The Failure Probability Analysis and Applied Research of the Flood Damage to the Submerged Wall

Abstract

The submerged wall is the important protective structure which constructed at the downstream of the pipeline as the oil and gas pipelines through the river. The invalidation of the submerged wall caused by the scour of flood impact will make the pipelines exposed or even ruptured. According to the characters of the submerged wall in the project of the long distance pipeline, it concluded that the flood flow velocity,the soil cohesion, the angle of internal friction, the gravity density of backfill and the angle of friction between the earth and the wall back were random variables. This paper constructed the analysis model for the failure probability and the corresponding limiting condition equations of the submerged wall.Based on the theory of Monte Carol method,combined with the west-east gas pipeline crossing project ,it calculated the failure probability of the anti-sliding and anti-overturning of the submerged wall. In addition, it also calculated the failure probability of the subsoil bearing capacity by taking the basal mean stress failure and the maximum compressive stress as a series system.This paper calculated the sensitivity of each random parameters under the different failure models, and compared the failure probability under different distribution of the soil parameters.The result shows that the failure probability of the subsoil bearing capacity is the biggest under the inducement of the flood,the flood flow velocity is the main controlling factors of the three failure modes ,the angle of internal friction has a big impact on the three failure modes,the distribution of the soil parameters have very little influence on the failure probability.