Experimental and numerical study to investigate the usability of walnut shell waste as an additive for foundations of highway embankments

Abstract

The main aim of this research is to query the effectiveness of walnut shell waste (WSW) as an additive to improve the strength and deformation characteristics of kaolin. In this context, a laboratory testing program is applied to both homogenous kaolin and improved soil specimens with WSW consisting of sieve analysis, consistency limit tests, uniaxial compression tests, and standard proctor tests. The effects of both the curing time and the amount of additive material are also discussed through the conducted uniaxial compression tests. The test results show that the increase of both the curing time and the amount of the additive significantly affected the strength properties of kaolin. Besides, finite element analyses using Plaxis software are conducted to reveal the applicability of the proposed new additive material to the foundations of highway embankments and determine the differentiation capacity of deformations. Consequently, an applicable thickness of the improved soil layer is suggested depending on the performed analyses.