In the spring of 2016, residents of
Champlain Towers South flooded complaint hotlines to fume
about construction activity at the neighboring Eighty Seven
Park project that had jostled their walls, closed their pool
and coated their balconies in dust.
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Champlain Towers South collapses near the Eighty Seven Park building under a control demolition Sunday night, July 4, 2021. |
Most of the readings along the wall came
in over that limit, but under levels that would do
significant damage, according to mining industry standards.
The vibration levels recorded at Champlain’s southern
perimeter were above limits used by the Federal Transit
Administration to prevent damage to reinforced concrete.
Still, tremors from five years ago could not have been the
ultimate cause of the June collapse, and readings along the
wall were still well below levels likely to damage
structural concrete, said Dr. Manoj Chopra, a geotechnical
engineer with the University of Central Florida. There would
be no reason to suspect the degree of shaking noted in the
report would harm a healthy structure, he added.
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A photo of the Champlain Towers South pool deck shows the slab disconnected from the southern wall during the June 24 collapse. Damage in the failure plain is not uniform, indicating pre-existing damage to portions of the connection, according to engineer Dawn Lehman. (Photo Robert Lisman) |
NV5, the subcontractor responsible for
the vibration monitoring for Eighty Seven Park, told the
Herald, “the vibration monitoring results did not warrant
any action.”
Photos from a 2016 visual inspection commissioned by the
developers show concrete at Champlain South was cracking
prior to construction commencing at Eighty Seven Park.
Inspectors noted superficial damage along the southern wall.
Condo board documents from the time also acknowledged that
heavy planters along the southern pool deck had leaked water
for years and caused damage to the concrete below. The
collapse also exposed damage inside the pool deck slab where
it connects to the southern wall that likely wouldn’t have
been visible prior to the cave-in, said Dawn Lehman,
professor of structural engineering at the University of
Washington and consulting engineer to the Herald. Lehman,
who examined photos of the collapse site, said the slab
damage pattern along the southern wall was not uniform,
indicating that some areas had sustained damage prior to the
collapse.
“Photographic evidence shows that it was damaged such that
the concrete is broken into large chunks,” Lehman said.
That’s different from other areas that disconnected during
the collapse that didn’t show “any ‘rubble like’ damage,”
she said. But there likely wasn’t just one single cause of
the pre-existing damage to the slab, which was more like the
cumulative result of various stressors, Lehman said.
One of them could have been vibrations from construction
next door, she said. But the measurements in the report are
“just borderline,” according to Eduardo Kausel, a retired
Massachusetts Institute of Technology professor who
specializes in soil dynamics. “I seriously doubt that had
anything to do with the structural damage,” Kausel told the
Herald. Vibration readings were not taken at any other time
during construction, even when the foundation piles were
driven, according to the developers.
‘I have never seen that report’
In the months leading up to the construction of Eighty Seven
Park, Champlain Towers South preemptively hired an attorney
to demand “a reasonable compensation package for the
construction and unavoidable nuisances that will undeniably
result from” the development project, according to his
letter to developers.
In the November 2015 letter, Champlain South’s attorney
Robert Zarco flagged a concern about “potential structural
damage to Champlain Towers stemming from the driving of
steel sheet piling into the ground.” After construction
crews finished driving the sheet piles and the building’s
foundation, representatives for Champlain South followed up
with a $2.4 million demand in May 2016 for cosmetic repairs
and clean up, but didn’t mention any structural concerns.
There’s no indication that representatives of Champlain
South were ever made aware of the report that showed
vibrations from construction had exceeded the developer’s
limits. “I have never seen that report,” Zarco told the
Herald. He said he was specifically told to avoid structural
claims. “They said we’ll handle structural at the time of
the 40-year [inspection],” he said, referring to the
structural review all large condo buildings in Miami-Dade
undergo at that age.
Champlain South was due for its 40-year recertification this
year. One former condo board member, who spoke on the
condition of anonymity, told the Herald that residents were
complaining in droves about the nuisances associated with
the construction, and that the board was unable to do much
with the complaints. Surfside town officials often deferred
to the city of Miami Beach, which had permitted the
construction but did not come down hard on violations, the
board member said. “The key people responsible for
addressing the issues each had their own agenda and turned a
blind eye,” the former board member said. Data from the
vibration report could have quantified some of the
residents’ concerns. The March 2016 vibration report, which
was prepared by GeoSonics, a subcontractor of NV5detailed 35
readings taken to measure vibration along Champlain South’s
perimeter wall during the installation of sheet piles
between March 3, 2016 and March 14, 2016. All but six
exceeded a target level of 0.5 inches per second.
