Late last week, Transbay Joint Powers Authority officials in San Francisco approved plans to repair a pair of fractured beams that were discovered at the now-shuttered Pelli Clarke Pelli Architects–designed Transbay Transit Center last fall. The plan calls for the installation of four sets of new steel reinforcing plates to shore up the failing members, The San Francisco Examiner reported. The peer-reviewed repair plans were approved in late December by the Metropolitan Transportation Commission (MTC), a transportation agency that works across the nine-county San Francisco Bay Area. MTC’s preliminary investigation concluded that the issues with the fissured beams were linked to the presence of welding access holes that had been cut into the beams to facilitate their installation. In all, four beams will be reinforced under the repair plan: the two fractured beams spanning over Fremont Street and a pair of corresponding but uncompromised beams located on the opposite side of the building. According to the report, the steel plates will be bolted together above and below the areas where the fractures occurred on each beam. A date for reopening the center has not been set, but authorities are at work on a construction schedule for the repairs. A further update to the plans will be presented to the board of the Transbay Joint Powers Authority later this week. The $2.2 billion transit center opened to much fanfare in August 2018 but closed just a few weeks after its debut because of the construction faults. The transit center spans three blocks and is capped by a 5.4-acre park designed by PLP Landscape Architects. Thornton Tomasetti is the design engineer for the project. The center has been closed for over 100 days and commuters have gone back to using a temporary bus depot that had been in operation during construction for their daily transportation needs.
Posts tagged with "San Francisco":
Preservationists in Twin Peaks, San Francisco, were aghast this past December when it came to light that much of a 1935 home designed by Richard Neutra had been illegally demolished months prior. Owner Ross Johnston had purchased the 1,300-square-foot 49 Hopkins Avenue—also known as the Largent House—for $1.7 million with plans to replace it with a 4,000-square-foot mega-mansion in 2017. Only the home’s garage door and frame still stand today, but on December 13, the City Planning Commission unanimously ruled that Johnston must build an exact replica of the house, as well as a plaque detailing the building’s history. The Largent House was one of only five buildings designed by Neutra in San Francisco. The two-story, whitewashed-concrete-block and redwood-timber building made ample use of glass bricks to let in natural light and included a greenhouse-like glass topper to enclose an indoor pool. The plague of illegal demolitions by San Franciscan homeowners hoping to build big or flip the property is widespread, and punitive repercussions are rare. The city is in the middle of a housing crisis, and when faced with the option of forbidding offenders from building on the demoed lot, the Planning Commission has let homeowners off the hook. Not this time. Johnson applied for a demolition permit and permission to build his new house two months after the home was razed, arguing that a fire in 1968 and remodels throughout the 1980s and ’90s had removed the home’s architectural significance. Rather than flipping the plot of land, Johnson claims that he was only building something that could accommodate his six-person family and that the demo was undertaken for safety and quality of life reasons. The Planning Commission disagreed, and in a 5-0 vote, ordered Johnson to rebuild the Largent House. Planning Commissioner Dennis Richards hopes that the move, along with the recently proposed Housing Preservation and Expansion Reform Act, which harshly penalizes illegal demolitions, would help curb speculation in the housing market. “The fact that it was a unanimous vote should send a message to everyone that is playing fast and loose that the game is over,” Peskin told the San Francisco Chronicle. “We want to preserve iconic, historic structures, but even more important, we want to protect our reservoir of more affordable housing stock. You want a 1,300-square-foot house to be worth what a 1,300-square-foot house is worth, rather than a mega-mansion.” Unfortunately, this isn’t a shocking story in 2018, as a number of architecturally significant homes, including a Venturi Scott Brown–designed house in Pittsburgh, faced under-the-radar demolitions and renovations.
