Effect of Compressive Behaviours of Tail Salt Filling Materials on Roof Deformation in Potash Mine

Table 2

Strain conditions under different compressive stress processes of individual plans.

Initial loading stress (MPa)	0–2 MPa strain	2–8.5 MPa strain	8.5–15 MPa strain	0–2 MPa strain percentage (%)	Stress-strain fitting equations
0	0.1039	0.2437	0.3133	33	ε = −0.09489 + 0.14417 ln (σ + 1.97227)
0.5	0.0605	0.1903	0.2613	23	ε = −0.20653 + 0.16111 ln (σ + 3.24689)
1.0	0.0370	0.1616	0.2632	14	ε = −1.74921 + 0.5509 ln (σ + 23.59429)
1.5	0.0230	0.1664	0.2432	9	ε = −0.24938 + 0.17066 ln (σ + 2.93484)
2.0	0.0341	0.1586	0.2400	14	ε = −0.50367 + 0.23888 ln (σ + 7.50037)
2.5	0.0269	0.1475	0.2405	11	ε = −1.2226 + 0.42359 ln (σ + 16.63269)
3.0	0.0163	0.1431	0.2255	7	ε = −0.46865 + 0.2242 ln (σ + 7.11966)