EXPERIENCE IN MEASURING EFFORT IN ROPE ELEMENTS OF CABLE BRIDGES

Abstract

The work is devoted to the issue of carrying out technical diagnostics of determining the forces in the cables of the cable-stayed bridge across the harbor of the Dnipro River in the city of Kyiv on the object: "Construction of the Podilsk bridge crossing over the Dnipro River in the city of Kyiv" at the final stages of jacking up the span structure of the bridge. As is known, the general methodology of technical diagnostics is based on conducting static or dynamic tests. Tests are conducted to determine the nature and magnitude of loads on the bridge structure, to determine the actual stress level in the elements. Moreover, sometimes some types of tests are carried out not only on bridges whose construction is finished, but also on structures during their construction. One of these types of tests is the tests performed to determine the amount of load in cable elements of cable-stayed bridges. Currently, one of these types of tests is the tests performed to determine the amount of load in cable elements of cable-stayed bridges. At present, the acceptable methods for determining the forces in the rope elements of cable-stayed bridges are: installation of electronic dynamometers in the places of anchoring of the ropes to measure the load, geodetic measurements of the sagging of the cable-stayed ropes, determination of the frequency of self-oscillations of the cable-stayed ropes, etc. The paper presents the results of the tests of measuring the forces in the cables of the span structure due to their own weight by exciting mechanical oscillations in them and determining the frequencies of the natural oscillations, and measuring the slack of the cables (arrows of the slack) by laser 3-D scanning of the cables.