Nearly three months after a pair of cracked steel beams were discovered at the Pelli Clarke Pelli–designed Transbay Transit Center in San Francisco, crews investigating the structural failures have begun to piece together what might have gone awry. According to recent investigations, the beams in question were not only fabricated with imperfections that rendered the steel more brittle and weaker than specified, but they were also altered by the fabricators before they were installed in a way that differed from the shop drawing designs that had been initially approved for the project, The Mercury News reported. The changes include the addition of so-called “weld access” or “weld termination” holes along the web of each joist to make installation easier. While it is still unknown exactly which type of openings were made in the beams—there are key design differences between the two types of holes—the resulting change is thought to have created an imbalance in how the loads from the building above were delivered down to the transit center’s foundations. As the center came under regular use, the buses and crowds that occupied its upper levels put enormous strain on the compromised beams, resulting in the debilitating fissures. The Mercury News reported that Stockon, California–based Herrick Corporation, the company responsible for fabricating the steel beams in question, prefers to refer to the openings as “weld termination” holes because those openings are less strictly regulated than “weld access” holes, which have more stringent design and finishing requirements. Design engineers Thornton Tomasetti have not provided comment regarding the nature of the openings in question. Robert Hazleton, president of Herrick Corporation told The Mercury News, “It may sound like a small thing, but it does change how you finish the inside of the hole,” adding, “There are less specific requirements for a weld termination hole.” The stresses resulting from the new openings compounded the inadequacies of the steel members, according to the report, which also highlighted a lack of specificity regarding these types of failures in San Francisco’s building codes as a key oversight in the building’s design. Potential fixes for the beams include welding supplemental steel plates to each member to improve their rigidity, though the Transbay Joint Powers Authority, the public agency tasked with building and maintaining the terminal, will not have a specific plan for repairs or an estimated date for reopening the $2.2 billion complex until January 2019. Until a final cause and remedy are found, San Francisco commuters will continue to use the temporary bus terminal created during construction of the Transbay Center for their transportation needs.
With Minneapolis, San Francisco, San Diego, and Los Angeles moving forward with progressive land-use and transportation reforms last week, much of the conventional thinking behind how American cities work could soon be upended. As the converging threats of climate change, housing unaffordability, and pollution continue to hamstring the country’s urban areas, cities across the country are taking matters into their own hands by enacting bold but common-sense reforms in the face of federal and state inaction. For one, a groundbreaking comprehensive plan update in Minneapolis that would eliminate the city’s single-family zones took a step forward last week after two years of public debate and negotiations. The so-called 2040 Minneapolis Plan would make the city the first in the country to upzone all of its single-family residential neighborhoods to allow up to three dwelling units per lot. Under the 2040 initiative, the city will be able to re-establish a tradition of building what’s known as “missing middle” housing, the types of naturally affordable small- to medium-scale neighborhoods that make up the backbones of most American cities built before the 1950s. The plan is designed to break down racial and income disparities between neighborhoods in the city while allowing Minneapolis to absorb expected job and population growth over coming decades. Housing activists across the country are now looking to Minneapolis to see how the experiment plays out as efforts to enact similar policies pick up across the country, especially in Seattle, where a similar effort is gaining steam. In Oregon, a plan to eradicate single-family zoning in cities with 10,000 or more residents took a step forward this week. Aside from taking on exclusionary zoning, other cities, including Buffalo, San Francisco, and San Diego, are looking to eliminate off-street parking requirements to varying extents as they work to reclaim the enormous amount of space taken up by parked cars. In 2017, Buffalo became the first municipality in the country to totally eliminate parking requirements city-wide. The effort comes as part of a new zoning initiative that will bring what is known as a “form-based code” (FBC) to the city. As the name implies, FBCs typically regulate the overall geometries of urban areas by setting particular height limits, setbacks, and other design guidelines that can be followed regardless of use. The