As compared to beam elements,3D shell elements can better simulate the mechanical behavior of tunnel structures influenced by soil.In order to promote the application of 3D tunnel structure calculation model with shell elements in large-diameter shield tunneling projects,this paper proposed a shell element-based parametric tunnel structure modeling(SPTSM)approach.SPTSM allowed for the quick generation of a tunnel structure model composed of shell elements based on the tunnel axis and cross-sectional radius.In the developed model,the common edges between adjacent rings were defined as linear hinges to simulate circumferential joint performance.The longitudinal joint stiffness of shield tunnel was processed by homogeneous ring method with introducing a discount factor.The load pressure,ground springs and restrained supports were applied to selected shell element nodes to simulate the mechanical behavior between the structure and surrounding soils.SPTSM also provide algorithms for automatic structural modeling and load calculation,and can integrate with the finite element structural calculation kernel of Karamba3D.To validate the effectiveness of SPTSM,it is applied to a 76 m interval section of a large-diameter shield tunneling project in Hangzhou.The calculation of structural deformation is compared to actual inspection results.SPTSM is shown to automatically generate a fine-grained 3D shell element model of the tunnel structure,and simultaneously complete the arrangement and settings of load pressure,ground spring,linear-hinged stiffness and restrained support.Comparing the structural displacement inspection results obtained from point cloud scanning and the results calculated by SPTSM,the results of SPTSM are within a reasonable range.It can approximately reflect the deformation or displacement trends at part of the tunnel structure.To sum up,SPTSM can provide strong support for intelligent structural design of shield tunnels.
维普
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