Abstract To study the longitudinal mechanical properties of shield tunnels with prefabricated assembly + cast-inplace internal structures and fully cast-in-place internal structures under overloading conditions, the Jinan Jiluo Road Yellow River Crossing Tunnel and Wuhan Sanyang Road Tunnel were taken as engineering backgrounds. A three-dimensional numerical model of the surrounding rock-segment-internal structure was established using ABAQUS finite element software, and the rationalityof the numerical model was verified through similar model tests.Comparative analysis of the deformation and mechanical characteristics of the segments and internal structures under different construction methods was conducted. Based on the damage distribution of the internal structures, optimization ideas for connections between components were proposed. The results show that the internal forces borne by the prefabricated assembly+ cast-in-place internal structure are smaller than those of the fully cast-in-place structure. The bending moment and shear force borne by the segments are greater, resulting in larger openings and dislocations compared to the fully cast-in-place structure, with the difference in openings being particularly significant, 10.02%~21.64% higher than the fully cast-in-place structure. Furthermore, the prefabricated assembly +cast-in-place internal structure is more prone to local damage due to stress concentration. When the internal structure experiences large-scale damage, the positive bending moment borne by the loading area decreases, while the negative bending moment borne by the undamaged area at both ends increases, reducing the bending stiffness of the structure and increasing the bending moments and inter-ring openings of the segments.
Abstract：
To study the longitudinal mechanical properties of shield tunnels with prefabricated assembly + cast-inplace internal structures and fully cast-in-place internal structures under overloading conditions, the Jinan Jiluo Road Yellow River Crossing Tunnel and Wuhan Sanyang Road Tunnel were taken as engineering backgrounds. A three-dimensional numerical model of the surrounding rock-segment-internal structure was established using ABAQUS finite element software, and the rationalityof the numerical model was verified through similar model tests.Comparative analysis of the deformation and mechanical characteristics of the segments and internal structures under different construction methods was conducted. Based on the damage distribution of the internal structures, optimization ideas for connections between components were proposed. The results show that the internal forces borne by the prefabricated assembly+ cast-in-place internal structure are smaller than those of the fully cast-in-place structure. The bending moment and shear force borne by the segments are greater, resulting in larger openings and dislocations compared to the fully cast-in-place structure, with the difference in openings being particularly significant, 10.02%~21.64% higher than the fully cast-in-place structure. Furthermore, the prefabricated assembly +cast-in-place internal structure is more prone to local damage due to stress concentration. When the internal structure experiences large-scale damage, the positive bending moment borne by the loading area decreases, while the negative bending moment borne by the undamaged area at both ends increases, reducing the bending stiffness of the structure and increasing the bending moments and inter-ring openings of the segments.
LIU Xiaohui1 FENG Kun1 GUO Wenqi1 LU Xuanyi1 PENG Changsheng2 LI Jiaoyang2
.Study on the Influence of Construction Methods of Internal Structures on Longitudinal Mechanical Characteristics of Shield Tunnels[J] MODERN TUNNELLING TECHNOLOGY, 2024,V61(4): 151-160
2024, Vol. 61 