Structural Health Monitoring of Cable Stayed Bridge

The Challenge

Wireless SHM of cable-stayed bridges requires sophisticated and reliable sensor systems. These devices detect structural damage and evaluate structural performance. Then, the monitoring data can be used to modify a finite element model of internal force. In order to monitor the structural health of a bridge, many sensors of various types are required, and it is important to synchronize the sensors with a network. Wired networks, which are traditionally used, are too expensive to install and maintain and take a lot of time to build.

Speaking about requirements for SHM, the first thing needed to be mentioned is a sensor system with a wide frequency range. It should be capable of measuring the tension of the cables. It should also be capable of monitoring pylons, cables, and deck. In addition, the system must be able to recognize changes in these parameters, which can affect the bridge’s structural integrity.

Judging from this, the key challenge was to replace the wired sensor network for bridge SHM with robust and less expensive wireless sensor network with corresponding capabilities.

The Solution

To meet this challenge, Dongil Engineering Consultants Co. has developed a smart sensor node, which can collect and process signals from various sensors and transmit the results using LoRa communication. The system is designed for long-term monitoring of cable-stayed bridges. It is easy to deploy and enables efficient data management. The core functions of the system are damage identification and status evaluation. The monitoring system determines the location, degree, and rate of damage and comprehensively evaluates the effects of each damage on the structure.

The creation of such an effective solution has become possible by deploying TEKTELIC KONA Macro IoT Gateway with the smart sensor nodes. KONA Macro IoT Gateway was a perfect match for the abovementioned requirements as it is a robust, high-performing outdoor gateway with hardened carrier-grade enclosure and versatile deployment options.

To organize SHM of cable strayed bridge, KONA Macro IoT Gateways were deployed right to the bridge strays and walls. It is a cost-effective and compact LoRaWAN gateway, which is an answer for a long lasting- challenge in the civil engineering sphere. Dongil Engineering Consultants Co. in partnership with TEKTELIC has managed to successfully build LoRa Wireless Sensor Network for Bridge SHM, which performs with low operational costs and is even better than wired counterparts.

Conclusion

Wireless structural health monitoring of a cable-stayed bridge requires the use of sensor modules to monitor the health of the bridge. These devices record the current conditions of the bridge, including its working environment and the different factors that affect the safety of the bridge. The monitoring data can then be used to make maintenance decisions and forecast problems.

The biggest achievement of this partnership is significant cost reduction when using a wireless solution. Replacing the existing wired sensor network with the smart sensor node and fully wireless TEKTELIC KONA Macro IoT Gateway, Dongil Engineering Consultants Co. saves more than 50% of the cost compared to the previous spending on wired solution. This smart solution greatly contributed to the increased efficiency of the monitoring process.

The current system is made up of wireless smart sensor nodes that detect vibration in the bridge caused by environmental and traffic loading. The data is collected and analyzed in real time, so it can be used to determine the serviceability of a long-span bridge. This solution serves a prominent example of a new technology for SHM of cable-monitoring.