Application of Modified Hoek–Brown Strength Criterion in Water-Rich Soft Rock Tunnel

Table 1

Parameters of soft rock under different immersion time.

Test specimen number	Immersion time (t/d)	Compressive strength ()	Poisson ratio ()	Elastic modulus (E/GPa)	P-wave velocity (V/m·s^-1)	Porosity (/%)
1-1	0	23.58	0.337	33.214	2650	0.467
1-2	0	23.40	0.348	33.383	2647	0.446
1-3	0	22.96	0.333	32.656	2539	0.421
2-1	30	18.12	0.336	30.007	2638	0.572
2-2	30	18.45	0.332	30.131	2609	0.568
2-3	30	18.32	0.337	29.952	2629	0.583
3-1	90	14.35	0.337	26.935	2578	0.762
3-2	90	15.13	0.330	27.917	2541	0.695
3-3	90	14.96	0.329	27.272	2558	0.707
4-1	180	10.92	0.336	25.029	2501	1.098
4-2	180	11.38	0.327	24.960	2458	0.974
4-3	180	11.10	0.336	25.510	2418	1.063
5-1	270	9.96	0.328	24.929	2449	1.218
5-2	270	9.82	0.334	24.137	2439	1.196
5-3	270	10.58	0.336	25.017	2321	1.101