题目内容：

英语翻译
where b 2 Rmþn; K 2 Rm\2m is symmetric positive definite,
B 2 Rm\2n has full column rank,and C 2 Rn\2n is
symmetric positive semi-definite.A more detailed
description of Biot\1s consolidation equations is given
elsewhere [1].It suffices to note here that the number
of displacement degrees of freedom (DOFs) m and the
number of pore pressure DOFs n has a ratio of about
0.1 (see Table 1 for examples).The matrix A is generally
sparse.Fig.1 illustrates the sparsity pattern of A from
a 5· 5 · 5 meshed footing problem.A wide class ofconstrained problems involving mixed finite-element
formulations also produces the above 2 · 2 block matrix
structure [2].