Experimental and Theoretical Studies to Characterize Structural Behavior of Dry-Stone Corbelled Arches under Support Disturbances

ABSTRACT

Complex dry stack stone corbel-vaulted structures are commonly constructed as assemblages of several corbelled sub-systems. While there is enough architectural documentation, limited studies explore their structural stability or factors affecting it considering that they are rather susceptible to support disturbances. A systematic study of the influence of geometry (global level), interactions between adjacent units (intermediate level) and material strength parameters, particularly joint friction (local level) on their stability is warranted. A series of static experiments are conducted on a 1:3 scaled model of an existing corbelled vault to various support movements replicating lateral actions caused by seismic or differential support movements, with non-contact measurements based on photogrammetry. Sensitivity to joint roughness and moisture conditions is also examined. Failure mechanisms categorized as overturning, joint sliding, or a combination of overturning and sliding, provide an insight on the redundancies available in complex-vaulted systems, and the interplay between one mechanism over another. The possibility of estimating collapse displacement or rotation using graphical methods in predominant overturning or the combination failure mechanism is discussed. In predominant sliding failure mechanism, a simple method to assess safety is explained with the use of the friction cone concept when subjected to known input forces.

KEYWORDS:

• Collapse displacement
• corbel vault
• dry-stone masonry
• friction cone
• overturning
• photogrammetry
• sliding failure
• support movements
• thrust line

Acknowledgments

The authors would also like to place on record the assistance received from Mr. Shibu Samson, MS student at Department of Civil Engineering, IIT Madras in the non-contact measurements in the experimental work.

Disclosure statement

No potential conflict of interest was reported by the author(s).

Additional information

Funding

Research work presented in the manuscript has been carried out with financial support from Ministry of Human Resource Development (MHRD), Government of India to the National Centre for Safety of Heritage Structures (NCSHS), Dept. of Civil Engineering, IIT Madras (D.O. No. 5-62013-TS-1) and MHRD scholarship for PhD to the first author.