Helical piles for gas and oil industry

Helical Pile Applications inOil and Gas Industry

by Howard A. Perko, Ph.D., P.E.Magnum Geo-Solutions, LLC

Copyright 2011 – Howard A. Perko, All Rights reserved. May be

distributed and printed by express written permission of the author only.

MAGNUM Informational Bulletin ISO-HAP1-12B

Copyright © 2011 – Howard A. Perko

What is a Helical Pile?

Helical Piles:Central Steel Shaft with One or More Helix Shaped Bearing Elements that is Screwed Into the Ground to Support the Loads of Structures

(a.k.a. Helical Piers, Screw Piles, Torque Anchors, Auger Screw Piles, Helix Piers)

Plate Cap

Extension

Coupling

Lead

Helix

Pitch

Pilot Point


Bearing Capacity & Sizing

Helical Piles are sized using traditional soil mechanics:

Individual Bearing

Q = R2(1.3cNc+Nq)

Cylindrical Shear

Q = 2RL(c+Ktan) +

R2(1.3cNc+ Nq)

Limit State = Cylindrical Shearor Individual Bearing,whichever is less.

From Perko (2009) Helical Piles


Why Use Helical Piles?Save Money

Easy to Transport to Remote SitesDoesn’t Produce Drill SpoilMinimal Site Work

Save TimeRapid InstallationNo Concrete CuringSet Platforms Directly on Piles

Proven Technology Invented in 1836Appears in 2009 IBC ISO2009 Accredited Manufacturer


Gas Compressor Pad

90 tons

Designing the foundations for vibrating machines is not as simple as dividing the weight amongst the piles. The lifespan and maintenance cycle of compressors and other machines is greatly diminished with improper foundation design and excessive vibrations.


Pipe Rack Foundations


Compressor Pad Construction


Completed Compressor Pad

Helical piles saved $100,000 per compressor pad versus conventional heavy reinforced concrete mat. Compressors were started without incident, vibrations were within target levels, and compressors continue to operate without flaw.


Installation and Load Tests

Load tests passed with good results. Measured 0.28 inches movement at 110 kips design compression and tension loads. Installation was completed on budget and on schedule.


Installation Photos

MH425 helical piles installed on schedule and on budget.


Installation Over Water

Installation of helical piles over water helped protect wetlands from risks of silt, spoil, and contaminants.


Use of Battered Piles

Contractor was able to replace 80 large pre-cast driven piles under this pipeline thrust block with just 20 helical piles by incorporating batter angle to handle lateral loads.


Pipeline Support

Adjustable caps were used under pipe racks so that bolting could be done instead of welding.


Limited Site Access

Helical piles installation equipment was able to access areas that drilling and pile driving equipment could not.


Platform Design

MAGNUM Patent Pending Design created by Magnum Geo-Solutions, LLC to provide harmonic dampening and keep harmonic motion within tolerable limits.


MAGNUM Quality

Many convenient features including steel plate for electrical, integrated access step, and crane lift points. Meets NEC specifications for grounding.


Platform Installation

MAGNUM Steel Platform is set in afternoon of same day as helical pile installation. Note same excavator being used to crane 9,000 lb platform in place.


Pump Unit in Place

Old SchoolPre-Cast New MAGNUM

“Concrete-Less” Pump Platform


Still Going!

MAGNUM Steel Platform resists frost heave, expansive soils, settlement, and shallow soil shifting. These foundations reduce risk of costly shut-downs.

Helical piles for gas and oil industry

Technology

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