Abstract: Using the countermeasures of the smooth implementation of the curved shield tunnel with micro curvature radius in Tokyo, Japan for reference, and relying on the inter-city railway in Zhuhai, China, this paper focuses on the analysis of the effect of the measures of shortening the shield length on the construction control for twin curved shield tunnels. 3D surface-to-surface contact is established to simulate the interaction between the segments by ABAQUS, and a specific constraint between the longitudinal bolt and the segments is established to simulate the installation of the inclined bolt. As a result, a refined simulation of the excavation of twin curved tunnels considering the characteristics of circumferential joints in the wedge-shaped segment is realized. On the basis of validated reliability of the refined numerical simulation method in this paper, a contrastive analysis of the construction control effects are completed. The results show that shortening the shield length can effectively reduce the ground settlement and the horizontal displacements of the soil at the inner and outer sides of the curved tunnels. Meanwhile, for the segment structure, the maximum bending moment is reduced and the safety factor is improved. Shortening the length of shield tunneling is a reliable measure to effectively control the soil deformation and to ensure the safety of the segment structure, which is worthy of popularization and application in engineering practice.

Key words: curved shield, twin tunnels, construction control, internal force of the segment, soil deformation