With the intensive development of China’s high-speed railway network and intercity railway network, the construction of the large-diameter shield tunnels and cross-passages is gradually increasing. The construction of large diameter shield tunnels and the excavation of cross-passages puts forward higher requirements for the stability and safety of segment structure. Based on the Wangjing tunnel project, this paper studies the segment displacement and mechanical response of the shield tunnel with a diameter of 10.5 m in the process of shield construction and cross-passage construction. The results show that during the construction of large diameter shield tunnels, the vault and invert produce inward displacement, the invert uplift usually is more severe than the vault settlement, and the arch waist on both sides produces outward displacement. Near the segment K (capping block), the mechanical performance of the segment is close to that of the hinge or chain rod, which can only effectively transmit the axial force but cannot resist the bending moment and shear force. During construction of the cross-passage, the maximum deformation and stress of shield tunnel segment are symmetrically located at the interface of the main tunnel and cross-passage. The upper and lower edges of the segment at the interface tend to change from compression to tension. At the same time, the steel bars on the inside and outside of the segment vault and the arch waist change from compressive stress to tensile stress, which can easily lead to segment damage, so these positions can be reinforced by erecting section steel frames before construction.

Elastic modulus and temperature are the main influences of dam stress. In order to study the Dongjiang dam stress for crack controlling, the critical parts stress of dam under different elastic modulus and high-low temperature seasons is analyzed by the finite element method. The results show that: (1) the arch crown and abutment principal tensile stress at upstream face and principal compressive stress at downstream face under high temperature season are greater than the calculation results under low temperature season for the whole at the normal storage water level; (2) the influence on stress caused by elastic modulus are more significant under high temperature season compared to low temperature season at arch crown and abutment, the maximum stress increase with the increasing of elastic modulus. (3) Dongjiang arch dam should pay more attention to the safety control under high temperature season and surface crack prevention and control work in low temperature season.