Abstract
Long-term assessment of aging highway tunnels requires linking spatial geometry with time-dependent rock-lining interactions. This study examined the 1147 m left tube of the Jinan Tunnel after 23 years of service to identify deformation-sensitive zones and inform maintenance. The tunnel is excavated mainly in weathered Cambrian limestone, classified as Grade IV (poor) to Grade V (very poor) rock. Terrestrial laser scanning (TLS) point clouds were compared with the design profile to quantify radial deviations and clearance convergence. A representative Grade IV section with an approximately 100 m overburden was simulated for 100 years using Fast Lagrangian Analysis of Continua in Three Dimensions (FLAC3D) and a Burgers viscoelastic model. At LK32+370, the crown deviation reached 109 mm, compared with 87.8 mm at the right arch waist and 46.3 mm at the left sidewall. Alignment-scale average radial deviations were approximately 40–50 mm in central sections but 60–70 mm near the ends, and Grade V sections exhibited average deviations that were approximately 1.5 times those of Grade IV sections. Modeled crown displacement increased from approximately 1.6 to 2.6 mm between years 10 and 20. From years 5 to 50, lining horizontal stress at the crown increased from 5.1 to 8.5 MPa and lining vertical stress at the arch waist from 5.5 to 10.5 MPa, with the steepest growth during years 10–20 and slower growth thereafter. The resulting framework integrates full-profile TLS screening with creep-based interpretation to prioritize poor-rock, shallow-cover, weak-interlayer, and vulnerable lining zones. Because the TLS survey represents one late-life epoch, the field quantities are design-referenced deviations rather than pure 23-year deformation.