Research On Mechanical Characteristics,Damage Mechanism And Treatment Measures Of Arch Bridge Flexible Suspenders

Flexibe suspenders are widely used in half-through and through arch bridges for their aesthetic advantages and convenience in construction. However, a few arch bridges collapsed or were damaged in recent years due to the failure of flexible suspenders. As the key component that links bridge deck with arch rib, the working condition of suspenders is very important to the safety of arch brideges. Therefore, it's quite meaningful for the operation safety of arch bridges to analyze and know well of the mechanical characteristics and damage mechanism of arch bridge flexible suspenders and related treatment measures based on their damage mechanism. Meanwhile, it is also helpful to put forward some reasonable evaluation indexes and methods on the safety and durability of arch bridge flexible suspenders.Based on the research findings about arch bridge flexible suspenders by both domestic and overseas scholars and experts, this thesis has, in detail, analyzed the mechanical characteristics and damage mechanism of arch bridge flexible suspenders with real bridge examples. And based on the analysis above, some treatment measures were then put forward. Specific details are as follows:(1) Mechanical characteristics of arch bridge flexible suspenders With the example of Changsheng bridge in Yixing county, this thesis has analyzed both static and dynamic characteristics of its flexible suspenders, and differences of long suspenders and short suspenders. The author has measured and analyzed the self-vibration frequencies of Changsheng bridge suspenders. With the measured vibration statistics, the author speculated and compared the axial forces of Changsheng bridge suspenders by the use of different theoretical models, and then analyzed the dynamic response of Changsheng bridge suspenders when a constant force passed by in a settled speed.(2) Damage mechanism of arch bridge flexible suspenders This thesis analyzed common diseases and causes of arch bridge flexible suspenders in service at great length. With the example of Wugang separated interchange bridge, this thesis described and analyzed the diseases and causes of its suspenders that were found in periodical inspection, and then evaluated the damage and corrosion degree of suspender anchor heads. With the static tensile experiments of sampled steel wire from suspenders, this thesis analyzed mechanical properties of steel wires from arch bridge flexible suspenders in service.(3) Treatment measures of arch bridge flexible suspenders This thesis introduced common construction methods in replacing arch bridge flexible suspenders and advantages, disadvantages and application conditions of these methods. Then taking the example of temporary suspenders method, this thesis described in detail the construction process and monitoring methods in replacing arch bridge flexible suspenders.