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- 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
Various reports produced by the National Research Council suggest that K-12 curricula expand Science, Technology, Engineering, and Mathematics to better help students develop their ability to reason and employ scientific habits rather than simply building scientific knowledge. Every spring, the Arizona Department of Education (ADE) in conjunction with Arizona State University holds a professional development workshop titled "Engineering Practices in the Secondary Science Classroom: Engineering Training for Grade 6-12 Math and Science School Teams". This workshop provides math and science teachers with the opportunity to either sustain existing engineering proficiency or be exposed to engineering design practices for the first time. To build teachers' proficiency with employing engineering design practices, they follow a two-day curriculum designed for application in both science and math classrooms as a conjoined effort. As of spring 2015, very little feedback has been received concerning the effectiveness of the ASU-ADE workshops. New feedback methods have been developed for future deployment as past and more informal immediate feedback from teachers and students was used to create preliminary changes in the workshop curriculum. In addition, basic laboratory testing has been performed to further link together engineering problem solving with experiments and computer modelling. In improving feedback and expanding available material, the curriculum was analyzed and improved to more effectively train teachers in engineering practices and implement these practices in their classrooms.
ContributorsSchmidt, Nathan William (Author) / Rajan, Subramaniam (Thesis director) / Neithalath, Narayanan (Committee member) / Civil, Environmental and Sustainable Engineering Programs (Contributor) / Barrett, The Honors College (Contributor)
Created2015-05
Description
Clean and accessible drinking water is a crucial and limited resource. As the world's population grows and demand increases, water resources will become more limited. This project aims to educate students on water resources, drinking water, and how biomimicry can allow society to improve its water usage. The project consists of a ten day unit plan which addresses several water topics such as: the various uses of water, water distribution, where drinking water comes from, the water treatment process, and more. After establishing background knowledge on water and surrounding issues, the students will be challenged to design a water bottle using biomimicry. Biomimicry is looking at nature to draw and inspire solutions to human problems. This unit has been optimized for use by elementary teachers. The ten day unit consists of a lesson summary, objectives, standards, and recommended activities for each day. Of the ten days, three lesson plans were fully developed using the 5E format. The research supporting this project is compiled in the following report.
ContributorsSalik, Rachael (Co-author) / Burke, Aurora (Co-author) / Walters, Molina (Thesis director) / Larson, Kelli L. (Committee member) / Civil, Environmental and Sustainable Engineering Programs (Contributor) / Division of Teacher Preparation (Contributor) / Barrett, The Honors College (Contributor)
Created2016-12