Evaluation of Cavitation Occurrence Based on Reliability in Chute Spillways by Using First Order Reliable Method and Monte Carlo Simulation Method from 18 Spillways Laboratory Models, Iran

Abstract

Controlling cavitation occurrence is one of the most important factors in chute spillways designing due to high velocity and the negative pressure of flow. A probabilistic design approach was implemented in the present study to estimate the probability of cavitation occurrence on chute spillways. In addition, the uncertainty presence of the effective parameters in the limit state function related to the cavitation occurrence was highlighted in the present design. The probability of cavitation occurrence was studied based on the reliability of first order reliable method (FORM) and it was controlled by Monte Carlo simulation method. The data was extracted from eighteen spillways laboratory models built by the Iranian Water Research Institute, among which ten were aerated and eight were without aerator. Accordingly, as a result of the performance of these spillways and the cavitation occurrence in the prototype, a graph and its relationship was found for controlling the cavitation occurrence and its failure probability based on the mean velocity and flow mean pressure along the chute spillway. According to the results of this study as a new method for designing based on reliability, it could be controlled the probability of cavitation occurrence.