Date of Award
Master of Science
Civil, Construction, and Environmental Engineering
Civil Engineering (Geotechnical Engineering)
Problem Statement: In 1998 Iowa State faculty, Dr. Kenneth Bergeson and Dr. David White conducted a study to evaluate the quality of Iowa's highway embankments. They concluded that the construction practices and embankment quality control were insufficient resulting in slope instability and uneven pavement surfaces. They later determined that existing tools and methods for construction quality control (specifically, the Dynamic Cone Penetrometer-DCP) needed to be adapted to more precisely and more efficiently evaluate engineering parameters of compacted embankment fills. DCP had not widely been used as a quality control tool in fine-grain soils that characterize most of Iowa's highways. They proposed two solutions: 1) adopting DCP to fine-grain materials in embankments; and 2) using Iowa State University (ISU)-developed Geotechnical Remote Acquisition of Data System (G-RAD) to collect and analyze data from the DCP. Goal of the thesis project: Given the opportunity to improve embankment construction, it is important to test and document uses of new and existing tools and technologies. The goals of this thesis project are: 1) To demonstrate and document how DCP is used as a quality control tool in testing strength and uniformity of cohesive soils. 2) To demonstrate and document how G-RAD can be used to make DCP data collection and processing more effective. This thesis clearly reviews the demonstration activities, presents the results of those activities, and documents a methodology for utilizing DCP in conjunction with G-RAD to measure and collect data to improve embankment construction. Conclusions: Based on the data gathered, it has been established that the use of DCP in Iowa's cohesive soil embankments improves construction methods by providing data that ensures adequate soil strength is achieved during construction. Traditionally, in-situ measurement of soil strength has been time consuming and impractical. This project demonstrates that G-RAD in conjunction with DCP improves not only the quality of construction but the accuracy and efficiency of the quality control processes. Future use of the DCP and G-RAD system are recommended as a quality control tool for construction of cohesive soil embankments of Iowa.
Joels Chishala Malama
Malama, Joels Chishala, "Evaluation of the Dynamic Cone Penetrometer (DCP) and Geo-technical Remote Acquisition of Data System (G-RAD) for earthwork quality control testing for cohesive soils" (2005). Retrospective Theses and Dissertations. 19174.