A method for hoisting and positioning control of prestressed steel beams in tower columns

Abstract

The invention relates to a hoisting and positioning control method for prestressed steel strands of tower columns, which comprises the following steps: selecting a beaming platform, and setting a conduit for beaming on the beaming platform according to the length of the steel strands; threading the steel strands one by one into the conduit; braid the lower end of the steel beam; then braid the upper end of the steel beam, and install the 1# anchor plate, use the steel strand card to lock the steel strand on the 1# anchor plate; #Anchor plate, use the hoop to tighten the 1# and 2# anchor plate; send the steel strand into the reserved hole; remove the hoop used to anchor the two anchor plates, take away the 2# anchor plate, and complete the steel beam installation; install a tension jack on the remaining 1# anchor plate, use 10%‑20% of the tension stress as the initial tension force, complete the unlocking of the temporary lock of the card and adjust the straightness and slack of the steel beam, and then enter In the prestressing and tensioning construction stage, the present invention has the advantages of simple operation, time saving and high working efficiency.

Description

technical field [0001] The invention belongs to the field of tower column prestressed construction, and in particular relates to a method for hoisting and positioning control of tower column prestressed steel beams. Background technique [0002] Prestressing is to improve the service performance of the structure. The preloading pressure is applied to the structure during the construction period. The preloading pressure during the service period of the structure can fully or partially offset the tensile stress caused by the load and avoid structural damage. Commonly used in concrete structures. The prestressed concrete structure is to apply pressure to the structure before it bears the load, so that the internal force of the concrete in the tension area when the external load acts produces compressive stress, which is used to offset or reduce the tensile stress generated by the external load, so that the structure Under normal use, no cracks or cracks occur relatively late. ...

AI Technical Summary

Problems solved by technology

[0004] However, when the prestressing construction site is narrow, the embedded parts at the tensioning port must be processed in the tensioning stage to make room for the tensioning, and a smaller jack is required to ensure normal tensioning Therefore, it is impossible to arrange a beam threading machine at the upper opening of the prestressed tunnel for beam threading operations

If the steel strands are hoisted by a crane, they are manually fed into the hole one by one, and a baffle is installed at the bottom of the tunnel to prevent the steel strands from sliding down. This measure is not only difficult to construct, but also easily causes the steel strands to fall due to their own weight. It needs to be reworked and re-threaded, and there are construction quality risks, and the weight of the steel beam is relatively large. When a baffle is installed at the lower part of the prestress and the steel beam is fixed with the upper part of the tunnel and the lead wire or steel wire rope, it is easy for the steel beam to fall into the hole, and The relative position of the steel strands is misaligned, requiring multiple adjustments of the steel strands, causing a lot of trouble to the prestressed construction. In addition, when the prestressed cables are stretched, in order to eliminate the straightness and sagging of the steel strands in the tunnel due to their own weight The degree of slack increases the loss of prestress, and it is necessary to perform single-top pre-tensioning and then stretch the entire bundle, which is complicated and time-consuming to construct.