San Francisco's new $ 2 billion transit center is closed above its cracked beam: NPR

San Francisco officials temporarily closed the city's huge transit center after a crack was spotted in a steel beam on the ceiling. Structural engineers are now inspecting all the beams of the Salesforce Transit Center, which opened a month ago, at a cost of more than $ 2.1 billion.

The crack was discovered early Tuesday, but the stop was only ordered a few hours later, forcing more than 30 bus lines to be redirected at the start of the afternoon rush hour. A key underpass on the side of the building was also closed, traffic from the rumbling area.

"Motorists are advised to avoid driving downtown," the Transbay Joint Powers Authority said on Tuesday, adding that "transit drivers are encouraged to allow more time for their trips."

The closure is in effect "until further notice", according to the San Francisco Municipal Transit Agency.

The transit center is located in the newly named "East Cut" neighborhood, near the San Francisco-Oakland Bay Bridge. As the KQED member station says, it should be able to accommodate 100,000 passengers every day of the week and up to 45 million people a year.

Mark Zabaneh, executive director of TJPA, apologized for the delays and detours: "The safety of all who visit the Salesforce Transit Center is our highest priority and we will work quickly to remedy this situation."

Zabaneh added, "Although this seems to be a localized problem and we have no information indicating that it is widespread, it is our duty to confirm this before allowing the public access to the facility and to continue to do so.

In an update on Tuesday night, Zabaneh revealed that the crack had been found near a weld on a horizontal beam, according to the Associated Press. "The beam behavior is unpredictable," he said.

The transit center is supposed to be a jewel in San Francisco's infrastructure. It has a futuristic design, with a bulbous facade of white metallic lace facing the street, masking several bus lane decks. Its roof is landscaped with trees and plants – part of a nearly 5.5-acre park featuring theme gardens, performance spaces and restaurants.

The structure extends over nearly three blocks, with large glass panels bringing sunshine into the building. The transit platform was on the drawing board for decades and it took eight years to build it. It was opened last month with great success – and it is planned to launch an aerial tramway that can carry up to 20 people at a park level.

The transit center is located near several large-scale buildings in downtown San Francisco, including the new 61-story Salesforce Tower, which is connected to the site. The software publisher bought the transit platform naming rights early in the year, paying $ 110 million for 25 years, as reported by KQED.

This is not the only ambitious project to have problems in the region. The AP reports:

"The transit center is adjacent to another dubious landmark, the so-called shipwreck condominium, Millennium Tower, which has stood about 18 inches since it opened over a former landfill in 2009. The owners alleging that the construction of the transit center caused the sinking of the Millennium Tower. "

Zabaneh said he did not think crack was related to this flowing issue – and John King, the San Francisco ChronicleUrban design critic, accepted.

"The foundation of the transit center is a 60,000-tonne, 5-foot deep concrete floor," writes King for the Chronicle. "The work on the foundation was completed in 2014, and there has been no evidence of disturbing settlement since then."

King and the experts he consulted said that the analysis and resolution of the beam problem could take time, but at least one of these experts also noted that it was easier to repair and strengthen a steel beam.

According to KQED, future transit center projects include an 800-foot tunnel to connect it to fast transit trains in the Bay Area.