The photo above shows the excavation and installation of the footing pads for the Six Flags 'Green Lantern' project in New Jersey. Standing 154 feet high and reaching speeds of 63 mph, the roller coaster will rank among the tallest and fastest of its kind anywhere in the world. Unlike traditional seated coasters, occupants stand throughout the entire course of the ride to deliver a ride experience unlike any other.
Structural loads of the rollercoaster are demanding, with upward, lateral and downward forces from the fast moving cars. Concrete contractor, Force Concrete & Masonary Corporation of Piscataway, New Jersey, chose Fastfoot® to reduce forming costs and eliminate a large inventory of plywood forms. Site Manager Bill Pavlic said:
"Today we poured our first footings at Six Flags. Against my judgement I used the Fab-Form for footings 3' 6" tall. Other locations at the same thickness I used conventional methods, symons forms with a double waler braced back to the bank. Today we poured a total of 100 cu. yds. into symon form boxes and the other 150 into footings constructed using your system."
"Never guess what happened... braces against the bank for the symons form panels let go causing a blow out. Nothing severe but none the less there weren't any issues with the Fab-Form. Largest footing was 3'-6" X 25' X 25'. The Fab-Form system has been criticized all week long by others on the jobsite, that problem has been solved after today's results. We began pouring the largest footing with over a dozen onlookers, including some very important executives from Six Flags main headquarters and engineers from Birdsall Group. Everyone was impressed. I will be ordering more material by the end of the week."
This video shows the layout for the new Green Lantern roller coaster.
2x8s were used for the screed rail. By locating the top of the screed located at the exact footing height, screeding of concrete is very easy.
With plywood, screeding is done inside the form, making accurate finishing difficult and time consuming.
Lateral pressures are reduced by up to 50% when using fabric as the lateral pressures in the bottom of the form are turned into downward pressures. This reduces bracing costs and labor dramatically.
The hydraulic loads from the bottom third of a fabric formed wall is taken by the fabric itself (the resistance between the fabric and the ground). With plywood these loads must be taken by the bracing. As a result, lateral pressures are reduced by up to 50% over plywood.
In this photo the plywood forms on the right failed. Fastfoot® performed perfectly.
Transfering the column loads into the footing demands a great deal of steel. Failure is not an option with roller coasters.
One of the advantages of Fastfoot® is that larger sections of the project can be formed and poured at the same time without the limitation of plywood inventory.
The final concrete lift is being poured. Note the three columns coming off the pad which will be supporting a triangular support for the roller coaster track. This pad is 42" deep.
The top of this column has three support templates.
Note the white expanded polystyrene blocks under the template to create shear keyways in the concrete.