DFOS Technology-Based Landslide Monitoring: The Majiagou Landslide Case Study (China)

The newly developed distributed fiber optic sensing technology (DFOS) offers a number of attractive advantages over conventional monitoring methods, such as better integration capability, higher accuracy and long-term stability, which are very suitable for the acquisition of multi-field information in slope. In this paper, the fields in slope are defined and proposed based on the engineering geological characteristics of slope. The fundamental principles of some typical DFOS technologies were introduced, and the details about the DFOS based monitoring system for the acquisition of multi-field information, including stress, temperature, seepage and deformation were described as well. In the end, a field study was conducted to investigate the effectiveness of the DFOS based system for monitoring the Majiagou landslide near Three Gorges reservoir in China. In order to acquire the deformation, temperature and seepage information deep inside the slope mass, six boreholes were set up at different altitudes to install the DFOS based inclinometers, osmotic pressure gauge, moisture meter and other optical fiber sensors. To understand the characteristics of stress field, the DFOS based stress and earth pressure gauge were installed inside the slide resistant pile. The monitoring system successfully obtained the multi-field information during the landslide evolution process. The locations with abnormal deformation could be accurately identified that corresponds to the potential sliding surfaces.