Borehole GPR investigations from underground for mapping the extension of old working at a Pb-Zn Mine in Rajasthan, India
S. Nelliat, Babu B Butchi, P.C. Jha, Y.V. Sivaram, Verma SN, Dutta S, Jha A
Available Online November 2016.
- https://doi.org/10.2991/rare-16.2016.82How to use a DOI?
- crosshole GPR; borehole GPR profiling; water-logged working; radar wave attenuation; radargram; conductive fluid; seepage; Pb-Zn mines
- Conventional GPR reflection surveys in base metal sulphide mines are sometimes marred by scattering due to heterogeneity or presence of disseminated sulphide minerals. Surface scanning in such areas have its own limitations as the depth of investigation is adversely influenced by the highly lossy medium. Alternatively, borehole GPR investigation from underground can be an efficient tool for sensing the proximity of old workings including cavities left over by past ore extraction. In the present study two borehole GPR techniques were used from underground to establish the boundary of old workings in a Pb-Zn mine. Crosshole transmission mode data from a stepped-frequency GPR was analysed to delineating the zone of influence created by ancient mining activity. Two parameters namely velocity and attenuation of radar waves were used to examine the intervening geological medium. Single-hole reflection survey was also carried out to scan the medium around the borehole. The result of crosshole GPR survey is a plot of radar wave attenuation along the horizontal plane of survey. The attenuation plot clearly delineated the zone affected by past mining activity; however cavity type features were not mapped. Even though exploratory drill holes showedevidences of old workings up to 250-260 m depthfrom the ground surface, the present borehole GPR investigation from an underground gallery at 298 m depth confirmed that old workings did not cross the horizontal plane of investigation
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Cite this article
TY - CONF AU - S. Nelliat AU - Babu B Butchi AU - P.C. Jha AU - Y.V. Sivaram AU - Verma SN AU - Dutta S AU - Jha A PY - 2016/11 DA - 2016/11 TI - Borehole GPR investigations from underground for mapping the extension of old working at a Pb-Zn Mine in Rajasthan, India BT - Recent Advances in Rock Engineering (RARE 2016) PB - Atlantis Press SN - 2352-5401 UR - https://doi.org/10.2991/rare-16.2016.82 DO - https://doi.org/10.2991/rare-16.2016.82 ID - Nelliat2016/11 ER -