For the advantages of prestressed anchor and some brief description of the program

For the advantages of prestressed anchor and some brief description of the program
Fixed (prestressed anchorage prestressed) is to increase retaining structure with anchorage method or a kind of measure the stability of rock mass.Its method is a hole through the possible sliding or have been sliding of the sliding surface, will be reinforced (or wire rope) fixed in the bottom of the hole at the end of the stability of rock and soil mass, then reinforced (or wire rope) taut that can produce a certain resilience (that is, the prestressed), then reinforced (rope) on the other side of the fixed in rock and soil body or surface of retaining structure, use reinforced back elastic compression may slide rock mass or retaining structure, to increase the shear strength of sliding surface, so as to improve or retaining structure on the stability of rock and soil mass.

The advantage of prestressed anchorage is:
1. In the high slope and tunnel mouth Ming dig in, can increase the slope stability, thus reducing the excavated volume, also create conditions for the advance into the hole;
2. In the normal operation of the reservoir conditions used for strengthening concrete dam body and dam foundation;
3. Used to repair concrete cracks or defects, concentrated load can be distributed to a wide range;
4. Reinforced cavern, improve the stress of the cavern conditions, such as high sidewall support for underground powerhouse.
5. These advantages make it around the world is widely used in water conservancy engineering.

Prestressed anchor construction procedure is:
1. The pretension, tensioning equipment and locking;
2. The anchoring fixed;
3. The seal hole grouting.
4. Pore;
5. Make up line;
6. Depth measuring hole and its aperture and skewness;
7. The anchor head processing;
8. The direction of the anchor hole bore can be divided into vertical, horizontal, inclined hole and upward hole.
Hole diameter is commonly 110 ~ 150 mm.Due to the tension of compression deformation and creep relaxation, anchor and anchor beam segment of sliding, will inevitably produce loss of prestress.Therefore, in the design of reasonable estimates is dealing with the loss of prestress.Generally in the process of tensioning, using pretension or repeated tensioning method, adjust the stress, in order to achieve the purpose of reducing loss of prestress.Sometimes after the formal tensioning also compensate tension.After the wire rope lock general use of cement grouting hole sealing;When the desire to compensate for loss of prestress and repeated tensioning, often in anti-seepage materials such as asphalt hole sealing.