Mechanical Properties Of The Railway Bridge Strengthened With After-prestressing Cables

With the train speed and load capacity increasing, a large number of existing railroad bridges have damage with different levels and transverse vibration of the bridge structure is most prominent among these damage, which has gained much attention recently. In this regard, reasonable and cost-efficient bridge retrofit measures should be presented in order to mitigate damage in deficient bridges, and help to improve the transport capability.In this paper, a potential retrofit measures named after-prestressing cables retrofit method for the railway bridge piers is proposed to restraint the transverse vibration of the deficient bridges. Theory for this method is explained detailedly and the selecting procedure of the cables and the designing of steel hoop are also presented.To qualitatively and quantitatively assess the efficiency of the proposed retrofit method, finite element simulations for the Dazhunxian Xigou Bridge have been carried out using the ANSYS finite elements software. The influences of various modeling parameters, such as the location of the cable, the initial value for prestressing, the inclination angle of the cable, are numerically assessed. Based on the analytical results, some proposal values for the aforementioned parameters are provided for their application to practical problems.A comprehensive research is conducted using detailed three-dimensional models of the entire bridge structure, since numerical analysis for application of the proposed retrofit method on single pier indicate the proposed retrofit method seems ineffective. An optimized layout plan for the prestressing cables is provided for the entire bridge structure. In addition, it is found that the proposed retrofit method effectively reduces the transverse vibration of the selected bridge and seems to be more cost-saving, compared with section enlargement method.