## Reliability Assessment of a Bridge Structure Subjected to Chloride Attack

Publikation: Bidrag til bog/antologi/rapport/konference proceeding › Konferenceartikel i proceeding › Forskning

### Abstract

ingress involves a number of parameters that are associated with large

uncertainties. Hence, full-scale measurements are strongly in demand. This

paper begins by summarizing statistical distributions based on measurements

taken from the Gimsøystraumen Bridge in Norway. A large number of

chloride profiles are available based on concrete coring samples, and for each

of these profiles the diffusion coefficient and surface concentration (due to sea

spray) are estimated. Extensive measurements of the concrete cover depth are

also performed. The probability distributions are input into a prediction model

for chloride concentration at the steel reinforcement. By also introducing the

critical chloride concentration as a random variable, the probability of

exceeding the critical threshold is determined as a function of time. To address

chloride attack on the entire bridge, a system model with 90 components is

introduced. Reliability updating based on observations at multiple sites along

the bridge is also investigated. First-order reliability methods typically become

inaccurate for large systems of this type, so an enhanced Monte Carlo

simulation method is applied. It is shown that the corresponding computation

time is significantly reduced compared to crude Monte Carlo methods.

### Detaljer

ingress involves a number of parameters that are associated with large

uncertainties. Hence, full-scale measurements are strongly in demand. This

paper begins by summarizing statistical distributions based on measurements

taken from the Gimsøystraumen Bridge in Norway. A large number of

chloride profiles are available based on concrete coring samples, and for each

of these profiles the diffusion coefficient and surface concentration (due to sea

spray) are estimated. Extensive measurements of the concrete cover depth are

also performed. The probability distributions are input into a prediction model

for chloride concentration at the steel reinforcement. By also introducing the

critical chloride concentration as a random variable, the probability of

exceeding the critical threshold is determined as a function of time. To address

chloride attack on the entire bridge, a system model with 90 components is

introduced. Reliability updating based on observations at multiple sites along

the bridge is also investigated. First-order reliability methods typically become

inaccurate for large systems of this type, so an enhanced Monte Carlo

simulation method is applied. It is shown that the corresponding computation

time is significantly reduced compared to crude Monte Carlo methods.

Originalsprog | Engelsk |
---|---|

Titel | Structural Engineering International |

Antal sider | 6 |

Publikationsdato | 2018 |

Status | Afsendt - 2018 |

Publikationsart | Forskning |

Peer review | Nej |

- Chloride ingress, Bridge test data, System reliability, Enhanced Monte Carlo Method