Fig. 1. Actual measurement diagram of instability measurement

Fig. 2. Structural schematic of water level measuring instrument system

Fig. 3. Framework of laser water level ranging

Fig. 4. Diagram of self-calibration 3D structure

Fig. 5. Schematic of self‑calibration plane structure

Fig. 6. Spatial coordinate system diagram of transverse motion

Fig. 7. Spatial coordinate system diagram of longitudinal motion

Fig. 8. Model schematics of foundation pit measurement

Fig. 9. Field measurement experiment

Fig. 10. Diagram of MATLAB simulation data analysis

Fig. 11. Data analysis of experimental results