Use of soil behavior demonstrations to increase student engagement in elementary soil mechanics

Abstract

An important aspect of the geotechnical engineering discipline in civil engineering is the understanding of the physical behaviors of different soil types. This understanding underlies and supports the engineer's intuition and insights on how a particular soil may impact the design and construction of a project. The first exposure of undergraduate civil engineering students to soil behavior typically occurs in an introductory soil mechanics course. In this class, it is common for students to be taught about key soil behaviors using verbal explanations in lecture and written explanations provided in textbooks, perhaps supplemented with diagrams or video. However, these approaches often do not provide students with a good "physical feel" for the behaviors and hence may not promote a deep appreciation and understanding of the topic. Even if there is a laboratory component of the course, the laboratory exercises often focus on testing procedures for measuring soil properties rather than a thorough exploration of soil behaviors and their causes. The purpose of the study presented here is to investigate the effectiveness of using physical demonstrations of key soil behaviors in soil mechanics lectures, along with follow-up discussions, to improve undergraduate student engagement and understanding of these behaviors. Some prior investigators have reported success in using physical demonstrations to improve student learning experiences in some undergraduate engineering courses. Others reported similar successes in engineering exploration programs for K-12 students, some of which included soil behavior experiments. However, none of these prior studies focus specifically on using soil behavior demonstrations in undergraduate soil mechanics lectures to increase student engagement and learning. In the current study, five different soil behavior demonstrations from the book Soils Magic by Elton1 were integrated into the lectures of an undergraduate soil mechanics course. For each demonstration, students were first asked to predict what would happen before seeing the experiment. They then observed the demonstration being performed and, lastly, were asked to explain the reasons for the behavior observed. Student responses to survey statements about the soil behavior demonstrations clearly indicate that an overwhelming majority of them felt the experiments were interesting and effective, made them think more about the soil behaviors investigated, and helped them to better understand the behaviors. The performance of students on two examinations given during the term was generally better in the course section that used the demonstrations, as opposed to prior sections that did not, which suggests some improvement in learning. Student ratings of the course and instructor at the end of the term were higher for the class section where the experiments were used indicating improved student perceptions of the course and, perhaps, increased student interest in the material. This encouraging study data, along with the fact that nearly all of the students taught with the soil behavior demonstrations agreed that they should be used in future offerings of the course, confirm the effectiveness of this approach for increasing student engagement and learning of this topic. © 2011 American Society for Engineering Education.