Experimental Study on Stiffness Softening of Soil-Rock Mixture Backfill under Metro Train Cyclic Load

Table 4

Fitting parameters of the stiffness softening model.

Rock content (%)	Consolidation stress (kPa)	Consolidation degree	A	B	C
20	100	0.98	0.7760	4.4490	0.0139	0.9340
		0.90	0.7063	3.3910	0.0150	0.9491
		0.80	0.6565	2.8960	0.0156	0.9564
	200	0.98	0.6969	3.2820	0.0172	0.9457
		0.90	0.6470	2.8160	0.0177	0.9532
		0.80	0.5371	2.1440	0.0185	0.9643
	400	0.98	0.6574	2.9000	0.0202	0.9463
		0.90	0.5975	2.4650	0.0207	0.9542
		0.80	0.3364	1.5500	0.0422	0.9800
10	200	0.98	0.5592	0.4200	0.0030	0.9961
40	200	0.98	= 0.9991;  = 0.0009
			= 1335;  = 2.2068