Tension force estimation of Extradosed bridge cables in VIetnam using vibration based method

Abstract

The external cable system in the Extradosed bridge structure has a similar structure, function and working principle to the cables in the cable-stayed bridge, so the tension force in the external cables is also considered an important parameter to ensure the bearing capacity and stability of the entire structure of this bridge. The tension force in the outer cable is strictly controlled from the design, construction and operation stages by installing direct force measuring sensors or indirect determination methods through analysis of outer cable vibration data similar to the tension control in the stay cables of cable-stayed bridges. However, the outer cables in Extradosed bridges usually have a smaller tilt angle and are not equipped with damping devices, so the influence of the parameters related to the tension in them is different from that of the cables of cable-stayed bridges. This article analyzes the test results of the tension value in the outer cables of Extradosed bridges using the method of using cable vibration measurement data. The influence of the actual cable construction parameters on the tension value is discussed and verified with the actual tension in the cables during the construction phase of some newly completed Extradosed bridges in Vietnam to improve the reliability when applied in practice.