Abstract: Combined with an in-service substation in Hunan Province, the bearing capacity of the ring section prestressed concrete herringbone frame is calculated by using two specifications, namely Design Manual for Structural Gantry of Switchyard and Technical Code for the Design of Substation Buildings and Structures. The differences between the formulas for calculating the bearing capacity under compression, bending and tension under the two codes are analyzed from the aspects of application scope, calculation convenience and parameter concept. The results show that the proposed formula the latter covers a wider range and is more convenient to calculate, and the calculation results and numerical difference are discussed. In addition, two common design variables, pipe diameter and reinforcement number, are selected to discuss the influence of pipe diameter and reinforcement number on the bearing capacity of ring section herringbone frame. On the premise of increasing the bearing capacity of the frame to ensure safety, the design scheme with the highest economic benefit is selected based on the cost, so as to provide reference for the frame design of new substation and the replacement of the in-service concrete frame.

Key words: prestressed concrete, structural frame, transformer substation, bearing capacity, comparative analysis