STAMFORD – Someone, it seems, failed to follow the building plan.
That’s the preliminary finding of an engineering firm hired by the city to investigate how part of an outdoor patio fell into the parking garage at a newly built luxury high-rise in Harbor Point.
The 20-foot by 15-foot slab that collapsed had no post-tension cables, which strengthen concrete, said John Cocca, an engineer with Wiss Janney Elstner Associates, the firm conducting an independent review for the city.
The slab that fell was a step-down from the exterior patio to the interior garage, so it had two levels, Cocca told the Board of Representatives’ Public Safety Committee Tuesday. The reinforcing cables were supposed to run from the lower level to the upper level, and out to the edge of the apartment building – the 22-story Allure at 850 Pacific St., constructed in 2019.
Instead, Cocca told representatives, “the cables terminated at the edge of the slab. It was not designed that way, so the design was modified at some point.”
His review, which is ongoing, revealed “some curious things,” Cocca said.
“There is a suspicion that some cables may be missing,” he said. “There is an area where we question whether all the cables that are supposed to be there are actually there. If so, we would have to extend the scope of the investigation to prove that cables are not missing from other areas of the building.”
Post-tension cables are made of high-strength steel strands wrapped in plastic. They are anchored to the building then pulled, or “tensioned,” after the concrete is poured. The cables reinforce concrete so slabs can be less thick and can extend longer between support columns.
There’s another possible problem, Cocca said.
“When a slab collapses, you lose tension in the cables. We have to see if other cables have been compromised or relaxed,” he said. “We are asking for inspection reports and sequencing documents to see how things actually were constructed in the field. Was anyone aware they deviated from the design drawings?”
The questions are for Stamford’s largest landowner and biggest developer, Building & Land Technology, which constructed Allure and several other apartment towers in Harbor Point, a major project on the South End.
The questions also go to Henderson Rogers, BLT’s design engineer of record for Allure and the coordinator of special inspection, and contractor Baker Concrete.
“We want them to carefully take the collapsed slab apart so we can tell where all the cables were, and take samples of the concrete and rebar,” Cocca said. “They’ve agreed to that.”
Representatives who sit on the board’s Public Safety Committee had lots of questions for Cocca, City Engineer Lou Casolo, Chief Building Official Bharat Gami and other officials they invited to their meeting.
City Rep. Phil Berns, a Democrat from District 16, said he is concerned about the tenants of the 435-unit Allure.
“If there are areas of limited safety, or possibly catastrophic problems, at what point do we start to question whether it is still habitable?” Berns asked.
Gami replied. “As we continue to investigate, we will know.”
BLT’s engineers have said Allure is structurally sound and the Feb. 1 collapse was an isolated incident.
City Rep. Bradley Bewkes, a District 1 Republican, wondered why the special inspector, required by the state to oversee construction of new buildings, didn’t see that the concrete work failed to conform to the design plan.
“Isn’t the special inspector supposed to be on site every day of construction?” Bewkes said.
“Correct,” Gami said.
Cocca said he is reviewing the special inspector’s report.
City Rep. Virgil de la Cruz, a Democrat from District 2, brought up another Harbor Point building, The Lofts, a converted 1900 lock factory with 225 apartments. Two-thirds of the tenants had to move out in July because the building is sinking, and the rest must be out by April 30. BLT built The Lofts but sold it to GAIA Real Estate in 2016.
“We have two major developments that have serious structural problems,” de la Cruz said. “So something must be wrong somewhere in the process.”
City Rep. Nina Sherwood, a District 8 Democrat, said she sees a pattern.
“It’s no secret that these buildings go up very fast, that permits are given really quickly. The city has a lot of dealings with BLT, and BLT has unlimited resources. The city has a lot to lose if it does not have a great relationship with them,” Sherwood said. “People need to feel their municipal government will be uncompromising with their safety even in the face of an entity that is incredibly powerful and politically connected. The city needs to take a hard, independent look at more than just Allure.”
A BLT spokesman said the developer has a decades-long history with the city and has worked with elected officials and stakeholders “to construct buildings and communities that we proudly stand behind.”
“From start to finish, we follow the design, permitting, and construction review process developed by the city and state to ensure the safety and quality of our buildings. At Allure, third-party structural engineers, as well as City of Stamford officials, have repeatedly stated that the building — where we, too, live and work every day — is safe for residents.”
BLT is working with the city “on the plan for repair and further inspections, to ensure that issues are limited to this specific area,” the spokesman said. “We are committed to serving our residents and the greater Stamford community, which is why we take any resident concern very seriously and our responsive and dedicated team is on site to address any issue.”