Abstract:With the purpose of acquiring rockmass deformation and geostress change characterization on the permanent shiplock slope of the Three Gorges Project (TGP),the original exploratory adit of No.8,which was intersected with the middle-isolated pier of the permanent shiplock slope,was utilized to be a place for installing multi-point borehole extensometers(MPBX) and geostress change sensors;and the whole process of rockmass deformation monitoring for the middle-isolated pier has lasted nearly 10 years in company with 3 years geostress change monitoring. On the basis of results of deep rockmass deformation monitoring,rockmass deformation characterization of the middle-isolated pier is investigated during construction period and navigation period;and the deformation tendency of rock wall of the middle-isolated pier is obtained;in addition,results of in-situ geostress change monitoring,numerical modeling results by FEM and back analysis results based on MPBX data are compared and analyzed. The stability of the permanent shiplock slope is discussed at last.