Best-fit models for predicting the geotechnical properties of FA–stabilised problematic soils used as materials for earth structures

ABSTRACT

The effect of fly ash (FA) on geotechnical properties of high plasticity clayey soils (known as problematic soils) has been investigated by several researchers. However, few studies have been developed to predict the geotechnical properties of FA–stabilised problematic soils. This study was undertaken in order to develop best-fit models for predicting the Atterberg limits (liquid limit; LL and plasticity index; PI), unconfined compressive strength (UCS), free swell index (FS), optimum moisture content (OMC) and maximum dry density (MDD) of FA-stabilised high plasticity clayey soils. For this purpose, many data sources were collected from several laboratory studies published in the literature over the past. All the developed models were validated and found to have a good ability where they can be used as a reliable tool to predict all the LL, PI, UCS, FS, MDD and OMC of FA-stabilised high plasticity clayey soils. In addition, the suggested models showed that the accurate prediction of all the studied physico-mechanical properties was highly beneficial for the engineering construction enabling it to avoid the cumbersome tests in the laboratory. From these results, the obtained equations may be useful in practices of civil engineering projects and in designing earth structures such as roadway subgrades, road embankments, trench backfills, landfill liners and earth dams.

KEYWORDS:

• Problematic soils
• fly ash (FA)
• atterberg limits
• unconfined compressive strength (UCS)
• free swell index (FS)
• optimum moisture content (OMC)
• maximum dry density (MDD)
• best-fit models

ORCID

Hamid Gadouri http://orcid.org/0000-0002-0753-3569