7 -A52 389 PROTOTYPE DRILL FOR CORE SRMPLING FINE-GRINEDPERENNIALLY FROZEN GROUND(U) COLD REGIONS RESEARCH AND

I ENGINEERING LAB HANOVER NH B E BROCKETT ET AL. JAN 85UNCLASSIFIED CRREL-85-t F/G 13/9 NL

EIWHUWUAEEHEGIEi lNBNB aIIEEE

rrr"~r~r -. 1 07 -K - .r- 7 - 77- 17 -aS

.611111 ' 1.1--L= - IIII

MICROCOPY RESOLUTION TEST CHART

NATIONAL BUREAU OF bTANUARDS ARt: A04

6.

".,.. '" .-.. . ...- . • :." •. .: " ." -: -'.;,. ..,-.-.I.-ROC...P.Y --

E.SO".LU,..I'.N. T-..--TCH'A.RT

-.' --' , -_ _ -_ , ,, , -, ,, ;,, . ._ : ... .- s ." " - - " _ '_ " L• .B•RE A U O F S T

,A. .." • .-'.b , .; .A

k7 W.7J.

fl

REPORT 85-1 US Army Corpsof EngineersCold Regions Research &Engineering Laboratory

Prototype drill for core samplingfine-grained perennially frozen ground

CLf

- 0O0

This documrent has been approvedfor public~ release and sale; itsdistribution is unlimited.

. . . . . .... . . . -------- .<

, - . - .

-. ~ r *- -. * *,,

For conversion of SI metric units to U.S./Britishcustomary units of measurement consult ASTMStandard E380, Metric Practice Guide, publishedby the American Society for Testing and Materi-als, 1916 Race St., Philadelphia, Pa. 19103.

4.'

1.

,I

. *_.- . . . . . .

CRREL Report 85-1January 1985

* Prototype drill for core samplingfine-grained perennially frozen ground

Bruce E. Brockett and Daniel E. Lawson

.I

Approved for public release; distribution is unlimited.

271-,I

UnclassifiedSECURITY CLASSIFICATION OF THIS PAGE (Wen Date Entered)

REPORT DOCUMENTATION PAGE READ INSTRUCTIONSBEFORE COMPLETING FORM

1. REPORT NUMBER 2. GOVT ACCESSION No. 3. RECIr~j'S CATALOG NUMBER

CRREL Report 85-1 -D A _ _ _ _ _ _

4. TITLE (and Subtitle) 5. TYPE OF REPORT & PERIOD COVERED

PROTOTYPE DRILL FOR CORE SAMPLINGFINE-GRAINED PERENNIALLY FROZEN GROUND

6. PERFORMING ORG. REPORT NUMBER

7. AUTHOR(e) 8. CONTRACT OR GRANT NUMBER(&)

Bruce E. Brockett and Daniel E. Lawson

9. PERFORMING ORGANIZATION NAME AND ADDRESS 10. PROGRAM ELEMENT. PROJECT, TASKAREA & WORK UNIT NUMBERS

U.S. Army Cold Regions Research and Engineering LaboratoryHanover, New Hampshire 03755-1290

ii. CONTROLLING OFFICE NAME AND ADDRESS 12. REPORT DATE

Office of the National Petroleum Reserve-Alaska January 1985U.S. Geological Survey 13. NUMBER OF PAGES

Reston, Virginia 22070 3414. MONITORING AGENCY NAME & ADDRESS(iI different from Controlling Office) IS. SECURITY CLASS. (of thin report)

Unclassified

ISa. DECL ASSI FICATION/DOWNGRADINGSCHEDULE

16. DISTRIBUTION STATEMENT (of this Report)

Approved for public release; distribution is unlimited.

