Abstract:

Through analyzing the Knothe time function model for the dynamic process of the ground surface subsidence due to underground mining, it is found that the model can’t accord with the observational data. By adding a constant parameter k to the Knothe time function, a new time function model has been set up. The velocity and acceleration worked out from this new time function model is in accordance with the dynamic process of the surface subsidence. In this new model the parameter c decides how long the subsidence would continue; and the parameter k decides the path of the subsidence on the axis of time. This new subsidence dynamic model fits well the curve of the observation data on the inclining section of the surface subsidence basin of a certain coal mine, the parameter c is obtained by practical consideration and the parameter k is obtained by least square method. Combining this new time function model with the section function of the surface subsidence basin or the basin model, a dynamic process model for the surface subsidence due to underground mining is set up; form this model the subsidence and velocity and acceleration of some point on the subsidence basin or the section could be worked out in anytime.

Key words: ground surface subsidence, section curve, dynamic process, time function model