approach runs counter to more common use-based codes that carve cities up into monofunctional areas with residential, industrial, and commercial districts. FBCs are seen both as a way of re-establishing mixed-use neighborhoods while also creating contextual and preservation-friendly zones. With the update, Buffalo joins Denver, Las Vegas, and Miami, which have also recently enacted FBCs. Over in California, as the state’s new legislature takes up a series of bold housing reforms, San Diego Mayor Kevin Falconer is one step ahead with a proposal to scrap parking requirements for transit-adjacent areas. A new proposal would eliminate required parking for housing located within 1/2-mile from a transit stop, a change similar to a state-wide effort that was derailed last year. The latest effort, according to the mayor, will be geared toward lowering the cost of building housing—a single parking stall adds between $35,000 and $90,000 in costs per unit of housing in the state—while also resulting in shorter and less bulky buildings. San Francisco has taken the proposal one step further by moving to become the largest city in the country to scrap parking requirements outright. City Supervisor Jane Kim put forward a measure this month to totally eliminate the requirement city-wide in an effort to bolster the city’s climate bona fides and help reign in housing costs. But don’t call it a “parking ban,” developers will instead be allowed to build parking up to a maximum threshold if they deem it necessary. The yet-to-be-approved initiative could go into effect next year. Nearby, Sacramento is working to enact a city-wide transit-oriented development plan that would limit drive-through restaurants and gas stations and lower parking requirements within 1/2-mile from transit stops in the city. Change is afoot even in car-loving Los Angeles, where an ambitious but currently under-funded plan to build 28 large scale transit projects by the 2028 Olympic games has prompted local officials to consider so-called “congestion pricing.” No official plan has been unveiled, but the Los Angeles Metro CEO Phil Washington last week presented several ideas that could potentially fill the funding gap, including requiring drivers to pay for traveling in some of the city’s most congested areas. To boot, Curbed reported that during a presentation to the Metro Board of Directors, Washington even proposed using the fees generated from congestion pricing to make Los Angeles the first city in the United States to offer free public transportation every day of the year.
After eight years of negotiations, the San Francisco Board of Supervisors approved the Central SoMa Plan on December 4, paving the way for a massive density increase, transportation improvements, and infrastructure investments in the heart of the city. The final plan for Central SoMa (South of Market), an area bounded by 6th Street to the west and 2nd Street to the east and Townsend Street to the south and Market Street to the North, ended up at over 1,600 pages (available here). The resultant “eco-district” is aiming to be socially, environmentally, and economically sustainable by 2040, in part by ensuring a diversity of businesses call the neighborhood home. Among the many changes, heights of 400-feet-tall are now on the table for certain developments. The plan allows for an additional 8,800 units of housing—33 percent of which must be affordable—as well as office space for up to 32,000 new jobs. $600 million will be allocated towards transportation infrastructure improvements, including mass transit options, sidewalks, and bike lanes. $64 million will go towards neighborhood schools to accommodate the influx of new residents, and an additional $185 million will go towards improving the area’s existing parks and public spaces, as well as the construction of new civic spaces. $100 million will go towards social programs and the upkeep of the neighborhood’s historic buildings. An unspecified amount of funding will be set aside for stormwater management and projects that will improve air quality, and the plan requires that Central SoMa transitions to non-greenhouse gas-based energy sources. Green roofs and walls will also be required. Hotels, retail, and entertainment options will be incentivized, and the plan looks to include light manufacturing in an Urban Mixed Use zone, which will create a buffer between the residential district and the Eastern Neighborhoods. Such an ambitious zoning update naturally met resistance. Before the December 4 vote, four lawsuits against the project had to first be dismissed by the Board of Supervisors. Community groups took the city to task over fears of gentrification and concerns over increased air pollution owing to the forecasted increases in traffic. A third group, the developer One Vassar LLC, filed a motion because they felt the plan wouldn’t increase housing enough in proportion to the amount of expected office space. Now that the Central SoMa plan has essentially been approved, height limits in the area will gradually rise over the next 22 years, first to 85 feet from the current 30, then to 130 feet, and finally 400 feet.
