Abstract: An inflatable rock bolt including an expansion tube, a bushing arranged at each end of the expansion tube, and at least one reinforcing member arranged outside the expansion tube. The at least one reinforcing member includes at least one of a strand extending along the expansion tube or a sleeve at least partially surrounding the expansion tube. A method for reinforcing an inflatable rock bolt.

Abstract: After a rock anchor (1), in particular an expandable friction tube anchor (1), comprising an anchor bolt (2) has been inserted into a pre-sunk borehole with an end sleeve (4) first, an adapter (6) having a liquid inflow and outflow is arranged on a sleeve (3). On the one hand, a holding pressure which secures the adapter (6) to the sleeve (3) is produced via a holding-pressure line (8). On the other hand, fluid flows into the anchor bolt (2) via an expansion line (7) and starts to fill said bolt. In the process, the increase in pressure (inflation pressure) causes the anchor bolt (2) to expand in the borehole, with the result that its outer surface presses against the borehole wall and thus secures the rock anchor (1) in the borehole. A gas supply connected to the adapter (6) makes it possible for a gas under pressure, in particular compressed air, to be introduced into the anchor bolt (2) before and/or after the expansion thereof.

Abstract: After a rock anchor which encompasses the anchor bolt, has been inserted with an end sleeve beforehand into a bore hole, on the sleeve there is an adapter with liquid supply and drain. Via the holding pressure line a holding pressure is produced which fixes the adapter on the sleeve. Via the expansion line fluid flows into the anchor bolt and begins to fill it. The anchor bolt expands as a result of the pressure increase in the bore hole, so that its outer surface adjoins the bore hole wall and fixes the rock anchor in the bore hole. Via a gas supply connected to the adapter, a pressurized gas, before and/or after expanding the anchor bolt, can be introduced into the latter. The compressed gas is relieved after removing the adapter and routs the fluid located in the anchor bolt almost completely out of the anchor.

Abstract: A method for providing a rock bolt (2) for rock bolting, wherein a rock bolt (2) having a tubular bolt portion (4) with a closed cross section is inserted and expanded for bearing contact in a bore hole (3) in a rock structure (1). The length of the tubular bolt portion (4) is determined such that maximum frictional force at pulling inside a bore hole (3) of a rock bolt with a tubular bolt portion with this length is below a predetermined maximum value. The invention also concerns a rock bolt.