Anchord cable prestress multistage tensioning method

Abstract

The application provides an anchor cable prestress multistage tensioning method, and belongs to the technical field of anchor cable prestress. The total elongation is split into hole section elongation and hole bottom section elongation by setting a temporary displacement reference measuring point in the middle of the free section of the anchor cable, the hole friction coefficient is inversely calculated according to the hole friction coefficient calculation formula, the compensation value of each stage tensioning force is calculated according to the friction loss compensation formula, the initial tension of each steel strand is balanced by adjusting the bite depth of the clamping piece, the whole bundle is pre-tensioned, the three-stage tensioning force is applied in stages, and the tensioning is paused when the deviation between the measured value of the hole section elongation and the theoretical value of the hole section elongation exceeds 6%, the control value of each stage tensioning force is the product of the design tensioning force and the over-tensioning correction coefficient, the actual locking force is verified by the load sensor after locking, and the tensioning is secondarily compensated when it is insufficient, so that the technical problem that multistage tensioning cannot be accurately controlled is solved.

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