The Transbay Joint Powers Authority (TJPA) board of directors has called for a complete structural evaluation of the Pelli Clarke Pelli–designed Transbay Transit Center in San Francisco after installation crews discovered failing steel structural beams there in September. Now, over a month later, the transit center has been closed for longer than it was open as crews work to discover what went wrong. This week, representatives from TJPA, structural engineer Thornton Tomasetti, contractor Webcor/Obayashi Joint Venture, steel fabricator Herrick Corporation, and material supplier ArcelorMittal are all convening in New York to study material samples that were removed from the failing girders for further analysis. Engineering News Record reported that crews discovered bottom-flange cracks near the midpoint of one of the eight-foot-deep shop-welded girders. A second, more serious fracture was discovered running the entirety of a flange on the second beam. The two beams run parallel to one another over an 80-foot span running over Fremont Street. At a recent meeting, the TJPA board called for a complete structural evaluation of the 1.2 million-square-foot transit center in order to inspire public confidence in the structure’s safety and design. Ultimately, however, TJPA officials currently have no idea why the beams failed and because the fissures were discovered by accident, it is unknown if other areas are prone to fail, as well. At the meeting, one TJPA board member asked, “Was the engineering done right?" before adding, “We need assurance." The structural review team will now work to understand what happened before making design recommendations for how to fix the problem. Once a consensus is reached regarding on the cause of the girder failures, engineers will design a permanent fix that will also be peer reviewed to ensure its safety, Engineering News Record reported. TJPA projects that repairs will begin in December and take several months to complete.
New York–based architects Perkins Eastman and engineers Arup have unveiled the latest batch of renderings for San Francisco’s Harvey Milk Plaza. The updated designs were submitted to city agencies this week in an effort to begin the formal approval process for the renovations envisioned for the plaza and its associated Muni subway station. The extensive renovations come as the city works to perform required Americans with Disabilities Act (ADA) upgrades for both facilities, including the addition of an elevator that will connect the street level to the subway platform. Backers for the project also seek to boost the plaza’s function as a memorial to Harvey Milk, San Francisco’s first openly gay elected official, and to create a new gateway into the city’s Castro neighborhood. Perkins Eastman was selected in 2016 as part of an international design competition held by Friends of Harvey Milk Plaza (FHMP), the volunteer group with business connections in the neighborhood. The latest renderings for Harvey Milk Plaza come after a previously-released iteration of the design was met with community opposition. Perkins Eastman revised the plans following four community workshops over the summer. The initial designs featured red paving and a uni-directional “stramp” (stair-ramp) that crossed the site going toward the west to create an elevated community amphitheater with the subway entrance located below. The new plans have flipped the arrangement by rotating the amphitheater and subway entrance 180 degrees so that they are located at the easternmost corner of the site, where it is expected that foot traffic would be greatest. The center of the plaza is now marked by a new elevator with the western edge of the plaza populated by low-slung benches and a grove of trees. The plaza bearing Milk’s name was planned before his death and was not named in his honor until 1985—Milk was assassinated in 1978— and according to FHMP, “the public has longed to see [the plaza] transformed into a place that captures [Milk’s] spirit; a place that embodies [Milk’s] passion to bring people together and see that all are treated with dignity and given voice at the tables of influence.” The plaza redesign is more-or-less the product of community input, Hoodline reports, a delicate dance the designers and organizers have played with local residents as they seek to win on-the-street approval for the project. The designs, however, are relatively unloved by San Francisco Chronicle urbanism critic John King, who has lamented that the plaza would weaken the vitality of the district’s street life by pulling pedestrians away from its key attractions. King added that the proposal’s function as a true memorial to Milk’s legacy could better be suited by other means, as well. King said:
If the desire is to celebrate Milk’s life and legacy, it might be easier to freshen up the current plaza and create an ongoing fund for its maintenance. Then, install plaques or informative artwork along the bridge-like walkway to Collingwood Street, a path that has serenity despite its surroundings.The design for the proposal is by no means finalized, however. As the bid makes its way through the approval process, changes and new approaches are sure to be recommended. A timeline for final approval and completion of the plaza has not been announced.
