REASURCH THE WORK OF THE TRADITIONAL CIRCULAR ARCH OF TIMBER JAMBS WITH AN OPTION OF ITS STRENGTHENING

The article discussesthe research of the traditional circular archs of timber jambs, designedin the 16-th century by the French architectPhilibert Delorme, with an option of its strengthening, which make this arch comparable to the glued timber one. The experimental research of a flat arch, made of small wooden bricks strung on a steel rope and prestressed from the foundationzone, was carried out in the NRU MGSU. According to the results, it was found, that the arch has a low carrying capacity and can work only on compression. However, by strengthening the arch by using a steel band along its upper face and thus moving to the truss structure, it is possible to increase significantly its carrying capacity and bring it closer to the glued timber arch. During tests, it was noted that by the character of its work this arch is close to the circular arch of timber jambs. In the LIRA-CAD PC a computer simulationwas carried out of the traditional and the strengthened by a steel band along its upper face circular arches of timber jambs, as well as the glued timber arch. The following results were obtained.During the deformation process, the deflection of the strengthened circular arch decreased by 31%, and the stresses in it decreased by 26% compared to the traditional one, and according to the carrying capacity the arch has become comparable to the glued timber one. On this basis the conclusions were obtained, that it is possible to create non-linear form constructions, inherent to the natural objects, using the strengthened circular arch.