Swelling Pressure of Double-Expansive Material and Its Active Support Effect for Coal Seam Gas Drainage Borehole

Figure 4

Variations of swelling pressure over time: (a) radial and axial swelling pressures-time curves in test no. 1; (b) radial and axial swelling pressures-time curves in test no. 2; (c) radial and axial swelling pressures-time curves in test no. 3; (d) radial and axial swelling pressures-time curves in test no. 4.

(a)

(b)

(c)

(d)