Abstract

Masonry domes are shell-like structures with a no-tension type material behavior [1]. The dome geometry, material behavior and the type of the loading define how the dome balances the load. It is known and proved that the dome could balance the load only by forces, without bending moment but cracks may appear since the material does not resist tension. The surface where the balancing forces are acting is called the thrust surface. The paper introduces the idea of the general thrust surface. It is such a balancing surface where the forces are not acting in the tangent plane of the thrust surface and otherwise it is moment free. A method is shown how to find the general thrust surface for a cracked spherical masonry dome. Numerical example illustrates the usefulness and effectiveness of the proposed method to determine the general thrust surface of a spherical dome when radial stereotomy is considered. By the help of the proposed model the safety of the more than 350 years old, cracked dome of Gol Gumbaz, India can be proofed.