Rock Bolting at launching chamber of New Delhi metro station.
Rock bolts are used for the support of underground and surface excavations.
Rock bolts generally consist of deformed steel rods with an end anchorage and a face-plate and nut at the rock surface, For short-term applications, the bolts are generally left un-grouted with end anchorage. For more permanent applications or the rock in which corrosive groundwater is present, the space between the bolt and the rock can be filled with cement or resin grout.
Anchor bars generally consist of deformed steel bars, which are grouted into the rock.
Steps of work will be as followed.
- Drill hole to be done as per approved design and drawing.
- After drilling of holes for end anchorage required no of fast setting resign capsules shall be inserted inside the holes.
- Rock bolts shall be inserted inside the hole in a rotary manner so that it can puncture the capsules for proper mixing with resin capsule.
- Rock bolts pull out test to be conducted as per design requirement.
- After satisfactory testing remaining drill holes to be grouted.
- At the face of the rock MS plate shall be used as washer & fixed at the face of the excavated rock.