Analysis of vertically freezing reinforcement for shield launching and accessing on load-structure model

Vertically freezing is a reliable method of reinforcement for shield launching and accessing. Engineers often use Japanese formula to determine the thickness of the reinforcement. At the same time, some engineers use another formula, which is deduced by the elastic theory about circular plate under different constraints. By finite element analysis on load-structure model this paper discusses the constraint characteristic of the reinforcement under different design parameters to judge the rationality of existing design method. Analysis results suggest that the Japanese formula is conservative. This paper presents modified calculation methods of maximum tensile stress, maximum deflection and maximum shear stress, and provides a new design method.