Directional difference characteristics of resistivity response of tectonic coal in process of load-bearing failure

Abstract

The uniaxial compression experiments of soft coal samples were carried out, and we analyze the stress-strain characteristics of the tectonic coal in the process of load-bearing failure, and obtain the resistivity response characteristics of the coal in different directions. The experimental results show that the specimen can be divided into four stages from loading to failure, which are compaction stage, elastic stage, plastic stage and failure stage; during the loading process of the coal, the coal is in the form of splitting failure, the cracks spread from the bottom to the top of the sample, and part of the cracks run through the upper and lower surfaces of the sample; the resistivity response characteristics of the specimen in the vertical and horizontal directions in the uniaxial compression process show obvious differences, the resistivity of the coal in the vertical direction decreases first and then increases in the process of teactonic coal loading, and the resistivity of the test block increases slowly, rapidly and sharply in the horizontal direction; after the failure of the test block, the change range of the resistivity in the vertical direction is far less than that in the horizontal direction, and the resistivity in the horizontal direction is characterized by continuous increase.

Keywords

• tectonic coal
• loading failure
• resistivity
• directionality
• uniaxial compression experiment