This paper deals with analysis of rock massif in connection with a planned
deposit of nuclear waste. This problem has emerged with renessaince of nuclear power
plants which are now considered as a stable and relatively clean source of electrical energy.
The deposits are located deep in rock massif and analysis of stress redistribution caused by
cave drifting and temperature changes is required. Difficulties with solution of systems of
non-linear algebraic equations were discovered and two variants of the arc-length method
were tested