Multi-Field Coupling Research on Performance Degradation of Anti-Seepage Curtains in High-Pressure Waterways

In order to study the deterioration law of anti-seepage curtain in high-pressure waterway of pumped storage power station, a mathematical model of multi-field coupling of anti-seepage curtain is established based on the principles of fluid dynamics, solute migration and chemical kinetics. The model is solved by finite element method and verified by engineering data. The research results show that the internal calcium of the anti-seepage curtain of high-pressure waterway is continuously dissolved and separated under the penetration and corrosion action of high water head for 30 years. In the deepest part of the anti-seepage curtain, 17.76% of solid calcium was dissolved and lost, its porosity increased by 29.38% compared with the initial porosity, the permeability coefficient increased by 2.49 times, and the impermeability and durability continued to decline. The seepage-corrosion damage of the high-pressure water channel anti-seepage curtain has the characteristics of temporal and spatial variation. The corrosion area of the contact part between the middle of the anti-seepage curtain and the high-pressure bifurcated pipe is the largest, while the top and bottom dissolution are mainly encircling dissolution, and its dissolution area is the second. The research results can provide a scientific basis for various preventive measures and control strategies to limit the deterioration of the anti-seepage performance of the high-pressure water channel anti-seepage curtain.