Building Charlotte's Third Ward
Atlanta-based Novare Group, one of the Southeast's leading developers of high-rise residential communities, has expanded its plans for development of the Third Ward in uptown Charlotte. The company has two major projects at different stages of construction currently under way.
R.J. Griffin & Company is the general contractor on Avenue, Novare's 36-story high-rise retail and condominium project at Church and Fifth streets. Featuring a 34,000-square-foot parking deck, 6,000 square feet of retail and 26 stories of living space, Avenue is scheduled to top out in spring 2007.
R.J. Griffin Group Manager William "Scott" Grigg explains that the project started with a bare site so no demolition was needed. After removing top soil, foundation work began with an H-pile system. Originally, the foundation design called for subcontractor American Deep Foundation to drive 710 H-piles, but after problems arose with the sound resonating from the pile driving, the foundation was redesigned halfway through the process to an auger cast system.
"We back up directly against the IJL building. We were getting production of four to five piles a day because they were going 80 feet plus," says Grigg. "It was taking too long to get them in the ground, and the constant hammering was just too much for the surrounding area. We had a center core section that had around 330 piles in it. We were allowed to get through that, but after that we actually had to go through a redesign on the foundation. We converted to auger cast."
These tight site conditions and the close proximity to existing structures have meant challenges for R.J. Griffin throughout the project. The neighboring Latorre's restaurant is housed in a historic structure on the southeast corner of the project. R.J. Griffin found that the building sat directly on a dirt foundation, raising additional concerns that the pile driving process would affect the structure. R.J. Griffin brought in Vibra-Tech to analyze the structure and monitor the building during pile driving, and the building was unaffected.
Grigg explains that construction also had to proceed around an existing drive used constantly by delivery trucks to access a loading dock on the back of the IJL building.
"(This drive) serviced 18-wheelers, and there were hourly deliveries. So, we had an existing drive cutting right through our project that we had to maintain during the foundation and the shoring construction process," says Grigg. This process became more complicated when the foundation went from H-piles to the auger cast piles.
R.J. Griffin coordinated the project so that foundation work proceeded on one side of the site, while a temporary road allowed deliveries on the other side. Everything then switched places to continue.
"That was difficult to coordinate," says Grigg. "It was a matter of us coordinating how we're going to put the foundation in, especially if you're doing an auger cast system. You can drive piles into the ground in a systematic manner all the way around your project site. (However,) with auger cast you have to wait for that pile to set up before you move to the other one. You can't do them side-by-side. This meant a lot of preplanning and picking out sections for the piles and doing those while maintaining the road."
Once the foundation was complete, R.J. Griffin brought in a tower crane to go vertical. The city allowed one lane of adjacent Church Street to shut down, which allowed R.J. Griffin to erect the crane outside the building. Scott Grigg explains that a typical tower crane structure is built into the foundation or a substructure; however, because of the tremendous amount of duct bank and structures running down Church St., R.J. Griffin had to go to a city base configuration for the crane.
"This crane looks like it's sitting on top of the ground, and it really is," says Grigg. "We supported it by strategically locating four piles in and around those utilities. You then have a city base, which is a huge chunk of concrete. The crane sits on top and you put weights on the outriggers. It typically ties back into the structure."
Work has flowed continuously on the condominium tower which features typical floors. Due to the configuration of the slab and the elevator wells, Superintendent Wayne Gross schedules three pours for each slab. This keeps work progressing by allowing Foothills Rebar to tie rods on one section of the slab while concrete is poured simultaneously on another section.
R.J. Griffin is also employing a self-climbing wall system on the center core to expedite construction. Beams on the system support the form panels, which are on rollers. Once the rebar is tied, the panels are rolled into place, the concrete is pumped and the panels are rolled away once the concrete has cured. With concrete delivered via a stationery pump at street level and a hard pipeline rising through the building, a concrete boom pump is attached to the top of the self-climbing wall system and rises along with it. Grigg points out that this has helped "being a one-crane project. The crane is running nonstop; it's flying up steel, flying up materials, flying truss tables."
