Reggio Calabria high speed railway line. Cosenza – Paola / S. Lucido doubling. New Santomarco tunnel. EPB – TBM and traditional technique tunnelling through potentially gassy rock masses. Technical – scientific advisory support

Client: Italferr S.p.A.
Project: Salerno – Reggio Calabria new railway line. Cosenza – Paola / S. Lucido doubling. New Santomarco tunnel
Date: March 2022- May 2024

The Detailed Technical and Economic Feasibility Design (PFTE*) of Cosenza – Paola / S. Lucido Doubling (Salerno – Reggio Calabria new railway line) includes the excavation of the new Santomarco twin tunnels, branch tunnels to S. Lucido and service tunnels (Figure 1).
SERENGEO provided technical – scientific assistance, during PFTE* design, on safety against air – methane mixtures detonation / deflagration during tunnels’ construction works.

Figure 1. Routes of the new Santomarco twin tunnels (sky blue line), branch tunnels to S. Lucido (orange lines) and service tunnels (magenta lines)

Project goals

  • Technical – scientific guidance for safe design and construction of tunnels (with EPB – TBM and traditional excavation technique) in potentially gassy rock masses.

Activities performed

  1.  Bibliographic and hystorical documentation’s analysis on:
    ◦ tectonic and geo-structural setting;
    ◦ seismic events near Santomarco tunnel route;
    ◦ surface methane emissions in the regional territory including the route (Figure 2);
    ◦ evidences of methane presence in the geological formations that will be involved in tunnels excavation;
    ◦ mining licenses, issued by the Ministry of the Environment and Energy Security (MASE), for the exploration and extraction of hydrocarbons (oil and/or gas) and stratigraphy of exploratory and production wells close to the route (Figure 3);
  2. Analysis and interpretation of the results of geognostic, geophysical (seismic reflection) and methane investigations, carried out along the route;
  3. Critical analysis of the geological, geotechnical, hydrogeological (technical reports and geo-structural profiles) and design documentation (excavation methods and techniques, section and technical data) of the underground works;
  4. Development, based on S&R results, of the safety measures and procedures, against air – methane mixtures’ detonation / explosion hazard, to be adopted during excavation with EPB-TBM and traditional technique of the new Santomarco tunnel and service tunnels to ensure the highest workers safety level.

Figure 2. Geo-structural profile of the new Santomarco tunnel. The red arrow locates the area where surface methane emissions were recorded (Martinelli et al., 2012; Minissale et al., 2016; “INGV-DPCV5” project)

Figure 3. Areas of “Bisignano” research permit and “Fiume Crati” prospecting permit, which include part of the new Santomarco tunnel’s route. The figure also shows the two research permits “E.R 41.CO” and “E.R 42.CO”, aimed at investigating the off-shore “coastal Graben”, off the coast of Paola (from ViDEPI project, UNMIG)