With less than a month to go before the 28-story Capital Plaza Tower is to be demolished in downtown Frankfort, the state has started to answer questions about special safety measures locals must take on implosion day.
On Friday, the Finance and Administration Cabinet issued the first of what it says will be a series of compiled questions and answers leading up to the tower’s implosion on Sunday, March 11, at 1:30 p.m.
On implosion day, workers will set up a 700-foot square buffer on all sides of the tower. This “exclusion zone” will be off-limits to all but homeowners in the area and Capital Plaza Hotel occupants on the day of the implosion, a news release said. The exclusion zone is designed to mitigate risks related to noise and debris, which is expected to be contained in the space bounded by Wilkinson Boulevard, Hill Street, St. Clair and Mero Street — all of which are well within the exclusion zone, the release said.
Residents and hotel guests in the exclusion zone will be required to remain indoors, with windows and doors closed, for the period starting 45 minutes before implosion to approximately 15 minutes after the implosion.
In the week to 10 days leading up to the implosion, implosion subcontractor CDI will meet with nearby building owners to inform them of the procedures that will be in place on the day of the implosion and to answer any questions, the release said. In its 67-year history, CDI has imploded more than 8,000 structures, including Louisville’s 24-story Commonwealth Building in 1994, according to the release.
Dust presents the “main unknown” following the implosion.
“How far the dust travels will depend on wind speed and direction that day,” the release said. “To help lessen the dust, for the last several months, the demolition contractor has been removing the majority of dust producing materials from the building such as drywall, plaster, ceramic tile, and carpet. Also, all hazardous building materials such as asbestos containing materials have been removed during the pre-implosion demolition process.”
The state is expecting most of the dust to settle within 15 minutes to 30 minutes of the implosion and says that surrounding homeowners don’t necessarily need to shut off air vents during that time. Workers will begin dust cleanup as soon as they are cleared to return to the site, the release said.
To minimize ground vibration, the implosion is specifically designed to “curl” the tower in on itself as it falls, the release said.
“The ground vibration is from the impact of the structure with the ground, not the explosives,” the release said. “The contractor is preparing a ‘building pad’ in the area where the building is expected to impact the ground, which will serve to additionally soften the impact and cause the seismic vibration to not be transferred to the bedrock below. The physical feeling of the vibration is difficult to quantify because of the uniqueness of each project. However, some describe the feeling is similar to standing next to a fast moving train or a thunderstorm.”
The state says it anticipates that the implosion will cause “little or no vibration to nearby structures” and that in the “highly unlikely event” that damage results from the implosion, subcontractor CDI will be liable and will be required to repair the damage.
To comply with federal and state regulations, CDI is required to have an independent geotechnical consultant inspect all structures within the exclusion zone for any pre-implosion damage and any alleged damage post-implosion, the release said. The Finance Cabinet’s Division of Engineering will review these surveys and they will also be provided to each property owner whose property is inspected.
On the day of the implosion, that same third-party consultant will measure ground vibration levels and compare them to the U.S. Bureau of Mines vibration criteria for residential/commercial structures to verify the implosion went as planned, the release said.
The state expects the actual implosion to last less than 30 seconds, though nearby roadways temporarily will be closed beginning no later than 12:30 p.m. and will reopen approximately 15 minutes after the implosion. Street-closure details have yet to be finalized, the release said.
Pets in the exclusion zone should also be sheltered indoors. For owners of pets that are typically unsettled by thunder or other loud noises, the state is recommending owners take precautions as they normally would during a storm.
The 28-story, 330-foot Capital Plaza Tower opened in 1972. Lexington developer-contractor team CRM/D.W. Wilburn began work on Capital Plaza redevelopment in December when they won a “built-to-suit” contract from the state. In a built-to-suit project, a private firm receives annual lease payments from the state for designing, building, financing and operating a building until the state buys back the property.
In exchange for leveling the area and building a replacement state office building, CRM/D.W. Wilburn will receive annual lease payments from the state of $7.3 million for 30 years starting in 2020. The team constructed and operates the state office building at 300 Sower Blvd. under a similar agreement.
CRM/D.W. Wilburn’s demolition contractor is Renascent, which is subcontracting implosion of the actual tower to Maryland-based CDI (Controlled Demolition Inc.).