Applications of Symmetric and Nonsymmetric MSSOR Preconditioners to Large-Scale Biot's Consolidation Problems with Nonassociated Plasticity

Table 4

Performance of different solution schemes for the pile-group example.

Load step no.	Number of nonlinear iteration	Average iterations for each linear system	Total solution time (hours)
Scheme 1: Newton + QMR preconditioned by nonsymmetric MSSOR
1	4	7400	0.951
2	5	7944	1.276
3	6 (1)	13967	2.601
Total	15	—	4.823
Scheme 2: IS (Chen) method + SQMR preconditioned by symmetric MSSOR
1	8	3300	0.464
2	13	3095	0.707
3	12	3020	0.636
Total	33	—	1.801
Scheme 2: 𝐾𝐺 (Chen) method + SQMR preconditioned by symmetric MSSOR
1	4	3410	0.242
2	5	3180	0.283
3	6	3284	0.349
Total	15	—	0.874