(1. School of Earth Sciences and Engineering，Nanjing University，Nanjing，Jiangsu 210093，China；2. School of Control Science and Engineering，Shandong University，Jinan，Shandong 250061，China；3. Department of Geotechnical Engineering，Tongji University，Shanghai 200092，China)
Abstract：Fiber optic sensing is a newly-developed distributed monitoring technology；it has great potential in slope engineering. A new method to evaluate the stability condition of slope based on strain distribution of slope mass measured by sensing fiber in real-time is proposed. A slope model test is conducted in laboratory and the Brillouin optical time-domain analysis(BOTDA) technology has been used to measure the horizontal strains at different depths of the slope model subjected to loading on the slope crest. The test results show that the tight-buffering optical fiber packaged by heat-shrinkage tubes can be used for monitoring strain distribution within the slope. In order to take temperature compensation into consideration and achieve the purpose of accurate positioning，the installation of loose fiber sections at key locations along the sensing fiber is recommended. The potential slip surface can be estimated based on the distributed strain monitoring results. The deformation behavior and stability condition of the slope model during testing was analyzed in detail. It is found that there is an empirical relationship between the averaged maximum horizontal strains and the factor of safety of slope，so as to provide a new approach to evaluate slope stability and perform early warning of landslides.