The left bank of Baihetan hydropower station is a high slope

which is a three-dimensional (3D) complex block system with strongly unloaded rock mass. The 3D geomechanical model test was adapted to investigate the slope deformation characteristic

failure process and mode

destruction mechanism

slope stability

and reinforcement effect. The model test shows that the slope failure exhibits the mode of the block sliding failure

which demonstrates the shear slipping among the bottom surfaces

the tensile crack along the trailing edge surface

and the block sliding along the bottom surface and side surface. The failure process basically experienced three stages

including the initially crack of discontinuities

crack expansion throughout the block boundaries

and the instability of the slope. The general safety factor of the left bank slope was obtained through the comprehensive geo-mechanical model test. The safety factors of given blocks were compared with the calculation results of both 3D-LEM and BEM

which shows good agreements. Simultaneously

the relative displacements at the interface of LS337 were monitored. From the results

we can see that by the reinforcement of the deep concrete replacement caverns

the sliding deformation among the bottom surfaces is effectively controlled

and the safety factors of the combination blocks of related discontinuities are improved

and the effect of slope reinforcement is more obvious. This paper provides significant guidance for the stability and reinforcement of the left bank slope of the 3D complex block system with the strongly unloaded area in Baihetan or other similar engineering slopes.