Distributed Fiber Optic Monitoring and Stability Analysis of a Model Slope under Surcharge Loading

• Published in: Journal of mountain science Vol. 11; no. 4; pp. 979 - 989
• Main Authors: Zhu, Hong-Hu, Shi, Bin, Zhang, Jie, Yan, Jun-Fan, Zhang, Cheng-Cheng
• Format: Journal Article
• Language: English
• Published: Heidelberg Science Press 01.07.2014; Springer Nature B.V
• Subjects: Earth and Environmental Science; Earth Sciences; Ecology; Environment; Fiber optics; Geography; Geological hazards; Geophysics; Geotechnology; Sensors; Slope stability; Stability analysis; 光纤传感器; 光纤监测; 分布式监控; 极限平衡分析; 测量模型; 稳定性分析; 边坡稳定问题; 附加载荷; Geotechnical monitoring; Slope stability; Distributed strain sensing; Brillouin optical time-domain analysis (BOTDA); Model test; Fiber optic sensor
• ISSN: 1672-6316; 1993-0321; 1008-2786
• DOI: 10.1007/s11629-013-2816-0

In the discipline of geotechnical engineering, fiber optic sensor based distributed monitoring has played an increasingly important role over the past few decades. Compared with conventional sensors, fiber optic sensors have a variety of exclusive advantages, such as smaller size, higher precision, and better corrosion resistance. These innovative monitoring technologies have been successfully applied for performance monitoring of geo-structures and early warning of potential geo- hazards around the world. In order to investigate their ability to monitor slope stability problems, a medium-sized model of soil nailed slope has been constructed in laboratory. The fully distributed Brillouin optical time-domain analysis （BOTDA） sensing technology was employed to measure the horizontal strain distributions inside the model slope. During model construction, a specially designed strain sensing fiber was buried in the soil mass. Afterward, the surcharge loading was applied on the slope crest in stages using hydraulic jacks and a reaction frame. During testing, an NBX-6o5o BOTDA sensing interrogator was used to collect the fiber optic sensing data. The test results have been analyzed in detail, which shows that the fiber optic sensors can capture the progressive deformation and failure pattern of the model slope. The limit equilibrium analyses were also conducted to obtain the factors ofsafety of the slope under different surface loadings. It is found that the characteristic maximum strains can reflect the stability of the model slope and an empirical relationship was obtained, This study verified the effectiveness of the distributed BOTDA sensing technology in performance monitoring of slope.