Detecting based on concrete box beam bridge web vertical pre-stress rib stretching force

Abstract

The invention relates to a system for detecting the tensioning force of a vertical presstressed reinforcing steel of a concrete box girder bridge web plate, which comprises a reinforced bar, a corrugated sleeve and nuts, wherein the lower part of the reinforced bar is vertically embedded into the concrete box girder bridge web plate and stretched into the vertical presstressed reinforcing steel; the upper part of the vertical presstressed reinforcing steel is provided with an exposed section; the exposed section is provided with an acceleration transducer and an exciter and electrically connected with a data acquisition unit, a notebook computer and a power supply; a signal analysis device which is used for being connected with the data acquisition unit is arranged and operated inside the notebook computer; the exciter obtains a command of the notebook computer to make the exposed section of the vertical tendon vibrate, converts the vibration into the natural frequency of the exposed section of the vertical presstressed reinforcing steel through the signal analysis device, and acquires the tensioning force between two nuts of the vertical presstressed reinforcing steel by application of a calculation relational expression. The detection system overcomes the defect that the prior system for detecting the tensioning force of the vertical presstressed reinforcing steel of a concrete box girder bridge can not meet the demand of on-scene large-area detection of the quality of the tensioning force of the vertical presstressed reinforcing steel, and is suitable for detecting the vertical presstressed reinforcing steel of the large-span prestressed concrete box girder bridge web plate.

Description

technical field [0001] The invention relates to the detection of the tensile force of prestressed steel bars of prestressed concrete components. In particular, it is a detection system based on the tensile force of the vertical prestressed tendon of the web plate of the concrete box girder bridge. Background technique [0002] The prestressed concrete continuous (rigid frame) box girder bridge structure system has the advantages of high structural rigidity, smooth driving, less expansion joints, low maintenance costs, and is suitable for various spans. Since the 1970s, it has become The first choice for the design of large and medium-span concrete bridges. In order to reduce and control the main tensile stress of the box web and prevent the web concrete from cracking, it has become one of the important contents of the design to set the vertical prestressed tendons on the box girder web. Using precision-rolled threaded steel bars as the vertical prestressed tendons of the w...

AI Technical Summary

Problems solved by technology

Its shortcoming is that the webs of many concrete box girder bridges still have different degrees of cracking during construction and operation, especially in the webs of long-span prestressed concrete box girder bridges.

At present, the vertical prestress measurement methods include installing pressure sensors under the anchor, pasting resistance sheet measurement methods on the prestressed surface, tension jack oil gauge test methods, and prestressed tendon elongation measurement methods. Among them, the tension jack oil gauge test method 1. Although the measurement method of prestressed tendon elongation is simple and easy, it is only suitable for prestress control during tension and has low precision. The pressure sensor and resistor sheet measurement method are too expensive and cannot be reused. Test accuracy, but it cannot meet the requirements of large-area detection of vertical prestressed quality on site, cannot be popularized and applied, and is only limited to scientific research

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