Abstract: Seepage damage of tailings stacking dam is one of the important reason for causing tailings dam dam-break accident, dewatering technology of radial well has been gradually applied in eliminating seepage and strengthening engineering of tailings stacking dam. To find out mechanical characteristics between main well and contact surface of tailings, concentric test device and test method which based on the own research, lab experimental study results of typical tailings sample are introduced, especially relations between friction coefficient and density of tailings stem, and calculation methods of practical normal force at different depth and so on had been studied experimentally.

Key words: Open caisson, Mine tailing, Concentric circles shear device, Friction characteristics