Influence of sample preparation method on static liquefaction behaviour of geotextile reinforced sandy soil

Abstract

This paper aims to evaluate the influence of soil deposition methods on the shear strength of reinforced sand using a triaxial test. Non-woven geotextile layers were used as reinforcement in the experiment to reconstitute specimens of natural sand prepared at loose relative density (Dr = 30%). Arrangements of reinforcement layers (0, 1 and 2 layers) on soil samples were prepared using two different deposition methods [dry funnel pluviation (DFP) and wet deposition (WD)] and consolidated under three levels of confining pressures. Result shows that geotextile inclusion improves the mechanical behavior of sand; a significant increase in the shear strength is obtained by adding up layers of reinforcement. However, it reveals also that the soil-geotextile reinforcement interface efficiency is directly related to the number of layers and the soil dispositional method as well as their initial state. Since, the DFP method exhibits samples strain hardening compared to the WD samples which is very sensitive to static liquefaction. It is important to note that the difference in behavior of test on reinforced WD samples was attributed to the strain at failure, where unreinforced soil tested at ({text{p}}_{{text{c}}}^{{prime }} = {50},{text{kPa}}) has attained complete liquefaction at small stain (εfa = 1.6% for sample tested at 50 kPa of confining pressure) compared to reinforced samples tests in which failure envelope be found for more axial strain.