Fig. 1. High frequency keyword spectrum of rock and soil mass deformation monitoring

Fig. 2. Typical classification of DFOS^[4]

Fig. 3. Measuring principle of FBG technology^[16]

Fig. 4. Geotextiles embedded with nylon fiber optic^[20]

Fig. 5. Measurement principle of BOTDR technology^[22]

Fig. 6. Measurement principle of BOTDA technology ^[26]

Fig. 7. Measurement principle of BOFDA technology^[28]

Fig. 8. Measurement principle of DAS technology^[31]

Fig. 9. Principle of temperature self-compensation sensor^[36]

Fig. 10. Refer to the fiber optic supplement method for fiber optic layout^[18]

Fig. 11. BOTDR temperature-compensating fiber optic layout^[40]

Fig. 12. Coupling process model of fiber-sand^[45]

Fig. 13. Controlled pressure cable-rock and soil mass coupling test device^[46]

Fig. 14. Attachment type layout technology. (a) Anchorage bolt and steel structure sticking arrangement method; (b) PHC pile grooves and concrete pre-embedded placement method^[48]

Fig. 15. Embedded layout technology. (a) Excavation trench layout method; (b) borehole implantable layout method

Fig. 16. Slope engineering monitoring system based on fiber optic sensing technology^[57]

Fig. 17. Flow chart of combined prediction model^[59]

Fig. 18. Volute fiber optic layout scheme^[62]

Fig. 19. Practical application of fiber optic sensing in tunnel^[65]

Fig. 20. Monitoring type of shield tunnel^[66]

Fig. 21. Subgrade collapse monitoring^[71]

Fig. 22. Pipeline structure state monitoring and evaluation process^[72]

Fig. 23. Fiber optic monitoring layout scheme for buried pipeline^[74]

Fig. 24. Railway engineering monitoring scheme integrating DAS and AI^[78]