Monitoring in the Stockholm metro

As part of the ongoing project “Monitoring of parameters of small and large-scale blasting by fiber optic sensors“, we had the opportunity to measure in Stockholm, where the Czech company Subterra a.s. is expanding the metro system.

The project is created in cooperation with Subterra a.s., Czech technical university in Prague and VSB – Technical University of Ostrava with the support of the Technology Agency of the Czech Republic.

Our main task was to develop an optical fiber sensory system for monitoring seismic and acoustic effects due to small- and large-scale blasting, including an evaluation cloud unit with support for the latest generation mobile networks. The evaluation unit is supposed to enable the processing and storage of large amounts of data using advanced algorithms and using innovative IoT principles.

For this purpose, we used our Periguard monitoring system in combination with a prototype of a 3-axis gyroscope based on optical fibers that was developed at the VSB – Technical University of Ostrava. We have tested the system for monitoring the transmission of vibration through Stockholm granite during three blasts of 700 kg of explosive emulsion at different distances from the face.

During testing, we obtained valuable data on vibrations/frequencies transmitted by rock, and these will be used in the upcoming phase of the project to develop further prototypes of these sensors. We believe that the technology being developed will provide reliable information on how the blasting works during the excavation of underground structures underground excavations, excavations of large construction pits, mining blasting or demolition works impacts on the newly built structures and structures of existing objects in the affected area.

This project has been financed with the state support of the Technology Agency of the Czech Republic and the Ministry of Industry and Trade of the Czech Republic within the TREND Programme.