The zonal disintegration phenomena will appear with the increasing of the depth of underground engineering which are different from shallow cavern. In order to investigate the formation mechanism and influence factors of the zonal disintegration

the true 3D geomechanical model tests for layered jointed rock mass containing soft interlayer have been carried out for the first time. Taking the deep tunnel of Dingji coal mine in Huainan mine area as engineering background

the test adopt model similar material and numerical controlling true 3D loading model test system. The model test results show that: (1) Based on some kind of stress conditions

the zonal disintegration will appear in layered jointed test model containing soft interlayer. (2) Soft interlayer is an important influence factor for zonal disintegration of layered jointed rock mass. Under the same stress conditions

the radial displacements and strains of surrounding rock increase obviously because of soft interlayer. The smaller space of soft interlayer is

the larger range of fracture zone is. (3) The shape of tunnel fracture zone is circle approximately. The shape has no correlation with the soft interlayer and its space. The model test results help to reveal the formation mechanism and influence factor of zonal disintegration

which lays a solid test foundation for further studying nonlinear deformation characteristics and failure mechanism of deep rock mass.