Stress state of protective shells in the area of holes due to prestressed reinforcement curvature

The stress state around the holes in cylindrical part of prestressed concrete protective shells is examined in this paper. This stress state is caused by general shell prestressing having the aim to compensate internal emergency pressure and the curvature of the reinforcement elements near technological holes in cylindrical part of shell. Presence of technological holes predetermines occurrence of so called “disturbed” stress state of a local nature (stress concentration). The exact solution of the stress concentration problem at any load does not exist even for a plate. So the approximate solution using complex functions and Fourier series for a plate with a hole is proposed. It can be concluded on the basis of the calculation results that the stress concentration due to curvature of reinforcement elements near hole has to be taken into account, since in this case the maximum compressive stress is considerable.