University of Twente Student Theses
Comparison of two linear excess stress modelling methods of soil erodibility for JET and "Mini" JET devices
Pacudan, L.K.B. (2024) Comparison of two linear excess stress modelling methods of soil erodibility for JET and "Mini" JET devices.
|
PDF
993kB |
| Abstract: | With increasing sea levels and climate change, soil erosion is becoming of greater concern in the Netherlands. With historical need and reliance on earthen structures such as dikes are becoming an emphasis with the changing climate. Securing these structures require adequate and reliable methods to pursue. One way of ensuring a reliable soil structure (such as clay coverage on dikes) can be done through erosion testing. However, the established method in the Netherlands is quickly becoming outdated. Newer methods of assessing cohesive soils to assess clays on dike structures are being asked of within the Netherlands. Jet erodibility testing (JET) is a newer form of soil erosion testing that can directly procure an erosion coefficient (kd) and critical shear stresses (τc) of soils. The Blaisdell method has been developed in methodology and written in literature as an established method to procure these parameters. Multiple newer methods have been developed to better derive these parameters and model erosion rates. A newer method, which will be referred to as the Linear regression method, has been developed with the objective to attempt the same derivations. It is necessary to assess the significance of the different methods to come to conclusions on what is appropriate for development. The comparison between the linear regression method and Blaisdell is conducted with results of three different types of clays and their erosion results from a JET device. The erosion data was processed through both methods to have a direct comparison. By developing a spreadsheet to calculate both methods and deriving the parameters, other results were procured to develop an assessment of both methods. Erosion category plots and Bland-Altman plots were developed to assess their similarity. A scour-depth-time plot was derived, and an NOF analysis was conducted to assess the accuracy of the modelling method in comparison to the original data. Both methods produced consistent results for the scour-depth-time plots which is in line with previously observed field research. However, the Linear regression method had produced significantly larger over-estimations. Despite both methods being statistically similar for parameter results, the Blaisdell method produced results closer to the original scour depth time data than with the linear regression method. |
| Item Type: | Essay (Bachelor) |
| Faculty: | ET: Engineering Technology |
| Programme: | Civil Engineering BSc (56952) |
| Link to this item: | https://purl.utwente.nl/essays/104470 |
| Export this item as: | BibTeX EndNote HTML Citation Reference Manager |
Show download statistics for this publication
Show download statistics for this publicationRepository Staff Only: item control page