Keynote Lecture: The Sochi Case: The First Real Comparison Between NATM and ADECO-RS-Paper

Paper

Pdf Summary

The paper compares the A.DE.CO-RS approach with the New Austrian Tunnelling Method (NATM) using the Dubler Kurortnogo Prospekta motorway tunnels in Sochi, Russia. A.DE.CO-RS focuses on predicting and controlling ground deformation from the start of excavation, including ahead of the tunnel face. It reinforces the “advance core” and uses pre-confinement measures, enabling full-face excavation. NATM, as described by the authors, primarily controls deformation behind the face through sequential excavation and support.<br /><br />The comparison involved ten NATM-bored tunnels and two A.DE.CO-RS tunnels, T8 and T8A. The latter faced more difficult geology, larger excavation areas (120–220 m² versus 113–115 m²), landslide conditions and more demanding stabilization requirements. Despite these disadvantages, the authors report that A.DE.CO-RS achieved 2.4 times the excavated volume per month per face and 40% greater productivity in completed tunnel length.<br /><br />The approaches also differed in the time required to install the final lining after face breakthrough. With A.DE.CO-RS, lining was completed in under three weeks; with NATM, the interval ranged from 10 to 43 weeks. The authors argue that faster completion of the lining improves safety by limiting deformation associated with excavation.<br /><br />The Sochi project was the first implementation of A.DE.CO-RS in Russia. The authors consider it successful in both productivity and safety, while acknowledging logistical constraints and the time needed to establish the method locally. They present the case as evidence that A.DE.CO-RS can be effective in difficult ground and under tight construction schedules, while noting that its introduction in Russia would require a gradual transition from the country’s established NATM practice.

Keywords

A.DE.CO-RS

NATM

tunnel excavation

ground deformation

Sochi Russia

Dubler Kurortnogo Prospekta

advance core

pre-confinement

tunnel lining

productivity comparison