Seismic Performance of Offshore Piers under Wave Impact and Chloride Ion Corrosion Environment

Yin Gu,Anhua Yu,Xiaolong Zhang,Piguang Wang

doi:10.1155/2021/8028869

Abstract

Offshore bridges may suffer from chloride ion corrosion, tsunami wave impact, and earthquake. However, the coupling effects of multiple factors have not been fully considered. This paper studied multiple degradation effects on the seismic performance of offshore piers considering tsunami wave impact, chloride ion corrosion, and their interaction. Firstly, through the scale model test of tsunami wave flume, the wave force of box girder structures and piers under different tsunami wave conditions is measured. Then, according to the corrosion characteristics of coastal chloride salts on reinforced concrete bridge piers, the corrosion parameters is selected by Latin hypercube sampling, and the influence of corrosion expansion and cracking of bridge pier cover on the chloride ion corrosion process is considered to modify the degradation model of corroded reinforced concrete materials. Finally, the wave load measured by the test is converted by the similarity criterion of the fluid mechanic test and loaded into the ABAQUS full-bridge model, and the pier after the tsunami wave is evaluated by the pushover analysis. The bearing capacity and lateral stiffness of the corroded pier before and after different tsunami waves are compared. The results show that the lateral bearing capacity and stiffness of bridge piers are, respectively, decreased by 27.6% and 6.2% after 30 years of service. Without corrosion, the lateral bearing capacity and stiffness of piers were, respectively, reduced by 11.45% and 10.6% after HXB-5 wave impact. After 30 years of service, the lateral bearing capacity and stiffness of bridge piers are, respectively, reduced by 41.8% and 22.5% under the combined action of corrosion and HXB-5 wave impact. It is found that the coupling effects of multiple degradation factors were more significant than the simple superposition ones. Therefore, the coupling effect of multiple factors should be considered in practical engineering.

Highlights

Bridges play an essential role in the transportation network
Due to the complexity of the structure environment, it is necessary to consider the degradation caused by multiple factors, so as to evaluate the seismic performance of the structure more accurately [4]. e research of reinforced concrete bridges under multiple degradation processes and their coupling effects is still in its infancy, so it is of great significance to study the seismic performance of offshore reinforced concrete bridge piers under the impact of the tsunami wave
Dong et al [11] used explicit dynamic software LS-DYNA to study the effect factors of the impact on the mechanical behavior of corroded reinforced concrete bridge piers subjected to corrosion in the marine environment. e results show that the increase of the diameter for the main rebar can improve the anti-impact properties of the bridge pier. e increase in the rate of main reinforcement corrosion and impact velocity will reduce the anti-impact properties of piers. e diameter of the stirrup rebar has less influence on the anti-impact mechanical properties of the bridge pier

Summary

Introduction

Bridges play an essential role in the transportation network. During the whole service period, the structure will deteriorate due to aging, regular operation, or extreme load/environmental conditions. E research of reinforced concrete bridges under multiple degradation processes and their coupling effects is still in its infancy, so it is of great significance to study the seismic performance of offshore reinforced concrete bridge piers under the impact of the tsunami wave. Dong et al [11] used explicit dynamic software LS-DYNA to study the effect factors of the impact on the mechanical behavior of corroded reinforced concrete bridge piers subjected to corrosion in the marine environment. Stephens et al [13] predicted the damage susceptibility of reinforced concrete (RC) and concrete-filled steel tube (CFST) bridges subjected to seismic and tsunami loading scenarios by using the open-source structural analysis software OpenSees and the open-source computation fluid dynamics software OpenFOAM. Is paper studies the influence of multiple degradations on the seismic performance of offshore piers from the perspective of tsunami wave impact, chloride ion corrosion, and their interaction. The wave load measured by the test is converted by the similarity criterion of the fluid mechanic test and loaded into the ABAQUS full-bridge model, and the pier after the tsunami wave is analyzed by the pushover analysis. e bearing capacity and lateral stiffness of the corroded pier before and after different tsunami waves are compared

Wave Force Test of Wave Impact on the Bridge Structure

Start Time and Current Density of Rebar Corrosion

Numerical Simulation Model

Corroded Piers

Results and Discussion