Many previous studies have been focused on the behaviour homogeneous granular soils under the quasi-static loading, however, various soil types exist in the field. Therefore, based on the evaluation of these previous studies, an extensive study has been addressed to expose the dynamic behaviour of cohesive-frictional soils associated with the effects of fines content, the effect of moisture content and the type of impact regime. The proposed study mainly investigates the behaviour of sand – clay mixtures to impact loading, both from a loaded plate dropped from different heights and one dropped repeatedly from a fixed height. The Aberdeen beach sand and the Teuchan clay were used for the study and mixed in different proportions to create soils of varying proportions. The six soil samples used have known volumetric proportions of sand : clay and the tests were carried out under the dry condition and two other moisture contents. The results determine the optimal percentage of fines content and its related moisture condition to obtain more stable performance of the granular soils under dynamic compaction. It can be implemented to enhance the quality of ground improvement techniques for the construction. A Soil Model Tester for 2-Dimension program (SM2D) [Chan (1988)] was used to modify the existing material model before being used for Finite Element simulation. The impact test results were used to verify the numerical model developed using an explicit u-w schemebased finite element program, GLADYS2E [Chan et al. (1992, 1994)]. Such use of explicit schemes requires the use of time step lengths which are smaller than a critical value, in order that stability and accuracy of solution are ensured. A semi-empirical formula has been developed for the critical time step determination using MATLAB.
| Identifer | oai:union.ndltd.org:bl.uk/oai:ethos.bl.uk:582709 |
| Date | January 2013 |
| Creators | Kwok Leung, Cheung |
| Publisher | University of Aberdeen |
| Source Sets | Ethos UK |
| Detected Language | English |
| Type | Electronic Thesis or Dissertation |
| Source | http://digitool.abdn.ac.uk:80/webclient/DeliveryManager?pid=201916 |
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