Abstract: The red mud in Zunyi Alumina Co. Ltd. is usually stockpiled by dry method. In order to determine the red mud cracking and the stability condition of the disposal dam during the dry and rainy seasons, a model dam for the red mud disposal was constructed before the production dam construction. The physical and mechanical properties of red mud in the model dam were tested and the stability of the model dam was monitored for providing the feasibility as well as cost information of production construction. Through the continuous human patrol and equipment observation of the model dam for more than two months, no obvious cracks, collapse, surface uplift or subsidence and sliding phenomenon were observed. After the monitoring, the measured displacement was not more than 10mm, the existing model dam was stable. Through the physical and mechanical indices tests, the degree of compaction reached more than 95%. The average value of consolidated undrained direct shear cohesion was 36.9 kPa, and the tested average value of internal friction angle was 33.1 degrees. The average cohesion of the triaxial test (consolidated undrained) was 45.0 kPa and the average internal friction angle was 17.6 degrees. The mechanical properties of the red mud dam body are acceptable. The model dam test results show that the construction procedures used in the model dam was feasible and the model dam was stable.

Key words: red mud disposal site, model of dam, physical and mechanical indices, stability, monitoring