Abstract In view of the influence of internal water pressure on the mechanical characteristics of the composite lining structure of the shield tunnel, and in combination with the Longquan Inverted Siphon Tunnel of the Central Yunnan Water Diversion Project, the shell-spring model of the composite lining is improved, and the mechanical behaviors of the double-layer lining structure under the internal water pressure are analyzed. The results show that the bending moment of the segment structure is less affected by internal water pressure, while the axial force of the segment and the flexural rigidity of the longitudinal joint decrease with the increase of internal water pressure; The axial force and the bending moment of the secondary lining are greatly affected by internal water pressure; The internal water pressure has a significant effect on the flexural rigidity of the joint with a larger bending moment, with a maximum decrease of 47.97% in the flexural rigidity of the joint; Under external soil and water loads, the deformation of the segment shows a trend of vertical convergence and horizontal expansion. After filled with water, the overall downward displacement of the lining structure leads to its further vertical convergence. Under the action of internal water pressure, the force between the segment lining and the secondary lining is mainly radial compression. When the longitudinal joint of the segment is subjected to a positive bending moment, the compressive stress significantly increases.When subjected to a negative bending moment, the radial interaction force is zero, and there is a separation trend between layers.
Abstract：
In view of the influence of internal water pressure on the mechanical characteristics of the composite lining structure of the shield tunnel, and in combination with the Longquan Inverted Siphon Tunnel of the Central Yunnan Water Diversion Project, the shell-spring model of the composite lining is improved, and the mechanical behaviors of the double-layer lining structure under the internal water pressure are analyzed. The results show that the bending moment of the segment structure is less affected by internal water pressure, while the axial force of the segment and the flexural rigidity of the longitudinal joint decrease with the increase of internal water pressure; The axial force and the bending moment of the secondary lining are greatly affected by internal water pressure; The internal water pressure has a significant effect on the flexural rigidity of the joint with a larger bending moment, with a maximum decrease of 47.97% in the flexural rigidity of the joint; Under external soil and water loads, the deformation of the segment shows a trend of vertical convergence and horizontal expansion. After filled with water, the overall downward displacement of the lining structure leads to its further vertical convergence. Under the action of internal water pressure, the force between the segment lining and the secondary lining is mainly radial compression. When the longitudinal joint of the segment is subjected to a positive bending moment, the compressive stress significantly increases.When subjected to a negative bending moment, the radial interaction force is zero, and there is a separation trend between layers.
MENG Qinghui1 FENG Kun1 YANG Guodong1 HE Xiao2 YANG Zhao2 HUANG Qingfu3 GAO Chong1,
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.Study on the Influence of Internal Water Pressure on the Composite Lining Structure of Water Conveyance Shield Tunnels[J] MODERN TUNNELLING TECHNOLOGY, 2023,V60(4): 33-42
2023, Vol. 60 