Abstract:

By analyzing the dynamic course of the surface subsidence due to underground mining, the conclusion has been drawn that the w-t curve of the ground subsidence appears S-shaped. The ground subsidence is increasing from 0 to the maximum and then decreasing to 0 in the subsidence process. So the time function which can describe the subsidence course of the ground must fit not only the w-t curve but also the v-t curve and the a-t curve. Time functions which are usually used to fit the w-t curve of the foundation or roadbed settlement now such as the exponential time function, the hyperbolic time function, the Gompertz time function, the logistic time function and the Weibull time function. Studying the w-t curve, v-t curve and a-t curve of these time functions finds that only the Weibull time function is feasible for describing the dynamic course of the ground subsidence due to underground mining. Two examples using the Weibull time function to fit the observation data of the dynamic course of two coal mine’s ground surface subsidence verify the test.

Key words: surface subsidence, dynamic course, Weibull time function