Orange County Branch Newsletter

December 2018

ASCE OC Luncheon

September Luncheon - LA Metro Regional Connector

By Jason Fix, PE

On September 20^th, Ivan Hee, PE (Skanska Civil USA) and Carlos Herranz, PMP (Mott MacDonald) presented the technical aspects of constructing the new Los Angeles Metro Regional Connector Station.

The Metro Regional Connector Project is a Design Build Project by Skanska and Traylor Brothers that extends from the Metro Gold Line Little Tokyo/Arts District Station to the 7th Street/Metro Center Station in downtown Los Angeles. The completion of the project will allow passengers to transfer to Blue, Expo, Red and Purple Lines, bypassing Union Station.  The project consists of a 1.9-mile alignment mile underground light-rail system and three new underground stations.

Shoring and Suspension of Existing Utilities near Downtown High Rises.

For the Downtown Los Angeles project, maintenance of traffic involved significant coordination. Cut/Cover construction was utilized to allow vehicular traffic during peak hours with construction during off times. A major obstacle at 2^nd and Broadway was an existing Storm Drain which was over 10’ in diameter. A replacement utility was coordinated and suspended above the construction area.

Construction in downtown Los Angeles is challenging due to the path the machine must navigate in a built-up area. For the Light Rail Tunnels between the stations, the Tunnel Boring Machine utilized the Sequential Excavation Method to build the tunnel. Through several steps the bore material was extracted with the lining of the tunnel constructed in several steps to create the final Rail Tunnel.

Tunnel Bores built through Sequential Excavation Method.