基于FDM与FBG技术的路基小变形监测研究

本研究从铁路路基健康监测出发，基于FDM(Fused Deposition Modeling)与FBG(Fiber Bragg Grating)技术开发了路基小变形监测系统。利用FDM技术和FBG传感技术设计带封装和锚固板的FBG传感器监测模型，标定试验可得荷载与土体位移的关系，结果表明：位移与荷载呈良好的线性关系，相关系数达到0.99，标试验测得最大位移为0.25 mm，最小位移为0.05 mm，传感器灵敏度达到4 nm/mm，最小分辨率达到0.62 μm。通过两种试验工况检验传感器可行性，包括监测路基在静、动载作用下的位移变化，静荷载作用下监测数据表明：波长及位移随时间呈阶梯性增长，试验成功采集路基的最小位移达到0.004 mm。动荷载监测试验结果表明传感器可以快速反映车辆模型荷载产生的竖向压力。

Study on Measurement Method of Small Deformation of EmbankmentBased on FDM and FBG Technology

Based on the railway embankment health monitoring, this study developed an embankment small deformation monitoring system based on FDM (Fused Deposition Modeling) and FBG (Fiber Bragg Grating) technology. Using FDM technology and FBG sensing technology to design the FBG sensor monitoring model with package and anchor plate, the relationship between load and soil displacement can be obtained by calibration test. The results show that the displacement has a good linear relationship with the load, and the correlation coefficient reaches 0.99. The test measured a maximum displacement of 0.25 mm, a minimum displacement of 0.05 mm, a sensor sensitivity of 4 nm/mm, and a minimum resolution of 0.62 μm. The feasibility of the sensor is tested by two test conditions, including monitoring the displacement of the embankment under static and dynamic loads. The monitoring data under static load shows that the wavelength and displacement increase stepwise with time, and the minimum displacement of the embankment is successfully collected, which reaches 0.004 mm. The dynamic load monitoring test results show that the sensor can quickly reflect the vertical pressure generated by the vehicle model load.