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Posted: October 3, 2017
Last modified: October 3, 2017

They come in all different shapes, sizes and compositions, but all piles serve the same purpose: to support the massive structures throughout the I-4 Ultimate project.

Nearly 7,000 piles will be used to safely disperse weight from traffic and other structures, including about 140 bridges. Piles are long, vertical structures either made of steel or concrete that are placed deep into dense layers of the ground to support different kinds of structures.

Construction crews drive the pile into the ground using two methods. Vibratory pile driving is a high-frequency and low-impact method that uses a clamp that attaches to the top of the pile to vibrate and excite the soil around the pile. It displaces the loose and less dense soil and the pile gradually pushes down. Vibratory pile driving allows steel pile to get situated around 100 feet below the surface and it also is effective at installing sheet pile, which supports wall structures.

Impact hammer pile driving almost always follows vibratory pile driving for steel pile. Impact hammer pile driving is a high-impact and low frequency-method that uses a hammer to drive concrete pile and to drive steel pile through dense underground layers. It is used primarily when vibratory pile driving reaches a certain level.

People near pile driving activity may notice a vibration or a familiar pinging. Humans have a highly-sensitive vibration perception, and can feel pile driving anywhere from .006-.019 inches a second. Pile driving on the I-4 Ultimate project averages slightly over .2 inches a second, and generally does not occur at night, unless the activity is far from certain occupied buildings.

In an effort to mitigate disturbances to people nearby and still ensure accuracy, inspectors carefully monitor levels of vibration along with the amount of blows it takes to reach a certain level.

Vibration levels can be affected by a number of factors, including the type of soil, building structure and where a person is standing. Noise levels may be determined by proximity, level of sound dampening in a building and frequency. Generally, vibratory pile driving is less noisy than impact hammer pile driving.

Per construction contract terms, pile driving may only occur from 7 a.m. to 10 p.m.

For questions or concerns regarding pile driving activity, please visit: i4ultimate.com/public-outreach-education/contact-us/.