Magnacore Self-Drilling Anchors

The Magnacore® Self Drilling Anchor (SDA) from MDTI is a hollow bar injection-bore micropile that serves as an economical solution for challenging soil conditions where installing conventional micropiles may not be the best option. For example, those with collapsible soils (those not conducive to open-hole drilling), large boulders, or other obstructions.

The micropile is formed in a single, top-down operation by the injection of a high-pressure, neat cement grout mixture that is pumped through the bar, while also serving as the drill string. The neat grout mix exits through ports at the end of the sacrificial bit and permeates into the looser adjacent soils forming a competent reinforced grout column.

Solid Bar Compared to Hollow Bar

Solid Bar

  • Predrilling required
  • Limited to shallow rock
  • Very stiff throughout soil strata
  • Casing needed in soft soils
  • Pre/Post grouting required
  • Several pieces of equipment

Magnacore SDA Hollow Bar

  • No predrilling
  • Rock at any depth
  • Can be installed in all soil types
  • Casing for lateral loads
  • Grouting completed during install
  • Only need rock drill & grout plant

Magnacore Applications

  • New construction
  • Underpinning
  • Settlement/stabilization
  • Earth retention
  • Slope stabilization
  • Tunneling

Benefits of SDAs

  • Difficult soil conditions
  • High installation rate
  • Limited access
  • No casing required
  • Extra corrosion protection
  • Decreased labor & material cost

Components of the Magnacore Self-Drilling Anchor

  1. Hex Nut
  2. Termination Plate for new construction or bracket for underpinning
  3. HDPE Pipe for unbonded length or additional corrosion protection
  4. Soil Cement Grout Body
  5. Final Injection Grout
  6. Magnacore Self-Drilling Anchor Bar allows injection while serving as drill strong
  7. Coupler
  8. Centralizer to keep the micropile centered in the hole to allow for optimal grout cover
  9. Sacrificial Bit
  10. Grout Flushing Holes

Magnacore Sacrificial Bits

The holes in each bit allow the grout/drilling solution to flow as the SDA is advanced, simultaneously creating the column.

  • Tungsten Carbide Button Bit for hard rock (Limestone, shale)
  • Tungsten Carbide Cross Cut Bit for softer rock (sandstone, soft shale, or fractured rock)
  • Clay Bit ideal for mixed fills and clay

Magnacore Specifications

U.S. Measurements

Bar TypeR32SR38NR51NT40/16T52/26T76S
Outer Dia1.26 in1.50 in2.01 in1.57 in2.05 in2.99 in
Inner Dia0.59 in0.75 in1.18 in0.63 in1.02 in1.77 in
Area0.81 in21.09 in21.66 in21.40 in21.99 in23.89 in2
Ultimate Tensile Load (Pu)80.93 kip112.40 kip179.85 kip148.37 kip208.85 kip427.14 kip
Yield Load (Py)62.95 kip89.92 kip141.63 kip118.02 kip164.11 kip337.21 kip
Ultimate Tensile Stress (Fu)99.96 ksi103.49 ksi108.42 ksi105.82 ksi104.71 ksi109.80 ksi
Yield Stress (Fy)77.75 ksi82.79 ksi85.38 ksi84.08 ksi82.28 ksi86.68 ksi
Weight2.76 lb/ft3.70 lb/ft5.64 lb/ft4.77 lb/ft6.79 lb/ft13.24 lb/ft

Metric

Bar TypeR32SR38NR51NT40/16T52/26T76S
Outer Dia32 mm38 mm51 mm40 mm52 mm76 mm
Inner Dia15 mm19 mm30 mm16 mm26 mm45 mm
Area520 mm2700 mm21070 mm2905 mm21290 mm22510 mm2
Ultimate Tensile Load (Pu)360 kN500 kN800 kN660 kN929 kN1900 kN
Yield Load (Py)280 kN400 kN630 kN525 kN730 kN1500 kN
Ultimate Tensile Stress (Fu)690 n/mm2715 n/mm2750 n/mm2730 n/mm2720 n/mm2760 n/mm2
Yield Stress (Fy)540 n/mm2570 n/mm2590 n/mm2580 n/mm2570 n/mm2600 n/mm2
Weight4.1 kg/m5.5 kg/m8.39 kg/m7.1 kg/m10.1 kg/m19.7 kg/m

Why MDTI?

In addition to materials and service, MDTI will provide continual support through the entire project, including: engineering/design, on-site support, load testing, installation expertise, competitive pricing, and rental equipment.

Call us at 888-262-7797 for more information or to receive a custom product quote.