Abstract:
In the past researches on inverted siphon penstock over active faults, two structural types of steel-lined reinforced concrete pipe and open steel pipe were often studied separately.There is no comparison on which pipe type is more suitable.In this paper, the finite element method was used to establish two pipeline calculation models for finite element analysis.The displacement and stress of the inverted siphon ground steel-lined reinforced concrete pipe and the open steel pipe under the action of fault creep deformation, stick-slip deformation and earthquake were compared and analyzed.The research results show that:(1) The steel-lined reinforced concrete pipe and the open steel pipe pipeline can better adapt to the fault creep deformation after arranging multiple bellows expansion joints.(2) The deformations of the bellows expansion joints of the two pipeline structures located in the main fault are more than 100 mm under the action of fault stick-slip deformation, so it is difficult to design.(3) Under the action of earthquake, although the displacement of steel lined reinforced concrete pipe in the main fault range is large, the stress caused by the earthquake is small, and the stress of the steel pipe at the fixed bearing is obviously deteriorated.(4) Based on the calculation results of various working conditions, the stress of steel lined reinforced concrete pipe is better than that of exposed steel pipe.However the exposed steel pipe has better condition of maintenance and reset during operation.The two pipeline schemes have their own advantages and disadvantages, so the pipeline structure should be reasonably selected according to the specific needs of projects.