Research On Key Technology Of Cable Exchange For Tongling Yangtze River Highway Bridge

As one of the main stress components of cable-stayed bridge,the cable is exposed to the air for a long time and is always in the high stress working state.It is easy to cause the damage of the cable protection system,lead to the cable aging ahead of time,and threaten the safety of the cable-stayed bridge.Cable replacement is one of the measures to solve this problem.Based on the cable-changing project of Tongling Yangtze River Highway Bridge,the key technology in the process of cable exchange is studied in this Paper.In this Paper,the characteristics of the most commonly used Parallel steel wire stay cables and the steel strand stay cables are coMPared and analyzed,and suggestions for the selection of the stay cable types are put forward.According to the commonly used cable exchange scheme,the finite element model is used to coMPare and analyze the cable force change,the deflection change of the main beam,the stress change and the influence of tower deviation under three different cable-changing schemes.The scheme of replacing two symmetry stay cables of the bridge tower at the same time is finally determined.In addition,because the anchor head of Tongling Yangtze River Highway Bridge is anchored inside the beam rib,the effect of slotting on the local stress state of the main beam is studied in this Paper.It is verified that the reinforcement with steel plate on the bottom of the beam has a significant effect on relieving the stress release caused by the slotting.This Paper also studies the influence of complex traffic conditions and temperature load on the bridge cable replacement construction,discusses the feasibility of the bridge traffic organization scheme based on the finite element calculation results,and guides the timing of cable replacement construction.Finally,this Paper summarizes and discusses the cable-changing construction technology of Tongling Yangtze River Highway Bridge.