STUDY ON THE EFFECT OF ASSEMBLING METHOD ON THE INNER FORCE OF SEGMENTAL LINING FOR CROSS-RIVER SHIELD TUNNEL WITH LARGE CROSS-SECTION

The effect of assembling method on the inner force of segmental lining for cross-river shield tunnel with large cross-section has been concerned for a long time. Different assembling plan yields different distribution characteristics of inner force. In this paper, theoretical analysis is carried out to discuss the mechanism of assembling effect of circular shield tunnel, especially the effect of longitudinal interaction on circumferential inner force. Then based on Nanjing Yangtze River Shield Tunnel project, a prototype test is conducted to study the mechanical distribution characteristic of circumferential inner force in different assembling plan and the mechanical distribution characteristic of inner force of target segment (B5) along the circumference and width direction. The results show that, the effect of the interaction intensifies bending moment in local area when using staggered assembling, and the growth of bending moment and decline of axial force become larger near the longitudinal bolts. And along the width direction, the positive bending moment distributes as a concave type, the negative bending moment and axial force distribute as a convex type. The result can provide valuable references to design and construction of large-profile underwater shield tunnels; meanwhile it can also provide important reference to the correlative studies.