MOISTURE BEHAVIOR/SUBSTANCE MIGRATION MEASURING SYSTEM IN STRATUM, SEARCHING METHOD AND OPTICAL FIBER FOR TEMPERATURE SENSOR

摘要

PURPOSE:To make it possible to motion and predict formation/retraction of overdried or water saturated layer, flow-out of buried contaminants, collapse of weak ground, e.g. a fill, by searching the behavior of moisture/migration of substance in a stratum for a long term while allowing the maintenance/ management of temperature distribution measuring system of the stratum to be performed for a long term. CONSTITUTION:Optical fibers 8 are laid three-dimensionally in the stratum 1 and coupled with a measuring unit 12 which is connected electrically with an operating unit 13. Temperature on the optical fiber 8 is determined instantaneously through the use of temperature dependency of anti-Stokes scattered light of an optical pulse delivered on the optical fiber 8 and recorded in the form of three-dimensional temperature distribution of the stratum 1. Measurement is effected at some time interval and a temporal variation of the temperature variation is determined. The temporal variation is then subjected to simulator analysis thus determining the behavior of moisture/migration of substance in the stratum 1.