  We study statistical properties of 3D classical spin glass layer of certain
width and infinite length. The 3D spin glass is represented as an ensemble of
disordered 1D spatial spin-chains (SSC) where interactions are random between
spin-chains (nonideal ensemble of 1D SSCs). It is proved that at the limit of
Birkhoff's ergodic hypothesis performance 3D spin glasses can be generated by
Hamiltonian of disordered 1D SSC with random environment. Disordered 1D SSC is
defined on a regular lattice where one randomly oriented spin is put on each
node of lattice. Also it is supposed that each spin randomly interacts with six
nearest-neighboring spins (two spins on lattice and four in the environment).
The recurrent transcendental equations are obtained on the nodes of spin-chain
lattice. These equations combined with the Silvester conditions allow step by
step construct spin-chain in the ground state of energy where all spins are in
minimal energy of classical Hamiltonian. On the basis of these equations an
original high-performance parallel algorithm is developed for 3D spin glasses
simulation. Distributions of different parameters of unperturbed spin glass are
calculated. In particular, it is analytically proved and by numerical
calculations shown that the distribution of spin-spin interaction constant in
Heisenberg nearest-neighboring Hamiltonian model as opposed to widely used
Gauss-Edwards- Anderson distribution satisfies L\'evy alpha-stable distribution
law which does not have variance. A new formula is proposed for construction of
partition function in kind of one-dimensional integral on energy distribution
of 1D SSCs