17. DISTRIBUTION STATEMENT (of the abstract entered In Block 20, If different from Report)

18. SUPPLEMENTARY NOTES

19. KEY WORDS (Continue on reveres aide if neceeeary and Identify by block number)

Arctic regions Fine-grained materialsAugers Frozen ground samplingCore sampling Ground iceCoring auger PermafrostDrilling machines

20. ABST'RACT (Cntiue a revere. af it necweary od Identify by block number)

An incxpensive drill has been modified to provide researchers with the ability to auger an open hole or to acquirecontinuous, undisturbed 76-mm-diam core samples of a variety of perennially frozen materials that are suitable for

chemical and petrographic analysis. It was developed by field testing in support of research from 1980 to 1983.Operation of the drill is based mainly on using a minimum of power to cut through frozen ground with tungstencarbide cutters on a CRREL coring auger. The ice content, temperature and grain size of the frozen sediments areimportant variables determining the sampling depth. Perennially frozen sediments with temperatures in the rangeof -O.5 0 C to -8.5'C have been continuously cored with this drill. Drilling and sampling are most efficiently

DIO F " 1473 EDITION OF V NOV 65 IS OBSOLETE Unclassified

SECURITY CLASSIFICATION OF THIS PAGE (Whben Data Entered)

. , - .

Unclassified

SECURITY CLASSIFICATION OF THIS PAGE(Whan Data Entesmd)

20. Abstract (cont'd).

conducted when ambient air temperatures are below freezing ai.J the active layer is frozen. The self-contained light-weight drill is readily transportable off-road by helicopter or tracked vehicle, or by towing over roads. It islocally self-mobile by use of a winch. Total cost of the drill and modifications is estimated at approximately S 10,000.

Un~classifiedSECURITY CLASSIFICATION OF THIS PAGE(Wlien Data Entered)

PREFACE .4

This report was written by Bruce E. Brockett, Physical Science Technician, andDr. Daniel E. Lawson, Research Physical Scientist, of the Earth Sciences Branch,Research Division, U.S. Army Cold Regions Research and Engineering Laboratory.Field studies were primarily funded by the U.S. Geological Survey, Office of the Na-tional Petroleum Reserve-Alaska (NPRA) and supplemented by funding from theOffice of the Chief of Engineers, through various military and civil works projects.

The authors thank Dr. Malcolm Mellor and Paul Sellmann of CRREL for tech-nically reviewing the report. The authors also wish to thank Paul Sellmann for hisassistance and discussions on drilling and core sampling, and his encouragement inpursuing the development of this drill. In addition, the authors acknowledge thehelpful discussions and assistance of the following CRREL personnel: Dr. JerryBrown, Dr. Malcolm Mellor, John Rand, Herbert Ueda, Gunars Abele, AustinKovacs, Frederick Crory, Larry Gould and Daniel Dinwoodie and the shop work ofFrederick Gernhart, Robert Forest and particularly Frank Perron, who carved,whittled and welded the drill to its present configuration. The authors express theirappreciation to Max C. Brewer and George Gryc of the U.S. Geclogical Survey fortheir support and encouragement in pursuing the NPRA studies. Field assistance byBrian Harrington, Sgt. Charles Newhouse, Lawrence Gatto and John Craig isgratefully acknowledged.

The contents of this report are not to be used for advertising or promotional pur-poses. Citation of brand names does not constitute an official endorsement or ap-proval of the use of such commercial products.

ACceSion For

NTIS GEA&IICq. TAB ,unarwounced -

T Justif ication-

ByDistribution/ - 4

Availability Codes

U- Avail and/or

Dist SpecialA

Q9 l 1

,i

CONTENTS

PageA bstract ................................................................ i J 1

P reface .... ..... .. ....... .......... ....... ...... ........... ....... ... ... iiiIntrod uctio n ............................................................. IBackground on developm ent ............................................... 2

Drill development and configuration ......................................... 4

Equipment ....................................................... 4

M odifications .......................................................... 4

O peratio ns .............................................................. 15

A ssem bly and disassem bly ............................................... 15Field transport and m ovem ent ............................................ 15Typical operating procedures ............................................. 17

Effect of material properties, weather and water ............................... 28Depth and hole com pletion time ............................................ 28

Sum m ary ................................................................ 28L iterature cited ........................................................... 29