A few years ago, it would have been impossible to predict that Casper, a startup with a single product, would launch an entire industry of mattresses ordered sight unseen online and become a global sleep powerhouse. It was inevitable that the company would outgrow the house where it was brainstorming the next breakthrough. That its new prototyping space, Casper Labs, is now based in a former industrial laundry service in San Francisco’s Mission District is an apt metaphor for the city’s tech-driven transformation. The company tapped hometown design firm Spiegel Aihara Workshop (SAW), led by principals Dan Spiegel and Megumi Aihara, to convert the warehouse space into its R&D headquarters. SAW’s design for the 11,500-square-foot, two-story office attests to the demands of an industrial workspace where mattresses and heavy prototypes are tested and hauled around. But it is also filled with nods to the company’s association with pillowy softness. The architects achieved this with an unlikely material—corrugated steel in a range of perforated profiles that are meticulously layered to read like fabric. “With a rough industrial material, it was about finding ways to give it a textile nature,” explained principal Dan Spiegel. “Once we had that in play, we could experiment with transparency.” On the ground floor, the white, powder-coated steel unravels at different heights, wrapping the metal shop, a testing lab, and a wood shop with rounded corners that reference the company’s iconic mattress. The opaque surface fades to a translucent screen as it rises above eye level. In other areas, the steel walls mask storage and service areas through a one-way transparency, admitting natural light without allowing views in. This play between opacity and transparency is further demonstrated in the entry area, where the Casper logo glows behind a corrugated surface. All it takes is the flick of a light switch for the letters, along with all the other signage in the space, to disappear. “We like the mystery that set up,” said Spiegel. “Even though there’s a lot of what ended up being opaque surfaces, you could begin to imagine that all of them had something going on just behind that skin.” With much of the program left open-ended for collaboration, the main work areas feature doorless openings lined in oiled steel plate that echo the steel columns that came with the space. The custom entryway desk continues the motif of rounded corners and transparency but incorporates a warm wood framing that takes its cue from the wood joists in the ceiling, with the whole piece sliding easily out of the way to access storage beyond it. Another design touch that highlights the tension between heavy and light, the industrial and the domestic, hovers above the common area for all-hands meetings. There, SAW’s custom lighting fixture floats like a geometric cloud composed of 117 Casper pillowcases folded and twisted onto a welded, tubed steel frame. It is details like these that elevate the lab beyond a typical industrial facility and gesture at the space’s raison d’être: a good night’s sleep.
A report issued by the Applied Technology Council, a group of independent engineers organized at the behest of the city of San Francisco, has concluded that building codes in the city are woefully inadequate with regard to seismic safety. According to the report, while structural codes in the city are written in order to ensure that buildings will not collapse in an earthquake, they pay little attention to whether the impacted structures will continue to be suitable for occupancy following a disaster. Specifically, the panel has called for inspecting and retrofitting existing tall buildings while also suggesting that stronger structural regulations are needed for new towers, The New York Times reports. In addition, the panel has recommended that structures be designed with a greater degree of rigidity and that infrastructural elements like plumbing, elevators, and electrical and information technology systems be built to a higher quality. The expert panel was organized during the tenure of late San Francisco mayor Ed Lee in response to the slow-moving catastrophe occurring at the Millennium Tower site in the city's central business district. There, the Handel Architects–designed tower has been listing to one side. Overall, the tower 58-story tower has sunk over 18 inches with no sign of stopping. The uneven distribution of the tower's settling has created potential fire hazards as the cladding on one side has begun to pull apart. The city even threatened to "yellow tag" the structure after a window on the 36th floor cracked over Labor Day weekend. The report's urgency has been underscored by recent structural failures at the Salesforce Transit Center, where a pair of structural steel beams supporting the terminal's rooftop park have cracked. The transit center has remained closed for the two weeks since and no projected opening date has been announced. Authorities are currently inspecting the structure and beginning to repair the fractured beams. The officials behind the new report have created a database of tall buildings that lists which structural systems were used for every tower. The list is part of an effort to spread awareness of the structurally-deficient welded steel moment-frame structural technique deployed in high-rises between 1960 and 1994. Structures built using this system are thought to be at risk of failure during the strongest possible earthquakes. The database lists 39 towers, including William Pereira's TransAmerica Pyramid and John Portman's Embarcadero Center, among others. The full report, titled Tall Buildings Safety Strategy, can be found here.
