According to the relative variable trend of slope displacement after its construction

this study declared the definitions of the relaxation zone and pre-compression zone

which are collectively referred to as the influenced zone. The construction process of the multi-stage slope was simulated through a large-scale model test. Meanwhile

the concept of the overlapping effect of influence zone was proposed. If the excavation relaxation zones (or pre-compression zones) of lower slope overlapped with pre-compression zones of the upper slope

it would produce relaxation (or reinforcement) effect on the soil and rock of the overlapped zone which belongs to the upper slope. As a result

the force of retaining structure in the overlap zone was influenced. Furthermore

it is found that the wider the overlapped region was

the stronger influence was. However

the overlapping phenomenon had no effect on retaining structures outside the overlapped region. Therefore

the reason for the force change of retaining structure was essentially caused by the overlapping effect in the influenced zone.