The New Austrian Tunneling Method (NATM), also known as the Sequential Excavation Method (SEM) or Sprayed Concrete Lining (SCL) Method, is a modern tunneling approach that utilizes advanced monitoring techniques to optimize wall reinforcement based on the geological conditions encountered during excavation. This method allows for real-time adaptation, ensuring efficient and safe tunnel construction.

Developed between 1957 and 1965 in Austria by Ladislaus von Rapcewicz, Leopold Müller, and Franz Pacher, NATM gained prominence in the 1960s for its innovative approach. The term NATM was introduced to distinguish it from earlier tunneling methods, emphasizing its economic advantage by utilizing the natural geological strength of the surrounding rock mass to support the tunnel, reducing the need for excessive reinforcement.

NATM/SEM has significantly transformed modern tunneling, making it the preferred method for various tunnel types, including metro, road, and railway tunnels. Its ability to adjust excavation techniques based on actual ground behavior has contributed to its widespread adoption worldwide.

Additionally, NATM is known for being highly cost-effective, even in challenging geological conditions such as karst formations, making it a reliable choice for complex underground projects.

Key Features:

• Utilizes the surrounding rock mass as a natural support system.
• Primary support is provided using sprayed concrete (shotcrete), rock bolts, lattice girders, and steel arches.
• Deformation monitoring is critical to adjust support measures in real-time.
• Cost-effective and flexible for varying ground conditions, particularly in weak or heterogeneous rock masses.
• Commonly used in metro, highway, and railway tunnels, especially in soft ground and urban environments.

NATM/SCL is preferred for minimizing settlement, optimizing tunnel stability, and ensuring safety through controlled excavation and progressive reinforcement.

We specialize in comprehensive tunnel design and engineering solutions using the New Austrian Tunnelling Method (NATM), Sprayed Concrete Lining (SCL), and Drill & Blast techniques. Our expertise ensures safe, efficient, and cost-effective tunneling solutions for complex underground projects.