Long considered an environmental steward and an urban booster, outgoing California governor Jerry Brown has signed a series of pro-density and housing-friendly bills into law as the final legislative session of his last term as governor draws to a close. Among the issues supported by the spate of bills are: efforts to build more densely around transit stations in the San Francisco Bay Area; a desire to enshrine Obama-era federal fair housing guidelines into California law; and plans to force wealthy municipalities to build their fair share of affordable housing. A list of some of the significant legislative gains signed into law by Governor Brown follows: AB 2923 Assembly Bill 2923 settles a long-running battle to give the Bay Area Rapid Transit (BART) authority a greater degree of control over the land that it owns surrounding its transit stops across the Bay Area region. The land in question is currently subjected to many of the strict density limits imposed by surrounding housing-adverse communities. The enaction of the bill will allow for up to 20,000 new housing units—35 percent of which would be affordable housing—to be built on the roughly 250 acres the authority owns by 2040. In a statement, BART general manager Grace Crunican celebrated the victory by sounding a conciliatory tone. She said, “Although AB2923 directs BART to adopt new transit-oriented development (TOD) zoning standards for each BART station, I want to assure community leaders and residents that BART is committed to continuing our collaborative approach. We have found that working closely with neighborhoods and local elected officials to consider community needs is not only respectful, it's the most efficient way to get the job done.” The measure gives local municipalities two years to update their zoning plans to accommodate the new housing or risk losing all control over BART-associated projects currently under their jurisdiction. AB 686 Assembly Bill 686 would require any housing- and community development–focused public agency to administer its programs and activities in a manner that supports the Affirmatively Further Fair Housing (AFFH) efforts of the 1968 Fair Housing Act. The bill represents an effort to enshrine those protections—as well as Obama-era fair housing programs—into California law amid a federal restructuring of fair housing priorities under the current administration. Housing and Urban Development Secretary Ben Carson has referred to AFFH unironically as a “social-engineering scheme” despite the fact that AFFH efforts serve to counter the long-standing legacy of federally-enacted and enforced racial segregation and redlining in American neighborhoods. Secretary Carson is currently working to “reinterpret” AFFH goals, which many racial equity activists have interpreted as an effort to dismantle the guidelines entirely. AB 1771 Assembly Bill 1771 aims to reform California’s Regional Housing Need Allocation (RHNA) law in order to make regional housing planning more data-driven and transparent by ensuring that high-income, job-rich cities plan and zone for affordable housing. The bill represents an effort to force wealthy cities like Beverly Hills and those surrounding San Fransico to plan for additional affordable housing so that existing low-income communities are not solely saddled with the burden of producing more housing. There is an emerging trend showing that these low-income communities have seen concentrated growth in both new market rate and affordable housing, a phenomenon that has fueled displacement and gentrification. AB 1771 aims for an initial and partial fix by beginning to hold wealthy areas responsible for producing their fair share of affordable housing. SB828 Last but not least, State Bill 828 would reform the methodology California uses when setting local housing goals for the RHNA mentioned above. Moving forward, the state will use several data-based metrics, including the percentage of renter households that are overcrowded and current vacancy rates, to calculate each municipality’s new RHNA goals. The newly-enacted laws follow several years’ worth of legislative gains for housing advocates in the state. However, the efforts have yet to meaningfully reduce the number of rent-burdened households in the state and have had an even smaller impact on racial segregation or access to homeownership for low-income households. These issues are expected to take center stage for California’s next governor when they take office in 2019 following the November election.
