821:
definitions. The most widely used definition was developed in 1964 by D. U. Deere. It is the borehole core recovery percentage incorporating only pieces of solid core that are longer than 100 mm in length measured along the centerline of the core. In this respect pieces of core that are not hard and sound should not be counted though they are 100 mm in length. RQD was originally introduced for use with core diameters of 54.7 mm (NX-size core). RQD has considerable value in estimating support of rock tunnels. RQD forms a basic element in some of the most used rock mass classification systems:
820:
Rock-quality designation (RQD) is a rough measure of the degree of jointing or fracture in a rock mass, measured as a percentage of the drill core in lengths of 10 cm or more. High-quality rock has an RQD of more than 75%, low quality of less than 50%. Rock quality designation (RQD) has several
588:
1033:
179:
330:
745:
1160:
838:
246:
1224:
809:
310:
44:
1292:
Hack, H.R.G.K. (25–28 November 2002). "An evaluation of slope stability classification. Keynote
Lecture.". In Dinis da Gama, C.; Ribeira e Sousa, L. (eds.).
583:{\displaystyle SCR=\left({\frac {l_{\mathrm {total~length~of~core~in~pieces~with~full~core~diameter} }}{l_{\mathrm {tot~core~run} }}}\right)\times 100}
595:
1365:
1040:
1244:
826:
1028:{\displaystyle RQD=\left({\frac {l_{\mathrm {sum~of~length~of~core~pieces~>100mm} }}{l_{\mathrm {tot~core~run} }}}\right)\times 100}
1384:
1305:
1353:
1277:
Deere, D U, Hendron, A J, Patton, F D & Cording, E J (1967). "Design of surface and near surface constructions in rock",
1389:
186:
1167:
752:
253:
1236:
321:
Solid core recovery (SCR) is the borehole core recovery percentage of solid, cylindrical, pieces of rock core.
174:{\displaystyle TCR=\left({\frac {l_{\mathrm {sum~of~pieces} }}{l_{\mathrm {tot~core~run} }}}\right)\times 100}
822:
1324:
1315:
Pantelidis, L. (2009). "Rock slope stability assessment through rock mass classification systems".
1300:. Funchal, Madeira, Portugal: Sociedade Portuguesa de Geotecnia, Lisboa, Portugal. pp. 3–32.
1357:
1361:
1301:
1345:
1332:
1240:
1162:= Sum of length of core pieces that are > 100 mm (4 inches) measured along the centerline
1328:
1378:
1346:
1272:
Proc. Symp. Rock Class. Engineering
Purposes, ASTM Special Technical Publications 984
1336:
32:
740:{\displaystyle l_{\mathrm {sum~of~solid~core~pieces~with~full~diameter} }}
20:
1263:
Deere, D U (1989). "Rock quality designation (RQD) after twenty years",
1155:{\displaystyle l_{\mathrm {sum~of~length~of~core~pieces~>10cm} }}
1270:
Deere, D U & Deere, D W (1988), "The RQD index in practice",
1239:
systems use core recovery parameters as input parameter, such as
1295:
1317:
International
Journal of Rock Mechanics and Mining Sciences
1256:
Deere, D U (1964). "Technical description of rock cores",
31:
Total core recovery (TCR) is the borehole core recovery
1170:
1043:
841:
755:
598:
333:
256:
189:
47:
1265:
U.S. Army Corps of
Engineers Contract Report GL-89-1
1267:, Waterways Experiment Station, Vicksburg, MS (67).
1218:
1154:
1027:
803:
747:= Sum of length of solid, cylindrical, core pieces
739:
582:
304:
240:
173:
1281:, ed. Fairhurst, publ. AIME, New York, (237-302).
19:describe the quality of core recovered from a
8:
1348:Engineering Geology: Principles and Practice
1344:Price, D.G. (2009). De Freitas, M.H. (ed.).
