Cefali & Associates, Inc. Consulting Structural Engineers, Los Angles, CA © 2019. All Rights Reserved

THE GRAND

Adjacent to the Walt Disney Concert Hall sat the “tinker-toy” parking structure that had long been slated for demolition and redevelopment.  The project is comprised of an entire block bounded by 1st, Olive and 2nd Streets and Grand Avenue.  It is now known as The Grand is a partnership of CORE and Related Companies who charged Frank Gehry to design a mixed-use development that changes the skyline of Downtown Los Angeles with two new towers.  It is intended to be a hub for neighboring entertainment destinations like The Broad, Dorothy Chandler Pavilions and the Disney Concert Hall.  Cefali & Associates was hired by Related to design the shored excavation.  The design accommodates a number of complexities including dipping bedrock, pedestrian and vehicular tunnels under the streets, a counterfort wall transition from Lower to Upper Grand, and the 2nd Street Tunnel.  In conjunction with Wood’s Geotechnical engineers, we developed a tieback-braced shoring system along 2nd Street with very short anchors to stay clear of the active 1920’s tunnel.  A prominent feature of the design is a multi-row waler system along the west at the existing retaining wall at the end of Lower Grand.  The counterforts supporting the wall prevent tiebacks from being installed. The walers provide a mechanism to transfer to the earth forces at piles where tiebacks could not be drilled to locations where they could.  This occurs at the deepest point of the excavation at 60 feet.  The retaining wall exerts a tremendous surcharge below the level of Lower Grand which required 4 rows of tiebacks in just the last 30 feet of the excavation.