Ammosov North-Eastern Federal University, Yakutsk, Russia:

F. F. Poselsky, Head of a Chair, Associate Professor, Candidate of Engineering Sciences
A. G. Alekseenko, Head of a Sector, Candidate of Engineering Sciences
V. S. Supletsov, Head of Laboratory, lab.nsk.82@mail.ru

With a view to estimating spare capacity, stress state of structural units at processing plants of ALROSA Company is analyzed using data of stress obsrvations from 1980 to 2014. The load-bearing capacity estimation takes into account criteria of actual fastening of the structures, actual cross-section dimensions and strength characteristics of materials the structures are made of. It is found that the structural units at processing plants possess sufficient load-bearing capacity and spare capacity to carry load and keep service ability under stable conditions and in case of minor deviation from the design and standards and norms. The main factor to reduce load-bearing capacity of the structures is the corrosive wear that has depleted capacity and serviceability of a few structures. At the same time, long-standing processing plants, which now suffer from the intensive corrosion wear, had higher safety factor in line with the norms and standards effective that time. The load-carrying structures of recent construction have lower spare capacity set by the new design standards. This circumstance should be taken into account when continuing operation of buildings at processing plants. Thus, a more complete knowledge on actual operation of processing plant buildings can be gained from in situ testing and determination of actual displacements and stresses. Estimate of capacity of a structure built under old design standards with regard to actual operating conditions may yield a considerable margin in the load-bearing capacity of the structure. At the same time, the buildings constructed under the modern standards have reduced spare capacity and insignifi cant defects and damage can result in structural overstressing.

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