Coal body and anchoring agent interface bonding strength testing method

Abstract

The invention discloses a coal body and anchoring agent interface bonding strength testing method. The method is characterized in that according to coal body existing conditions, a coal matrix (1) iscompacted, a through hole (2) is formed at middle of the coal matrix (1), an elastic circular column (3) is placed at the middle of the through hole (2), an anchoring agent cylinder (4) is formed by injecting an anchoring agent in the through hole (2), the elastic circular column (3) is subjected to pneumatic compression, after the anchoring agent is completely acted while a certain air pressure is kept, the elastic circular column (3) is changed to a rigid cylinder (6), two ends of the through hole (2) are plugged to form a test piece, then the test piece is placed on a servo press (10), an aperture same with the through hole (2) is placed at a lower part of the test piece, the aperture is aligned with the through hole (2), a pressure head (8) is a cylinder having a same diameter with theanchoring agent cylinder (4), the pressure head (8) is lowered for testing the bonding strength, and finally data is collected for analysis. The real coal body is taken as an anchoring matrix, and the testing result is more close to on-site condition.

Description

technical field [0001] The invention relates to a method for testing cohesive strength, in particular to a method for testing the interface cohesive strength of a coal body and an anchoring agent, and belongs to the field of mining engineering. Background technique [0002] Bolt support is one of the main support forms of coal mine underground rock formation roadway and coal seam roadway. Its construction method and function principle are as follows: first drill holes in the rock mass or coal mass, and put resin anchoring agent, and then anchor The rod is inserted into the borehole. After the resin anchoring agent takes effect, the anchoring agent will bond the anchor rod with the coal rock mass on the inner wall of the borehole, so that the end of the anchor rod extending into the borehole is fixed in the coal rock mass, and finally when the anchor rod extends One end of the drill hole is used to fix the pallet, so as to restrain the deformation and damage of the surroundin...

AI Technical Summary

Problems solved by technology

[0004] The strength of the coal body is low, and the anchoring situation is different from that of the rock. In the experiment, it will be difficult to process the test piece by conventional methods; especially when the coal body is loose and broken soft coal, the roughness of the anchorage interface is affected by the adhesion The degree of bonding is very different from that of rock or artificial cement matrix, and the medium of this type of coal is inhomogeneous, discontinuous, and anisotropic; when drilling on this type of soft coal, the inner wall of the borehole is a rough interface, while the rock or The inner wall of the borehole of the artificial cement matrix is ​​usually relatively smooth; at the same time, during the period of stress disturbance, the internal structure of the loose and broken soft coal and the physical and mechanical property parameters of the anchoring material are constantly changing, and these factors have a great influence on the bond strength of the anchoring material; and for When conducting experiments on soft coal with extremely low strength, it is extremely difficult to process the coal sample into the test piece required for the experiment after sampling the soft coal

Therefore, there is still a lack of systematic research methods for the measurement and effect analysis of the bond strength between the coal body and the anchoring agent interface (the second anchoring interface) under the special environment of bolting in loose and broken soft coal.

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