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

Table 5

Comparison of test values with the BP neural network.

Experimental factors	Calculated test value			PSO-BP arithmetical inversion
	E (GPa)	c (MPa)	μ		φ (°)	E (GPa)	c (MPa)	μ	φ (°)
Test 1	40	0.4	0.2		20	38.446	0.432	0.246	21.213
Test 2	40	0.6	0.25		22	40.723	0.506	0.258	23.092
Test 3	40	0.8	0.3		24	40.703	0.684	0.296	23.232
Test 4	45	0.4	0.25		24	44.999	0.400	0.249	23.987
Test 5	45	0.6	0.3		20	44.587	0.632	0.295	20.314
Test 6	45	0.8	0.2		22	48.064	0.798	0.203	22.187
Test 7	50	0.4	0.3		22	50.001	0.400	0.300	22.001
Test 8	50	0.6	0.2		24	48.614	0.811	0.202	22.106
Test 9	50	0.8	0.25		20	50.004	0.816	0.202	22.019