Matching Items (3)
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- All Subjects: Flipped classrooms
- Creators: Civil, Environmental and Sustainable Engineering Programs
Description
This dissertation details an attempt to experimentally evaluate the Giroud et al. (1995) concentration factors for geomembranes loaded in tension perpendicular to a seam by laboratory measurement. Field observations of the performance of geomembrane liner systems indicates that tears occur at average strains well below the yield criteria. These observations have been attributed, in part, to localized strain concentrations in the geomembrane loaded in tension in a direction perpendicular to the seam. Giroud et al. (1995) has presented theoretical strain concentration factors for geomembrane seams loaded in tension when the seam is perpendicular to the applied tensile strain. However, these factors have never been verified. This dissertation was prepared in fulfillment of the requirements for graduation from Barrett, the Honors College at Arizona State University. The work described herein was sponsored by the National Science Foundation as a part of a larger research project entitled "NEESR: Performance Based Design of Geomembrane Liner Systems Subject to Extreme Loading." The work is motivated by geomembrane tears observed at the Chiquita Canyon landfill following the 1994 Northridge earthquake. Numerical analysis of the strains in the Chiquita Canyon landfill liner induced by the earthquake indicated that the tensile strains, were well below the yield strain of the geomembrane material. In order to explain why the membrane did fail, strain concentration factors due to bending at seams perpendicular to the load in the model proposed by Giroud et al. (1995) had to be applied to the geomembrane (Arab, 2011). Due to the localized nature of seam strain concentrations, digital image correlation (DIC) was used. The high resolution attained with DIC had a sufficient resolution to capture the localized strain concentrations. High density polyethylene (HDPE) geomembrane samples prepared by a leading geomembrane manufacturer were used in the testing described herein. The samples included both extrusion fillet and dual hot wedge fusion seams. The samples were loaded in tension in a standard triaxial test apparatus. to the seams in the samples including both extrusion fillet and dual hot wedge seams. DIC was used to capture the deformation field and strain fields were subsequently created by computer analysis.
ContributorsAndresen, Jake Austin (Author) / Kavazanjian, Edward (Thesis director) / Gutierrez, Angel (Committee member) / Civil, Environmental and Sustainable Engineering Programs (Contributor) / Barrett, The Honors College (Contributor)
Created2016-05
Description
In the Spring 2013 and Fall 2013 semesters, a survey was taken of students enrolled in the principal undergraduate civil engineering structures course, CEE 321: Structural Analysis and Design, to assess both the prevalence of technology in the lives of the students and the potential ways this information could be use to improve the educational experience. The results of this survey indicated that there was a considerable demand for additional online resources outside of the formal classroom. The students of CEE 321 requested online lecture videos in particular, and so a project was launched at the start of the Spring 2014 semester to deliver a large body of academic instructional videos. In total, a collection of 30 instructional videos which covered all key topics covered over a semester of CEE 321 was published. The driving interest behind this creative project is to increase the level of understanding, comfort, and performance in students enrolled in the class. Although the quantity of initial student feedback is relatively small, the reactions are distinctly positive and reflect an improvement in understanding amongst the responding students. Over the course of upcoming semesters, qualitative and quantitative assessments of the impact of the videos are expected to provide a better indication of their quality and effectiveness in supporting student comprehension and performance in CEE 321. Above all, the success of these videos is directly tied to their ability to function as living, adaptable resources which are continuously molded and improved by student feedback.
ContributorsReasor, Drew Donn (Author) / Rajan, Subramaniam (Thesis director) / Hjelmstad, Keith (Committee member) / Civil, Environmental and Sustainable Engineering Programs (Contributor) / Barrett, The Honors College (Contributor)
Created2014-05
Description
Teaching methods in the present day are beginning to transition from the traditional lecture style to the flipped learning style. The flipped classroom, also known as an engaged learning classroom, follows the model where students are presented with lecture material prior to attending class. Instead of being lectured in class, they work on applications of the material with the help of their peers and the instructional staff. One component that many engaged learning environments have in common is lecture videos for the students to view prior to attending class. An undergraduate civil engineering course at Arizona State University is modeled using an engaged learning environment; however, it does not provide lecture videos for the students. Many students in this course are seeing an engaged learning environment for the first time and need guidance on how to prepare for the course, how to approach course material, and how to interpret feedback, in addition to getting help in the technical concepts. This project aims to create supplemental lecture videos based on the concepts that students in the class identified as needing more information, as well as topics that will help students make this transition to an engaged learning environment. A series of sixteen videos were created and posted for the students to view prior to attending recitation periods. The feedback from the students regarding the videos was studied and implementation techniques for future semesters were tested.
ContributorsFlys, Victoria Pilar (Author) / Hjelmstad, Keith (Thesis director) / Baisley, Amie (Committee member) / Civil, Environmental and Sustainable Engineering Programs (Contributor) / Barrett, The Honors College (Contributor)
Created2015-12