光纤布拉格光栅(fiber Bragg grating, FBG)作为一种新型的监测元件, 具有精度高、抗干扰能力强和可实时监测等优点. 为了研究在循环荷载作用下土工格栅加筋路堤的力学性能和筋材的变形特性, 采用 USTX-2000 加载装置进行加载, 利用 FBG 传感器进行筋材变形监测, 在不同加筋层数和加筋间距等工况下对加筋路堤进行了模型试验. 试验结果表明: 在长期循环荷载作用下, 土工格栅的应变在水平方向上呈现出由加载板正下方向两侧递减的规律, 且沿筋长方向呈非线性分布; 而在同一工况的竖直方向上, 土工格栅的应变则随着路堤深度的增加而减小; 加筋能够有效减小路堤的沉降量和坡面的法向变形, 路堤内部的土压力也随着加筋显著增加. 该试验证明了 FBG 新型传感技术在路堤边坡监测应用中的可行性和优越性.

Fiber Bragg grating (FBG) is a new type of monitoring and sensing element with advantages of high accuracy, strong anti-interference ability, and real-time monitoring. A USTX-2000 loading device was applied using FBG sensors to evaluate the mechanical properties of a geogrid-reinforced embankment and monitor the deformation characteristics of the reinforcement under cyclic loads. A series of model tests were performed under different conditions, such as different reinforced layers and reinforced spacings. The test results showed that the geogrid strain decreased from the centre direction of the loading plate to both sides in the horizontal direction and was non-linearly distributed in the longitudinal direction of the geogrid. The geogrid strain decreased with an increase in the embankment depth in the vertical direction for the same condition under long-term dynamic loads. The reinforcement could effectively reduce the settlement of the embankment and the normal deformation of the slope, and the earth pressure in the embankment significantly increased with the reinforcement. The study demonstrated the feasibility and superiority of FBG new sensing technology in embankment slope monitoring.