Study on time function model of residual subsidence atsurface coal mining subsidence area

In order to scientifically and quantitatively evaluate the surface ground residual deformation in the reutilization of the land above the mine goaf affected to the stability of the building foundation, based on the definitions of the surface ground movement duration time in the "three underneath" coal mining regulations, the paper provided the definitions of the surface ground residual subsidence deformation and the surface ground remained subsidence deformation. In combination with the Knothe time function, a surface ground residual subsidence time function based on the time was established and the parameter calculation and determination method were provided. The study results showed that after the duration time T of surface ground movement, the time section from the surface ground subsidence speed v (t) less than 60 mm/day to the surface ground subsidence speed v (t) equal to 1 mm/day could be considered as the surface ground residual movement period. The residual subsidence time function established could be applied to quantitatively calculate the residual subsidence influences and could provide the danger degree. In order to adjust and optimize the building layout on the surface ground, the rational anti-deformation building measures, the building construction and the goaf handlings and others could provide the quantitative indexes.