetating the areas disturbed during construction. The site will be further enhanced by a 3-year monitoring project to remove non-native, invasive plants and encourage native plant re-establishment.

For more information, call 707/441-3998.