Mechanical Properties and Failure Behavior of Composite Samples

Figure 1

Coal pillars with two different geometries in longwall mining systems. The lower figures are in situ roof-coal-floor combinations and simplified RCR samples. (a-1) and (b-1) are the 3D schematics of longwall mining systems. (a-2) and (b-2) are the magnified figures of pillars. (a-3) and (b-3) are the two kinds of in situ roof-coal-floor structures with different height ratios. (a-4) and (b-4) are the schematics of RCR samples with different height ratios. (c-1) Rock-coal (RC) sample. (c-2) Rock-coal-rock (RCR) sample.