Electrohydraulic valves in the modern tunnelling process

By Staff Report February 13, 2025 3:27 pm IST

A Tunnel Boring Machine (TBM) is a sophisticated equipment designed to create tunnels for various underground purposes, such as transportation, mining, or utility installations. Unlike traditional excavation methods that involve drilling, blasting, and removing debris, TBMs streamline the process by drilling and installing support structures. These massive machines consist of a rotating cutter head equipped with cutting tools that break through the soil or rock while a conveyor system removes the excavated material for disposal. Tunnel Boring Machines are preferred for their efficiency, speed, and reduced environmental impact compared to conventional excavation methods, making them essential for large-scale infrastructure projects.

Imagine a giant metal beast navigating through the earth, not with brute force, but with the finesse of a dancer. This dance is orchestrated by electrohydraulic valves responsible for powering and controlling the movement with extraordinary accuracy, transforming the tunnel boring machines into precision instruments. Known for their commitment to precision engineering, extensive product range and reliability, Atos valves are the driving force behind the smooth movements of TBMs.

Atos expertise for Tunnel Boring Machine

TBMs are indeed complex pieces of engineering, moved by tens of hydraulic actuators and completely controlled by hundreds of valves. Adaptivity is one of the crucial key characteristics of a TBM: the frontal cutter head motor must adapt the cutting speed and force based on the type of ground being excavated. Atos offers a range of proportional electrohydraulic valves with an integrated p/Q algorithm to control the force and speed of the digging discs.

Thrust and Steering are managed by controlling the many hydraulic cylinders on the TBM structure’s outer ring. These, pressurised at up to 420 bar, provide the necessary thrust to push the machine forward through the tunnel and to control steering mechanisms that allow the machine to navigate through curves and changes in alignment along the tunnel route.

As the Tunnel Boring Machine advances, it installs support structures to stabilise the tunnel walls and roof. This is typically done by placing precast prefabricated concrete segments onto the tunnel walls using erector arms or other mechanisms always controlled by valves with Axis control for the highest levels of accuracy.

This is always in compliance with strict safety regulations to protect workers and the environment during tunnelling operations. Atos’s safety-certified range allows these machines to be operated fully and safely, greatly simplifying the manufacturer’s certification of the entire machine.

Digital control to enhance productivity

These monsters of engineering, moving silently under our feet, work like a perfect orchestra in which each component moves in tune with all the others.

Atos digital electronics, advanced control systems, and electrohydraulic valves make all this possible. They allow for remote monitoring, adjustment, and optimisation of hydraulic parameters, ensuring optimal performance and enhancing overall Tunnel Boring Machine efficiency, reliability, and safety.