A study of thin reinforced concrete shallow shells and their strengthening

In this paper the causes of significant deformations of reinforced concrete thin shallow shells of octagon shape are discussed. Causes of deformation and loss of stability of thin shallow shells of the same type in rectangular plan are analysed. The paper discusses the reasons for the appearance of excessive cracks on the surface of very shallow reinforced concrete shells of the same type of square plan of floors. Check calculations have been implemented using the finite element method with further calculations done using a method of limit analysis. The example of strengthening and safeguarding the shells of square plan is given. The method used for the shell strengthening was assumed as a basis for developing the method of strengthening ancient stone domes. The authors believe that the design principles applied in these projects can provide a substantial contribution to successful conservation of much larger projects, along with the increase of their earthquake resistance.