241:{\displaystyle l_{\mathrm {sum~of~pieces} }}
1219:{\displaystyle l_{\mathrm {tot~core~run} }}
804:{\displaystyle l_{\mathrm {tot~core~run} }}
305:{\displaystyle l_{\mathrm {tot~core~run} }}
1176:
1175:
1169:
1049:
1048:
1042:
973:
972:
865:
864:
858:
840:
761:
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754:
604:
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597:
528:
527:
357:
356:
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332:
262:
261:
255:
195:
194:
188:
119:
118:
71:
70:
64:
46:
7:
1279:Proc. 8th U.S. Symp. Rock Mechanics
1258:Rock Mechanics Engineering Geology
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1207:
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1189:
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1128:
1125:
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1119:
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1107:
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1101:
1095:
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1086:
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1077:
1074:
1071:
1065:
1062:
1056:
1053:
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1007:
1004:
1001:
995:
992:
989:
986:
980:
977:
974:
962:
959:
947:
944:
941:
938:
935:
932:
926:
923:
920:
917:
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908:
902:
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872:
869:
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795:
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153:
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108:
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99:
96:
93:
87:
84:
78:
75:
72:
14:
832:RQD is defined as the quotient:
324:SCR is defined as the quotient:
38:TCR is defined as the quotient:
248:= Sum of length of core pieces
1:
1337:10.1016/j.ijrmms.2008.06.003
1406:
1226:= Total length of core run
811:= Total length of core run
312:= Total length of core run
1274:, Philadelphia, (91-101).
1385:Rock mass classification
1237:rock mass classification
1231:Rock mass classification
816:Rock quality designation
17:Core recovery parameters
823:Rock Mass Rating system
1220:
1156:
1029:
805:
741:
584:
306:
242:
175:
1221:
1157:
1030:
806:
742:
585:
307:
243:
176:
1168:
1041:
839:
753:
596:
331:
254:
187:
45:
1390:Tunnel construction
1329:2009IJRMM..46..315P
317:Solid core recovery
27:Total core recovery
1216:
1152:
1025:
801:
737:
580:
302:
238:
171:
1367:978-3-540-29249-4
1203:
1188:
1136:
1115:
1100:
1091:
1070:
1061:
1013:
1000:
985:
952:
931:
916:
907:
886:
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788:
773:
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694:
679:
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643:
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616:
568:
555:
540:
495:
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465:
450:
429:
420:
405:
396:
375:
289:
274:
216:
207:
159:
146:
131:
92:
83:
1397:
1371:
1351:
1340:
1311:
1241:Rock Mass Rating
1225:
1223:
1222:
1217:
1215:
1214:
1213:
1201:
1186:
1161:
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1158:
1153:
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983:
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905:
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771:
746:
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734:
707:
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656:
641:
623:
614:
589:
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569:
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522:
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311:
309:
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129:
113:
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90:
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65:
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1396:
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1375:
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1286:Further reading
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5:
1403:
1401:
1393:
1392:
1387:
1377:
1376:
1373:
1372:
1366:
1341:
1323:(2): 315–325.
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1307:972-98781-2-9
1303:
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168:
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67:
61:
57:
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34:
26:
24:
22:
18:
1347:
1320:
1316:
1293:
1278:
1271:
1264:
1260:, 1 (16-22).
1257:
1234:
831:
819:
323:
320:
37:
30:
16:
15:
1298:EUROCK’2002
1379:Categories
1356:. p.
1251:References
825:(RMR) and
33:percentage
1020:×
575:×
166:×
1354:Springer
1245:Q-system
827:Q-system
21:borehole
1325:Bibcode
1035: %
1364:
1304:
1294:Proc.
1202:
1187:
1135:
1114:
1099:
1090:
1069:
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999:
984:
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288:
273:
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145:
130:
91:
82:
1235:Many
1362:ISBN
1302:ISBN
1296:ISRM
1243:and
1138:>
954:>
1358:450
1333:doi
1023:100
957:100
578:100
169:100
1381::
1360:.
1352:.
1331:.
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1319:.
1247:.
1141:10
829:.
35:.
23:.
1370:.
1339:.
1335::
1327::
1310:.
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852:=
849:D
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769:t
766:o
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344:=
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100:e
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52:C
49:T
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