Monitoring and analysis of internal displacements of a slope and relationship with rainfall infiltration

Abstract

The internal displacement of a slope is a key parameter for assessing the safety of a slope. This paper introduces a sensing technique for measuring internal displacements of a slope. A series of sensing bars embedded with fiber Bragg grating (FBG) sensors was developed and used to monitor the internal deformation. These sensing bars were installed at different depths of two deep boreholes. Monitoring work was carried out and data were collected from 20 June to 25 September 2010. The internal displacements of the slope were analyzed together with the rainfall data which collected by a rainfall gauge. The results show that rainfall has a strong influence on the internal displacements of the slope. But the influence of rainfall reduces dramatically when the depth is beyond 8.0m. In addition, numerical results indicate that the rainfall intensity has a significant effect on the slope stability, especially when the rainfall intensity is larger than 100mm/h.