Description of D-bolt

The D-Bolt reinforces the rock mass by constraining the dilation between the anchor points. When the rock mass dilates, the anchor points assume the load and the smooth sections between the anchor points stretch. The load on the smooth sections increases quickly with a small increase in the dilation, until the yield load is reached. Once the yield load is reached the smooth sections undergo plastic elongation until failure. The D-Bolt absorbs the dilation energy by fully mobilizing the strength and deformation capacities of the bolt material. The smooth sections of the D-Bolt provide localized and independent reinforcement to the surrounding rock mass. This has the important advantage whereby failure of one section of the bolt would not affect the reinforcement function of other sections along the length of the bolt. The anchor points are designed to mix two-component cartridge resins when the D-Bolt is spun into the borehole. The D-Bolt steel is manufactured using micro-alloyed, engineered carbon steel using specific properties that result in an optimal combination of yield strength, ultimate tensile strength and elongation. The D-Bolt is also available with a hot dip galvanized (HDG) and/or powder coating that provides further resistance to corrosion.