Fiber Optic Inclinometer for Landslide Monitoring

As a main parameter reflecting the security status of slope, internal displacement monitoring has been an important issue to geotechnical engineering. An optical inclinometer is demonstrated, which utilizes FBG sensors attached to the casing of a conventional inclinometer. Three arrays of sensors at an interval of 90 degrees are glued to the outside of inclinometer. The authors carried out model experiment, in which characterization of the sensor revealed good agreement with theory and conventional displacement measurements. Meanwhile, angle monitoring result was rewarding, monitoring value of 44.3 and 29.5 degrees corresponding to the actual value of 45 and 30 degrees respectively.