ILLUSTRATIONS

Figure

I. A lightweight, chromed 76-mm-diam CRREL coring auger .................. 2

2. Haynes Earth Drill Model 500 or "Little Beaver" with CRREL coring auger.. 3

3. General Model 550 Dig-R-Mobile drill .................................. 3

4. Prototype drill in 1983 ................................................ 5

5. C lose-up of drill ..................................................... 5

6. Close-up of front end of drill set up on site in northern Alaska in 1981 ........ 6

7. Back end of drill with stock tires ....................................... . 6

8. D rill w ith sm all tires .................................................. 7

9. Hartwell pin ........ ........................................... 7

10. Fabricated pin and plate system for systematically adding or removing drill rod

in deep holes ...................................................... 8

II. Core catcher of aluminum tube ......................................... 9

12. Rod retriever fabricated to retrieve a drill string that is accidentally dropped

dow n a hole ....................................................... 1013. Rod stabilizer for controlling excessive wobble in drill string ................ .I

14. Auger guide and simplified coring auger head ............................ 12

15. Adapter for use of CRREL coring auger on output shaft ................... 12

16. Round male to square female adapter for attaching rods to output shaft ...... 13

17. "Crown" adapter for attaching winch cable to drill string .................. 13

18. Square male to round female adapter for use of continuous flight auger onsquare rod ........................................................ 13

19. Square male to round female adapter for use of square rod with the originalhead of the coi ing auger ............................................. 13

iv

Iw

Figure Page20. Tool box ....................................................... 1421. Prototype drill suspended from cable attached to inverted 'V' hook ............ 1522. Drill movement by self-winching..................................... 1623. Sequential photos of typical operating procedure for continuous coring deep

drill holes in northern Alaska in 1981 ................................. 1824. Examples of core samples of different grain size and ice content .............. 2125. Thin sections under cross polarized light of representative cores obtained using

the CRREL coring auger and drill ................................... 2526. Thin sections under cross-polarized light of representative cores obtained using

a modified Shelby tube and Mayhew 200 rotary drill rig .................. 27

v

A PROTOTYPE DRILL FORCORE SAMPLING FINE-GRAINEDPERENNIALLY FROZEN GROUND

Bruce E. Brockett and Daniel E. Lawson

INTRODUCTIONTherefore in late 1979, we evaluated equipment

As part of a research project on the environ- and techniques that were developed specificallymental effects of former exploratory drilling op- for augering or coring permafrost, or for generalerations in parts of northern Alaska (Lawson et al. use in near-surface, frozen materials. In making1978, Lawson and Brown 1979, Lawson 1982), this evaluation, we were seeking a drill that couldstudies were begun in 1977 on the origins and 1) auger a shallow open hole and continuouslycharacteristics of the perennially frozen ground, core to depths of 20 to 30 m, 2) obtain core sam-or permafrost, which underlies this region. This pies of materials with different compositions thatstudy required subsurface geological information were as unstressed and undisturbed as possible,and undisturbed samples of the perennially frozen and 3) be cost-effectively transported into andsediments that overlie frozen bedrock at depths about remote, roadless regions without significantranging from 10 to 30 m. disturbance to the vegetation and permafrost. In

It became clear after our initial efforts in ob- addition, we were seeking a low-cost drill systemtaining subsurface information that existing that could be operated safely and successfully byequipment and techniques were not suitable for re- research personnel with little or no drilling experi-searchers inexperienced in drilling who wished to ence.core sample below depths of around 2.0 m. There- We were also advised that the CRREL ice cor-fore, drawing from previous experiences (e.g. Sell- ing auger referred to in this report as the "coringmann and Brown 1965, Davis and Kitze 1967), auger" (Fig. l)(Ueda et al. 1975)could obtain highMellor and Sellmann 1975, Sellmann et al. 1976, quality, basically undisturbed cores of fine- rNixon 1977) we conducted a subsurface sampling grained, perennially frozen materials, and we se-program employing professional drillers and lected it as our sampling tool. A suitable powerequipment (Lawson and Brockett 1980). These unit, however, had not been adapted to this coredrillers used a Mayhew 200 rotary drill rig with barrel to meet our requirements. Specificationschilled compressed air for circulation and periodi- for the power unit were therefore based upon thecally sampled the permafrost at designated depths requirements for optimizing performance of thewith a modified Shelby tube. While this operation corer, and based upon our review of equipmentdefined the basic character of the perennially fro- and techniques, a portable, lightweight drill waszen sediments above the bedrock, we were not sat- adapted for use with this coring auger.isfied with the quality or quantity of the core sam- Because the primary goal for our efforts was topies. Each sample was heavily disturbed by the obtain undisturbed core samples of permafrost inmodified Shelby tube and stress-fractured by the support of on-going research and not to fabricatetorque generated by the drill; thus they were not a totally new drill, we did not undertake a con-entirely useful for laboratory analyses. Further, trolled, systematic design and testing program.the field costs of this operation, including several The configuration of the drill, as described in thistrips by helicopter to transport equipment and report, has resulted from field experiences dut ngpersonnel between each drill site, were quite high. the period of 1980 to 1983, and subsequent modi-

