The Comprehensive Guide to Self-Drilling Anchors VS Standard Helical Piles

Which Anchoring System is Right For You?

This comprehensive guide aims to highlight the key differences between self-drilling anchors (SDAs) – also known as Hollow Bar Micropiles and the standard helical piles by examining critical factors such as their suitability for diverse geotechnical conditions, drilling depth capabilities, spatial constraints, and job site complexity. Keep reading to learn how experts in Deep Foundation Construction rely on Intech Anchoring Systems. 

Not a big reader? Watch the summary video here. 

Steel Anchors in piling Guide

Should You Use Helical Anchor Piles or Hollow Bar Micropiles?

Differentiator Helical Anchors Hollow Bar Anchors
Load Light to Moderate Moderate to Very High (or shallow bedrock)
Type of Soil Soft soil, loose sand and lean clay Any soil
Soil Conditions Minimal obstructions Boulders, Cobbles, Existing Footings
Piles at Capacity via In Bearing Plates Skin Friction (along length)
Pressure Bulb 2:1 slope No lateral effects
Grouting N/A Yes, continuous
Column Diameter Plate Size (6-14" diameter) Grout Size (4-8" diameter)
Spatial Requirements 3" spacing 3" Spacing

Exploring Helical & Self-Drilling Anchors

In the construction industry, particularly concerning foundational integrity, selecting the appropriate anchoring systems is paramount. Among the leading choices available are self-drilling anchors (SDA) and the standard helical piles. Both options provide unique advantages suited for various applications, requiring geotechnical engineers to make informed decisions that  with project specifications.

The two main considerations when differentiating the two is:

  • What type of load is it?
  • How are the soil conditions?

Using Helical Piles

Helical piles gain capacity from in-bearing at the plates rather than the length of the pile.

The pile diameters are generally larger due to the plates being driven into the ground which can be from 6-14 inches diameter. 

As the pile gets loaded the load is transmitted down the shaft onto the plates. When the plates load the soil – it creates a pressure bulb which is terminated at 2 diameters down from where the load is applied. 

To avoid isobar interaction – keep spacing at 3″ diameters. 

Using Hollow Bar Micropiles

Self-drilling anchors (SDAs) like our Magnacore Hollow Bar solution – excel in diverse geological conditions, even unstable ones, making them perfect for complex projects.

They penetrate deeper than traditional rock bolts, reducing drilling resistance for deep foundations. With adjustable lengths for tight spaces, their drilling and grouting integration speeds up processes, ensuring timely completion in fast-paced construction.

helical-equipment-seawall-bulkhead-application

Advantages of Helical Anchors

We provide ICC-ES evaluated helicals, made with 98% recycled American 80 KSI steel and integral forged couplings. The line features a more traditional small diameter square shaft (1.5” and 1.75” – up to 70 kips) or round pipe (2 7/8” to 5.5” OD – up to 235 kips).

These piles can also be grouted to achieve higher loads, increase lateral capacity, eliminate buckling concerns, or protect the steel.

Helical piles can be large diameter piles up to 20” OD with up to 500 tons of capacity.

Advantages of
Self-Drilling Anchors

Hollow bar micropiles, like the Magnacore® Self Drilling Anchor, provide a cost-effective and efficient foundation solution in challenging environments, such as collapsible soils or areas with obstructions.

The streamlined installation process uses the hollow bar for drilling and grout injection, reinforcing the micropile and enhancing load-bearing capacity.

This innovative technique avoids open-hole drilling, ensuring quick and reliable installation even in difficult conditions, making Magnacore® micropiles a valuable asset in modern construction.

magnacorehollow-bar-micropile

We are the Trusted Anchoring Equipment Supplier

Helical Piling Equipment

Manufactured from the industry’s strongest steel – our helical anchors and drive kits provide a sturdy solution for deep foundation requirements. 

Requiring zero heavy equipment and no grouting necessary, helical anchors equate to a cost-effective and environmentally-friendly product for soil stabilization under your toughest builds. 

Plus, all steel can be cut to customized lengths if necessary. 

SIZES AVAILABLE

Square:

  • 1.25″
  • 1.5″
  • 1.75″

Round:

  • 2.875″
  • 3.5″

 

EQUIPMENT REQUIRED
  • Rock Drill
  • Steel Helicals
  • Drive Kit
  • Proper Sized Drill Bits

Hollow Bar Micropiles

Our in-house manufactured Magnacore® Self-Drilling Anchor from Intech Anchoring exemplifies innovation designed to address challenging soil conditions that may impede traditional micropile solutions. 

  • R32
  • R38
  • R51
  • T40
  • T52
  • T76
 

Standard lengths of 4.92 ft (1.5 m) and 9.84 ft (3 m) are available, with options for custom orders, including lengths and sizes tailored to unique project needs, alongside a comprehensive selection of accessories.

SIZES AVAILABLE
  • R32
  • R38
  • R51
  • T40
  • T52
  • T76
EQUIPMENT REQUIRED
  • Excavator
  • Rock Drill
  • Grout Plant
  • Proper Sized Drill Bits

Your Trusted Partner in Anchoring Systems

We’re not your average materials distributor – we’re better. We operate as a Value-Add Engineering team to help your structural build be completed with the right product for the right application. Built on a handshake and a promise to lend our expertise – we’ve developed the right balance of helpful and supportive resources available to our partners whether they opt for our equipment rentals or product installation work.

GAIN VALUABLE SUPPORT FROM THE EXPERTS

Tim Comb

President

Tim is the President of Intech Anchoring and has 25 years of experience in the Civil Engineering and Geostructural Industry. Tim has developed extensive industry knowledge by working to support the needs of specialty contractors at each and every business level. Tim’s diverse industry background has given him exposure to a wide variety civil construction projects, ranging from the simplest residential applications to the most complex commercial and industrial projects. Coupled with a highly skilled and educated team, Tim focuses on providing the highest quality products and solutions to Intech Anchoring’s customers in order to consistently exceed expectations.