ABSTRACT
This chapter discusses the discrepancies between the true characteristics of the line of thrust and its associated properties, which is illustrated through the study of the masonry straight arch, taking into account various stereotomies. Thrust line analysis of masonry construction has a centuries-old tradition. The controversies present in the literature regarding the properties or the construction of the line of thrust to investigate the limitations and possibilities of the method. An ideal, amply thick, uncracked semi-circular arch without any deformation is a hyperstatic system, which theoretically can contain infinite number of admissible thrust lines for a given loading. The proposed stereotomies result formally admissible thrust lines to thinner arches–indicating that finding a limiting case might be the true challenge. In the case of compressiononly structures, they must be thick enough, to accommodate the so-called thrust line for a given loading.
