By installing FBG sensors on the geogrids, smart geogrids can both reinforce and monitor the stability for geogrid-reinforced slopes. In this paper, a geogrid-reinforced sand slope model test is conducted in the laboratory and fiber Bragg grating (FBG) sensing technology is used to measure the strain distribution of the geogrid. Based on the model test, the performance of the reinforced soil slope is simulated by finite element software Midas-GTS, and the stability of the reinforced soil slope is analyzed by strength reduction method. The relationship between the geogrid strain and the factor of safety is set up. The results indicate that the measured strain and calculated results agree very well. The geogrid strain measured by FBG sensor can be applied to evaluate the stability of geogrid-reinforced sand slopes.

The Pulse-Pre-Pump Brillouin Optical Time Domain Analysis (PPP-BOTDA) based distributed fiber optic sensing (DFOS) technique has a unique advantage of achieving full-distributed structural strain with cm-order spatial resolution, which is ideal for fine stress monitoring of the pile foundation. The high spatial resolution helped to detect local changes and defects while inevitably led to noisy data meanwhile, especially a certain part of anomalous sensing data. Therefore, a robust algorithm of random sampling consistency (RANSAC) was employed to extract and process the DFOS data. In a field static load test, the variation of strain along a precast pile was measured with PPP-BOTDA interrogator. The axial force and frictional resistance were calculated based on the RANSAC processed strain data. The pile-soil interface properties were estimated as well. It shows the feasibility and good performance of PPP-BOTDA in the measurement of precast piles stress test. The RANSAC proves to be an effective method for processing DFOS data with a certain number of outliers. This work presents a valuable reference for DFOS based pile stress test and data analysis which will promote its application in other related structural health monitoring purpose.

By installing FBG sensors on the geogrids, smart geogrids can both reinforce and monitor the stability for geogrid-reinforced slopes. In this paper, a geogrid-reinforced sand slope model test was conducted in the laboratory and fiber Bragg grating (FBG) sensing technology is used to measure the strain distribution of the geogrid. Based on the model test, the performance of the reinforced soil slope is simulated by finite element software Midas-GTS, and the stability of the reinforced soil slope is analyzed by strength reduction method. The relationship between the geogrid strain and safety factor is set up. The results indicate that the measured strain and calculated results agree very well. The geogrid strain measured by FBG sensor can be applied to evaluate the stability of geogrid-reinforced sand slopes.