- ,~-. , s- '- --- '-~n- ~ r r-- r --

II.

a. Coring auger.

b. Adjustable cutters and head of core barrel.

higure 1. A lightweight, chromed 76-min-diam CRREL coring auger mnodi-

fied for use in fine-grained, perennially frozen materials.

tications to the original configuration that result- quiring a unit powerful enough to drive the coringed from those field experiences, auger in a variety of materials without producing a

In this report, we describe the development and torque that would overcome the strength of theconfiguration of the prototype drill for continu- operator(s), the unit had to be portable and light-ous undisturbed core sampling of permafrost. In weight for use in remote regions. Some of theaddition, we discuss pertinent aspects of the drill's hand-held units that have been adapted to the cor-performance and limitations. ing auger were described by Ueda et al. (1975).

One power unit commonly used is the HaynesEarth Drill model 5(X9 or "Little Beaver" (Fig. 2).

BACKGROINI) ON I)EVLOPMENT -his unit is powered by a 5.0-hp Briggs and Strat-ton four-cycle engine. Power is transmitted

Since the coring auger was developed and through a flexible shaft to a centrifugal clutch andmodified for use in fine-grained fro/en materials 10:1 gear reduction transmission. The model 500(Ucda ct al. 1975), locating a power unit ,uitable seighs approximately 45 kg. Including samplitntfor sampling pertmafrost at depths greater than a accessories, the weight is approximately 136 kg.few meters has pros en difficult. In addition it, re- 1he major problern that we encountered with

2I

°.S

Figure 2. Haynes Earth Drill Model 500 or "Little Beaver" with CRREL cor-ing auger.

N

Figure 3. General Model 550 Dig-R-Mobile drill with hex-to-round adapter (/), coring auger(2), and core catcher (3) as used in Alaska in 1980.

this unit was sticking of the core barrel in the hole. the operator could physically control. After rota-The core barrel often stuck when thawed or par- tion stopped the barrel froze to the hole walls andtially thawed zones were encountered. In these could not be pulled out. We had difficulty in ob-zones, cuttings built up on the flights, jamming taining core samples below 2.0-m depth and foundbetween the core barrel and hole wall. As the resis- the unit too cumbersome for use over tundra vege-tance to rotation increased, the governed motor tation.increased power to compensate for this resistance, On the basis of our research requirements asthereby increasing the torque beyond that which stated previously, we selected a small, trailer-

3

mounted post hole auger, the General Model 550 Modifications described in the next section wereDig-R-Mobile for use with the coring auger. This based upon the 1980 field tests and subsequentdrill has the simplicity of operation, power, ease field tests of modified versions of the drill rig inof mobility and feed control necessary for deeper 1981, 1982 and 1983.coring. This unit (Fig. 3) uses a 7-hp Tecumseh en-gine, and an enclosed spur gear reduction trans-mission that produces 381 N-m (281 ft-lb) of tor- DRILL DEVELOPMENTque and a maximum of 144 rpm. The power unit is AND CONFIGURATIONmounted in a cradle for vertical travel on a mast.Vertical travel and feed is controlled by a 40-mm Equipment(16-in.) hand-operated wheel that raises and The following major pieces of equipment werelowers the cradle and drill head through a double purchased to develop the drill in its present config-reduction chain drive. The mast tilts 100 on lateral uration:axis and 15 ° on longitudinal axis for adjusting the i. Model 550 Dig-R-Mobile from the Gen-mast to a near vertical position. The basic drill eral Equipment Co., Owatonna, Minnesota.weighs approximately 318 kg. 2. Implement jacks, 900-kg capacity, with

