Introduction

In this project, the use of large-scale experimentation to support undergraduate engineering education has been implemented at three institutions and shows promise for integrating several more in the future. The developed educational module incorporates state-of-the-art experimental tools into the undergraduate education curriculum via web-based technologies that enable real-time video monitoring, tele-control, and shared execution of experiments. The project provides students at three different engineering universities with new educational tools for improving their understanding of various geotechnical engineering concepts. The main goals of this project are: to develop and pilot test educational models utilizing the centrifuge facility at one of these universities; to provide visual observation of the response of soil and soil-foundation systems; and to promote student-based use of instrumentation, interpretation of acquired data in order to analyze the measured response. Students were able to access, interpret, evaluate, and exchange relevant technical information via the Internet thereby bringing major experimentation into geotechnical engineering classes.
The virtual laboratory environment coupled with the geographically diverse student teams facilitates remote collaboration in an ever increasingly globalized world. The developed and tested education module has been verified by the student participants. It enhances the undergraduate classroom curriculum by tying in cutting-edge experimental tools and actively verifying core concepts that are typically presented in a passive manner. The students were able to participate in a dynamic design process, which necessitated a multi-faceted solution. The synergistic approach to design and testing resulted in a deeper understanding of the material, as stated by the students. Furthermore, the students were given access to analysis and visualization tools, which enhanced their ability to internalize the results. The pretesting by the undergraduate researchers at the host institution mitigated potential sources of error and misinterpretation.

Synopsis

Objective

As in many engineering fields, experimentation and computational analyses are currently the backbone of engineering education and research. Geotechnical engineering is a major component in many education and research applications within the broader discipline of civil engineering. In spite of the fact that geotechnical engineering systems are relatively complex in nature, undergraduate students tend to struggle to link experiments performed in the lab on small soil elements to the theoretical part of the course that focuses on the response of larger geotechnical systems. To overcome these shortcomings, physical modeling and testing has been recently incorporated in undergraduate geotechnical engineering.
In this project, the impact of introducing an Internet-based course module that utilizes major research instrumentation in the regular undergraduate curriculum in three different universities was examined. The experimental learning module is a collaborative effort among Southern Methodist University (SMU) of Dallas, TX, Rensselaer Polytechnic Institute (RPI) of Troy, NY, and the University of North Carolina at Charlotte (UNCC) of Charlotte, NC. The module allows for real-time video monitoring, tele-control, and execution of cutting-edge experiments utilizing RPI’s Geo-centrifuge facility. The goals of the project are to actively engage students in a stimulating and informative educational environment. We aim to provide students with broader insight into advanced research equipment and increase their motivation to learn about geotechnical systems by creating a learning environment that integrates physical modeling into undergraduate engineering education. The educational activities and experiment are intended to enhance students' ability to access, interpret, and evaluate relevant technical information in a timely and effective manner. The project formative assessment indicated that the new internet based course module led to student better understanding of the physical meaning of engineering principles and improve students' capability to design civil engineering systems and conduct advanced data analysis.

Approach

In geotechnical engineering, reduced scale physical models tested under 1-g environment suffer from the limitation that soil behavior is highly stress-dependent and small scale 1-g models fail to mimic actual field conditions. Geotechnical centrifuge modeling overcomes this shortcoming by subjecting a small scale model to a high gravitational field that produces stress levels in the small scale model similar to those in the prototype (similar to wind tunnels for studying cars aerodynamics).
The students’ activities within the developed module were centered around building a model of a shallow foundation on a sand deposit utilizing the RPI centrifuge. Specifically, a centrifuge experiment was introduced in geotechnical engineering courses to examine the performance of a shallow footing constructed on a deposit made of dry, uniform sand. The readily available tools at the RPI facility were used in this project. The following learning outcomes were set for the module. As a result of participating in the module/lab, students will be able to: (a) describe the actual stress distribution in the soil and the shape of the area loaded to failure; (b) design experiments using advanced procedures, instrumentation and applications; and (c) monitor, evaluate, analyze and design soil and soil-foundation systems using appropriate instrumentation, electronic data collection and state-of-the-art geotechnical engineering workplace applications and technologies.
The instructors at the three institutions collaborated in planning the learning activities for the project. The instructors faced a number of issues associated with synchronizing the project tasks at the three schools. A lecture covering centrifuge concepts and scaling laws along with examples of their implementations was presented by RPI instructor. The lecture was held live for RPI students and was streamed in real-time over the Internet to SMU and UNCC students. Using video-conferencing technology, remote students were able to engage in a question and answer session towards the end of the remote lecture and during the experiment.

Engagament

The module was a term project composed of two assignments. The first assignment contained the following pre-experiment activities: 1. Gather information about centrifuge technology and associated scaling laws relevant to the problem under consideration, 2. Design the model of the test (define dimensions and materials) and specify what needs to be measured as well as the type and proper locations of sensors for the application, and 3. Use available engineering theory to predict expected system performance under different loading scenarios planned for the test.
Following the completion of assignment 1, the students remotely observed loading the model shallow foundation in the centrifuge facility. WebEx and specialized telecommunication tools were used so that students at the remote sites could observe the live experiment from different camera angles. The recorded data was made available to all students and they were handed the second assignment. In this assignment, the students were asked to compute the theoretical stress distribution and compare it to the experimental data. They were also asked to predict the bearing capacity of the footing and compare it to the experimental results. In doing so, students must first convert all data to prototype units. Students were also asked to comment on the results and discuss the potential sources of differences, if any.

Impact

The overarching aim of this project was to create and test an online lab to support learning of a specific set of geotechnical engineering learning outcomes. The project team’s vision was that this lab would provide a much needed lab experience for students at schools that do not have physical laboratory equipment equal to that at RPI. By making this available online, instructors and students could collaborate on various experiences and thus broaden the learning opportunities for these students.
On the whole, the project accomplished its aims and added to the knowledge base about using online labs for teaching across multiple institutions.
Student responses to the surveys all indicated that no matter how the lab was implemented over the years, they felt they had engaged in a challenging learning experience. Grades for the students in the courses taught by the original team members indicated that student learning of the material was at a high level.
The implemented course module enhanced students’ understanding of geotechnical systems and the link between elementary soil testing and system design. Students acquired actual system test data that are similar to field data and compared it against the outcome of using theoretical analysis that is based on element testing. Such a comparison stimulates the thinking necessary to identify the approximations in the theory and/or the setting of the experiment that may lead to differences between computed values and measured data. The module introduced a unique physical modeling environment to the course and lab and the results suggest that remote facilities such as the centrifuge used in this study can be made conveniently accessible to students and faculty; thereby helping to save scarce institutional educational resources.

Next Steps

This project aimed to introduce a new learning experience for students into the geotechnical engineering curricula at three institutions that were geographically disperse. The project team devised and tested a remote lab experience that took advantage of equipment that is not widely available to most institutions. The first step in this type of project is making sure it works; technically, for it if this aspect of the project is not accomplished, no student (or faculty member) will benefit. The project team readily accomplished this step. It also accomplished the next steps: making sure that students interacted with the technology as planned and that they were engaged in the learning exercises. Their goal to integrate teamwork into the lab was the major challenge the project team faced. Virtual collaborative learning is the area where this project may have the most to say, at two levels: what it takes for faculty members to collaborate and teach virtually, and what it takes for students to work together in virtual teams. This project was one important part of learning about virtual collaboration and the research team has created a framework for future research in the area, should they decide to do so. Even if that is not the case, they have created a useful, workable, online lab for the learning of geotechnical engineering that previously had not existed, and they have integrated it into the curriculum of the three participating universities.

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