To explore the means for the determination of excavation disturbed zone (EDZ) of rock slope and its related theoretical problems, multiple methods are used to investigate the EDZ and its rock mechanical behaviors for the high slopes in Three Gorges Project (TGP). Major work and its characteristics are summarized as follows:
(1)The triaxial compression and the confining pressure reduction test are carried out. The mechanical characteristics of the Three Gorges granite specimens and its crack growth pattern and post-peak strain softenin behaviors under different stress paths are studied.
(2)Based on the analysis of the complete stress-strain curves and the damage mechanism of the Three Gorges granite, it shows that the brittle rock mainly occurs lateral damage and exhibits the similar damage evolutionary rule under different stress paths, and a damage model considering the unloading effect and a failure criterion in strain space are established.
(3)One back analysis model of mechanical parameters is established by using orthogonal design theory, least squares support vector machines and particle swarm optimization, and the relative mechanical parameters of damage model are back analyzed. and the
excavation process of the permanent shiplock slope in TGP is simulated by three-dimensional fast Lagrangian method (FLAC3D).
(4)Based on the tests and monitoring of EDZ, critical criteria of shear strain and element safety factor for the permanent shiplock slope in TGP are established.
(5)The slope excavation softening factor is introduced to Hoek-Brown empirical strength criterion, based on the deficiencies of using Geological Strength Index (GSI) to estimate the rock mass mechanical parameter of EDZ.