Image courtesy of the Transbay Joint Powers Authority

$2.2bn San Francisco transit hub closed after broken beams discovered

27 September 2018 | By Joe Quirke 1 Comment

A $2.2bn transit station on Fremont Street, San Francisco has been shut after two cracked steel beams were found.

The Transbay Transit Centre and Salesforce Park, which was opened last month, is intended to be the primary bus terminal – and future rail terminal – for the San Francisco Bay Area. It was closed after a cracked beam was discovered yesterday (26 September) in the third-floor bus deck during an inspection.

Website Curbed San Francisco reported that a second cracked beam was then found last night.

A statement from the Transbay Joint Powers Authority (TJPA) said the second fissure was located on a beam adjacent to the first.

Image courtesy of the Transbay Joint Powers Authority

It added that ultrasonic testing will be used to determine the extent of the damage, and engineers will inspect other locations that have similar designs, but have not yet displayed any cracks.

The TJPA said its engineers and contractors were developing a shoring plan to relieve loading on the beams to prevent any further damage. It added that its team would open the station as soon as possible, then design permanent repairs.

Mark Zabaneh, TJPA executive director, said: “We apologise for this inconvenience to the public and commuters. I would like to assure the public, this is a localised issue within the transit centre and there is no impact to any adjacent properties.

“Additionally, our current analysis shows that this is contained within the Fremont Street area. The safety of everyone who visits the Salesforce Transit Center is our highest priority and we will work expeditiously to address and rectify this situation.”

A fissure located on flange on the bottom portion of the beam that spans over Fremont Street (Transbay Joint Powers Authority)

The San Francisco Chronicle reports that Skanska USA Civil West won a $189m contract for steel work on the project in 2013.

Skanska USA sued general contractor Webcor/Obayashi, saying that they were unable to “plan and execute the work in such a way as to mitigate damages due to delays and inefficiencies”.

The station was designed by Pelli Clarke Pelli Architects. It has 140,000 sq m of space and connects 11 transit systems to northern California. The designer says the centre has a “gently undulating wall, floating above the street on angled steel columns”.

Top image courtesy of the Transbay Joint Powers Authority