Why clear and grub precedes other preconstruction work

“Clear and grub” appears in multiple Construction Notices for the I-405 Sepulveda Pass Improvements Project, and although the term may sound like the name of an unsuccessful County Western duo, clear and grub actually describes one of the first steps in construction.

For the land within the southwest ramp (or loop) connecting the I-405 freeway and Wilshire Bl, for example, approximately a dozen trees and shrubs had to be removed from the 2.5-acre site to prepare this busy “loop” for reconstruction. This later work will include pile driving to build supports for the widened and reconfigured Wilshire Bl on- and off-ramps to the I-405.

To prepare for construction on the Wilshire Bl/I-405 connecting ramps, clearing and grubbing work removed trees and vegetation from the 2.5 acres of land inside the southwest loop.

Using heavy equipment, the ground was scoured of foliage during the night hours of May 20, while water trucks and workers periodically watered the soil to ensure that dust did not leave the worksite. This watering process is a component of the project’s Fugitive Dust Management Plan.

Kiewit Pacific Co., the project’s prime contractor, in coordination with Caltrans, Metro and the South Coast Air Quality Management District staff, developed the Fugitive Dust Management Plan to prevent, reduce, or mitigate the amount of dust created by construction. Kiewit must also meet the regulations specified in the California Air Resources Board's Portable Equipment Registration Program (PERP) regulations.

While clearing and grubbing continued, workers took borings to test soil density and moisture content to see if the soil required more compaction.

For the thousands of commuters who rely on the Wilshire Bl/I-405 loops daily, the completed project will deliver widened and reconfigured ramps that can hold a greater volume of traffic, reducing backup to Wilshire and Sepulveda boulevards. The Wilshire Bl undercrossing will also be widened to accommodate the wider I-405 northbound lanes. The Wilshire Bl off-ramp from the northbound I-405 will also be replaced.

Stephen Murray, Wilshire segment manager for the I-405 project, estimates that commuters will see construction of the ramps beginning this summer.

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Near 11 p.m. on May 20, a worker sprays water over the worksite to ensure dust remains within the construction area.

A loader waits at right while a water truck moistens newly graded soil.

Ned Racine