Application of Fiber Bragg Grating Strain Sensors to a Centrifuge Model of a Jacked Pile in Collapsible Loess

Abstract

The use of traditional sensors in a geotechnical centrifuge model test usually causes deviations in the monitoring data. This is because of the mutual interference among centrifugal field electromagnetic waves that is caused by the independent transmission lines. In recent years, the development of fiber Bragg grating (FBG) sensing technology has substantially improved the accuracy and reliability of monitoring the strain and temperature in geotechnical centrifuge model tests. This study follows a series of centrifuge model tests carried out on a 60 g-ton geocentrifuge, with FBG sensing technology used for monitoring the strain on a static pressed pile; the strain is caused by soil collapse around the pile. During the test, an improved packaging and installation method of the quasi-distributed FBG sensor system was employed to monitor the strain of a jacked pile in a loess field with immersion collapse. The model test results show that the proposed FBG-based sensor assembly monitored the strain distribution of the jacked piles effectively, proving that it is a promising solution for strain monitoring in a geotechnical centrifuge test.