Metasensing for Drill and Blast Tunneling

Tunnels leverage subsurface spaces for roads, railways, subways, water systems, and sewage networks, facilitating connectivity and utility distribution. Also, tunneling allows for minimizing the ecological footprint of development projects by preserving natural landscapes and reducing surface disturbance.  

In tunnel construction projects, geological and geotechnical surveys assess subsurface conditions to identify potential risks like unstable soil or groundwater issues. Throughout construction, advanced instrumentation monitors structural, ground, and environmental changes in real-time, with continuous data analysis ensuring alignment with safety standards and project specifications. These steps help adapt construction strategies to emerging conditions, optimizing safety and efficiency.    

Monitoring and Surveying of Drill and Blast Tunnels 

Geological and Geotechnical Surveying 

The success of any tunneling project begins with a thorough understanding of the subsurface conditions. Geological surveying is critical in the initial phases, where the composition and variability of rock types are mapped. This step is crucial for identifying geological anomalies, such as faults and folds, which could pose risks to structural integrity. 

Following geological exploration, geotechnical surveying offers insights into the physical and mechanical properties of subsurface rock and soil materials. This data is vital for assessing the stability and load-bearing capacities of the soil and rock, informing the design of the tunnel’s support structures, and influencing decisions on the appropriate construction methodologies and equipment, including the selection of the Tunnel Boring Machine (TBM) type.  

Surveying and Monitoring Technologies 

Ensuring the precision and alignment of tunnel construction requires sophisticated surveying technologies. Global Positioning Systems (GPS), Automated Motorized Total Stations (AMTS), and laser scanners play pivotal roles. These navigational points ensure that every tunnel segment aligns with design specifications, maintaining a consistent trajectory. Using Automated Motorized Total Stations (AMTS) with foldable prism targets further allows for ongoing post-blasting deformation checks and stability analyses. This enables continuous monitoring and real-time adjustments, which are crucial for maintaining the design fidelity of visionary projects.   

Further technologies like the Global Navigation Satellite System (GNSS), Light Detection and Ranging (LiDAR), and Interferometric Synthetic Aperture Radar (InSAR) further enhance the surveying process. These tools provide detailed terrain mapping and are indispensable for navigating complex geological landscapes. 

Encardio Rite specializes in providing these surveying technologies along with their in-house manufactured geotechnical sensors and data loggers. Along with instrumentation, surveying, and monitoring, we work with technologies like fiber optics, GNSS, and remote sensing like InSAR. All the data integrates into Proqio along with geological and face mapping data, construction progress, chainage and schedule data, TBM data for complete project management and data integration, analysis, reporting, and analysis for each stakeholder.  One such NATM tunnel project where Encardio Rite and Proqio currently provide complete turnkey services is at Neom-The Line in Saudi Arabia, which aims to integrate futuristic urban planning with sustainable development. 

Highlighting a few Encardio Rite Projects 

Encardio Rite has been at the forefront of integrating these monitoring and surveying technologies across several challenging projects: 

• Pir Panjal Railway Tunnel: Situated in the Pir Panjal Mountains of Jammu & Kashmir, this tunnel is a key part of the 202 km (about 125.52 mi) Udhampur – Srinagar – Baramulla rail link project. Operational since October 2009, the tunnel at 11 km (about 6.84 mi) long, includes the T-80 section, which is the second-longest transportation railway tunnel in Asia. Encardio Rite's comprehensive safety monitoring systems, including rock bolt load cells, piezometers, and inclinometer systems, have ensured structural integrity through the tunnel's challenging geological settings.   

• Northeast Frontier Railway Projects: In the unpredictable terrains of northeastern India, custom-tailored geotechnical instrumentation like strain gauges and inclinometers has been crucial for the Jiribam-Tupul and Imphal tunnels, ensuring their ongoing stability and safety. 

• Udhampur Srinagar Baramulla Rail Link (USBRL): This extensive 312 km (about 193.87 mi) railway project, connecting Udhampur to Baramulla, is noted for its complexity, with 80% of the Katra to Laole section consisting of tunnels and bridges. Encardio Rite's role has included the deployment of multipoint borehole extensometers, concrete pressure cells, and bi-reflex targets, among others, to monitor and support the structural integrity of nearly 20 large tunnels in this project. This ensures the rail link's safe construction and operation, enhancing connectivity within the Kashmir Valley. 

Beyond Drill and Blast Tunnels Encardio Rite has worked on several TBM Metro tunnels, including the Dubai Metro, Delhi Metro, Doha Metro, Copenhagen, and more. Our expertise also lies in micro tunneling projects. One critical project was UAE's Strategic Tunnel Enhancement Programme (STEP), which involved constructing a massive deep gravity sewer tunnel designed to improve the capacity and sustainability of the region's wastewater management. The main tunnel stretches over 40 kilometers (about 24.85 mi), making it one of the longest gravity-driven sewage tunnels in the world. Implementing a project of this magnitude in an urban setting requires minimizing the impact on the community and existing infrastructure. This includes managing construction noise and traffic disruptions and ensuring no structural damage to existing buildings and roads. It was at depths ranging from 60 to 100 meters (about 328.08 ft) below the surface, which posed significant engineering and logistical challenges. The use of Slurry Tunnel Boring Machines addressed the challenges of high groundwater pressures. Lastly, road and railway tunnels have also been monitored by Encardio Rite, and two key examples are the Brenner Base Tunnel, where we handled the monitoring and instrumentation, which included a nearly horizontal rail tunnel running 55 km (about 34.18 mi) between Innsbruck and Fortezza. It forms part of the world's longest underground railway system, totaling 64 km (about 39.77 mi). Sheikh Zayed Tunnel, formerly known as the Al Salam Street Tunnel, is the longest tunnel in the Middle East at 3.6 km. It features four lanes in each direction and aims to enable a signal-free route in Abu Dhabi, reducing travel time significantly. This project demanded customized engineering solutions to minimize the impact on residents and businesses during the 15 m deep underground construction.   

As cities continue to grow and the demand for innovative infrastructure solutions increases, Encardio Rite's dedication to enhancing asset safety through meticulous surveying, persistent monitoring, proactive maintenance, and Proqio sets the standard for excellence in the tunneling industry. Encardio Rite commits to providing monitoring solutions that ensure total asset safety across the entire lifecycle of tunnels worldwide.