Development and Validation of Multi Spatial-Temporal Scale Monitoring and Data Fusion for Rock Slope Early Warning

The rock slopes in Taiwan are highly risky due to the influence of climate and earthquakes. In the previous research, according to different survey scales and data accuracy, the geological conditions and failure mechanisms of the rock slopes were discussed, and the rock slopes were analyzed for different trigger factors, simulating the impact range of rock slope sliding, but the overall project in the early stage is mainly based on laboratory experiments and numerical analysis. It still lacks application and verification of substantive monitoring technology. The research and development of multi spatio-temporal scale monitoring technologies integrated into the early warning of rock slopes is main topic of this sub-project. This task will be based on the survey results of Sub-project 1 and Sub-projects 3 to 6 for different rock slope failure mechanisms and approach monitoring technologies at different time and space scales. First, the space scale to be monitored will be from long-range satellite or ground based InSAR monitoring long-term LOS (Line of Sight) displacement, combined with the development of dual-band sacrificial GNSS displacement monitoring device in the local area for comparison and verification; Furthermore, based on the results of Sub-project 2, the simultaneous development of long-term real-time photogrammetry of a simple optical and thermal image modules will be applied on the surface monitoring of a rock slope. In order to introduce and test distributed strain sensing by optical fiber, conjunction with laboratory tests and evaluations accompanied to Sub-projects 2, 3, and 4 for monitoring slope deformation will be proceeded; extended to distributed vibration sensing (Distributed Acoustic Sensing, DAS) for vibration (earthquake or falling rocks), or even long-term seismic analysis, can further observe the change of the shear wave velocity in the rock slope with time; in addition, through the time domain reflection method (Time Domain Reflectometry, TDR ), which can be used to monitor rock nails or anchors. This Sub-project is the integrated base of the above-mentioned novel monitoring methods, so as to feed back to the calibration and validation of the physical and numerical modes of each sub-projects.