Faults are an important factor inducing mine safety accidents, and it poses difficulties on the identification of faults within 5 m of drop.Taking the Liupanshui coalfield of Guizhou province as the study area, this paper investigated the coalfield strata and carried out an on-site survey.It proposed a seismic physical model and used the unique velocity ratio of 1∶1.74 to realize the construction and analysis of small faults with a burial depth of 800 m, 1 000 m and 1 200 m and a drop of 5 m, 3 m and 1 m.This paper extracted a variety of seismic properties by seismic dynamics method to analyze small faults, and obtained the sensitivity of seven seismic properties to the characteristic response of small faults, including amplitude envelope, amplitude first derivative, and amplitude second derivative, and the correlation between seismic properties and drop was established accordingly.The results show that when the small fault drop of the coal seam is less than or equal to 5 m, there is a linear relationship with the traditional amplitude attributes, and a linear relationship with the seismic properties related to phase and frequency.There is high correlation between the amplitude envelope and the amplitude imaginary part, and low correlation between the instantaneous frequency, the amplitude first derivative, the cosine instantaneous phase, the amplitude second derivative and the amplitude envelope.

Small faults are an important factor that affects the safe and efficient mining of coal mines.In recent years, although great progress has been made in seismic wave identification methods for faults including small faults, it is still a difficult problem to identify small faults with a drop of less than 5 m in coalfield.Southern coalfields generally have complex topography and well-developed fault.In order to promote the seismic exploration of small faults in southern coal fields, this paper selects a typical southern coalfield—the Liupanshui coalfield in Guizhou Province as the study area.The coal-measure stratigraphic seismic physical model is established for seismic data acquisition, processing and interpretation, from the seismic wave kinematics and dynamics.The angle identifies small faults with a drop of 5 m, 3 m, and 1 m at different depths.The research results show that it is difficult to identify small faults with a drop of 1 to 5 m by using seismic wave kinematics method because coal seam is in a low-velocity layer on the surface.However, the application of dynamic method to extract multiple seismic attributes for analysis can find that the amplitude attributes are more sensitive to the identification of small faults, and the resolution ability is strong.Through the seismic physical model test, under the condition of the seismic source frequency of 60 kHz, the small faults with a drop of less than 5 m were successfully explained, and the results are consistent with the actual small faults of the coal-measure strata seismic physical model.