The invention relates to a pressure relief boundary quantification method based on surface dynamic settlement and
coal wall stress dynamic evolution, and belongs to the technical field of pressure relief boundary quantification, and the method comprises the following steps: S1, collecting a
coal sample of a protected layer of a specific mine, carrying out
desorption experiments under different
constant load conditions, determining a stress value corresponding to gas rapid
desorption, and determining a stress value corresponding to gas rapid
desorption; setting the pressure relief
critical stress value as a pressure relief
critical stress value of the protected
coal seam; s2, determining the deformation value of the overlying strata according to the relationship between the pressure relief value and the stress-strain of the overlying strata; s3, determining a mining overlying strata surface settlement value according to the coal seam mining thickness and the overlying strata deformation value; s4, determining the
stress distribution rule of the whole overlying strata according to the dynamic settlement rule of the overlying strata surface, and delimiting the
evolution rule of the pressure relief boundary based on the definition of the pressure relief boundary; and S5, analyzing the convergence time criterion of the dynamic
time function of ground surface settlement, substituting the convergence time criterion into the dynamic evolution function of the three-dimensional pressure relief boundary of the overlying strata, and finally determining the spatial position of the convergence of the pressure relief boundary.