Study on the Permeability Evolution and Its Formation Mechanism of Xiaojihan Aquifer Coal Seam under Plastic Flow

Figure 6

The bow sensor and static strain gauge. Note: 1: cylinder as a three-axis chamber; 2: coal sample; 3: static resistance strain gauge; 4: radial displacement sensor bracket; 5: fastening bolt; 6: clamping piece; 7: strain gauges; 8: hinge pin.