Abstract: The consolidation related concerns were raised during a height increase of a tailing dam for its capacity expansion. Asa a result, one dimensional consolidation tests were conducted on the cohesive tailing dam materials. The objective of the tests is to investigate various impact of potential influence factors on the secondary consolidation properties of the cohesive tailing dam materials. These factors are: loading ratio, dry unit weight, magnitude of preloading and duration. The results indicate that, the loading ratio has some effect on the coefficient of secondary consolidation when the confining pressure is less than 600 KPa; The coefficient of secondary consolidation does not change when the confining pressure is greater than 600 KPa. The coefficient of secondary consolidation increases with the dry unit weight of the sample, after the preloading, the settlement is significantly less than samples without preloading. The influence of the preloading on the coefficient of the secondary consolidation has effect when the confining pressure is within the range of 100 KPa to 800 KPa. The preloading effect is not obvious when the confining pressure is greater than 800 KPa. The preloading duration has effect on the coefficient of the secondary consolidation when the time is less than a threshold value. After this value, the preloading effect is not obvious. It is also concluded that the relationship between the coefficient of secondary consolidation and the compression index can be statistically represented by a linear regression formula.

Key words: Mine Tailings, Secondary Consolidation, Loading Ratios, Dry Density, Pre-loading Method