Metro contractors are preparing to conduct a series of geotechnical field tests in the Beverly Hills area as a part of the Final Environmental Impact Statement/Environmental Impact Report (Final EIS/EIR) for the Westside Subway Extension. This work will build on the data gathered during the Draft EIS/EIR for the project and provide further soil and seismic information along the route of the Locally Preferred Alternative (LPA). In certain areas, noise and vibration tests will also be conducted. Following the tests, the data will be analyzed and used to make further informed decisions about subway construction.
This next part of the work to be performed will consist of field seismic testing. The field seismic testing will be performed using several pieces of equipment to collect seismic reflection data. The seismic reflection surveys will be performed between 9am - 4pm on residential streets. The equipment to be used during the field testing is described below:
"Mini-Vib" Truck Seismic Surveys: Equipment to be used will consist of a "Mini-Vib" truck, seismograph recording truck, cable sensors, electric generator and a geophysical survey crew of up to 6 people. Sensors will be placed along the street. Approximately every five feet, the truck will place a "plate" on the surface of the street, then, vibrate the plate in order to take a reading of the vibrations along the street (see photo). The "Mini-Vib" truck will move through each testing location and remain in front of any given location for about 15 to 20 minutes. Residents may encounter some moderate noise as the truck performs the test. The sound level at a distance of about 50 feet from the truck should be no more 70 decibels, or similar to that of average daytime traffic.
"Micro-Vib" Seismic Surveys: Equipment to be used will consist of a portable "Micro-Vib" vibration source box, seismograph recording truck, electrical generator, cable sensors, and a geophysical survey crew of up to 6 people. Sensors will be placed along the street. Approximately every two feet, the portable "Micro-Vib" box will be vibrated by the electrical generator source (see photo). The "Micro-Vib" box will be moved manually through each testing location and remain in front of any given location for about 20 to 30 minutes. For "Micro-Vib" box testing, the sound level should be no more than 60 decibels, or similar to light daytime traffic.
Where: City of Beverly Hills
When: 9am - 4pm (Weather Permitting)
Note: Should any work need to be cancelled and rescheduled, Metro will inform you of new work date(s)/time(s).
What to Expect During Field Seismic Testing:
Other Important Information
Comments may be submitted by:
Online: Complete our electronic Comment/Question Form
By U.S. Mail:
David Mieger, Project Director
DEO, Countywide Planning & Development
Los Angeles Metropolitan Transportation Authority
1 Gateway Plaza, M/S 99-22-5
Los Angeles, CA 90012
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