This complete evidence-based practice paper discusses the strategies and results of an introduction to mechanics course, designed to prepare students for introductory-level physics and other fundamental courses in engineering, such as statics, strength of materials, and dynamics. The course was developed to address historically high failure (DFW) rates in the physics courses and is part of a set of interventions implemented to support student success in a college of engineering and computer science. The course focuses on providing in-depth understanding of Newton’s Laws of motion, free-body diagrams, and linear and projectile motion. Because it focuses on a limited number of competencies, it is possible to spend more time on inquiry-based activities and in-class discussions. The course framework was designed considering the Ebbinghaus’ Forgetting Curve, to provide students with learning opportunities in 6-day cycles: (i) day 1: a pre-class learning activity (reading or video) and a quiz; (ii) day 2: in-class Kahoot low-stakes quiz with discussion, a short lecture with embedded time for problem-solving and discussion, and in-class activities (labs, group projects); (iii) day 4: homework due two days after the class; (iv) day 6: homework self-reflection (autopsy based on provided solutions) two days after homework is due. The assessment of course performance is based on the well-characterized force concept inventory (FCI) exam that is administered before the intro to mechanics course and both before and after the Physics I course; and on student performance (grades) in Physics and Statics courses. Results from the FCI pre-test show that students who took the introduction to mechanics course (treatment group) started the physics course with a much better understanding of force concepts than other students in the course. The FCI post-test shows better normalized gain for the treatment group, compared to other students, which is also aligned with student performance in the course. Additionally, student performance is significantly better in statics, with 25% DWF rate compared to 50% for the other students. In summary, the framework of the course, which focuses on providing students with in-depth understanding of force concepts, has led to better learning and performance in Physics I, but importantly it has also helped students achieve better performance in the Statics course, the first fundamental course in civil and mechanical engineering programs.
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Biocementation for All, Anywhere: A New Experiment for Introductory Soil Mechanics Courses
This paper presents a novel laboratory experiment that can be incorporated into introductory soil mechanics courses to introduce students to the field of biogeotechnical engineering and the use of biostimulated microbially induced calcite precipitation (MICP). Applying MICP to granular soils results in an increase in peak strength and shear stiffness of the soil as a result of the precipitation of calcium carbonate on soil particle surfaces and at soil particle contacts. The authors developed protocols to treat small volumes of soil and to test the effectiveness of the treatment using a simple strength test based on ASTM D3967-16. In fall 2020, the experiment was piloted as a four-week, course-based research experience that can be conducted by students remotely or in a traditional laboratory environment. This paper provides an introduction to MICP and describes the protocols for conducting the experiment. The paper also suggests approaches for how the experiment can be incorporated into a traditional introductory soil mechanics course.
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- Award ID(s):
- 1632963
- NSF-PAR ID:
- 10335451
- Date Published:
- Journal Name:
- Geo-Congress 2022: Advances in Monitoring and Sensing; Embankments, Slopes, and Dams; Pavements; and Geo-Education
- Page Range / eLocation ID:
- 472 to 484
- Format(s):
- Medium: X
- Sponsoring Org:
- National Science Foundation
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null (Ed.)Geotechnical engineering undergraduate curriculum typically consist of courses in soil mechanics and foundation design that include a variety of topics that are difficult for students to understand and master. Behavior of the below grade natural and built geomaterials discussed in these courses can be difficult for students to visualize. Typically, the mechanisms of behavior are demonstrated using small-scale laboratory tests, two-dimensional sketches, simple table-top models, or video simulations in the classroom. Students rarely have the opportunity to observe large-scale behavior of foundations in the field or laboratory. The authors from Rose-Hulman Institute of Technology and Saint Louis University designed and implemented a large-scale foundation testing system to address several topics that students tend to struggle with the most, including 1) the difference in strength and service limit states in shallow foundation design, 2) soil-structure interaction associated with lateral behavior of deep foundations, and 3) the influence of near-surface soil on lateral behavior of deep foundations. This paper provides a detailed overview of the design, fabrication, and implementation of two large-scale experiential learning modules for undergraduate courses in soil mechanics and foundation engineering. The first module utilizes shallow foundations in varying configurations to demonstrate the differences in strength and service limit state behavior of shallow foundations. The second module utilizes a relatively flexible pile foundation embedded in sand to demonstrate the lateral behavior of deep foundations. The first module was used in the soil mechanics courses at Rose-Hulman Institute of Technology and Saint Louis University to compare theoretical and observed behavior of shallow foundations. The second module was used in the foundation engineering course at Rose-Hulman Institute of Technology to illustrate the concepts of soil-structure interaction and the influence of near-surface soil on lateral behavior of deep foundations.more » « less
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Rahman, M. ; Jaksa, M. (Ed.)The field of biogeotechnics has emerged from the realization that processes intrinsic to natural systems can provide new approaches and inspiration through which the efficiency, sustainability, and functionality of geotechnical systems can be improved. Of these processes, microbially induced calcite precipitation (MICP) has advanced the most rapidly with the use of ureolytic microbial activity providing an opportunity to control the precipitation of calcium carbonate minerals throughout a soil matrix, thereby significantly improving soil engineering behaviors. The process affords increases in soil stiffness, strength, and dilatancy, with utility across a breadth of geotechnical and geoenvironmental applications, including mitigation of earthquake- induced soil liquefaction. This state of the art paper first covers: (1) enabling scientific processes, (2) treatment methods, and (3) monitoring techniques, which are broadly useful for different engineering applications. The second part focuses on how MICP can: (1) improve engineering behaviors at the element scale, (2) be modeled at the particle- and continuum-scales, (3) be applied at the field-scale, and (4) improve the resistance to liquefaction triggering and reduce the consequences when it does occur.more » « less
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Viana da Fonseca, António ; Ferreira, Cristiana (Ed.)Microbially induced carbonate precipitation (MICP) is a bio-mediated ground improvement technique that can increase soil stiffness and produce cohesion within granular material. Most experimental investigations on MICP-treated soils are performed on idealized granular materials. Evaluating a narrow range of particle sizes dismisses the potential influence of soil fabric on MICP treatment efficiency. Therefore, little is known regarding the influence of soil fabric on the level of improvement achievable post-MICP treatment. We investigate the influence of the coefficient of uniformity (Cu) on the level of improvement that can be obtained from MICP treatment. This study couples unconfined compression testing with microscale observations obtained from x-ray computed tomography (CT) of two sand mixtures with different Cu values. A soil column and CT specimen of each sand mixture were prepared and received the same number of MICP- injections. The shear wave velocity (Vs) of the soil columns was monitored to evaluate the increase in soil stiffness over time. After MICP treatment, the bio-cemented columns were subjected to unconfined compressive strength testing. Results indicate that for a similar mass of carbonate, the soil with a larger Cu experienced a greater increase in Vs but a lower maximum unconfined compressive strength. Through CT imaging, the soil with a smaller Cu was observed to have a more uniform distribution of carbonate within the sand matrix whereas the soil with a larger Cu has more sporadic MICP trends. This study elucidates the influence of soil fabric on the level of improvement that can be achieved through MICP treatment and assesses the reliability of x-ray CT scanning of MICP-treated sands with moderate carbonate content.more » « less
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- Free Publicly Accessible Full Text
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Accepted Manuscript1.0
- Conference Paper:
- https://doi.org/10.1061/9780784484067.047
