Metro Los Angeles, Westside Extension

subway extension Purple Line, phase 1


Los Angeles County Metropolitan Transit Authority


Skanska-Traylor-Shea Joint Venture

Consultant for SEM/NATM: Beton- und Monierbau USA, Inc.
(100 % subsidiary of BeMo Tunnelling GmbH, Austria)
1 SEM/NATM Project Engineer/Manager on site since September 2019

Project location

Willshire Boulevard
Los Angeles

Start of construction


End of construction


Project total value

1 million €


Fernando and San Padro formation, tar impacted sands

Technical Data

Know-how-Transfer Project of the New Austrian Tunnelling Method (NATM) at the Purple Line subway extension project in Los Angeles (westside extension underneath Wilshire Boulevard).
The order includes constructional consultancy for the excavation of cross-passages between two TBM-driven tubes.

In the years 2016 and 2017 BeMo has already provided:
• Design reviews
• Equipment studies
• SEM/ NATM - technical feasibility studies

Technical details:
• Support during excavation of 23 cross passages in very difficult ground conditions
• ground improvement measures: jet grouting, dewatering, possibly freezing

Further project related information

• Site in urban, densely populated environment