Pre-stress construction system

Abstract

The invention belongs to bridge construction devices, and particularly relates to a pre-stress construction system. The pre-stress construction system comprises at least two groups of tension devices, wherein each group of tension devices comprises a hydraulic station, a reversing valve group, a jack, an A / D (analog-to-digital) acquisition module, a PLC (programmable logic controller) and a man-machine interface; wherein the PLCs in each group of tension devices are electrically connected; the pressure oil pumped out by the hydraulic station is conveyed to the jack through the reversing valve group; a pressure signal generated by the jack is transmitted to the PLCs through the A / D acquisition module; the PLCs output control signals to control the reversing of the reversing valve group and output the control signals to the man-machine interface to be displayed; an even number of tension devices are provided; and the tension devices further comprise a direct dynamometry device, a friction test device and a security device. The pre-stress construction system solves the problems in the prior art of being low in measurement precision and the like, and has the advantages of high measurement precision, good security protection, low maintenance cost and the like.

Description

Technical field [0001] The invention belongs to a bridge construction device, and particularly refers to a prestressed construction system. Background technique [0002] The accuracy of bridge prestress tension is affected by many factors such as force measurement method, pipe friction coefficient, temperature effect, etc. Prestress tension accuracy is the primary condition that determines the safety and normal operation of the prestress structure. Once the prestress tension accuracy is out of control, Will cause inevitable engineering accidents. [0003] At present, a small number of manufacturers have developed automatic control systems for highway prestressing tensioning, which basically only have the tensioning function, and do not have other functions for multi-functional prestressing construction. [0004] At present, the force measurement method of the highway prestress tension automatic control system existing on the market is the method of converting the pressure of the hyd...

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Problems solved by technology

[0007] But in fact, when the radius of curvature of the tunnel is small, the prestressed steel strand will have a large radial effect under the same tension control force, and the prestressed steel strand will tend to sink into the inner wall of the tunnel, which will increase the friction coefficient

In addition, with the increase of the number of prestressed steel strands, the stress on the steel strands arranged along the small radius of curvature will be uneven, and the friction between the prestressed steel strands and between the steel strands and the tunnel wall will also increase. These factors will lead to the increase of the friction coefficient, which will directly lead to the increase of the prestress loss.

As a result, the actual tensile stress exceeds the maximum adjustable tensile stress in the design. In the end, the method of increasing the number of prestressed tendons on the basis of the original number can only be adopted to ensure that the prestress of the beam body meets the design requirements and increase the number of prestressed tendons. It will lead to a large discrepancy between the budget and the pre-project budget cost, resulting in inaccurate project budget, which is equivalent to occupying other parts of the funds, which will cause a series of project cycle extensions due to lack of funds for the construction project.

There are also individual beam types that can only be used in a downgraded manner. The occurrence of this situation has buried potential safety hazards for the project.

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