The 0.5 inches per second target — a measurement of the
movement of sediment at a given location — was based on
studies by the U.S. Bureau of Mines that found consistent
vibration at that level can cause cosmetic damage to
plaster. A higher threshold is typically used to gauge the
potential for structural damage, according to experts.
NV5, an engineering and consulting firm based in Hollywood,
cited a figure of 3.0 inches per second in its report as the
rate at which damage to “block and mortar” is possible. None
of the readings along the pool deck exceeded 1.0. The
Federal Transit Administration standards use 0.5 inches per
second as the limit for preventing damage to reinforced
concrete. A spokesperson for NV5 defended the company’s use
of the U.S. Bureau of Mines figures, calling them an
“accepted national standard” and saying the Federal Transit
Administration standards pertain to noise and vibration from
“cars, buses, trains and other vehicles.” But parts of the
FTA’s standards specifically address construction impacts,
noting that the construction activities that cause the most
severe vibrations are “blasting and impact pile-driving.”
Those impacts can be disproportionate for “fragile”
buildings, the agency said in a 2006 report. “Ground
vibrations from construction activities do not often reach
the levels that can damage structures, but they can achieve
the audible and feelable ranges in buildings very close to
the site,” the report said. “A possible exception is in the
case of fragile buildings, many of them old, where special
care must be taken to avoid damage.”
The developers maintain that the vibration report absolved
Eighty Seven Park of having any impact on Champlain South
with their construction, and that engineers checked for
indications of damage at the time. “We conducted a visual
inspection on the south side of the wall, which did not
reveal any issues from the installation of the sheet piles,”
said the spokesperson, who insisted on anonymity. “By
setting the benchmark at a conservative .5 in/sec., the
contractor was able to keep all of the vibrations below the
safe levels of vibrations for residential structures set by
the U.S. Bureau of Mines,” the spokesperson said. “At no
time did the vibrations approach levels that would have
caused structural damage to CTS.”
But lawyers for the collapse victims say it’s too soon to
know. On Wednesday, attorneys for the developers turned over
the report to victims’ lawyers as part of a court-ordered
release of documents. Stuart Grossman, an attorney and
liaison for a group of lawyers representing the victims,
said Thursday that a team of experts hired by the group is
reviewing the report. “No lawyer can tell you what the
report means, except to say it opens the door to the theory
we have long held — which is that Eighty Seven Park being
built right [next to] Champlain Towers South did it no
good,” Grossman said. ‘Very many complaints’ Construction of
Eighty Seven Park roiled Champlain South residents.
In January 2016, the condo association board sent out a
building-wide email with the construction noise complaint
hotline for Miami Beach. By March, the complaints were
piling up. “We have received the very many complaints and
concerns you each have expressed to Board Members as well as
the Management Office,” the board wrote to residents in an
email on March 14, the final day of vibration monitoring by
NV5. “These have included the recent oil on cars parked on
the street level, the vibrations to the building, the dust
and debris which is preventing access to balconies, the
noise from the very early morning food truck with blasting
music, the concern that workers begin to drill at 7 a.m. and
the debris and noise caused by the auger that is drilling
directly next to the pool which is preventing residents from
going to the pool.”
The project stretched on for years and continued to cause
ire among Champlain South residents. In January 2019, a
condo board member wrote to Surfside’s then-chief building
Ross Prieto, complaining that the Eighty Seven Park project
was “digging too close to our property and we have concerns
regarding the structure of our building.” The email that
board member Mara Chouela sent to Prieto included two
pictures of a backhoe working against Champlain South’s
southern wall along the property line. Less than a half hour
later, Prieto responded to Choluela’s request to stop by and
check on the situation. “There is nothing for me to check,”
he wrote back. “The best course of action is to have someone
monitor the fence, pool and adjacent areas for damage or
hire a consultant to monitor these areas as they are the
closest to the construction.” Eighty Seven Park was
completed later in 2019.