Hollow Bar Micropiles in Chicagoland

Hollow Bar Micropiles (HBM) are deep foundation piles that are used for new construction and in remediation tie-back applications. HBMs utilize a hollow steel bar (from 30mm to over 100mm in diameter) with a continuous thread along the outer surface. A drill bit is fitted to the end of the bar to penetrate the structure or soil. Cement grout is injected through the hollow bar and ejected from the drill bit during drilling. The grout under pressure is forced back along the outside of the bar to bill the space created by the drill bit and creates a strong grout friction column while improving the surrounding soils.

No Pre-Drilling Required

As the HBM is drilled into the ground, cement grouting continuously fills the hollow bar and the annular space created by the drill bit until the HBM reaches its final depth. The hollow bar micropile can drill to any depth and be used in various soil types. A rotary percussion drill and grout plant are the tools needed for HBM installation. This allows us to provide viable solutions in tight spaces and where obstructions may be present as there is no pre-drilling required. Site and soil conditions, as land becomes scarce within communities, often contains fill materials including brick, concrete, and boulders. The proper drill bit attached to the HBM can provide for penetration through difficult fill materials, saving on adding a pre-drilling operation to penetrate problematic fill.

To learn more about Hollow Bar Micropiles, call us today at 847-994-2526 for a free consultation in the Chicagoland area.