The Study and Applications on Fiber Bragg Grating (FBG) Monitoring System for Deep and Large Deformed Soft Ground

The fiber Bragg grating (FBG) technology is studied based on the current monitoring status of the highway soft ground settlement, for instance, the low degree of automation, the unsatisfied accuracy of the device, the slow data transmission and the greater measurement errors. The limited measuring range and the difficult situations of the soft ground burying and installing of the fiber optic sensor still need to be addressed. This thesis has analyzed the development of the long range optical fiber displacement sensor as well as its burying techniques which are suitable for soft ground settlement monitoring. Both of them have been successfully applied to De Chang Highway D10 subject. The study also shows that the long range optical fiber displacement sensor is able to meet the requirements of the soft ground monitoring. And data can be accurately monitored by means of real-time or on-line continuously. This is of great significance in pushing forward the development of the fiber optical monitoring technology in the field.