• Baghajatin Flyover and Ultodanga Flyover are the sites/bridges where we have installed the SignaGuard Sensors to primarily monitor bridge health and validate our sensor analytics by comparing with market ready sensors. ​
• The following bridge locations are generally selected for installation – ​  Mid-span of girder(L/2), 3L/4 or L/4 of girder, bearing.

CCTV cameras are installed along with sensors in the installation sites. It is done to see the correlation between the load type on the bridge with the vibration signature. In future we can also work on video analytics and machine learning to find new intelligent features of health monitoring and also traffic control.

---

• The Flyover is located on EM Bypass. It is a vulnerable bridge and it is also monitored by other civil engineering expert consultants. We have installed sensors in the bearing and mid-span of both the new and old bridge.

The suspected problem observed is difference between deflection pattern of Old and New Bridge.

From the data collected from Mid-span we can observe that the Old bridge is taking more time to come back to its initial position as compared to the New Bridge. Supporting data is attached in the next page.

Comparative study of Midspan from old(Patuli bound) and new(Science City bound) bridges with Camera feed.

---

• In March 2013, a massive chunk of the Ultadanga flyover collapsed. The wing was reconstructed with additional steel support. Some shear cracks were observed in the span by visual inspection.
• Objectives – Monitoring of Inner vs Outer Bearing and Monitoring of Original vs Reconstructed span
• Currently sensors were installed in Inner and Outer bearing. More sensors will be installed in Mid span for further monitoring and analysis.

SignaGuard sensor setups come with option to add Energy Harvesting, where solar or wind energy is used to generate enough electricity to run the system 24*7. It can be used in remote bridges where ready electric supply is not possible.

LVDT(Linear Variable Differential Transformer): LVDTs provide reliable position measurement in structure health monitoring. It is a common type of electromechanical transducer that can convert the rectilinear motion of an object to which it is coupled mechanically into a corresponding electrical signal. It can measure movements as small as a few millionths of an inch up to several inches.

Strain Gauge: A strain gauge is a device used to measure strain on an object. It is a sensor whose resistance varies with applied force; It converts force, pressure, tension, weight, etc., into a change in electrical resistance which can then be measured.

Load Cell:

A load cell is a type of force gauge. Weight of on-passing load in measured with it. With the incorporation of load cell along with sensors it is possible to relate the deflection and other dynamic parameters with the corresponding load on the girder. This will provide the scope of comparing the vertical deflection with the theoretical deflection giving an indication about the changes in the concrete properties and thereby the condition of concrete. This will be further corroborated by carrying out the dynamic analysis from the results of vibration monitoring.

Partners	What They Do	Role in SignaGuard SHM
Ado Additive Mfg.	Construction chemical manufacturers	•Civil and Construction engineering expertise •Sales and Marketing
CMDA, PWD, HIDCO	Govt. run physical infrastructure development organisation.	•Providing Lead of bridge for installation
IIT Kharagpur	Educational Institute	•Expertise •Lab Equipment
JU/Aliah University	Educational Institute	•Expertise •Lab Equipment
Individual Consultants	Civil Engineers/ Experts	•Providing Lead of bridge for installation •Expertise incorporating sensor data in the diagnostics and design of rehabilitation measures.

• IoT enabled smart bridges which can be remotely monitored.
• Alerts and Alarms before any catastrophe so that precious lives can be saved and the bridge can be restored.
• Maintenance can be planned smartly and vulnerable parts can be automatically detected.
• Bridge data collection and load testing, without halting the traffic.
• Control of traffic in a bridge by integrating with camera feed.

• Extension of use of IoT based sensors in in-depth investigation:

State of-the-art electronics, magnetic and optical based techniques involving sensors, actuators and other devices are definitely going to be more accurate, time saving as well as having monitoring advantages.

These developments can definitely contribute in investigation field particularly related to delamination, corrosion investigation, prestressing cable corrosion and breakage, reinforcement location and its condition, integrity of concrete. This can also cover some of the aspects which are not possible by available method of tests till now.