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Shield-driven tunnels are widely adopted in the development of underground spaces for transportation and utility networks in soft soils. Numerical modeling has now become an important element in the design of underground excavations in soils and rocks. Numerical analysis can provide realistic representation of the field conditions taking into account key elements of the excavation such as the geomechanical characteristics of the ground and the in situ stress condition. In order to solve the problems of section design and verification of concrete segments, the computational models are proposed for designs of concrete segments with symmetrical reinforcement bars under the action of bending moments and axial forces. Based on the constitutive model of steel bars and similarity criterions of strains in beam section, the analytical expression of stress on reinforcement bars located in compressive region is derived. Influences of axial forces on the ultimate bearing bending moment of segments and the area of reinforcement bars in tension region are discussed through analyzing two practical underground tunnels with concrete segment linings. The investigation shows that the depth of compressive region increases with increasing axial force on segment. The ultimate bearing bending moment of concrete segment increases with increasing axial force on segment when area of reinforcement bars is constant.