Visualization of Atterberg Limits Test through a Virtual Soil Laboratory

ABSTRACT

In this study, the Atterberg limits tests (ASTM D4318 Standard Test Methods for Liquid Limit, Plastic Limit, and Plasticity Index of Soils) are visualized by creating a game that presents a virtual soil lab environment via MATLAB App Designer. The environment consists of a graphical user interface (GUI), allowing students to gain hands-on experience on the test. In this environment, a specimen can be prepared by adding water to soils, then placed into a virtual Casagrande apparatus enhanced by animations and sound effects. After that, a groove tool is used, and the apparatus is operated as if it was used in reality. The number of drops is counted to obtain the liquid limit of the soil. While performing these procedures, the virtual laboratory automatically generates some soil properties with randomized features, focusing solely on the processes rather than the measurements and calculations. Moreover, continuous feedback is provided, such as the rotation speed or the suitability of the different specimens with distinct water contents. In determining the plastic limit, kneading and rolling actions are driven by mouse clicks. The plastic limit is obtained after the roll is crumbled. The soil is then classified according to the Unified Soil Classification System (USCS) plasticity chart. With its randomized nature, the game aims to create a realistic laboratory experience. The game is inspired by the COVID-19 pandemic, which prevents most students from joining laboratory sessions essential for understanding experimental soil mechanics. The authors believe that this game will allow students to perform each step of an experiment, which sometimes cannot be achieved in laboratories due to time constraints. In addition, the game will likely engage students to a commonly performed soil mechanics test by pre-test quizzes, feedback, and visualizing features. With the advances in computer technology, this game offers a strengthened learning experience interactively.