Detection system and method of steel bar tension force of vertical prestress of web of concrete box girder bridge

Abstract

The invention discloses a detection system and method of the steel bar tension force of the vertical prestress of a web of a concrete box girder bridge. The system comprises steel stranded wires, a bellows, an anchorage, an anchor backing plate, a non-tension-end anchor backing plate, and a non-tension-end anchorage, the steel stranded wires are sleeved by the bellows, the bellows is located between the anchor backing plate and the non-tension-end anchor backing plate, one ends of the steel stranded wires penetrate through the anchor backing plate and the anchorage, the anchorage and the anchor backing plate maintain contact, the other ends of the steel stranded wires penetrate through the non-tension-end anchor backing plate and the non-tension-end anchorage and are anchored in the web of the concrete box girder bridge, the non-tension-end anchoring plate, the non-tension-end anchorage, the bellows and the anchor backing plate are anchored in the web of the concrete box girder bridge, the anchorage is provided with an acceleration sensor and a vibration exciter, and the acceleration sensor is connected with a computer. According to the system and method, the problem of failure due to over-high prestress loss is thoroughly solved, the failure of a concrete structure of the prestress steel stranded wires can be effectively prevented, and the structural stability and reliability can be improved.

Description

technical field [0001] The invention relates to a detection system and method for the tensile force of the vertical prestressed tendon of the web plate of a concrete box girder bridge. Background technique [0002] The invention patent is based on the tension detection system of the vertical prestressed tendon of the web of concrete box girder bridge (patent number: ZL2008 1 0143752.8, the inventors Zhong Xingu, Shen Mingyan, Yang Tao) proposed the vertical prestressed finish rolled threaded steel tension method, Local standards and industry standards have been formed. This method is based on the fact that the degree of engagement between the nut and the exposed section of the vertical prestressed tendon is different under different tensions. The greater the tension, the tighter the nut engagement. Different degrees of occlusal will cause different bending stiffness of the anchorage section, and different bending stiffness will lead to different vibration frequencies of the ...

AI Technical Summary

Problems solved by technology

The biggest problem with the steel strand is the large amount of retraction and slack. Secondary tensioning is generally used to eliminate the loss of prestress caused by the amount of retraction and relaxation. It is determined whether the tension is in place by measuring the displacement of the secondary tensioning of the anchorage. Due to the randomness of the anchorage preset in the project, it is difficult to measure the displacement of the second tension of the anchorage, and the actual second tension has become a decoration. Effective tension is uncertain

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