Model testing device and method for pressure reducing performance of flexible cushion layer behind retaining wall

The invention belongs to the field of geotechnical engineering model testing, and discloses a model testing device and method for the pressure reducing performance of a flexible cushion layer behind aretaining wall. The device comprises a model box, a panel, the flexible cushion layer, a panel moving assembly, a sandy soil backfilling assembly, a movable baffle and a testing unit. The flexible cushion layer is arranged on the surface, facing the movable baffle, of the panel. The sandy soil backfilling assembly is arranged on the upper portion of the model box. The movable baffle is detachablyconnected to the model box. The testing unit is arranged adjacent to the model box. The mounting position of the movable baffle is changed, and then the width of backfilled sandy soil is changed. Thepanel moving assembly is used for changing the moving distance of the panel, and then the retaining wall with different kinds of translation displacement is simulated. The sandy soil backfilling assembly achieves movement of a