THE POTENTIAL USE OF FRUIT SCLEROMETER TO DETERMINE THE UNDRAINED SHEAR STRENGTH OF BANGKOK CLAY

Abstract

A fruit sclerometer is used to test the hardness of a fruit to evaluate its maturity by applying a pressure head press to fruits gradually and vertically, and it has a working principle similar to that of the pocket penetrometer used to estimate the undrained shear strength of cohesive soil. This study investigated the potential use of a fruit sclerometer to determine the undrained shear strength of fine-grained soils, especially Bangkok clay. A fruit sclerometer and an unconfined compression test were conducted in 82 undisturbed soil samples to measure the undrained shear strength, and the correlations of the undrained shear strength obtained from both methods were constructed to verify the potential use of fruit sclerometer in the determination of undrained shear strength for Bangkok clay. The results revealed that the undrained shear strength obtained from the fruit sclerometer was about two times greater than that obtained from the unconfined compression test. A reduction parameter was recommended for converting undrained shear strength from the fruit sclerometer test to the unconfined compression test. Nevertheless, further study is required to confirm this relationship for the other locations and the number of samples. It is essential to note that a fruit sclerometer is a primitive instrument subject to many errors. It should not replace laboratory testing and field analysis or be used to produce foundation design data.