A second cracked steel structural beam was discovered at the Salesforce Transit Center in San Francisco Wednesday during an overnight examination, The San Francisco Chronicle reports. AN reported the initial cracked beam Tuesday afternoon. The Chronicle reports that the initial fissure discovered in a steel structural beam supporting the transit center’s 5.4-acre, PWP Landscape Architecture–designed park measures roughly 2-1/2 feet long by four inches deep and runs across the bottom of a 60-foot-long spanning element located above Fremont Street between Mission and Howard Streets on the transit center’s east side. The second damaged steel beam that was discovered runs parallel to that element and features a crack that is "slightly smaller," according to the report. As a result of the escalating situation, the transit center will remain closed at least through October 5 as crews work to investigate other elements of the structure, according to the Transbay Joint Powers Authority (TJPA), the entity that oversees the transit center and managed its construction. Pelli Clarke Pelli Architects designed the terminal as well as the Salesforce Tower located next door. During a news conference Wednesday afternoon, Mark Zabaneh, executive director of the TJPA, said, “We will not open the transit center or Fremont Street until we are certain the issue is 100 percent rectified.” Officials at TJPA are worried the structural elements might fail and are therefore operating with a high degree of caution with regards to keeping the transit center closed. The steel beams in question were fabricated in Stockton, California, by Herrick Corp. as part of a $189-million contract struck between Skanska USA Civil West of New York and TJPA. TJPA authorities are inspecting the structure with the project contractors—Webcor and Obayashi entered into a joint venture for the job—and structural engineering firm Thornton Tomasetti, which was the engineer of record for the structure and also performed construction work on the building. Those authorities also plan to bring in independent engineers to reassess the facility’s design. AN will continue to report on this story as it develops.
The recently-opened, $2.2-billion Pelli Clarke Pelli Architects–designed Salesforce Transit Center in San Francisco was closed unexpectedly this afternoon after a major crack was discovered in a steel beam that supports the structure's 5.4-acre roof garden. The fissure is located on the third level bus deck on the eastern side of the transit center. Bus operations that serve the terminal were rerouted back to the so-called “Temporary Terminal,” a makeshift bus depot at Howard and Main Streets that was used while the transit center was under construction over the last eight years. Mohammed Nuru, chairman of the Transbay Joint Powers Authority, the entity that oversaw construction of the transit center, told The San Francisco Chronicle, "I'm told there's a problem with a steel beam," without elaborating further. NBC Bay Area reports that Mark Zabaneh, executive director of the Transbay Joint Powers Authority issued the following statement:
“The safety of everyone who visits the Salesforce Transit Center is our obligation and highest priority. While this appears to be a localized issue and we have no information that suggests it is widespread, it is our duty to confirm this before we allow public access to the facility."Thornton Tomasetti, the engineer-of-record for the project, did not immediately respond to requests for comments for this story. PWP Landscape Architecture was the landscape architect for the project. It is unclear if the issue at hand is in any way related to recent reports of the pothole-like depressions that have been spotted along the walkway of the rooftop garden in recent days. The nearby Millennium Tower designed by Handel Architects has also suffered mysterious structural anomalies since it opened in 2016. A recent report indicates that the structure was leaning as much as 18 inches to the west. AN will continue to monitor the situation and report updates as news on the transit center takes shape. Update 10:30am PST: The streets around the transit center remain closed this morning as crews work to inspect the structure for further anomalies. Reports indicate that the cracked support member was last inspected a year ago and that it is made from American-produced steel. Salesforce Transit Center officials have planned a news conference for noon Pacific time to provide an update on the investigation.