The exterior of the parking deck and the retail shops will be a precast skin finish with integrated brick panels. The exterior of the condominium tower features a window wall system that goes from slab to slab and column to column to give future building tenants an expansive view of Charlotte.
Currently, R.J. Griffin has reached the 25th level of the tower, has framed up through the 20th level and has begun installation of the cabinets and certain finishes on the 10th level. When completed, residents of the 386-unit tower will enjoy a meeting room, bar, pool, exercise room, and a rooftop garden in addition to high-end finishes and a contemporary design.
Demolishing The H.D. Power Building
Just down from the Avenue building, D.H. Griffin Wrecking Co. has started demolition of the H.D. Power Building, the former headquarters of Duke Power. Bounded by Church, Mint, First, and Second streets, the Duke Power site was the fourth Charlotte acquisition for Novare Group.
David Vanderhorst, general manager, and Chad Drake, project manager, and the D.H. Griffin crew are demolishing approximately 500,000 square feet and have employed some unique equipment to accomplish the task.
In addition to four Komatsu PC300 excavators, D.H. Griffin is using a Caterpillar 365B excavator with a 135-foot custom-made boom to demolish the building, which ranges in height from five stories to seven stories. The boom was specifically designed for D.H. Griffin and is the only one on the East Coast.
"The boom will actually reach 12 stories high," says Vanderhorst. "It has a LaBounty hydraulic breaker, or we can put on a shear or a hammer because we have all the hydraulic lines going up to work it. This is the tallest boom in our fleet, and it gives us an advantage."
Mechanic Timmy Simpson explains that it takes three flatbeds and a lowboy to get the excavator and the boom to the site and eight hours to put it together. "We perform regular preventive maintenance and grease it every day," says Simpson.
To keep down dust during demolition, D.H. Griffin is employing a DustBoss, which is a fully automatic, oscillating ducted fan with a high pressure misting system that creates a high-performance dust barrier. Vanderhorst explains that the DustBoss is much more efficient than using a typical fire hose to control dust.
"We could stand there with the fire hoses like we normally do — and we still do sometimes — but the water only shoots out 50 feet to 60 feet and then drops off," says Vanderhorst. "The DustBoss shoots mist up to 200 feet in the air to catch the dust." This mist then blankets the site, anywhere from 5,500 square feet to 21,000 square feet, with dust-attracting water particles. In addition to saving water, the DustBoss also saves on labor costs by freeing up a man from operating a fire hose.
The demolition of the H.D. Power building is a typical project for D.H. Griffin Wrecking Co. and the crew has had only one significant challenge on the job — protecting an elevated walkway over First Street. Since the walkway was first constructed, zoning laws have changed and if a walkway is torn down it cannot be replaced. Fortunately, the walkway is supported by two columns, so shoring has not been needed. However, D.H. Griffin has had to separate it from the H.D. Power building in order to prepare for demolition and then temporarily seal it to inhibit dust infiltration into Duke Power's newer building across the street. The walkway will be tied back into the new building once it is constructed.
A tunnel running under First Street between the two buildings has also been maintained during demolition so that it can be connected to the new building as well.
Vanderhorst estimates that D.H. Griffin will achieve a recycling rate over 95 percent on the project. The building's doors, mahogany paneling, marble, and brick have been salvaged and will be resold. All of the concrete is going to D.H. Griffin's yard on Graham Street for crushing; it is then sold as aggregate. All of the metal — steel, copper, aluminum, etc. — is being separated and sent to recycling facilities.
D.H. Griffin is scheduled to complete demolition by the end of March. Novare's plans then call for construction of three high-rise condominium towers with 1,400 units — two towers with street-level retail and one tower that would be a development of Novare's TWELVE Hotels & Residences, a boutique hotel of approximately 150 suites and 300 condominium units. In addition, the site would feature a 300,000-square-foot to 400,000-square-foot Class-A office building and a retail and parking building. All of this will be delivered in phases with an expected completion date of 2011.