Tunnels are inherently designed for transportation.. Societal and economic development has led to the continuous construction of large-span bridges and underground tunnels over rivers, lakes, and seas. These projects are large in scale and structurally complex and have harsh service environment. Compared with underground tunnels, a bridge structure is more lightweight and flexible. However, it easily suffers from frequent traffic loads, fluctuating wind loads, rainstorm attacks, and temperature effects. Structural performance can easily degrade under the above loads or actions, posing a risk to the safe operation of the structure and even causing collapsed accidents.
In addition to these, Ventilation effectiveness due to high concentration of Carbon Monoxide, traffic analysis, intelligent Surveillances Systems.
The impetus for Structural Health Monitoring (SHM) of national assets like Tunnels is not only dictated by the considerations for transportation, safety, commercialize and economy of a region, but also by the implications to the nation's defense and preparedness; thus, necessitating REAL TIME STRUCTURAL HEALTH MONITORING (SHM) with Safety and Security to become an important constituent of any Tunnel management system.
Photonics Monitoring is breakthrough in NDT procedures. The systems are novel and innovatively uses principles of laser back scattering in the environment of operation. CATS is only company providing single laser Sensor that can monitor and records various Movement, Force, Environment, Acceleration, Displacements, Velocity, Load impact, damage detection, Sound etc. It is one of its kind non-contact & non-imaging technique for remote monitoring. Accurate qualitative and quantitative data is collected in real time using a single laser source as a function of time and space.
VEDA (Vibrational Effects Detection Analysis) is a real time off board Vibration and Health Monitoring of Tunnels. These systems can be installed on Tunnels and all vibration data from the Road or Rail will be collected and transmitted to centralized system for health analysis.
This innovative photonic / laser technologies and the algorithms employed in the development of the system ensures real time extraction of the following information :
Classifying and Discriminating Vehicular and pedestrian traffic with Statistic's.
Moving Vehicular identification (type, size)
Individual Vehicle Weigh in Motion.
Vehicle speed, approximate Distance and Geo Position.
Recording Sound of the intruder and filtering other environmental sounds
Covert Intrusion detection for Security and Surveillance
VIDUR (Vibration Intelligence Data Unravelling Remotely), is real Time on board Vibration and Health Monitoring of Tunnels. Vidur collects the information and help in diagnostics and fault detection for improving the safety of structures and passengers in addition to saving maintenance costs. Thus VIDUR monitoring can, in many cases, be extended to provide primary protection, but its real function is to attempt to recognise the development of faults at an early stage.
AUM System is integrated with Photonic Pollution Monitoring system AUM, herein the system can detect and monitor various pollutants that are concentrated and clustered in tunnels like CO2, CH4, Hydrocarbons, Pm2.5, NOX, SOX
REAL TIME CONDITION & VIBRATION MONITORING
These real time photonic monitoring systems will substitute Routine Inspection Module (Rim) & Detailed Inspection Module (Dim). Vibration and Condition monitoring of TUNNELS using Photonics enables the following crucial information related to structural integrity in real time, even under the impact of live loads (static and dynamic).
Accurately monitors vibration amplitude, velocity and acceleration in both time & frequency domains simultaneously, that elucidated to aesthetics, functionality, strength parameter, Balance service life and data analytics of Tunnels. This results in structural integrity, safety and security.
Photonic systems scan's the entire Tunnel for occurrence of geometric deformation, multi-point displacement and sub millimeter deflection in real time with dynamic loading, up to 1000 data points per second.
Monitors strains in Commuter Tunnel Linings and concrete pre-cast segments. VIDUR measures and investigates tension in rock bolts and anchors used in tunneling projects, by monitoring strain variations and monitoring loads on struts.
VEDA vibration monitoring can be important during the tunnel construction and operation stages to monitor vibrations associated with the tunneling activity. It can also be important to understand whether subsequent vibration effects due to separate construction actions conducted on the surface are causing vibrations that might have a harmful effect on existing tunnel or subways within proximity of the new project location. Thus, stakeholders are able to take informed actions in a timely manner.
Highly sensitive and accurate compared to any conventional technologies.
Patterns / Trends of strain and deflection on real time can be analyzed and historical data can be mapped and Geo-coded.
Detects Cracks and damage due to Water seepage, delamination & porosity, Corrosion etc.
Allowing in the future, the periodical check of the structural performance under service loads.
Photonic systems also monitor, and records Counts, Type, Speed & Weight of Vehicle / Pedestrian thereby ascertaining security and surveillance. The system can record overloaded impermissible vehicle as well.
TUNNELS health can be determined depending upon the age, traffic count, material of construction & Structural form. Thereby expected loss of service life, due to corrosion and expected balance service life of TUNNELS can be evaluated.
The sensitivity and accuracy of the monitored parameters are very high compared to conventional sensor measurements. The multifarious advantages of the systems include smaller time responses, higher accuracies, one system to measure a host of parameters in the time, frequency and spatial domains and the freedom from many known constraints associated with conventional sensors.