Project: Statics of drystone walls

Engineered dry stone masonry

Many people imagine dry stone walls to be small, relatively unstable structures of rural culture, as they are known from terracing or free-standing pasture walls. For them, dry stone walls are a building technique that can no longer keep up with our modern times and today's technical requirements.  However, dry stone walls are also able to withstand great loads and can be dimensioned according to engineering standards.

Numerous dry-stone retaining walls still support railway lines in Switzerland today.

Slide image
ENGSTM_01
Slide image
ENGSTM_02
Slide image
ENGSTM_03
Slide image
ENGSTM_04

The large drystone masonry avalanche barriers in the Swiss Alps still protect villages, roads and railway lines today.

Slide image
ENGLAW_01
Slide image
ENGLAW_02
Slide image
ENGLAW_03
Slide image
ENGLAW_04

These dry-walled structures date from the end of the 19th century, when new, larger roads were built across the Alps in the course of the industrial revolution, and shortly afterwards also railways. Because cement and concrete had only just been invented and transport was almost impossible in the difficult-to-access terrain, people were dependent on using the stone available on site as a building material. The numerous retaining walls that were necessary for the construction of the road and railway routes were built as natural stone walls, often as mortar masonry, but where possible also as dry masonry.

Slide image
ENGDRW_01
Slide image
ENGDRW_02
Slide image
ENGDRW_03
Slide image
ENGDRW_04

The origins of engineered dry-stone walling probably date back to the Age of Enlightenment, when military engineers in France used new mathematical methods to explore the theoretical foundations of traditional building techniques. At that time, in order to move the large armies, military roads had to be built that could withstand the weights of the cannons they carried. The quality of such structures was no longer left to chance, but was laid down in guidelines and building regulations.

Today, great efforts are being made to keep this tradition alive and to revive it.

In France, for example, a research project is underway that is subjecting dry-stone retaining walls to structural tests. The aim of this project is to re-establish dry-stone masonry as a "standardisable" construction method.

Term statics

Structural analysis of building structures is the study of the safety and reliability of load-bearing structures in the building industry. Statics of a dry stone wall therefore refers to the assessment and calculation of the stability and load-bearing capacity of a dry stone wall.

In the vast majority of cases, the load-bearing capacity and stability of retaining walls are to be assessed. Other areas of structural analysis include the assessment of the earthquake resistance of masonry structures.

Three factors play a role in the load-bearing behaviour of a dry stone wall: the weight of the stone material and the friction between the stones lying on top of each other, as well as the arrangement and position of the stones in the body of the wall.

Literature and Links

Stützmauern in Trockenmauerwerk

Merriman M. A Text-Book on Retaining Walls and Masonry Dams. New York: Wiley; 1892. 

( https://ia800900.us.archive.org/16/items/atextbookonreta01merrgoog/atextbookonreta01merrgoog.pdf )

McCombie PF Morel J-C Garnier D. Drystone Retaining Walls : Design Construction and Assessment. Boca Raton: CRC Press; 2016. doi:10.1201/b19095

Villemus B Boutin C Institut national des sciences appliquées de Lyon (Lyon). Etude Des Murs De Soutènement En Maçonnerie De Pierres Sèches = the Study of Dry-Stone Masonry Retaining Walls. 2004.

( https://www.decouverte-cevennes.fr/wp-content/uploads/2018/03/Thesepierreseche.pdf )

Ciblac T Morel J-C. Sustainable Masonry : Stability and Behavior of Structures. London: ISTE; 2014. http://site.ebrary.com/id/10899799. Accessed November 11 2022.

Mundell, C.; et al. Drystone retaining walls: from full scale testing to construction requirements. Proceedings of the 11th International Conference on Non-conventional Materials and Technologies NOCMAT 2009

Schweizerischer Ingenieur- und Architekten-Verein. Trockenmauerwerk in Naturstein : Bautechnik Erhaltung Und Ökologie. 1. Auflage ed. Zürich: Schweizerischer Ingenieur- und Architektenverein; 2020.

https://de.wikipedia.org/wiki/Schwergewichtswand

Erddruck

https://de.wikipedia.org/wiki/Erddruck

https://en.wikipedia.org/wiki/Lateral_earth_pressure 

Reibung

Wyllie DC. Rock Slope Engineering : Civil Applications. Fifth ed. Boca Raton FL: CRC Press Taylor & Francis Group; 2018.