Ryzhykov K. Improving of calculation methods of steel-liner reinforced concrete high-pressure penstocks of HPP and PSP taking into account temperature effects

Dissertation is devoted to improving calculating methods of the stress state and strength of steel-liner reinforced concrete high-pressure penstocks in the operational period, taking into account the influence of temperature effects in a deterministic formulation, as well as the development of probabilistic methods of calculations of penstocks within reliability theory of complex technical systems. Techniques based on numerical solution of heat conduction problem, as well as analytic solutions of one-dimensional steady and unsteady heat conduction problems for a uniform ring, simulating cross-section of the composite conduit to determine the thermal regime of the penstocks in the operational period are proposed. Two methods for determining of stressed state of steel-liner reinforced concrete penstocks to the internal pressure of the water, taking into account temperature effects in the operational period are proposed. First is based on the solution of the plane problem of mechanics of deformable body using finite element method. Second is engineering method of calculating the strained state of the high-pressure penstocks with single and double reinforcement on the basis of the mathematical relationships. The technique of probabilistic calculation of reliability and safety of high-pressure steel-liner reinforced concrete penstocks on the assumption of the strength of the bearing elements (steel shell, the inner and outer ring reinforcement) is proposed as part of the reliability theory. Branch - construction.