Reservation pillar can control the deformation and the movement of the rock strata in seabed metal mining. But the deformation of pillar is greatly influenced by stress distribution and mining time. Maintaining the stability of pillar under long-term stress and seepage action is directly related to the safety of seabed mining. In order to study the stability of under-sea point pillar stope under long-term stress and seepage action, a new nonlinear creep constitutive model and a damage evolution equation are proposed based on statistical damage theory and Nishihara model. Meanwhile, a judgment method for transition from primary creep to accelerated creep stages is suggested. ANASYS is used to calculate the stress distribution of the stope. On this basis, the model is then applied to analysis of the viscosity-elastic-plastic damage and seepage property of an under-sea point pillar in Xinli district of Sanshandao gold mine. The result shows that the structure of the stope is stable. In the coming design of mine stopping, the number of pillars can be appropriately decreased so that the loss rate of ore will be reduced. The model gives enough thought to the mechanics paramater of rock mass as well as the result of engineering geological survey, so that it can be extended to other rheology models. It is also adapative to other large-scale rock engineering and has a rather high application value.

undersea mining  /  pillar  /  damage model  /  nonlinear creep  /  seepage