Prestressed anchor cable tension

1. After the strength of grouting reaches 80% of the design strength, a tensioning prestressed anchor cable is started. The tensioning equipment is required to be used, and the pressure gauge reading - tension relation curve is drawn to be submitted to the supervision engineer in a formal document by the calibration of the identification institution. Pressure gauges that have been removed, serviced or subjected to a strong impact must be re-calibrated.

2. The prestressed anchor cable tensioned with a single pretensioning method for the whole tensioning. To ensure that the steel strand is smooth and uniform, the steel strand should be pretensioned by 10% of the design load. The official teng adopts the overall tensioning, with the design value of 25%, 50%, 80%, 100%, 110%, and the level of level 5. The load applied uniformly, the loading rate should not exceed 0.1 of the design stress per minute, after each stage of tensioning for 5min, while measuring the elongation value of the cable body and making a good record. If the actual elongation value is greater than 10% or less than 5% of the theoretical elongation value, it is necessary to stop tensioning the cause and take remedial measures.

3. The homework personnel shall not enter the prestressed anchor cable tensioning operation areas, the tensioning jack the output are strictly forbidden in the direction of 45 ° stand.