Expansive Clay Cracking Behavior through Digital Image Correlation

¹ Dept. of Engineering, Federal Rural University of the Semi-Arid, Rua Gamaliel Martins Bezerra n°587 Alto da Alegria, Angicos, Brazil
² Dept. of Civil Engineering, Federal University of Pernambuco, Av. Acadêmico Hélio Ramos s/n Cidade Universitária, Recife, Brazil

^* Corresponding author: arthur.araujo@ufersa.edu.br

Abstract

Expansive soils may present cracks arising from the drying process and their evolution can cause irreparable damages to engineering projects. Investigating this phenomenon is vital to understanding its geomechanics. The objective of this article is to present numerical modelling of the formation and propagation of cracks in expansive soil. A desiccation experiment was therefore carried out using an expansive silty clay from Paulista, in northeastern Brazil. The drying process was monitored by measuring the temperature and relative humidity of the air, as well as by capturing images with a camera. The digital images were correlated using the Ncorr numerical tool in MATLAB. As a result, this study made it possible to conclude that the soil cracking dynamics presented a non-orthogonal pattern during the dryness test, while the image treatment made it possible to observe the tendency of cracks to appear and propagate on the soil surface, allowing for the detection of crack growth and propagation trends.