DYWI Drill Hollow Bar Micropile

A self-drilling system for loose or collapsing soils, no casing required.

DYWI Drill Hollow Bar Micropiles can be installed in restricted access areas or in close proximity to existing buildings. Due to the fully threaded system, the micropile can be extended and grouted in areas where the founding level is deeper than expected.

The rotary percussive drilling method ensures minimal disturbance is caused during installation compared to driven piling systems, enabling the foundations of old structures or buildings to be upgraded without damage.

  • Drill and grout simultaneously for faster installation

  • Minimal disturbance to existing structures during installation

  • Left-hand thread compatible with percussive drill tooling for complete installation flexibility

  • Bar diameters R25-R51 supplied with rope thread; T76-T103 supplied with trapezoidal thread

  • Range of drill bits for soils and rock, including tungsten carbide buttons and chisels to suit all applications

  • External thread enables the bars to be cut and coupled at any point, as well as terminated with a nut, for easy on-site length adjustments

Main standards for steel nuances

Europe : EN 10083-1​

UK :  EN 10083-1 ​

USA :  EN 10083-1


  • Rotary injection adapters to connect between the hammer and the hollow bar, enable grout to be injected into a rotating bar

  • Drill bit adaptor sleeves offer the option of using larger diameter drill bits with smaller bars

  • Range of drill tooling including reducing couplers, box/pin adaptors and drill spanners

  • Corrosion protection options include grout cover, sacrificial corrosion allowance, hot-dip galvanizing, Duplex (hot-dip galvanizing and epoxy coating)

  • Bearing plates with angle compensation or shear tubes

  • Hex nuts, couplers and steel spacers

  • Pinch Valves allowing the installation of micropiles within sites with a high-water table, without the need to dewater.

Commercial & Residential Buildings