STUDIO DI ACCELEROMETRI MEMS E LORO UTILIZZO COME INCLINOMETRI PER MONITORAGGIO FRANE

The study carried out in this thesis had as purpose the implementation of triaxial MEMS accelerometers (Micro Electro-Mechanical System) for inclination measurement, aiming to their use in landslide monitoring. MEMS inclinometers have been compared with conventional applications (mobile inclinometer going down in special tubes with guides) and in fixed innovative systems. The comparison with traditional methodologies confirmed the possibility of replacing servo-inclinometers, very expensive and requesting high caution to avoiding shocks and thermal variations, with MEMS inclinometers integrated in silicon microchip which benefit possibility of integration with control electronics, miniaturization and of high insensitivity to the collisions (they can withstand shocks beyond 1000 g). The extremely low cost, low consumption and possibility of using a high number, allowed continuous monitoring systems to better in-time intervention and landslide evolution control as well issue of possible alarms. The test confirmed the possibility of traditional accelerometers replacement with the MEMS; fundamental attention is on power supply stabilization and temperature monitoring allowing the corrections (ratiometric for the tension, of offset and span for temperature). The sensor of temperature allows also indirect information on the composition of the layers and their ground water content by analyzing the short period differences relative to the yearly base sinusoidal trend.