Normet D-Bolt®

The D-Bolt® represents the new generation of energy-absorbing rock bolting systems, designed for efficient and reliable rock strata reinforcement. Anchored with cement grout or resin, the D-Bolt® effectively absorbs rock dilation energy thanks to the strength and deformation capacities of the bolt material and the patented design.

The D-Bolt® comprises of a strong, yet highly deformable smooth steel bar with a number of swaged sections that act as anchor points along the bolt’s length. The collar end of the D-Bolt® is threaded and is designed to be used in a system with a face plate, spherical washer and a nut, or dome nut, that tightens the plate to the rock face. When properly installed the bolt is fully encapsulated in a borehole, only constrained to the resin or cement grout at the anchor points. This allows the smooth sections of the bolt, between the anchor points, to de-bond from resin or cementitious grout and deform without constraints while absorbing a high amount of energy as the rock mass dilates. The D-Bolt® is available in different lengths as per customer requirements, from approximately 1.5 to 6 meter. 

The Connectable D-Bolt® complements the standard model by being extendable through specially designed couplings, perfect for smaller profile spaces where longer bolt anchoring is required.