Little truck, big job, for Westside subway planning

Link: Little truck, big job, for Westside subway planning | Zev Yaroslavsky

Little truck, big job, for Westside subway planning

January 7, 2010

That rumbling outside isn’t the Big One—just a little visit from the

The “minivib”—a small truck that plays a starring role in seismic testing for the Westside Subway extension—will be paying a visit to Century City and Westwood neighborhoods next week. Its “field seismic investigations” will take place on Century Park West and Warnall Avenue on Jan. 12 and 13, beginning at the parking entrance for 1930 Century Park West and ending on Warnall at Eastborne Avenue. On Jan. 14 and 15, the work starts on Selby Avenue, beginning at a point between LaGrange and Missouri Avenues and ending at North Temple Way.

The seismic testing will produce an electronic image of the soil, including rock layers, near-surface faulting and information on bedrock elevations and depths. The process involves placing sensors along the street and then having the minivib press and vibrate a “plate” every two feet to obtain readings of the vibrations.

Ultimately, the work will help determine placement of subway tunnels and stations in Century City and Westwood. Anyone with questions about the testing can leave a message at (213) 922-6934 or email Metro via the “Contact Us” link here. For urgent matters, call (323) 889-5311.

About 240 letters have gone out to residents alerting them of the work, which will take place between 10 p.m. and 6 a.m. The night shift is necessary, according to Metro, to avoid competing vibrations from daytime traffic and to minimize disruption on nearby Santa Monica Boulevard, which will be reduced to one lane in each direction during the testing.

Metro says the noise will be moderate–not more than 70 decibels, in the range of daytime traffic volume–and should take no longer than 30 minutes in front of any one residence.

It’s a busy week for after-hours transportation action on the Westside–on Tuesday night, work also will begin on the 405 Sepulveda Pass widening project, as crews begin delineating new, narrower lanes to accommodate a work zone for the construction of a northbound carpool lane.