Research on Disengaging Detection and Repair Technology of Turbine Spiral case

The aging and disengaging phenomenon of the elastic asphalt cushion between the isolated type cushion spiral case and its external reinforced concrete, which may lead many serious hidden troubles, are very common. Based on the numerical analysis results of the stress characteristics of the spiral case structure of a 55-year old hydropower station, the effect of flexible filling materials on the structure was analysed, and a kind of bi-component, self-leveling and high-durability sealant (Hydraulic Structure Disengaging Filling Special Sealant) and a construction technology of filling and repairing the spiral case disengaging were developed. By comparing the geological radar method, impact-echo method, neutron detecting method and manual hammer knock method; the authors explored an appropriate detection technology of spiral case disengaging of the turbine. The study achievements have been applied to the repairing project of spiral case disengaging of the 1# turbine in the Xin’an River Hydropower Station, and achieved excellent effects.