
DYWI® Drill Hollow Bar System
Rock bolts are passive ties; typically classified as lightly loaded, short installations. The DYWI® Drill Hollow Bar System provides a practical rock bolt that is quick and easy to install through fractured or broken ground. The system is available with a range of harder drill bits (Tungsten Carbide: button or chisel) for efficient drilling in stronger material.

Air or water flush percussive drilling is normally employed for installation, followed by subsequent grout injection through the bore of the bar. Injected grout provides the bond for the DYWI® Drill Hollow Bar and also helps to consolidate fractured ground. For mining applications, the DYWI® Drill Hollow Bar System is used as self-drilling rock bolts in areas of high stress at pillars, crossheads or abutments. Other applications include the use of the self-drilling bar as an injection conduit for resin, grout or waterproofing agents.
Spiles provide a protective canopy, to enable the heading of a tunnel to be advanced without the risk of falling debris. Often used with NATM - New Austrian Tunneling Method - construction. DYWI® Drill Hollow Bar System Spiles enable drilled installation, reducing localised disruption and providing a conduit for grouting. Subsequent grouting assists in the consolidation of the surrounding ground.