Abstract: The stability of strip coal pillar under high stress is obviously affected by water abundance of coal seam. In order to study the influence of moisture content on creep characteristics of strip coal pillar, creep tests of coal specimens with different moisture content have been carried out firstly, and the results have revealed that moisture content has obvious influence on creep characteristics of coal speci- mens, to be more specific, with the increase of moisture content, the creep deformation gets bigger, but the creep threshold value, the creep strength and the creep coefficient get lower. The fitting results of creep tests have shown that the creep mechanical properties of coal can be well described with the im- proved Burgers model. Based on the creep test results, the creep characteristics and stability of strip coal pillar with different moisture content have been analyzed with the FLAC3D numerical simulation soft- ware. With the increase of moisture content, the distance between the peak stress position and the strip coal pillar boundary will increase, so will the plastic zone of the strip coal pillar; meanwhile, the vertical stress of coal pillar and the creep deformation will decrease, but the bearing capacity of coal pillar will reduce, and the time the strip coal pillar using to gets into long-term stability state will in- crease. The simulated results have indicated that when the moisture content is 0.78%, 1.07% and 1.36%, the widths of plastic zone of the strip coal pillar are 10, 12 and 16 m respectively and the period the strip coal pillar gets into long-term stability is 18, 24 and 36 months respectively when other conditions remain unchanged.

Key words: moisture content, creep test, numerical simulation, strip coal pillar, stability