Stability Study and Strengthening Strategy of Spiral Case-Encased Concrete Structure of Pumped Storage Power Station

With the development of global hydropower, the scale of hydropower stations is increasing, and the operating conditions are becoming more complex, so the stable operation of hydropower stations is very important. The vibration of the turbine unit will cause resonance in the powerhouse, and the structural stability of the powerhouse will be affected. Many scholars pay attention to the stability of the turbine unit operation, and there are few studies on the powerhouse of the hydropower station. Therefore, this paper relies on the Weifang Hydropower Station project to study key issues such as the tensile strength of concrete and how to arrange steel bars to increase the structural stability by changing the material properties through FEA. Three schemes are designed to evaluate the safety of the powerhouse structure when the turbine unit is running through the safety factor. Our findings indicate that the stress variation patterns observed on the inner surface of the powerhouse remain consistent across different operating scenarios. Notably, along the spiral line of the worm section, we observed that the stress levels on the vertical loop line decrease gradually with increasing distance from the inlet. Conversely, stress concentrations arise near the inlet and the tongue. Additionally, it has been noted that the likelihood of concrete cracking increases significantly at the tongue region.