Método e algoritmo de reconstrução de curva para o monitoramento de deslocamento de solo através de sensores a rede de Bragg

Abstract

The present study proposes an alternative to the geotechnical instrumentation that uses inclinometers, aiming for a continuous and permanent solution, in order to quantify the ground movement, for example, from earth dams, landfill sites and slopes. A system based on optical sensors, Fiber Bragg Grating sensors, is proposed to achieve the goal of this study: a tube, with sensors installed along its length, capable of measuring its own profile, in other words, its bi-dimensional position in Cartesians coordinates. Potentially, the in-field deployment of this monitoring system – installation and commissioning – would be executed only once, minimizing or extinguishing the need of periodic interventions. An algorithm was developed with the purpose to rebuilding bi-dimensional curves from its curvature data, which are associated to the displacement profile of the tube instrumented by the optical sensors, and employing the Frenet-Serret equations. Real data from in-field monitoring measured by a slope indicator system (inclinometers) was used to assess the response of the developed algorithm. Moreover, laboratory tests were performed to simulate the methodology of the present study and to assess the performance of the entire monitoring system in a small-scale scenario.