Abstract: Drainage consolidation of wet heaping tailings slurry can be accelerated effectively by adding vertical drainage to improve the stability of soil mass. In order to research the drainage consolidation law of step heaping tailings slurry under the action of drainage， the drainage consolidation process was simulated by model experiments. The test results showed that: in the process of soil drainage consolidation， the changes on both pore water pressure and settlement in different layers are not fully synchronized with the stress change behind the strain change； After the heaping stops at day 35th， the pore water pressure dropped obviously， and the free water seepage was transiting into the pore water seepage under the external water head. The drainage process of step heaping tailings can be divided into 5 stages such as settlement flocculation， flocculation compression， compression consolidation of flocs， overlying water self-weight consolidation and self-weight compression consolidation； a pore seepage model of tailings under the action of drainage body was established， and the maximum influence radius with different heaping height of drainage body has been calculated by this model， indicating that the maximum influence radius decreased with the increasing of tailings consolidation. The influence radius of the drainage with 0.5 m and 1.0 m heaping height are respectively decreased to about 1.7 m and 2.2 m after 35 days.

Key words: Tailings, Drainage consolidation, Step heaping, Seepage