THE INFLUENCE ON THE SAFETY AND REiABILITY OF THREE GORGES PROJECT CAUSED BY THE CORROSION DAMAGE OF PRESSURE PIPELINES

摘要

Pressure pipeline is an important part of the hydroelectric station. The corrosion on penstock will influence the safety and durability of hydroelectric station. Based on the prediction and analysis of damage pressure on corroded steel lined reinforced concrete pressure penstock situated in three gorges dam, the safety of corroded pressure pipelines is assessed in this paper,. At first, the factors which have effect on the corrosion of pressure pipelines are analyzed and a calculation model is developed. According to the model, failure pressure of corroded pressure pipelines is calculated. The topic about how corrosion depth, length, width and shape influence the safety of pressure pipelines is also discussed Secondly, statistical properties of random variables within performance function of pressure pipelines used in three gorges dam are presented and the corrosion reliability analysis model is obtained. The prediction method of residual service life of corroded pressure pipelines is presented. In the end, according to above analyses and calculations, it is concluded that corrosion depth plays a crucial role on the safety of penstocks and the residual service life of pressure penstocks greatly depends on the age, corrosion length and corrosion depth.