In order to evaluate the performance of this 0.38-m travel (2 ea.).power unit with the coring auger, we rented a 3. Implement jack, 900-kg capacity, 0.25-mModel 550 and field tested it while conducting re- travel (I ea.).search during May and June of 1980 in northern 4. Implement jack mounts (3 ea.).Alaska (Fig. 3). The only modification made to 5. Goodyear Xtra-trac Terra tires, 31 xthe rental unit was welding a hook on the top of 15.50, 4-ply tubeless nylon, mounted on rimsthe mast for sling transport by a helicopter. An with wheel studs and lug nuts.adapter was fabricated to connect the CRREL 6. Portable winch, gasoline engine driven,corer and its extension rods to the output shaft, with a 6:1 gear reduction system, and 90 m

We were successful in recovering high quality of 6.35-mm ( A-in.) wire cable.cores of ice-rich and ice-poor frozen sand or silt 7. Constant speed electric winch, reversi-and ice wedge ice. Sixty holes were continuously ble, 112-V a.c., with 60 m of 4.76-mm (/,,-cored to an average depth of 2.5 m and a maxi- in.)-diam galvanized aircraft cable.mum depth of 5.3 m. Depths of sampling were pri- 8. Portable generator, 3-kW, 120-V, 1800marily limited by the material types, difficulties in rpm.pulling the core barrel and rod extensions by hand 9. Fabricated metal skis (3) of 6.35-mm-below 4 m, and a conservative approach for these thick aluminum channel of 0.305-m widthfirst field tests to ensure that research objectives and 1.2-m length.were met. 10. Continuous flight auger, 57-mm-diam-

Nevertheless, the field test demonstrated that eter, 1 m long (designed by A. Kovacs).the model 550 with certain modifications couldprovide a suitable base unit for core sampling con- Modificationstinuously to depths exceeding 5.3 m. Researchneeds required samples to depths of 20 m and we Base unitfelt it highly likely that, with modification, 20 m A hinged mast extension is added to the Dig-R-could be attained with the model 550. Mobile using a 1.2-m-long, 0.1-xO.l-m steel tube

rwo basic assumptions were made before im- (Fig. 4). Two cable rollers are made from 19-mmplementing any modifications to the model 550: aluminum plate and positioned so that the winch

I. The CRREL coring auger equipped cable will hang centered over the hole. A standoff"ith tungsten carbide cutters is suited for bracket is attached to the top of the extension forcore sampling ice-rich, fine-grained frozen the purpose of locking the extension to the mastsediment and produces a clean hole that when in the down or transport position (Fig. 5).eliminates the need for drilling fluid. The extension is installed or removed by inserting

2. The only two factors that govern the or pulling the hinge pin. Initially the extension waspenetration rate of the coring auger are the locked in the upright position by a snap clampdepth of cut of the carbide cutting inserts mounted on the rear of the mast; this clamp wasand the revolutions per minute of the core eliminated after the first field season due to itsbarrel; thus, excessive downward pressure or tendency to vibrate open. The extension is nowhigh torque are unnecessary. bolted to the top of the mast with 16-mm bolts and

4

Only certain imnporant aspects of coring are brief-ly described below.

The basic procedure is as follows. After estab-lishing a vertical pilot hole, the coring auger is at-tached to a 0.5-ni length of drill rod and the out-put shaft, and coring is begun (Fig. 23a). As thehole progressively deepens, lengths of drill rod areadded (Fig. 23b). After each core is cut, the motor >cradle is sw~ung aside arid the rod and barrel areraised by the electric winch. The rod is removedusing the pin and plate system. The plate is slippedaround the rod and the pin inserted through thehole in the rod (Fig. 10). The drill string is lowered \N ~-until all weight is suspended from the pin that restson the plate. Sections of rod are disconnected, re-moved from the winch cable, and set aside (Fig.23c, d). The cable is reattached to the top of the 0remaining drill rod. The suspended drill string isthen raised slightly, the pin and plate removed andthe drill string is raised until the next rod-to-rodconnection is above the ground surface. The%%inch cable is kept taut at all times. This process isrepeated until the core barrel is retrieved (Fig. 23e,f). When lowering the core barrel back to the bot-ton of the hole, the addition of sections of rod byusing the pin and plate system, as described above, a. Attaching coring auger for core sampling afteris~ reversed. These core sampling procedures effec- augering pilot hole in active layer.ikely provide a safe operating environment, asthere is never a need for personnel to be near thecore hole when the motor is in use and the drillstring is rotating. All trips up and down the holeare made without rotation.

