METHOD FOR TESTING INTERFACIAL STRENGTH OF BROKEN COAL MASS REINFORCED BY GROUTING

• Main Authors: JULI LIANG, SUHUI ZHANG, JIAGUANG KAN, JIAHUI XU, GUICHEN LI, YUANTIAN SUN, NONG ZHANG, QINGLIANG CHANG, CHANGLUN SUN
• Format: Patent
• Language: English
• Published: 31.08.2022

Disclosed is a strength test method for an interface of a fragmentized coal body after grouting reinforcement. The main steps comprise: manufacturing two coal substrates and grout, and filling a space between the two coal substrates with the grout to form a sample; horizontally placing the sample in two direct shear boxes arranged one above the other, and respectively fixing, by means of fixing the direct shear boxes, the two coal substrates one above the other; starting a direct shear instrument, and applying an indenter to a top surface of the sample; adjusting a vertical stress to a set value; using displacement control to slowly move the lower direct shear box, and collecting a shear force in real time; stopping the experiment after the sample is completely sheared off, and recording parameters, such as displacement, a peak shear force, and a residual shear force; and finally calculating, by means of data fusion, the peak value of a coal body, residual cohesion and a residual internal friction angle. By means of configuring a control experiment, the change to the strength of an interface of a fragmentized coal body after grouting reinforcement is measured. By taking a real coal body as a substrate, the strength between structural planes of the coal body after grouting can be subjected to quantitative calculation, and a test result is closer to a site situation.