Linde-Griffith – based in 1909 – was primarily a pile driving contractor till about 20 years in the past when it expanded into basis drilling. “We have seen increasingly more engineers searching for strategies that supply larger capability with much less noise and vibration,” says Linde-Griffith’s Senior Govt Vice President Mike Shannon. 

Within the midst of condo buildings and companies, the yellow mast of a Bauer BG 36 H Drilling Rig towered greater than 90 toes over the panorama. The Linde-Griffith area crew braved 30-plus-mph winds and single-digit windchills because the linchpin machine of its FDP operation bored by way of the frosty soil.

The Hackensack undertaking began out as a pushed pile undertaking. The earlier contractor had run a Pile Driving Analyzer (PDA) Take a look at and was unable to succeed in the design capability regardless of putting in varied pile varieties to depths of as much as 175 toes. 

The proprietor and engineer reached out to Linde-Griffith’s John Shannon searching for concepts.

Linde-Griffith advised utilizing FDP piles. Mike Shannon summarizes the FDP approach: “The piles do not relaxation on rock right here, you get your load bearing as a result of the displacement and compaction of the soil, and grout column construct up sufficient friction to satisfy capability.”

“The outcomes have been spectacular once we Static Load Examined the piles,” remembers Shannon. “We have been in a position to obtain the hundreds they wanted with a 55-foot FDP pile.” 

The swap to FDP piles was additionally probably the most environmentally sound selection, in response to Shannon. “They did all of the remediation however nonetheless did not need any materials to be exported,” he says. “FDP allowed us to maintain all soils within the floor the place they belong.”

BG 36 H the centrepiece drill
The FDP operation revolved across the BG 36 H Drilling Rig. Linde-Griffith owns a fleet of drilling rigs, together with two Bauers acquired from Tools Company of America’s (ECA) New York/New Jersey department.

It was January 2018 when the BG 36 H executed check piles at Hackensack. The unique plan was to have two rigs driving the FDP operation. The opposite was to be a BG 28 H. 

By the point allowing and environmental delays had been cleared, Linde-Griffith’s BG 28 H was tied up on different tasks. It was agreed that the BG 36 H can be the one drilling rig on web site.

Linde-Griffith labored with ECA to equip the BG 36 H with 510-mm (20-inch) FDP Tooling to drill 1,322 FDP piles from 52 to 57 toes. Every pile consisted of a 20-inch grout column with a 10-inch-by-1/4-inch hole pipe within the centre to supply further shaft friction. The FDP piles created sufficient shear and base resistance so touchdown the pile on competent rock was pointless. 

Linde-Griffith executed every FDP pile in a sequence. First, the displacement device bored all the way down to the specified depth to loosen and densify the encompassing soil, leaving an open excavation. 4 1/2 to five 1/2 cubic yards of 5,000-psi grout was then pumped into every gap underneath stress by way of a hole drill stem because the BG 36 H extracted the displacement device. 

The rotation of the device densified  any unfastened materials. The reinforcement cage was then dropped, and in some circumstances vibrated, into the recent concrete to complete off the pile.

“On an auger forged pile you are relieving the stress of the bottom as you are drilling down and the spoils are popping out,” Shannon explains. “Right here, you are truly creating extra stress as a result of the soil is staying within the floor and pushing in opposition to the perimeters.”

The FDP piles have been specified by a grid sample with single piles across the perimeter for grade beams and caps containing as much as six piles for areas supporting the heaviest column hundreds.

Drilling was not particularly difficult in these soil circumstances, however the grid sample and FDP course of itself brought on growing resistance with every pile. “In these clusters,” Shannon explains, “the primary couple are all the time lots simpler as a result of you haven’t any resistance. However the extra piles and concrete you place in, the extra you are displacing and densifying the soil across the present piles and it will get tighter and tighter.”

One other problem was that Linde-Griffith needed to keep a 10-foot distance from piles with uncured concrete. 

“It is primarily based on how your structure is with the spacing of your piles, and the way you intend,” says Shannon. “With such a pile (FDP), it’s worthwhile to actually undertaking two to 3 days forward to take care of manufacturing.”

FDP tooling crucial to operation
Bauer tooling was crucial to the FDP operation, in response to Shannon. “It is all Bauer displacement tooling designed particularly for this undertaking,” he says. “It was engineered to realize the required hundreds with these soil circumstances.”

Friction was a difficulty. The soil circumstances and grout acted like sandpaper on the tooling, particularly the displacement bulb above the auger flight and the slicing tooth on the wear and tear plates.

“High quality management is essential out right here so we alter the tooling out as soon as per week,” says Shannon, noting that extras are available always. “Then we simply refurbish, re-weld, hardface, and produce them out once we want them.”

“The primary concern on this job was {that a} pushed pile could not obtain the load required,” says Shannon. “Our determination to herald the bigger 20-inch full displacement tooling mixed with the standard management this machine provides made this undertaking. The quantity of data you get from that machine is exclusive and really spectacular.”

The standard management Shannon speaks of is pushed by the patented Bauer B-Tronic System. Each Linde-Griffith and the undertaking’s third-party engineer have entry to such knowledge as stroke depend, grout stress, and drilling depth by way of a desktop laptop or cell system. There is no such thing as a second-guessing whether or not a pile is pushed to the right depth and accommodates the correct quantity of concrete. There was additionally a security profit because the engineer was in a position to monitor drilling from a secure distance as a result of B-Tronic transferred the operator’s view to an iPad.

The B-Tronic System would not merely present knowledge. It additionally has a function known as B-Drive, which automates monotonous operations. Linde-Griffith’s operator, for instance, was in a position to program the BG 36 H to drill to a particular depth by merely typing in parameters. Throughout concrete placement, he plugged within the focused grout quantity and stress. B-Drive mechanically extracted the tooling as soon as these numbers have been achieved. Not solely did this guarantee a persistently grouted column, but it surely additionally allowed Linde-Griffith to share the precise quantities of concrete consumed with the proprietor.

“We’ve got it arrange the place I can view it from wherever,” says Shannon, noting that he travels between websites all day. “I maintain a laptop computer in my automobile so if I am not right here, I can see what is going on on.” 

Linde-Griffith was putting in as much as 25 FDP piles in lower than 10 hours every day, which may have been even greater. Productiveness was hampered by shorter days, muddy web site circumstances, and as much as 45 minutes spent cleansing the BG 36 H and tooling on the finish of every day.

Linde-Griffith began drilling the primary week of October 2019 and completed by February 2020. Robust manufacturing and sensible planning resulted within the undertaking being accomplished on schedule.

Brian M. Fraley is proprietor of Fraley Development Advertising.

The article initially appeared within the May 2020 situation of Heavy Tools Information.