Contractors drill to record depths for downtown condo tower

Contractors building the 62-story One Thousand Museum condo tower drilled to Miami-Dade County-record depths earlier this week to lay the foundation for the ultra-luxury downtown building, the project’s developers said.

Workers at the construction site on Biscayne Boulevard drilled two shafts into the earth — one at a depth of 177 feet, the other at 171 feet — for pilings that will support the 709-foot-high building. The rest of the tower’s 225 shafts went down 155 feet, the required depth for its height.

The previous record for depth was 158 feet, held by the 60-story Porsche Design Tower in Sunny Isles Beach.

Kevin Venger, a co-developer of the One Thousand Museum project, said that tall towers in South Florida require deep drilling because the limestone rock layer needed to anchor the buildings usually lies 120 to 130 feet below sea level.

The contractor HJ Foundation drilled the shafts, which are 30 inches in diameter. In a process known as augercast piling, the shafts are then filled with concrete grout and reinforced with steel rebar.

Pritzker Prize-winning architect Zaha Hadid is designing the 83-unit project, which is located across the street from the Pérez Art Museum Miami and is selling at an average price of $1,300 per square foot.

Venger said the building will be finished by the fourth quarter of 2017.

Venger, Gregg Covin and Louis Birdman are partnering with the Regalia Group to develop the project.

This story was originally published April 3, 2015 at 5:24 PM with the headline "Contractors drill to record depths for downtown condo tower."