Development and operation of a fiber Bragg grating based online monitoring strategy for slope deformation

Abstract

Purpose – The purpose of this paper is to investigate an online monitoring strategy that incorporates fiber Bragg gratings (FBGs) for deformation displacement detection, with the background that slope deformation monitoring is crucial to engineering safety supervision and disaster prevention. Design/methodology/approach – A “beam element” method has been proposed, introduced and experimentally verified in detail. The deformation displacement along a flexible bar can be obtained based on this method, using the distributed strain detected by the FBGs embedded in the bar. A novel sensor structure containing inclinometer casings and a series of connected flexible pipes with FBGs embedded has been proposed. Based on the features of this structure, two FBG deformation sensors have been manufactured and installed into a slope. A matched monitoring station which permits real-time supervision, warning and remote access across the Internet was established and operated. Findings – Displacement data from September 2013 to August 2014 are obtained, which is basically consistent with the practical situation. Originality/value – The FBG deformation sensors demonstrated a robust and reliable measurement performance, which is promising for real-time disaster warning in slope engineering.