Project context
Project profile for Metro BLOC Tunnel, supporting transit-adjacent underground construction and constructability-focused engineering.
The Metro BLOC Tunnel connects riders in Metro 7th Street Station directly to the shops and restaurants of the BLOC complex in Downtown Los Angeles.
Cefali helped determine how the connection could be made while the active roadway and public stairway above remained undisturbed.
A system of beams and columns was designed to be installed as excavation progressed from the BLOC toward the station. Before wall removal, a grout tubing system improved ground conditions to prevent caving.
The work involved confined spaces, access restrictions, fumes that prevented welding, low overhead, and multiple bolted splices in beams and columns. The system also had to stay clear of the permanent concrete passage for the final condition.