The most difficult aspect of using the drill andcoring auger is having the patience to maintain aconsistent rate and depth of cut. At a depth of 20in for example, it takes a minimum of 10 minutesto descend the hole, cut a sample, pull the rod andcore barrel to the surface and remove the core.

When cutting a core, only seven revolutions ofthe wheel should be made, as this number of revo-lutions equals a penetration depth of 0.3 m or one-Ithird the length of the core barrel. This length iscritical because for every 0.3 m of core that is cut,0.6 m of cuttings is collected on the coring auger'sflights and within the core barrel. Exceeding thisdepth of cut or having improperly matched car-bides will cause cuttings to accumulate above theflights, where they will be compacted during re-trieval, causing the core barrel to jam within thehole and subsequently freeze to the hole walls. TheAIoniy successful method found to free a jammedand frozen core barrel is by lowering the freezing '

point of the cuttings and causing them to thaw by b shl e n rl o scntnul depouring antifreeze solution into the hole. Depend-wihrdsalzesorden.ing on ground temperatures, it can take 12 to 24wihrdsaliesorden.hours before the core barrel is freed. Recently we Figure 23. Sequential photos of tYpical operating .6have reduced this time to / hour by injecting air procedure for continuous coring deep drill holes infrom a portable air compressor directly above the northern Alaska in 1981.

18

? J .' . r .m. -. .

roads, the unit can be towed behind vehicles hav- less than 2 m deep if the cuttings can be removeding a 2-in. (50 mm) ball trailer hitch. Off road, we by running the auger up and down the hole period-have towed it by tracked vehicle and snowmobile. ically while under rotation. We have not found itThe modified drill, unassembled, will fit into a necessary to use auger slips during our operations.small plane (e.g. a Twin Otter). Based on our experiences, operating augers with

The drill can be incrementally moved by attach- the universal joint connector between the outputing the winch cable to a fixed object, such as a shaft and auger flights is recommended.dead-man, and reeling it in (Fig. 22). When towing A continuous flight 57-mm-diam auger equippedthrough deep snow or large tussocks, we have with tungsten carbide teeth (Fig. 20a) worked wellfound that having the winch at the rear of the drill in ice-rich perennially frozen ground for defining(pulling towards the smaller front tires) adds the subsurface conditio,,s when core samples were notadvantage of vertically rocking the drill as the needed. The open hoie produced is clean and un-winch cable is strained. This rocking motion lifts contaminated. Using this tool, we have augeredthe front wheels off the surface, momentarily re- ice and fine-grained ice-rich frozen sediments todistributing the weight slightly behind the larger depths of 12 m. These depths are not possible ifrear tires, and causing the drill to waddle forward. any gravels or unfrozen materials are encoun-

Precise positioning of the drill with the motor tered.shaft centered over the desired sampling location It is important to start with and maintain a ver-is relatively easy to do. This positioning can be ac- tical hole when augering. If the drill should move,complished by rotating the large tires by hand, it must be recentered over the hole to avoid exces-pushing from front or rear. The size of the tires sive strain to the oil seal and bearings of the out-provided excellent leverage while minimizing the put shaft. Movement of the drill is a common oc-adverse effects of tundra vegetation in restricting currence esp,-cially when larger diameter augersmovement, are used. The movement is due to vibration, and

even with the jacks set, the lightweight drill canTypical operating procedures walk off the hole.

