A Design Method for Row Spacing Between Pressure Relief Boreholes

Abstract

The invention relates to a design method for row space between pressure relief boreholes. The method comprises the following three steps of: before the row space between the pressure relief boreholes is designed, firstly, requiring to evaluate the stress environment of a pressure relief site, and calculating a working face (roadway) surrounding rock supporting pressure peak value [Sigma]p and a peak value position Lp; selecting a surrounding rock on the Lp as an analysis object, adopting a corrected surrounding rock elastoplasticity analytical solution to calculate a borehole plastic zone radius rp, taking the rp as an index for evaluating the single-hole action range of the borehole, and determining the maximum row space between the boreholes as R which is less than or equal to 2rp; and meanwhile, adopting the elastoplasticity analytical solution to calculate the evolution curve of the circumferential stress [Sigma][Theta] of the borehole, taking the stress of a crosspoint of the circumferential stress curves of the adjacent boreholes as [Sigma]m, taking the stress [Sigma]0 of primary rock of an experiment site as an evaluation index, and determining the condition of the minimum row space R between the boreholes as [Sigma]m which is greater than or equal to [Sigma]0. The method is simple in operation and high in practicality and can be applied to fields including high-stress roadway pressure relief, rock burst prevention and treatment, high gassy seam permeability increasing and the like, the design accuracy of the row space between the boreholes can be effectively improved, and a borehole engineering quantity is lowered.

Description

technical field [0001] The invention belongs to the field of coal mining, and relates to a design method for the row spacing between pressure-relieving boreholes, which can be extended and applied to the fields of pressure-relieving in high-stress roadways, prevention and control of rock burst, anti-permeability enhancement in high-gas coal seams, and the like. Background technique [0002] At present, drilling pressure relief technology is mainly used in projects such as rock burst prevention, high-gas coal seam permeability enhancement, and high-stress roadway stress. Although the functions in various projects are not the same, there is a large similarity in principle . For example, the prevention and control of rock burst is mainly through the artificial construction of large-diameter pressure-relief drilling holes in the coal rock layer, using the deformation and destruction of the drilling holes to release the elastic deformation properties accumulated inside the coal r...

AI Technical Summary

Problems solved by technology

At present, the empirical analogy method and empirical formula method are mainly used to determine the row spacing between pressure relief boreholes. If the spacing is too large, the pressure relief effect will not be achieved, and if the row spacing is too small, it will not be conducive to maintaining the stability of the coal and rock mass, and will increase the amount of drilling work. It is of great significance to exert the pressure relief effect of drilling

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