Determination of the Sensitivity and Thixotropic Effects of Clay Soil for Selected Sites in Diwaniya City - Iraq

Abstract

This paper is conducted to determine the sensitivity and thixotropic effects of clay soil for selected sites in Diwaniya city which are: (Dawr Aldubbat, Al-Zawra square, 14 Ramadan square, Al'iiskan Alaqadim and Military square). The main aim of this investigation is to study the sensitivity and thixotropy of clay soil, and determination and classification of soils to (Insensitive), (slightly to very sensitive) and (slightly to extra quick)) relying on special test methods in sensitivity and thixotropic phenomena. The experimental tests that were done including geotechnical, chemical and mineralogical tests to natural soils and special tests were for the identification and classification of sensitivity of soils. The results of sensitivity of soils test displayed low to medium for all the types of the soils in the study area. The results of the thixotropic strength ratio test showed a small increase in thixotropic strength ratio values with time. The results of Atterberg limits test indicated that increasing the proportion of the clay causes an increase in the plasticity index of the soil. While the results of the liquidity index varied from 0.24 to 0.70, which reflects the low sensitivity of the clay soil in the study area.

Evaluation Method for Thixotropy of Clay Subjected to Unconfined Compressive Test

“…The thixotropy of clay is generally measured by studying the variation rule in yield stress (Landrou et al, 2018), strength (Chan, 2015), viscosity (Jeong et al, 2015), and ratio of strength (Zhang et al, 2014b;Wang et al, 2015;Al-Rubaiee and Al Salami, 2020) with time after clay has been disturbed to reflect thixotropy. Du et al (2020) proposed a model to explain the effect of ionic strength on the thixotropy and yield stress of sodium montmorillonite gel by reflecting the thixotropic behavior of sodium montmorillonite through change in yield stress increment with time.…”