Performance monitoring of superlarge-diameter rock-socketed piles by optic fiber sensors

Abstract The available fiber optic sensing technology is increasingly becoming a superior nondestructive means for stress monitoring of civil engineering structures. To understand the mechanical properties of superlarge-diameter rock-socketed piles under complicated geological conditions, field tests were performed using distributed fiber optic sensors in this paper. At first, the feasibility of fiber optic sensing technology in testing compressive stress of piles was testified by indoor model tests and its correlation coefficient was acquired as well. Then, the in-situ installation of fiber optic sensors were carried out on the superlarge-diameter rock-socketed piles of Hezhang Bridge. By the testing data collection during construction and the data treatment and analysis, the bearing behaviors and load transfer mechanism of superlarge-diameter rock-socketed piles were explored. Based on the comparison of the testing results and the actual force and settlement of the support engineering, the fiber optic sensing technology in monitoring pile stress was further testified to be feasible and proposed as well. The research results in this paper have reference value to pile theory and the application of fiber optic sensing technology on similar projects.