Pile box foundation level cyclic load shear deformation testing device

The invention discloses a pile box foundation level cyclic load shear deformation testing device which comprises a model box (2), the model box (2) contains silt and is covered with a sand-gravel cushion (4), and a caisson (5) is arranged on the sand-gravel cushion (4); the testing device further comprises a vertical counterforce beam (11) which is horizontally arranged above the caisson (5) and a jack (12); the testing device further comprises a horizontal counterforce beam (13) vertically arranged on one side of the caisson (5), and a hydraulic server (14) is arranged between the horizontal counterforce beam (13) and the caisson (5); the end of the hydraulic server (14) is provided with a pulling pressure sensor (15), a plurality of strain pieces (16) are attached to each testing pile (6), and the side wall of the caisson (5) is provided with a displacement meter (17). By means of the testing device, shear deformation and damage mechanism of a pile box foundation under level cyclic load can be observed and