Temperature Effect on Tension Force of Stay Cable of Cable-Stayed Bridge

Abstract

Cable is the main element of cable-supported bridge, such as suspension bridge, cable stayed bridge and arch bridge. For the cable-stayed bridge, the cable receives the load from the bridge deck and transfer it to the pylon. As the ambient temperature change, the internal force in bridge element including stayed cable will change. This research investigate the ambient temperature effect to the tension force of stayed cable of cable-stayed bridge by comparing the result of finite element model analysis with the field measurement form electromagnetic sensor data. The finite element model of Merah Putih Cable-Stayed Bridge has been developed based on detailed engineering design data. The finite element model is validated using the natural frequency data from dynamic load test of the bridge. The ambient temperature and bridge elements temperature were measured for 24 hours. The finite element analysis were conducted based on field measurement data and the contribution of pylon and girder temperature to the cable tension forces variation was investigated. The output of finite element analysis then compared to the actual cable tension as measured by an electromagnetic sensor. It was found that the ambient temperature will affecting the magnitude of tension force at stay cable and the variation of cable tension has similar pattern of both from the finite element model and electromagnetic data. As the temperature of bridge element increases or decreases, the bridge will experience a deformation. Since the stay cable connected to the pylon at one side and to the girder at the other side, its will make the stay cable elongated or contracted which in turn will affecting the tension force at stay cable. When evaluating the bridge condition based on the tension force at stay cable, the effect of temperature variation need to be considered.