LI X, XIE J B, XIE L Z,et al.Numerical analysis of reverse tunnel breakthrough based on real scene modeling and parameter back analysis[J].Journal of Henan Polytechnic University(Natural Science) ,2026,45(4):77-85.

doi:10.16186/j.cnki.1673-9787.2024060038

Received:2024/06/18

Revised:2024/08/19

Published:2026/06/17

Numerical analysis of reverse tunnel breakthrough based on real scene modeling and parameter back analysis

Li Xu, Xie Jinbo, Xie Lizhao, Lu Xiaoyou

Technology Center， CCCC Third Harbor Engineering Co.， Ltd.， Shanghai 200032， China

Abstract: Objectives Highway tunnels often suffer from unsymmetrical loading， shallow overburden， and fractured surrounding rock， leading to significant discrepancies between theoretical calculations and field monitoring data. To develop a refined calculation method for shallow-buried tunnels in Class V rock and to analyze the spatial effect， a refined finite element analysis method based on 3D real-scene modeling is proposed. Methods A shallow-buried portal section of a highway tunnel in Henan Province was selected as the case study. An unmanned aerial vehicle （UAV） oblique photography technique was used to build a high-precision real-scene model. Contour lines were extracted to establish a refined 3D finite element model， which realistically represents the actual overburden load on the tunnel. Using field monitoring data of crown settlement， the mechanical parameters of the Class V rock were back-calculated. The accuracy of the calculated values was then verified using monitoring points from subsequent construction sections. The calculated results from 2D tunnel finite element models with different overburden depths were compared with those from the 3D model to analyze the spatial effect of the shallow-buried tunnel.  Results With the Mohr-Coulomb constitutive model and an elastic modulus of E=0.2 GPa， the finite element results matched the field crown settlement data closely， with verification point errors of 3.9% and 8.7%. The settlement deformation during construction of the shallow-buried tunnel exhibits a significant spatial effect. When the ratio of tunnel depth（H） to tunnel width（B） equals 2， the 2D model can predict tunnel settlement deformation reliably. For H/B <2， the 2D model overestimates the settlement compared with the 3D model； for H/B <2， the 2D model underestimates the settlement.  Conclusions Using a real-scene model generated by UAV oblique photography， a finite element model can be established rapidly. The back-calculation of parameter E based on monitoring data effectively predicts tunnel settlement. Moreover， the crown settlement deformation of shallow-buried tunnels shows a clear spatial effect.

Key words:shallow-buried tunnel;oblique photography;finite element analysis;parameter inversion;spatial effect