Measurement of the Lateral Earth Pressure Coefficient of Clayey Soils by Modified Oedometer Test

Abstract

The coefficient of lateral earth pressure at rest (K0) explains the connection between the effective vertical and lateral stresses. Geotechnical engineers have studied K0 for many years for its being a key element in the designs and analysis of various geotechnical problems such as slope stability, piles, and earth retaining structures. Moreover, K0 has played a critical phase in any numerical study of the soil-water combined geotechnical boundary value issues requiring parametric stress-strain time formulations During the previous few decades. A modified apparatus consisting of a standard Oedometer equipped with Force Sensitive Resistance (FSR) is used to investigate the value of lateral pressure () due to the vertical stress. The Oedometer test is carried out on three samples with different organic contents, with the K0 values obtained from each sample; empirical equations were also used to estimate K0 values for comparison purposes. From the analysis of the results, it can be stated that the K0 value is inversely proportional to the organic matter percent in the soil. It varies from 0.6125 in soil with 25.1% organic percent to 0.76 at a percent of 9.8%. The Force Sensitive Resistance (FSR) technique's performance is practical enough for estimating lateral earth pressure at rest (K0) of normally consolidated organic soil with many advantages; it is far less time-consuming and has a low operating cost than the traditional K0 estimate methods. Furthermore, K0 decreases with the increase of organic content.

Keywords

• force sensitive resistor (fsr)
• lateral earth pressure at rest (k0)
• modified oedometer
• organic soil