Based on the load-structure theory and using the object-oriented programming method

the theoretic basis of CAD software (GeoFBA) for shield tunnel lining is described and its usage and feature are also expounded. The software provides the various possible linear and nonlinear models as well as verification for segment design specification

and is suitable for two segment assembling types with the straight joint and the staggered joint. The software has been used widely in practice

which is a powerful tool to designers and researchers

and enhances greatly the productivity of designers.