Geotechnical Fieldwork: Westwood Area
Metro contractors are preparing to conduct a series of geotechnical field tests in the Westwood 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.
The upcoming work will consist of borings to assess soil conditions in the area. Work will be conducted using a truck-mounted rig with a crew of up to four people. The drill bit will be advanced to the anticipated tunnel depths in the area, or greater. Drilling fluid consisting of bentonite slurry will be pumped into the borehole and circulated into a wash-tub at the ground surface, where cuttings will be removed prior to re-circulating the fluid through the hole. Soil sampling will be performed at 2½ to 5-foot vertical intervals by advancing a sampler using an automatic hammer. At the conclusion of drilling, the slurry will be placed in drums, tested, and disposed of off-site. The drums will be removed from the work site on a daily basis. The borehole will be filled with grout and its top patched with asphalt to match the surrounding grade.
Where: City of Los Angeles (Westwood Area)
When: December 27 – 30, 2010 Weekdays; 9am-3pm (Weather Permitting)
- Rochester Ave/Warner Ave
What to Expect:
- Crew consisting of up to 4 personnel per rig; 1 rig per location
- A truck-mounted drill rig and another truck equipped with additional drilling supplies
- Wash tub to collect and circulate drilling fluid at ground surface during drilling operations, and drums to contain drilling fluid for sampling and disposal at conclusion of drilling
- Parking lane and/or one lane of traffic will be blocked while work is under way on residential streets
- Moderate noise and vibration
- Lanes will be cleared at the end of the work period and re-opened for regular use
Other Important Information
- All work has received necessary permits and approvals.
- It may be necessary to conduct additional fieldwork following this testing. If this is necessary, we will inform the area(s) where this work will take place.
- For more information about the Westside Subway Extension, please leave a message at 213-922-6934 or online at www.metro.net/westside .
- For day-to-day testing location updates, please follow us at twitter.com/westsidesubway
- For emergencies or issues needing immediate attention, please call 323-236-2117.