Table 4.

The material constants of different samples.

	Jiangxi clay	Boston blue clay	Toyoura sand	Commercially available clay
Basic constants	$\mathrm{\Gamma }$ = 2.255	$\mathrm{\Gamma }$ = 2.501	$\mathrm{\Gamma }$ = 2.067	$\mathrm{\Gamma }$ = 2.134
	$\lambda$ = 0.095	$\lambda$ = 0.184	$\lambda$ = 0.05	$\lambda$ = 0.173
	$\kappa$ = 0.018	$\kappa$ = 0.036	$\kappa$ = 0.0064	$\kappa$ = 0.05
	$\mu$ = 0.3	$\mu$ = 0.3	$\mu$ = 0.3	$\mu$ = 0.3
	$M$ = 1.36	$M$ = 1.35	$M$ = 1.3	$M$ = 0.772
Yield constants	$r$ = 2.2	$r$ = 2.718	$r$ = 12	$r$ = 2.718
	$n$ = 3.5	$n$ = 1.8	$n$ = 2	$n$ = 2
Hardening constants	$h_{\text{m}}$ = 95	$h_{\text{m}}$ = 40	$h_{\text{m}}$ = 80	$h_{\text{m}}$ = 750
	$h_{\text{c}}$ = 10	$h_{\text{c}}$ = 25	$h_{\text{c}}$ = 55	$h_{\text{c}}$ = 35
	$r_{\text{c}}$ = 0.95	$r_{\text{c}}$ = 0.9	$r_{\text{c}}$ = 0.7	$r_{\text{c}}$ = 0.95
Initial internal variables	$v_0$ = 1.88	$v_0$ = 2.01	$v_0$ = 1.71	$v_0$ = 2.15
	${\overline{\alpha }}_0=\mathrm{O}$	${\overline{\alpha }}_0=\mathrm{O}$	${\overline{\alpha }}_0=\mathrm{O}$	${\overline{\alpha }}_0=\mathrm{O}$
	OCR = 1:	OCR = 1:	$p$ = 1 MPa:	$p_{\text{c}0}$ = 450 kPa
	$p_{\text{c}0}$ = 98 kPa, $R_0$ = 1	$p_{\text{c}0}$ = 196 kPa, $R_0$ = 1	$p_{\text{c}0}$ = 8 MPa,	$R_0$ = 1
	OCR = 2:	OCR = 2:	$R_0$ = 0.125
	$p_{\text{c}0}$ = 196 kPa, $R_0$ = 0.5	$p_{\text{c}0}$ = 392 kPa, $R_0$ = 0.5	$p$ = 2 MPa:
	OCR = 8:	OCR = 8:	$p_{\text{c}0}$ = 10 MPa, $R_0$ = 0.2
	$p_{\text{c}0}$ = 784 kPa, $R_0$ = 0.125	$p_{\text{c}0}$ = 1568 kPa, $R_0$ = 0.125	$p$ = 3 MPa: $p_{\text{c}0}$ = 10.5 MPa, $R_0$ = 0.286