Fibre optic sensing monitoring system for pile on slope

Abstract

Monitoring system is very important in geotechnical works. In slope reinforced with pile, monitoring system is needed to monitor the displacement of the pile due to the slope instability. Therefore, this study will focus on a newly develop monitoring system using an optical fibre sensing technology to measure the strain of the pile install on the slope. The strain on the pile will be measure due to the slope instability and load increment on the slope crest. The advantage of using Optical fibre sensing technology is that it can give the strain measurement along the optical fibre length instead of from discrete points. This paper describes the experimental work conducted with the use of a distributed sensing technology called Brillouin Optical Time Domain Analysis (BOTDA). A small scale physical soil slope model was stimulated to measure the strain and calculate the displacement of the pile. The physical model result is then compared with numerical modeling using SLOPE/W and SIGMA/W. As a result, fibre optic is a good approach for geotechnical instrumentation and monitoring since they are sensitive toward the movement of geotechnical structure and soil. The optical fibre can measure the strain along the pile up to micro strain (UE).