The BART Extension to the San Francisco Airport is a major subway project which, when completed, will connect the existing BART system to the San Francisco Airport and extend the system as far south as Millbrae, California. A large portion of the new subway alignment is adjacent to the existing PCJPB (Caltrain) commuter rail line. Berti-Lindquist is providing the PCJPB with independent design review of temporary and permanent structures that are within the influence of the Caltrain railroad tracks. The reviews include the temporary excavation shoring (deep sheet pile and soil-mix wall cofferdams below the water table and adjacent to the railroad tracks), as well as the design criteria and detailed designs of the permanent subway cut-and-cover structures that are being constructed adjacent to, and in some places beneath, the PCJPB tracks.

Owner Bay Area Rapid Transit District (BART) | Client Peninsula Corridor Joint Powers Board (PCJPB)

Analysis of Existing Structures for Temporary Construction Conditions, Temporary Trestle & Excavation Shoring

This $120+ million project involves the complete retrofit of all the South Approach Structures to the Golden Gate Bridge. Berti-Lindquist has been retained by the general contractor to analyze existing structures for temporary construction conditions and loading, as well as to design miscellaneous temporary facilities including excavation shoring and a trestle for heavy equipment. Engineering assignments to date include the design of protection for an existing historic seawall, the temporary support of a portion of the roof and a wall of the South Anchorage Housing when the supporting columns and foundations for these structures are removed, and the excavation shoring required to retrofit the existing foundations of the South Approach Structures.

Owner  Golden Gate Bridge District | Client Shimmick Obayashi, JV

Berti-Lindquist is providing detailed demolition engineering for Cleveland Wrecking Company for the removal of the concrete and steel cone-shaped roof of the sphere enclosure building at San Onofre Nuclear Generating Station. This demolition work is part of the decommissioning of the Unit 1 Reactor at the power plant. The enclosure building that surrounds the steel spherical containment vessel is a thick, heavily-reinforced concrete cylinder with an insider diameter of 145 feet. The concrete and steel enclosure roof structure rises to a height of about 95 feet above the ground surface at a slope of 1 vertical to 3 horizontal. Engineering assignments include analyses of the structure at various stages of roof removal with demolition equipment operating on the partially demolished roof structure.

Owner Edison | Client Cleveland Wrecking Company

Working for the general contractor, Lindquist and Berti designed a sheet pile cofferdam for a new pump station at Mallard Slough. The pump station projects into Mallard Slough from an existing levee underlain by soft organic clays and peat. The cofferdam sheets are supported by combination of a sheet pile deadman on the landward side to resist significant unbalanced loading from the existing levee together with a single level of cross-lot bracing. The depth of excavation was approximately 30 feet. Developed an alternative sequence for the pump station that reduced the construction cost as well as risks associated with the contract-specified scheme. Also, designed solidor pile and lagging shoring for jacking and receiving pits for the three pipe jacking locations.

Owner Contra Costa Water District | Client Homer J. Olsen, Inc. |

Vasona Light Rail Project - Contract C345 - San Jose Diridon Tunnels

Temporary Structures (Excavation Shoring & Bridges)

San Jose, California

Description: The project consists of the construction of 1500 feet of the VTA’s light rail system, including approach channels, a subway section, and an extension for an existing pedestrian tunnel. The project is located in downtown San Jose, adjacent to the San Jose Arena. The subway and pedestrian tunnel extension cross the main Diridon Station rail yard (twelve tracks). As subconsultants working for the project structural engineer, Lindquist and Berti provided detailed design of the temporary shoring for excavations up to 30 feet deep required for construction of the reinforced concrete boxes and channels. The shoring system consists of soldier pile reinforced deep-soil-mix wall supported by cross-lot bracing. A temporary rail bridge and platform were also designed to maintain rail traffic and platform access across the open subway excavation.

Owner Santa Clara Valley Transportation Authority (VTA) | Client Biggs Cardosa & Associates

Moss Landing Power Plant Stack Demolition Engineering

Moss Landing, California