FEM-Based Reinforcement Design of Surge Shaft Illustrated with a Case Study of Xiaowan Hydropower Plant

The method of FEM-based reinforcement design of surge shaft is proposed. As the concrete of surge shaft is applied after excavation and has to spend a period of time to exert its strength, the method to calculate and apply load to the concrete structure is put forward. As the design codes only provide linear solution of concrete with potent basis, the concrete is calculated elastically and the rock mass is calculated iteratively. In view that the design code only gives general principles for the reinforcement of non-member and mass concrete structures, the specific implementation approach based on FEM solution is put forward for these complicated structures. The maximum tensile stress principle is employed to conduct the reinforcement and maximum crack width estimation method is presented to assess the reliability of reinforcement design scheme. A case study is illustrated on the reinforcement design of the surge shaft concrete structure at Xiaowan hydropower plant. It is shown that the proposed method is rational and effective, providing the reinforcement design of complicated structures with direct convenience.