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In-situ subsurface density estimations using a seismic technique
Thesis (PhD)--University of Pretoria, 2007.
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| Format: | Thesis |
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University of Pretoria
2013
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| _version_ | 1867613538185379840 |
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| access_status_str | Open Access |
| author2 | Van Rooy, J.L. (Jan Louis) |
| author_browse | Van Rooy, J.L. (Jan Louis) |
| author_facet | Van Rooy, J.L. (Jan Louis) |
| collection | Thesis |
| dc_rights_str_mv | ©University of Pretoria 2007 D544/ |
| description | Thesis (PhD)--University of Pretoria, 2007. |
| format | Thesis |
| id | oai:repository.up.ac.za:2263/23395 |
| institution | University of Pretoria (South Africa) |
| last_indexed | 2026-06-10T12:37:44.183Z |
| license_str | Other — see source repository |
| provenance_str_mv | Harvested via OAI-PMH from UPSpace — University of Pretoria Institutional Repository |
| publishDate | 2013 |
| publishDateRange | 2013 |
| publishDateSort | 2013 |
| publisher | University of Pretoria |
| publisherStr | University of Pretoria |
| record_format | dspace |
| source_str | UPSpace — University of Pretoria Institutional Repository |
| spelling | oai:repository.up.ac.za:2263/23395 In-situ subsurface density estimations using a seismic technique Van Rooy, J.L. (Jan Louis) sfourie@csir.co.za Fourie, Christoffel Johannes Stephanus In-situ Density measurements Density estimations UCTD Thesis (PhD)--University of Pretoria, 2007. A new geophysical method was developed to satisfy a need for in-situ density measurements. Various situations, such as a gravity dam wall requires that density measurements should be done without damage to the structure. The sample volume should also not be that large in order to be sensitive enough for variations. This method measures the in-situ density of the weathered layer and other man made structures, using seismic waves in three directions. The seismic waves utilized are P-waves and S-waves. It is however surface waves that are treated like body waves because they do not separate at this shallow depth. These waves are very sensitive to the attenuation factor, which is in turn sensitive to certain physical properties of the propagation medium. This factor is utilsed when the multi layer problem is encountered. The maximum depth of exploration is 2-5m and depends solely on the seismic skin depth. This method utilises a large base plate. The source is a large sledge hammer and shots are done at each side of the base plate. Different dominant frequencies are identified and used to calculate the densities of the layers associated with that specific frequency. The velocities of the subsurface are determined by small seismic refraction surveys. The method will find application mainly in the civil and engineering geology fields. The main application will be to determine subsurface densities and small movement elasticity modulli for engineers to aid in obtaining adequate design parameters. Case studies on three different geologic environments are presented. The results indicate that this method will be useful, although certain modifications are recommended to make this method even faster and more user friendly. Geology unrestricted 2013-09-06T15:16:53Z 2009-04-07 2013-09-06T15:16:53Z 2008-09-03 2007 2009-01-16 Thesis 2007 D544/gm http://hdl.handle.net/2263/23395 http://upetd.up.ac.za/thesis/available/etd-01162009-110629/ ©University of Pretoria 2007 D544/ application/pdf application/pdf application/pdf application/pdf application/pdf application/pdf application/pdf application/pdf application/pdf University of Pretoria |
| spellingShingle | In-situ Density measurements Density estimations UCTD In-situ subsurface density estimations using a seismic technique |
| title | In-situ subsurface density estimations using a seismic technique |
| title_full | In-situ subsurface density estimations using a seismic technique |
| title_fullStr | In-situ subsurface density estimations using a seismic technique |
| title_full_unstemmed | In-situ subsurface density estimations using a seismic technique |
| title_short | In-situ subsurface density estimations using a seismic technique |
| title_sort | in situ subsurface density estimations using a seismic technique |
| topic | In-situ Density measurements Density estimations UCTD |
| url | http://hdl.handle.net/2263/23395 http://upetd.up.ac.za/thesis/available/etd-01162009-110629/ |