Mechanism Study Of Degradation Of Anti-impact Capability Of The Pier Caused By Corrosion Of Steel Rebar

Ship collision load will cause adverse influence on reinforced concrete piers,leading to local damage such as pier cracking or stripping,a large impact force will cause the piers to a displaced fracture,overall collapse and other serious accidents.Steel corrosion in reinforced concrete piers will cause the carrying capacity decreased and impact resistance deteriorated,especially in splash zone of the marine environment,steel corrosion is a widespread and severe phenomenon under the influence of dry-wet circulation.This article based on the bridge pier collision problem and steel corrosion problem to carry out the research of dynamic response and damage properties of pier the under the impact load.Then qualitatively reveal mechanism of degradation of anti-impact capability of the pier.Model testing research and finite element simulation analysis were supplied to the research.The main study work and results summarized as follows:(1)Obtaining the corrosion pier components through the electric accelerated corrosion test,pier model were supplied to the impact test,through the bridge dynamic response and damage character to focus on the pier collision performance under the influence of steel corrosion.Results show that the overall dynamic response and local damage of pier increased significantly with the increasing degree of steel corrosion.(2)Different collision velocity and different strength of concrete were supplied to the research,trying to obtain the regular of the overall dynamic response and local damage of pier under the influence of the impact speed and strength of concrete.Results show that dynamic response and damage of the rust piers will increase by the increasing of impact velocity,dynamic response and damage of the rust piers will decrease with the increasing of concrete strength.(3)Through the analysis of the dynamic response and damage of corrosion pier under the dynamic loading,mechanism of degradation of anti-impact capability of the pier were concluded under the influence of steel corrosion:(1)steel corrosion caused by steel bar itself effective area is reduced,appear even reinforced the fracture,the stress performance fell sharply;(2)steel corrosion lead to the bond strength between steel bar and reinforced concrete are weakened,the integrity of the pier is destroyed;(3)elastic modulus of concrete decreased,strength and stiffness falling,cracking and spalling of concrete in severe case;(4)the integral stiffness,the compressive bearing capacity and the flexural bearing capacity of the pier decreased obviously.