Reinforced Interfaces Between Drums in Ancient Columns

The current paper presents part of the content of a research program, aiming at investigating the effect of interfaces, reinforced using vertical connectors (gomfoi) on the seismic behaviour of ancient monuments, and more precisely on the seismic behaviour of columns and colonnades, where the interfaces between drums are crossed by shear connectors. The ancient Monuments are constructed following the dry construction system, i.e., structural members (of porous stones or marble) with large dimensions are positioned without mortar. This is typical for columns as well. In addition to the perfect contact along the interfaces of consecutive stones, iron or timber connectors of various geometries are frequently used both in horizontal and vertical members. Two distinct types of vertical connectors are identified in ancient constructions, namely, the system of “poloi-empolia” (of cylindrical shape) and the “gomfoi” (of orthogonal parallelepiped shape). Even though gomfoi are known to connect mainly stone blocks composing horizontal members (beams and wall blocks), in case of monuments constructed in the Hellenistic Era, vertical connectors are used also between the drums of columns, in an arrangement suggesting that it was intended to improve the behaviour of the columns against seismic actions in any direction. In this paper, the documentation of the characteristics of vertical connectors-gomfoi in ancient columns is presented, together with a literature review of the available experimental and analytical works. The data, together with preliminary analysis, are necessary for decisions to be made related to the shake table tests that will follow.