Documentation and Experimental Behaviour of Vertical Connectors in Ancient Monuments Under Cyclic Actions

Ancient monuments are constructed following the dry construction system. Large dimension structural members (stones) are placed without mortar, while perfect contact along their interfaces is ensured. In addition, iron or timber connectors of various geometries are used both in horizontal and vertical members. Three types of connections are identified, namely, the system of “polos-empolion”, placed (vertically) in columns, the horizontal connectors (clamps), and the vertical connectors (gomfoi), used in structural parts such as cella walls. The connectors do not contribute to the transfer of static loads, but they are activated when relative displacements are imposed to the structural components, e.g., in case of earthquakes. The paper focuses on vertical connectors, crossing the interfaces between successive courses of stones, and investigates their behaviour under seismic conditions. Vertical connectors are usually made of iron, and they are positioned in grooves chiselled in the structural members. The space between the walls of the groove and the connector is filled with melted lead. Documentation of vertical connections in ancient Greek monuments is presented, namely, their topology, and dimensions, and the typical pathology of both connectors and connected members. Several monuments are studied through literature survey and in situ observation. This documentation has assisted the design of the experimental campaign. Its purpose is to investigate connections between marble members, simulating the typical original ones, crossed by iron connectors. The testing of full-scale specimens has confirmed the pathology surveyed in situ, thus, proving the function of the vertical connectors in ancient monuments.