Method of de-tensioning a rod
A method of de-tensioning a rod by attaching a gripping unit removal device to a gripping unit and rod, positioning a chair frame over the gripping unit, positioning a rod tensioning unit along the rod with one end of the rod tensioning unit being in contact with the chair frame, applying a first force to the rod tensioning unit, positioning a bearing plate on the rod in contact with the rod tensioning unit, positioning a load cell in contact with the rod on the rod tensioning unit, securing a drive unit to the chair frame such that a portion of the drive unit is in contact with the rod, applying a second pressure to the rod tensioning unit, actuating the drive unit, and releasing the second pressure on the rod tensioning unit.
1. A method of detensioning a rod, the method comprising:
removably attaching a gripping unit removal device on a gripping unit where the gripping unit engages the rod;
positioning a chair frame on the rod over a periphery of the gripping unit;
positioning a rod tensioning unit on the rod with a first end of the rod tensioning unit being in contact with a surface of the chair frame;
applying a first force to the rod tensioning unit;
positioning a bearing plate on the rod in contact with the rod tensioning unit;
positioning a load cell in contact with the rod on the rod tensioning unit;
securing a drive unit to the chair frame such that a portion of the drive unit is in contact with the rod;
applying a second pressure to the rod tensioning unit;
actuating the drive unit;
releasing the second pressure on the rod tensioning unit.
2. The method of claim 1 wherein the first pressure is sufficient to increase tension in the rod.
3. The method of claim 1 wherein the second pressure is sufficient to separate the gripping unit from a trunnion.
4. The method of claim 1 wherein the driving unit includes an engagement portion that is in contact with the rod.
5. The method of claim 3 wherein the drive unit actuates to move the gripping unit a predetermined distance from the trunnion.
6. The method of claim 1 wherein the drive unit is hydraulically driven.
7. The method of claim 1 wherein a central control unit is communicatively coupled to the drive unit.
8. The method of claim 7 wherein a plurality of cameras is optically connected to the central control unit.
9. The method of claim 8 wherein at least one of a plurality of cameras is positioned to capture an image of a side of the gripping unit.
10. The method of claim 1 wherein the first pressure is less than the second pressure.