What is an EPB TBM?

Tunnel boring machines have forever changed the way we build tunnels. In the past, digging underground was a complex, dangerous and time-consuming task. Today, with advanced machines like the EPB tunnel boring machines (Earth Pressure Balance), we can open roads under cities, rivers or mountains with astonishing precision. But, what makes these machines so special? And, more importantly, why are they key to modern infrastructure projects?

In Eurohinca, we are experts in tunnel boring machines and subway projects. This article will take you to discover everything you need to know about EPB TBMs and their impact on civil engineering.

History of tunnel boring machines

The beginnings: How did it all start?

Imagine 19th century London, with its growing population and crowded streets. There, in 1825, Marc Isambard Brunel designed a revolutionary machine: the first "tunnelling shield", to excavate the tunnel under the River Thames. Although rudimentary, this machine marked the beginning of an era.

Since then, technology has not stopped evolving. Modern TBMs are heirs to decades of innovation, adapting to different terrains and challenges.

The leap to EPB tunnel boring machines

In the 1970s, a need arose: digging in soft and mixed soils, where traditional tools failed. Thus were born the EPB tunnel boring machinesdesigned to maintain ground stability as they move forward. Since then, they have become an essential tool for urban and subway projects.

What does EPB mean?

Unraveling the name

EPB stands for Earth Pressure Balance or "Earth Pressure Balance". But what does it really mean? These tunnel boring machines are designed to controlling and balancing ground pressure while excavating. This prevents cave-ins and maintains safety at all times.

What makes an EPB TBM unique?

• Perfect balanceThey use the excavated material itself to keep the ground stable while drilling.

• AdaptabilityThey are ideal for soft, mixed terrain and even in the presence of water.

• Controlled pressureThey avoid collapses thanks to advanced pressure regulation systems.

Why are they key in cities?

In urban projects, where any vibration or movement could affect nearby buildings, EPB TBMs are the best choice. They allow excavate under streets, rivers o infrastructures existing with total security.

Essential components of an EPB tunnel boring machine

Cutting head

It is the "face" of the TBM, equipped with discs and spades that break the ground. It is designed to adapt to the type of ground, from sand to harder materials.

Worm screw

This component transports the excavated material from the cutting head to the rear of the machine. It also regulates the pressure to maintain balance during excavation.

Support systems

EPB TBMs are equipped with systems that reinforce the tunnel walls as they advance, preventing collapse and ensuring stability.

How an EPB tunnel boring machine works

Step by step

1. ExcavationThe cutting head pierces the ground while maintaining the necessary pressure.

2. Transport of materialThe auger conveys the excavated material to an extraction system.

3. Tunnel liningAs the machine moves forward, it installs concrete or steel segments to reinforce the walls.

Total control

EPB TBMs are equipped with sensors and monitoring systems that control every detail: from ground pressure to tunnel alignment.

Why choose an EPB TBM?

Advantages that make the difference

• SecurityMinimize the risk of landslides.

• AccuracyIdeal for projects in densely populated environments.

• EfficiencyThey can work in challenging geological conditions quickly and reliably.

Applications in real projects

Urban infrastructure

EPB TBMs are essential for building subways, water sewers and utility tunnels under cities. For example, they have been key in projects such as the Madrid subway or tunnels in Guadalajara, Mexico.

Subsea outfalls

They are ideal for installing pipelines under rivers or coastsas in Eurohinca's projects in Algeria and Chile, where they guaranteed accurate and reliable results.

Transportation systems

On roads and railway lines, EPB TBMs allow for tunneling in complex terrainimproving connectivity without affecting the environment.

Challenges and how to overcome them

Common problems

• Unexpected materialRocks or debris can affect the advance.

• Tool wear: The cutting head requires constant maintenance.

Solutions

• Use of specialized tools according to the terrain.

• Continuous monitoring and real-time adjustments.

Innovation and sustainability

Advanced technology

The latest generation EPB TBMs include real-time monitoring systems, automated controls and energy efficiency improvements.

Environmental impact

These machines minimize the impact on the surface, protecting existing ecosystems and structures. In addition, many of the excavated materials can be reused in other projects.

Eurohinca: Leader in EPB TBMs

At Eurohinca, we have more than 25 years of experience in complex subway projects. Our EPB tunnel boring machines have played a leading role in international projects that stand out for their precision, safety and sustainability.

Why trust us?

• Global experienceSuccessful projects in Europe, Latin America and Africa.

• State-of-the-art technologyMachines adapted to the most demanding challenges.

• Specialized equipmentHighly trained engineers and operators.

If you are looking for innovative solutions for subway projects, Eurohinca is your ideal ally.