提出了一种基于分布式光纤光栅的边坡监测与报警系统。根据强度折减法, 利用ANSYS软件分析出边坡的软弱面及滑体所在的具体位置, 从而在该处安装经过特殊封装的拉线式光纤光栅位移传感器。滑体的位移通过拉线转换为作用在光栅上的应力, 而光纤光栅反射波长与应变具有良好的线性关系, 因此通过检测光栅反射光的中心波长的偏移量, 就可以解调出滑体的位移信息, 从而获得滑坡的健康状况和破坏程度, 实现对边坡的实时监测。实验结果与理论相符合, 在-20~80℃范围内测量精度可达到±0.02mm/200mm, 表明本系统能够满足边坡监测的要求。

The monitoring and alarming system of slope based on distributed optical fiber grating is presented. According to the strength reduction finite element method, the weak structural plane and sliding location can be analyzed by using the ANSYS software. So the specially packaged displacement FBG sensor with pulling thread can be installed there. The sliding displacement can be transferred to the strain acting on the FBG by the pulling thread. Because the reflected wavelengths of the FBG have a good linear relationship with the strain, the sliding displacement can be demodulated by detecting the offset of the center wavelength. Then the status and the damage of the landslide can be obtained and the real-time monitoring of the slope can be achieved. The experimental results are consistent with the theoretical results, the measurement accuracy can reach ±0.02mm/200mm in the range of -20℃ to 80℃. The results show that this system can meet the requirement of real-time monitoring slope.