A ugering Core samplingOnce on site, the drill is positioned over the The success of cutting and retrieving core sam-

sampling location. The mast is first coarsely ad- pies of undisturbed quality is a function of severaljusted to a near-vertical orientation by using the factors, perhaps most important of which is un-mast leveling adjustments. The mast is then lev- derstanding and experience with the CRREL cor-eled using the jacks that have been set on boards ing auger. In our opinion, this coring auger is theto retard sinking into thawed soil or a snow cover, best tool now available for extracting undisturbedFinally, the wheels are firmly chocked. Drill rod core samples of fine-grained perennially frozenand related equipment are laid out and all sam- ground. The core samples are uncontaminatedpling equipment is set up about 5 m away from and suitable for both petrographic and chemicalthe drill. analyses. A detailed description of the coring

If the active layer is unfrozen or surface water is auger and its use, with which an operator shouldpresent that will flow into the hole, casing must be be familiar, is given by Ueda et al. (1975).used. After removal of the thawed materials by Physical factors that can affect the success ofaugering, the casing is inserted (Fig. 7). The casing extracting high quality core samples include theprevents collapse of thawed soil into the upper temperature, ice content and grain size of the per-part of the hole, and retards the flow of water into ennially frozen materials, the thermal state andthe hole where it freezes on the hole wall and hin- moisture content of the active layer, and the ambi-ders removal of the core barrel. When the ground ent temperatures. Operational factors include theis froen, the use of casing is unnecessary and rate of penetration, as determined by the anglesampling is initiated at the ground surface, and depth of cut of the carbides, and rpm of the

Augers of 0.15-m diam are usually used to set output shaft. Furthermore, the core barrel andcasing. When augering, we generally operate the tungsten carbide cutters must be maintained indrill motor at the maximum speed (144 rpm) al- good condition, with correct radial clearance (I.D.though the selected speed will vary for materials of and O.D.) set on the carbide cutters.differing composition and temperature. The great- Because of the potential variability of these op-er speed aids in clearing the cuttings from the hole. erational and physical factors, we cannot possiblyContinuous flight augers are not required in holes explain every detail of a successful core sampling.

17

- - - .C. VWV ~W. .2W.~. *-- ,'-7 -771 T77 .. rr -7 Yr . r

a. Using gas winch mounted on platform withwinch cable attached to a dead-man.

b. Using electric winch mounted on front plate,with cable doubled back on itself, front ski

mounted under the trailer tongue.

c. Self-winching from a dead-man on the steep 4.slope of Weather Pingo near Prudhoe Bay,A laska.

Figure 22. Drill movement by self-winching.

16

7-1

, -. . . . -. .. : .- . . . .- . -.- ,-, ., ., , - - - . °-" . . . - 7 . - , - .- , . . . . . _ , _ _ , , . ,

.-.. -7

Other -idditions for augering and core sampling OPERATIONSinclude the incorporation of three auger flights Assembly and disassemblywith a three-step, six-carbide bit for augering Asse d isassemblIf the drill is shipped completely unassembledthrough a coarse-grained active zone and a 76-mm- and crated, two people can assemble the unit in -'

diam CRREL-style coring auger of 1.5-m length. about 4 hours, provided that an elevated plat-

form, tripod-type overhead structure, or fork liftis available to aid in lifting the mast. An assembly

A storage box was fabricated and mounted on time of less than 1 hour is possible if the base unitone side of the drill platform. The bottom com- is intact. A third person is required if assembly orpartment (Fig. 20a) contains 15, I-m-long flights disassembly is done in the field. No specialized orof 57.2-mm-diam auger. The middle tray (Fig. unique tools are necessary.20b) contains a CRREL corer, stabilizers, core We used a total of 14 boxes for shipping theretriever, and assorted adapters, while the top tray drill, camping equipment and sampling supplies to(Fig. 20c) contains spare cutters and a variety of field locations, with an approximate total weightnuts, bolts, and tools. The cover of the tool box is of 1800 kg and volume of 11 Im 3 . The modifiedmade from wood and provides electrical ground drill and sampling supplies accounted for aboutprotection when hooking the drill to a hovering 900 kg and 7.4 n3

.

helicopter. Static electric charges can build up dur-ing the hookup operation and result in a heavy jolt Field transport and movementto the person attaching the choker swivel. Transporting the drill to and from remote field

The winch is powered by the 3-kW 120-V gener- sites is typically done by attaching a choker cable

ator. A generator with a 1800-rpm specification and slinging it beneath a helicopter. With thewas selected for arctic operations, because some choker cable attached to the top of the mast and

motors that operate at 3600 rpm have had a tend- the powerhead positioned at the bottom of the

ency to heat unevenly when exposed to arctic mast, the drill is a compact, balanced sling load

winds and mechanical failures have resulted.* that resists the tendency to spin (Fig. 21). Over

