In the previous post we have discussed about TAPERTUBE pile application in foundation construction of different terminals of JFK International Airport. Now in this post we will discuss about shape and size of TAPERTUBE pile.
The test conducted at JFK Airport on TAPERTUBE pile were used a 25’ long pile section with bottom section of 8” diameter and top section of 18” diameter. The piles were made of 0.312” thickness steel having 12 sided polygon shape. The steel was of 50 Ksi grade. We are discussing this test as this test brings success to TAPERTUBE pile and adopted in the next terminal buildings of JFK and then spreaded from this airport to different highway, airport and railway structure construction. After driving a concrete of 5000 psi were poured. This was for testing 150 ton capacity of pile.
It is worth mentioning that the polygon shape having 12 sides is rounded at top portion of taper mechanically. This rounding technology is still using in this patented pile technology.
TAPERTUBE piles can be of various shapes and also of various sizes to meet geotechnical and structural considerations. As discussed above polygon shape having 12 sides is most common application. The usual sizes vary from 8” to 24” for bottom to top diameter and this is tapered through a length of (10-35) feet. As tested before 50 ksi (grade 50) steel is used to manufacture this pile. The thickness assigned ranging from (3/16” to 5/8”).
As mentioned earlier, the circularization of top portion of polygon provides conformation of diameter of extension as steel pipe. To facilitate it butt welds used to ensure full strength development of piling elements.
These types of piles have been found effective in granular type soils. But these types of piles used in cohesive soil and found performing well. But a few tests were done in cohesive soil. We are waiting for elaborate test results in these types of soil.