Role of Shear Deformability on the Response of Tunnels and Pipelines to Single and Twin Tunneling

Tunneling can compromise the safety and serviceability of existing buried infrastructure because settlements, crack openings, dislocations, material strains. A continuum-based soil-structure interaction model, implementing an equivalent Timoshenko beam, is used to evaluate excavation-induced settlements longitudinal deformations tunnels pipelines. Both single twin tunneling scenarios are examined. The shear flexibility shield sprayed concrete lining may be significant. This increases tunneling-induced while it decreases tilt, curvature, associated bending moment, with implications for optimal monitoring installations. In this work, a new dimensionless factor introduced, governing relative importance accounting settlement trough width. if pure-bending, shear-dominated, or mixed deformation mode should expected. Design charts assess affected by either proposed.