Multiparameter Inversion Early Warning System of Tunnel Stress-Seepage Coupling Based on IA-BP Algorithm

Table 4

Orthogonal test table.

Experimental factors	Elastic modulus	Cohesive force	Poisson’s ratio	Internal friction angle	Subsidence value of point B	Vault displacement value	Subsidence value of point C	Horizontal convergence value
	E (GPa)	c (MPa)	μ	φ (°)	mm	mm	mm	mm
Test 1	40	0.4	0.2	20	12.44	15.4	12.41	4
Test 2	40	0.6	0.25	22	8.76	10.84	8.74	1.92
Test 3	40	0.8	0.3	24	6.23	7.5	6.23	1.46
Test 4	45	0.4	0.25	24	8.62	10.74	8.59	2.29
Test 5	45	0.6	0.3	20	7.79	9.57	7.76	3.14
Test 6	45	0.8	0.2	22	8.08	9.95	8.06	0.64
Test 7	50	0.4	0.3	22	8.11	9.98	8.07	3.86
Test 8	50	0.6	0.2	24	7.78	9.7	7.76	0.88
Test 9	50	0.8	0.25	20	7.13	8.71	7.12	1.58