Method and system for equally tensioning multiple strands
AssigneeVSL International AG
InventorJean-Baptiste Domage
Life of this patent
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Abstract
A method and system are described for tensioning structural strands 1 of a tendon in a duct. Each strand 1 is fitted with its own load cell 22, so that the individual tension values in each individual strand 1 can be measured during the tensioning of the strands 1. The load cells 22 may be removed after tensioning, or left in situ to enable ongoing monitoring of the tension in the strands 1. The load cells 22 may be calibrated simultaneously by tensioning the strands 1 to an equal tension using individual jacks 10, then normalizing the signals from each load cell 22 to the known equal tension value. A further calibration to a global strand load measurement may also be performed.
Claims21
Method of tensioning a plurality of strands, the method comprising:
- a first step of arranging a plurality of individual load cells so that each of the load cells can measure the individual tension in an individual strand,
- a second step of using an individual jack per strand to individually tension each individual strand to a common first tension amount so that all of the strands are tensioned to the common first tension amount,
- a third step of, when each strand is tensioned to the first tension amount, using the plurality of individual load cells to measure a first individual tension measurement value for each strand,
- a fourth step of calibrating the load cells having the first individual tension measurement values to the common first tension amount.
System for tensioning a plurality of structural strands, the system comprising:
- an individual jack per strand for individually tensioning each of the strands to a common first tension amount so that all of the strands are tensioned to the common first tension amount,
- a common jack for tensioning all of the plurality of strands at the same time to a second tension, the second tension being higher than the first tension,
- the system being characterized in that it comprises
- a plurality of individual load cells arranged to detect individual tension measurement values for each of the strands, and
- first calibration means for calibrating the load cells having the individual tension measurement values to the common first tension amount.
Dependencies are inferred from the claim text.