Supporting and ensuring the safety of tunnel projects throughout their life cycle
Sixense Limited is uniquely positioned to work in partnership with UK clients who design, build and maintain tunnel infrastructure, providing specialist engineering, monitoring and digital solutions that support the safe delivery and long‑term performance of underground assets.
With extensive experience across major transport, utilities and civil engineering projects, Sixense helps clients manage risk, protect existing assets and maintain public confidence throughout all stages of the tunnel lifecycle.
During construction, Sixense supports contractors and asset owners through the design and implementation of integrated instrumentation and monitoring systems, geotechnical expertise and data‑led decision‑making tools.
These services enable early identification of ground movement, structural behaviour and environmental impacts, helping project teams to maintain safety, comply with UK regulatory requirements and keep delivery on programme and within budget. By combining on‑site engineering insight with advanced digital platforms, Sixense provides clear, actionable information that supports confident, timely decisions.
Beyond construction, we also work alongside tunnel owners and operators to support inspection, maintenance and asset management activities. Through long‑term structural health monitoring, digital twins and predictive analytics, Sixense can help clients understand how assets perform over time, optimise maintenance strategies and extend asset life.
This collaborative, lifecycle‑focused approach ensures UK tunnel infrastructure remains safe, resilient and fit for purpose in an increasingly demanding operational environment.
Solutions and services tailored for tunnel infrastructure
We provide tunnel operators with a variety of solutions and support services that are designed to optimise and prolong the life cycle of tunnel infrastructure.
- Support the digitalisation of your infrastructure and processes
- Offer decision-making and reporting support tools
- Qualify the risks associated with tunnel projects via specialist engineering and structural, geotechnical and environmental monitoring
- Advise on the levels of climate vulnerability to the operation the resilience of tunnel infrastructure
- Produce digital twins as well as the modelling of your infrastructure.
Protecting and Prolonging rail infrastructure performance
Throughout the lifecycle of tunnel infrastructure, from early design and concept development through to construction, operation and long‑term maintenance, it is essential that designers, contractors, asset owners and operators have access to reliable information and a detailed understanding of the ground conditions, structural systems and surrounding environment. A clear appreciation of potential geotechnical, structural and operational risks is critical to ensuring the safety, resilience and operational integrity of tunnel assets over their intended life.
During the construction of new tunnels, principal contractors are under continual pressure to meet demanding programme, productivity and cost constraints while delivering complex underground works to exacting standards. Managing ground behaviour, interactions with adjacent assets and construction‑related risks is vital to achieving safe delivery of tunnels that are designed to perform reliably for decades.
Furthermore, throughout the operational life of tunnel infrastructure, it is necessary to maintain high levels of availability, safety and performance. Optimising inspection and maintenance regimes, managing ageing assets and improving resilience to environmental and climate‑related factors are therefore fundamental considerations in ensuring tunnels continue to operate safely and efficiently for users.
We provide solutions and support services during the life cycle of your rail assets
Instrumentation and Monitoring
We work in accordance with relevant UK and European standards and operate throughout the UK and Northern Europe, delivering high‑precision, cost‑effective and, most importantly, safe instrumentation and monitoring solutions for tunnel and underground infrastructure.
Our services include the design, supply, installation, management and maintenance of bespoke instrumentation and monitoring systems. These systems measure the effects of tunnelling works and adjacent developments on existing underground assets, as well as monitoring new tunnels during construction and providing long‑term structural health monitoring throughout their operational life.
Our solutions enable tunnel owners and operators to gain a clear understanding of the structural integrity, behaviour and condition of their assets, supporting informed decision‑making and effective risk management. We provide a wide range of monitoring solutions capable of recording geotechnical behaviour, structural movement and environmental influences within and around tunnel infrastructure.
Monitoring solutions range from simple manual survey techniques, such as precise levelling, convergence monitoring and deformation surveys, through to geotechnical instrumentation installed within groundworks and tunnel linings. These can be complemented by fully automated, site‑based systems incorporating automated total stations and datalogged structural and geotechnical instrumentation.
Our in‑house Atlas InSAR monitoring solution is also available, providing precise, efficient measurement of ground and asset movement across wide areas. Using satellite‑derived geospatial data, this solution supports the monitoring of entire tunnel corridors and surrounding infrastructure over extended periods.
Asset Mapping
Sixense provides advanced asset mapping services that allow infrastructure owners to build a clear, accurate and shared understanding of their assets and the environments in which they operate. By combining geospatial data, survey information, asset records and engineering knowledge, Sixense helps clients create structured, reliable asset inventories that support decision‑making across design, construction and operations. These services reduce uncertainty around complex assets, improve coordination between stakeholders and form a robust foundation for effective asset management and risk mitigation.
A key element of this digital offering is Sixense Pika, a cloud‑based digital twin and data intelligence platform that connects asset information with inspection, monitoring and performance data. Sixense Pika transforms static asset records into living digital twins, enabling users to visualise asset condition, track changes over time and identify emerging risks through intuitive dashboards and analytics. By integrating real‑time and historical data, Pika supports predictive maintenance, scenario analysis and lifecycle optimisation, helping asset owners improve safety, resilience and long‑term value while reducing operational costs and unplanned interventions.
Geophysical surveys and soil characterisations
Sixense delivers a range of geophysical survey services that support the investigation, assessment and management of complex infrastructure assets and ground conditions. These services are used across the lifecycle of projects to characterise subsurface conditions, assess structural behaviour and reduce uncertainty during design, construction and operation. By combining geophysical techniques with engineering expertise, Sixense helps clients identify potential anomalies, defects or changes in material properties that could affect safety, performance or durability.
Among these services, hammer tests are commonly deployed by Sixense as a non‑destructive method to assess the stiffness, integrity and dynamic response of structures such as tunnel linings, slabs and foundations. Hammer tests provide valuable insight into material condition and structural behaviour without disrupting operations, and can be used to validate design assumptions or support condition assessments. When integrated with other geophysical survey data and monitoring results, hammer testing forms part of a holistic, data‑driven approach that enables asset owners to make informed decisions, optimise maintenance strategies and manage risk throughout the life of their infrastructure assets.
Our experts hold the largest number of AGAP quality approvals in the profession (www.agapqualite.org). This provides our clients with assurance regarding the sophistication and effectiveness of the methods we use, and the quality and reliability of the services we provide.
Climate resilience
Sixense supports tunnel owners and operators in assessing and strengthening the climate resilience of their assets by combining engineering expertise, monitoring data and advanced digital tools. Climate‑related hazards such as flooding, groundwater rise, extreme rainfall, heat stress and long‑term ground movement can significantly affect tunnel performance and safety.
Sixense undertakes vulnerability assessments that evaluate how these hazards may impact tunnel structures, systems and operations over time. By integrating historical data, climate projections, asset condition information and monitoring results, Sixense can help clients identify critical risks, assess potential failure modes and prioritise adaptation measures that enhance resilience across the tunnel lifecycle.
To complement this approach, we work closely with our sister company Resallience, the group’s design and engineering office dedicated to climate change adaptation.
Resallience brings specialist expertise in climate hazard modelling, resilience analysis and adaptation strategy development, enabling a holistic assessment of tunnel infrastructure at asset, corridor and territorial scale. Together, Sixense and Resallience support the development of practical, data‑driven action plans that improve preparedness, optimise asset management and reduce the impact of extreme climate events on tunnel availability and safety.