In-situ Monitoring of Rock Slope Stability in Seismic Areas

Abstract

In cooperation with the Hunan Support Project for the Reconstruction of Lixian, which is intended to reconstruct the highway that runs from Lixian to Xiaojin, we conducted an in-situ monitoring study of Baozizui rock slope in Lixian, where three earthquakes with magnitudes that exceed 4.8 times the normal level occurred during the monitoring period. On the basis of the monitoring results, we conclude that slope deformation was attenuated and tended to stabilize after two months of construction. The anti-inclined structural face in the slope indicates that compacting deformation, which was beneficial to slope stability, occurred in the rock mass under seismic loading. Seismic loading also considerably influenced the horizontal deformation of the structural face in the surface rock layer. This influence is attributed to the regional stress-bearing compression and shear in the nappe structures located on the upper plate thrust faulting of the slope. In early stages, the variations in horizontal deformation frequently occurred at the road curve, where seismic excitation effects (except those caused by traffic loads) occurred. Later observational data indicate that deformation has stabilized.