Steel lined reinforced concrete penstock is commonly used as a hydraulic structures in recent years. Because of the complex structure of the penstock, so far no design specification can follow at home and abroad. In this paper, general finite element calculation software is used to conduct nonlinear analysis, the stress of the steel liner with the increased internal pressure variation elastoplastic distribution of outsourcing concrete and the development law of joints cracked concrete for the penstock of Yisa River Station II. Analysis shows that, the steel lined reinforced concrete penstock design of the I I Hydropower of Yi Sa river is reasonable, pressure piping structure will not crac k occurred in the design load, the structure meet the stren gth requirements, the deformation values of pressure pipel ines is small and meet the stiffness requirements. The desi gn of structural is economical, safe and reliable.

Bifurcated pipe belongs to complex spatial structure, and when it bears the inner and the external water pressure, the bifurcation structure enters in complex stress state. Dongjiang Hydropower Station is located upstream of the Xiangjiang River tributary in the southeastern territory of Zixing, Hunan province and it is a large hydropower projects with comprehensive benefits such as a power generation, flood control, navigation, and industrial and agricultural water using and so on. In this paper, using the finite element method of reinforced concrete bifurcation structure of Dongjiang hydropower station analyzes the stress so that the analysis results play a vital role in providing strong theoretical evidence for the operation if it is safe. The results prove that the surrounding rock are binding on the bifurcation pipe so that fork tubes can significantly reduce stress and have a positive impact on the safety for the bifurcation pipe.