Dry masonry

17th Century Wall at Machols Castle , Scotland

Dry masonry is a construction method in which buildings or their elements are built of stone without using a binding solution. The stability of the dry masonry is ensured by the presence of a bearing facade of carefully selected mating stones. This is the most archaic of masonry methods. It is usually used for the construction of walls, however, whole buildings and bridges constructed by a similar method are known.

The first builders who paid special attention to the seismic resistance of capital buildings, in particular, the dry masonry of the walls of buildings, were the Incas , the ancient inhabitants of Peru . The Inca architecture features an unusually thorough and tight (so that knife blades cannot be inserted between the blocks) matching stone blocks (often of irregular shape and very different sizes) to each other without the use of mortars ^[1] .

Thanks to these features, the Inca masonry did not have resonant frequencies and stress concentration points, possessing additional strength of the arch . During earthquakes of small and medium strength, such a masonry remained practically motionless, and in case of strong earthquakes, the stones “danced” in their places, without losing their mutual position, and at the end of the earthquake they were laid in the same order ^[2] .

These circumstances make it possible to consider the dry masonry of walls by the Incas one of the first devices in the history of passive vibration control of buildings.