?url_ver=Z39.88-2004&rft_val_fmt=info%3Aofi%2Ffmt%3Akev%3Amtx%3Adc&rft.relation=http%3A%2F%2Fmiis.maths.ox.ac.uk%2Fmiis%2F466%2F&rft.title=Diamond+drilling+for+core+sampling&rft.creator=Benjamin%2C+B.&rft.creator=Whiten%2C+B.&rft.subject=None%2FOther&rft.description=The+drilling+for%2C+and+recovery+of+core+samples+from+the+earth's+crust%2C+sometimes+at+distances+of+up+to+3+km+from+the+surface%2C+is+subject+to+many+practical+problems.+One+of+these+problems+involves+the+jamming+of+core+samples+inside+the+recovery+cylinder+during+drilling.+There+is+a+need+to+analyse+the+forces+involved+when+the+recovery+cylinder+is+sliding+over+the+core.+Several+simple+mechanisms+associated+with+naturally+occurring+variations+in+rock+and+soil+structure+were+suggested+as+possible+causes+of+jamming.+The+results+suggest+that+the+simplest+mechanisms+are+not+the+cause+of+the+problem%2C+but+combinations+of+these+simple+mechanisms+might+well+be+the+cause.+The+results+and+discussion+indicate+some+experiments+that+would+be+useful+in+a+further+study+of+the+problem%2C+and+data+from+the+drilling+operations+that+should+be+kept+for+further+analysis.&rft.date=1994&rft.type=Study+Group+Report&rft.type=NonPeerReviewed&rft.format=application%2Fpdf&rft.language=en&rft.identifier=http%3A%2F%2Fmiis.maths.ox.ac.uk%2Fmiis%2F466%2F1%2FDiamond-drilling-for-core-sampling.pdf&rft.identifier=++Benjamin%2C+B.+and+Whiten%2C+B.++(1994)+Diamond+drilling+for+core+sampling.++%5BStudy+Group+Report%5D+++++