Rectangular Blocks vs Polygonal Walls in Archaeoseismology

Abstract

Collapsed or deformed walls in ancient structures constitute important evidence in archaeoseismology, where damage is interpreted in terms of earthquake ground motion. A large variety of wall types have been developed during the millennia in different cultural backgrounds. Often walls with polygonal-shaped building blocks are regarded as more earthquake-resistant than a wall consisting of rectangular elements and, as is sometimes speculated, that the irregular wall types were intentionally developed for that purpose. We use simply structured discrete element models of four walls with different block geometries, perfect rectangular, an Inca-type structure and two polygonal designs, to test their dynamic behavior. In addition to an analytic calculation of ground motion, we use measured strong motion signals as boundary conditions for the 3D wall models with varying height to width ratios. At peak ground accelerations between 1.0 and 9.0 m/s 2 and major frequencies of 0.5 to 3 Hz, numeric experiments with the horizontally applied analytic ground motions result in clear differences in the resistance of the four wall types with the rectangular block wall being most vulnerable. For more complex measured 3D motions the Inca-type wall proves more stable than the rectangular block wall; however, height to width ratio still has equally strong influence on the stability. Internal deformation of non-collapsed walls shows some correlation with the parameters of the driving motion. For simple impulsive ground motions, a peak ground displacement threshold exists between toppling and remaining upright for all four models but peak acceleration cannot be reliably back calculated.

Fabrication Methods of the Polygonal Masonry of Large Tightly Fitted Stone Blocks with Curved Surface Interfaces in Megalithic Structures of Peru

“…In general, a polygonal masonry is not something unprecedented, such masonry has been used in Europe since antiquity. 5,6 In the Peruvian version, only the quality of the curved interfaces is striking, which is not easy to repeat even in our time. The methods suggested by both the scientific community 7,8,9,10 and the enthusiasts 11,12,13 for fabrication of the Peruvian polygonal masonry do not explain all the observed features and are often far from a reality.…”

Reconstructing the slip velocities of the 1202 and 1759 CE earthquakes based on faulted archaeological structures at Tell Ateret, Dead Sea Fault

“…The pulse fulfils the boundary conditions of zero acceleration, velocity, and displacement at the start and zero acceleration and velocity at the end of the signal, while the final displacements match those between the two plates. This signal type was previously successfully applied in archaeoseismological research; the displacement history of the pulse is similar to the horizontal ground movement close to a strike slip event (Hinzen 2009;Hinzen and Montabert 2017).…”

Historical Earthquake Scenarios for the Middle Strand of the North Anatolian Fault Deduced from Archeo-Damage Inventory and Building Deformation Modeling

“…We could find repairs for all the major construction periods of the city, from the 9 th century to the Ottoman times (for the list, see Table S3 in the electronic supplement). For the earlier periods, we could only find possible seismoresistant techniques of construction in the theater with the use of polygonal imbricated ashlars (Garduño-Monroy et al, 2012;Hinzen and Montabert, 2017).…”