Abstract: FBG sensor is used in geotechnical engineering gradually. Success rate of embedded instrument is an important indicator for successful application. Based on the principle, structure, installation and embedment of FBG sensor, this paper summarized multiple failure causes in engineering application and studied the typical characteristics of wavelength changing when FBG relaxed. In order to enhance the success rate of embedded instrument and to realize monitoring purposes, the paper put forward some advices on the protection of optical fiber cable, sensor package, aging screening, etc., for reference.

Key words: FBG sensor, invalidation, wavelength, improvement method

摘要： FBG传感器在岩土工程中逐步应用，埋设仪器完好率是应用成功与否的重要考核指标之一。从FBG传感器原理、结构及埋设安装等出发，总结了在工程应用中的多种失效原因，并详细分析了典型的光纤夹持松弛时应变光栅波长的变化特点。提出了FBG传感器在尾缆的保护、传感器封装、老化删选等方面的一些建议，以提高埋设仪器完好率、实现监测目的。

关键词: FBG传感器, 失效, 波长, 改进方法