Tunnel Structural Health Monitoring Systems

With more than 60 years of experience delivering comprehensive tunnel monitoring solutions that combine proven geotechnical sensors, intelligent data acquisition, and powerful software. Our systems give engineers clear, real-time insight into tunnel behaviour and performance - from construction through to long-term operation.

We support owners and contractors on demanding tunnel projects worldwide, helping them control deformation, manage ground-structure interaction, and protect adjacent assets with confidence.

Dataloggers and Remote Platforms (VWLOG2, GPRS, Sensly Monitoring Platform)

Read, record and display data from distributed tunnel sensors to create a single, coherent view of tunnel and ground response.

Remote cellular transmission enables near real-time alerts and reduces the need for frequent site visits in constrained underground environments.

Extensometers (Tape Extensometer, Continuous Rod Extensometer)

Enable manual measurement of tunnel cross-section convergence and wall displacement to verify design assumptions and construction methods.

Support early detection of overstressing or instability so support systems can be optimised before issues escalate.

Inclinometers (Digital Inclinometer, GEOSmart, Smart In-place Inclinometer, Inclinometer Casing)

Monitor horizontal subsurface deformation and potential slip planes in slopes and ground above or adjacent to tunnels.

Provide long-term movement trends that inform excavation sequencing and ground treatment strategies.

Joint and Crack Monitoring (VW Crackmeter, VW Triaxial Jointmeter, Mechanical Jointmeter)

Measure opening and closing of joints and fissures in tunnel linings and walls to assess structural integrity over time.

Capture multi-directional movements that help differentiate between benign cracking and developing structural issues.

Load and Pressure Cells (VW Load Cell, Strain Gauge Load Cell)

Quantify loads and pressures acting on tunnel linings and support elements, to validate design models and support performance.

Identify changes in load transfer that may indicate ground relaxation, consolidation or unexpected loading conditions.

Strain Gauges (VW Strain Gauges)

Measure strain in reinforcing steel and mass concrete within tunnel linings to assess stress distribution.

Support understanding of long-term effects such as creep, shrinkage, and temperature-related tunnel performance.

Tilt sensors (Mems Tiltsensor, Electrolevel Beam Sensors, Tiltmeters)

Monitor differential displacement and rotation of tunnel walls, station boxes and sensitive surface structures within the tunnel influence zone.

Provide highly sensitive movement detection essential for protecting historic and high-value buildings above tunnelling works.

Piezometers (VW Piezometer)

Measure pore pressure change associated with groundwater variation and soil consolidation around tunnels.

Support effective dewatering control, lining design, and ground improvement measures to maintain stability and limit settlement.

Fiber Optic Sensors (Distributed Strain and Deformation Sensors)

Localize and quantify deformation of tunnel linings along the whole length of the tunnel.

Detect and localize cracks in steel and concrete load-bearing elements.

References:

TUNNELS AND RAILWAYS

Victoria Underground Station Upgrade

Victoria’s underground station is at the heart of London’s transport network and is one of the busiest stations, used by around 100 million passengers each year.

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TUNNELS AND RAILWAYS

Crossrail C701

The Crossrail project was the biggest tunnel project in Europe to date, with around 21km of the total 118km route contained within newly bored tunnels.

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