DYWI® Drill Hollow Bar System
The DYWI® Drill Hollow Bar System is a fully threaded steel bar which can be drilled and grouted into loose or collapsing soils without a casing. The bar features a hollow center for simultaneous drilling and grouting and a rope thread for connection to standard drill tooling. Manufactured by cold rolling heavy wall steel tubing, DYWI® Drill Hollow Bar forms a standard rope thread profile (R25 - R51, T76 has a trapezoidal thread). The rolling process refines the grain structure of the steel, increasing the yield strength and producing a durable drill rod suitable for a range of applications. DYWI® Drill Hollow Bars can be installed into a variety of different soils and ground conditions ranging from sand and gravel to inconsistent fill, boulders, rubble and weathered rock, as well as through footings and base slabs.
- Ability to work with small drill rigs without casing in narrow spaces
- Similar installation methods for all ground conditions
- Simultaneous Drill and Grout Installation: Combines both operations into a single construction cycle, enabling high rates of production
- No Casing Required: Can be installed into loose or collapsing soils without the need for a temporary casing to support the borehole
- Rotary Percussive Drilling: Allows quick rates of installation, good directional stability and assists in the consolidation of the grout within the borehole
Wide Range of Applications
DYWI® Drill Hollow Bars are suitable for:
- Soil Nails, Micropiles, Ground Anchors for temporary works, Rock Bolts and Spiles.
- Fully Threaded Rod Sections: Continuous thread ensures that rods can be cut and coupled at any point.
- Thread Profile Standard ISO rope thread (R25-R51) or trapezoidal thread (T76) produces an excellent bond between the bar and grout, and enables connection to conventional drill tooling.
- The hollow core serves for flushing with air or water during drilling, but also for grouting the hole.
- Choice of drill bits for different ground conditions
- Enhanced corrosion protection is available upon request