Experimental and numerical analysis of soil desiccating cracks in compacted and non-compacted specimens

Abstract

This paper presents the results and analysis of two cracking tests carried on specimens of silty clay. One specimen was prepared in slurry conditions without applying energy and the other specimen was compacted. They were dried in an environmental chamber at a constant temperature and relative humidity to study the effect of the initial consistency on the cracking behaviour. Weight measurements and photographic images taken at regular intervals documented the evolution of the specimens. THM models were then carried to capture the unsaturated flow in the porous medium due to evaporation, and its resulting shrinkage. All the numerical analyses were coupled, incorporating the effect of porosity change on the balance equations and the constitutive model. The transfer coefficients in the imposed drying boundary condition were based on calculations of aerodynamic surface resistances, taking into consideration the new fronts for evaporation created by the cracks. The constructed numerical model results capture the gravimetric water content loss and the occurring shrinkage for both specimen conditions.

Tensile strength of a compacted vegetated soil: Laboratory results and reinforcement interpretation

“…In the case of soil slopes, it leads to a better understanding of the soil response in the upper portions, which may be subjected to horizontal stress reduction and tensile stress paths due to downward mass movements 15 . Moreover, it also allows studying the occurrence of the detrimental effects caused on the soil by tensile cracks linked to shrinkage and swelling cycles [26][27][28][29] . So far, there have been some attempts to characterise this behaviour in bare 27,30,31 or fibrereinforced samples [32][33][34] .…”

Towards the development on new high capacity tensiometers capable of measuring soil matric suction beyond 3 MPa

“…One of the continuous drying tests was conducted in a soil sample prepared from slurry with the well-known Barcelona silty clay that was sieved below 2 mm and with Atterberg limits of 32% and 16% for the liquid limit and plasticity index, respectively (Gens et al, 1995;Barrera, 2002). The second continuous drying test was conducted in a soil sample cut from a dynamically compacted larger sample, using the proctor hammer, at a water content of 19% (equivalent to a degree of saturation of 92%) with the locally sourced Agropolis clay that was sieved below 2 mm and with Atterberg limits of 29% and 12% for the liquid limit and plasticity index, respectively (Cordero et al, 2020). These tests were performed by clamping the N-HCTs to a support platform where the soil samples, with initial dimensions of 50 mm in diameter and 20 mm in height, were placed on top of the N-HCT as shown schematically in Figure 13.…”