Goaf stability dynamic evaluation method based on BQ and numerical simulation

Abstract

A goaf stability dynamic evaluation method based on BQ and numerical simulation belongs to the field of goaf stability evaluation, and comprises the following steps: (1) performing rock mass quality calculation based on a BQ index; (2) generating and sectioning a rock mass three-dimensional fracture network model; (3) drawing an RQDt anisotropy diagram; (4) providing an optimal threshold t solvingmethod based on BQ inversion; (5) performing an RQDt anisotropy solving method; (6) performing an improved method of a Mathews stability diagram method; (7) improving a Mathews stability diagram evaluation method; (8) performing a surrounding rock stability dynamic analysis method; and (9) performing a goaf stability dynamic evaluation method. According to the invention, the optimal threshold t of the RQDt, the anisotropism solution of the RQDt and the improvement of the Mathews stability diagram method are realized, and the goaf surrounding rock stability dynamic evaluation combining the improved Mathews stability diagram method and the numerical simulation is realized. The invention is clear and suitable for dynamic evaluation of goaf surrounding rock stability.

Description

technical field [0001] The invention relates to a dynamic evaluation method of airspace stability based on BQ and numerical simulation. In particular, the invention calculates RQD by inversion based on BQ index, fracture network model and generalized RQD theory. t The range of the optimal threshold t and the optimal threshold t value, giving the RQD t Anisotropic solution method and based on RQD t The anisotropy of , an improved method of the Mathews stability diagram method and an improved Mathews stability diagram evaluation method are given. Combined with the numerical simulation method, a dynamic evaluation method of the stability of the air space based on BQ and numerical simulation is provided, which belongs to Goaf stability evaluation field. Background technique [0002] After a long period of underground mining in metal mines, a large-scale group of goafs will be formed. The groups of gobs are connected, overlapped and concentrated with each other underground. The...

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Problems solved by technology

Deer proposed the concept of borehole RQD in 1964. Due to the following two shortcomings in the application of borehole RQD: whether the threshold value of 100 mm is reasonable for different engineering scale rock masses; the drilling direction of the borehole is limited, and the obtained RQD can only reflect local rock mass conditions, but cannot reflect RQD anisotropy

[0013] The anisotropy of RQD directly affects the quality of the rock mass, and the mechanism of the influence of RQD anisotropy on the quality of the rock mass has not yet been explored clearly

In terms of the threshold t, no scholars have given the calculation method of the optimal threshold t, so the RQD based on the optimal threshold t has not been obtained. t Anisotropy calculation formula, and the RQD that can best reflect the quality of rock mass has not yet been obtained t Anisotropy solution method

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