PLAXIS 2D Helps Model Madrid’s Traditional Tunnel Construction Method

• Proeksa Meas
• 24 October 2026
• Construction Focus
• 554 Views

Engineers have developed a methodology using PLAXIS 2D to simulate tunnels built with the Traditional Method of Madrid (TMM), offering a faster alternative to complex three-dimensional analyses.

Used in the Madrid Metro since 1917, the TMM divides tunnel excavation into small sections, typically less than 5 square meters. Each section is temporarily supported with timber planks, steel waler beams, and timber struts before being lined with unreinforced concrete. The approach helps control ground deformation and maintain stability, particularly in urban and soft-ground conditions.

The construction is generally divided into three stages: top heading, bench, and invert. Excavation advances typically range from 1.25 to 2.5 meters, with the side walls constructed alternately to maintain support for the tunnel crown before the invert completes the section.

Because the method produces significant three-dimensional effects, the study created both PLAXIS 3D and 2D soil-structure interaction models. The 2D model was calibrated against the 3D model, using Mstage to reproduce the confinement and ground relaxation associated with the advancing excavation face.

The results demonstrate that a carefully calibrated 2D model can reproduce key aspects of the TMM’s three-dimensional behavior, potentially providing a practical tool for early-stage tunnel design when faster analysis is required.

• Bentley
• Bentley Systems
• Plaxis