Evaluate of different plasticity index effective on scouring and self-resilience of clay soils with nanoclay additives

Document Type : Original Article

Authors

1 Assistant Professor, Department of Civil Engineering, Ayatollah Borujerdi University, Iran

2 M.Sc.,Grad. Department of Civil Engineering, Ayatollah Borujerdi University, Iran

10.22034/tri.2020.106962

Abstract

Dense clay layers are one of the most common impermeable layers in most geotechnical structures such as earth dams and urban and radioactive waste landfills. Due to the specific geotechnical properties, these layers are damaged by cracking over their lifetime. These cracks increase the permeability of the layer and reduce its efficiency. Considering the necessity of knowledge and understanding of factors affecting the stability of geotechnical structures made with these layers, in this research, it has been tried to use a self-resilient property of clay soils to improve soil yield in different conditions. In the present study, it has been shown by numerous experiments that increasing the plasticity index's clay soils can increase the crack restoration rate. The results show that the addition of nanomorillonite to soil improves the self-healing process of the cracks; the time elapses the effect of this increase in the process of repairing cracks created in the specimens. The discharge rate of the samples is measured relative to the time elapsed during the self-repair and are examined according to the graphs. The experiments showed that the percentage of nano-clay montmorillonite is unaffected and reduces the amount of flow in the specimens, which is the self-restorative symptom of cracking by the addition of nano-clay. The total amount of discharge outflow in nano-clay samples from the non-additive samples was much lower, and nano-clay can be used as repairing cracks in clay soils at a depth of 5 cm.

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