This generator was initially mounted on the plat-form. To reduce the weight of the drill and thenoise level, we now position it about 30 m away

from the work site.The following items are also recommended for

inclusion in the field supplies:I. Power pull-I ea.2. Handiman type jack-I ea.3. Pipe wrenches-2 ea. of 0.46-m (18-in.)

length4. Double-faced hammer of 1.8-kg weight5. Ratchet set (19 mm)6. Speed wrench set7. Mirror8. Length of chain with safety hooks9. Spray lubricant

10. Small assortment of wooden blocks andboards

II. Assortment of nuts and bolts12. Wire brush and assortment of files13. Emery cloth14. Casing, 150 mm in diameter15. Bench grinder

Figure 21. Prototype drill suspended from cableattached to inverted 'V' hook. In helicopter trans-port, it is a high density balanced load that resists sway-.

A. Kovacs, CRREL., pcr,,onal communication, 1982. ing.

15

a. Bottom compartment containing 15 sections of continuous flight auger.

b. Middle tray containing 1-rn-long coring auger and adapters.

c. Top tray containing tools, spare parts, and mniscellaneous bolls, screws,etc.

Figure 20. Tool box.

14

lnjure' 6. Round mtale to square female adapter for at- Figure 17. "Crown" adapter fr attaching winch cable

tachtn rods to Output shaft. to drill string.

I4

/ iiure 18. Square male to round female Figure 19. Square male to round female adapter for use of square

dupte'r !or uase of continuous flight auger rod with the original head of the coring auger.

t.5 7 mn diammi) on square rod.

,,,rh %,,ater, is unaffected by low temperatures, Mobile gear box to the coring auger head or exten-

and waas readily available. sion rods (Fig. 15).A scries of adapters were fabricated to inter- 3. A round (32-mm-diam) male to square fe-

changc the various augers, core barrels, drill rod, male adapter attaches the square rods to the out-

core and rod retrievers. The adapters are briefly put shaft of the gear box (Fig. 16).

described below: 4. A "crown" adapter is used to attach the

I. An auger guide insert reduces the standard winch cable to the square rod (Fig. 17).15)-mm guide for use with the continuous flight 5. A square male to 17.5-mm round femalk

57-min-diam auger (Fig. 14a). A simplified head adapter allows use of the 57.2-mm continuous

for thc coring auger adapts directly to a square rod flight augers with the square rod (Fig. 18).

0 ig. 14h). 6. A square male to round fenale adapter joins

2. A 35-in hex female to 32-mm round fernale the square rod to the original CRREI. coring

adapwcr joins thc out put shaft of the Dig-R- auger head (Fig. 19).

13

- --

a. Con,,nuou5 flightl 57-mm-diam auger flight

b. SiminIfied head.insert,

Figure 14. Auger guide and simplified coring auger head.

a . H x e n of ada p er .b . F e m a le ro u n d en d .Figure 15. Adlapter for use Of CRRE,. coring auger on output shaft.J

12

a. Fabricated of wood and tape in the field in 1981.

*b. Stabilizer fabricated of Synthane tube at CRREL.

Figure 13. Rod stabilizer for controlling excessive wobble in drill string.

slip into the holes in the drill rod. We have not had rod connections and to ensure ease in reconnecting*to use this retriever to date for its designed pur- rods. Experimental stabilizers were initially whit-

pose, but it has been used extensively for recover- tied from wood timbers while in the field in 1981ing core (as described below in Typical Operating (Fig. 13a). They were covered with fiber tape andProcedures), dropped over each section of rod as the drill string

Rod stabilizers are necessary to control the wob- was assembled. Because these stabilizers wereble of the drill string, particularly at depths greater found to effectively control the wobble, we fabri-

*than 10 m. Wobble is a result of the loose inter- cated stabilizers from Synthane tubes, epoxy resinconnections of the rods. We opted for loose con- and aluminum rod (Fig. 13b). Synthane was se-nections to prevent thawed sediment from binding lected as a base material because it does not ab-

111

* .. *. a .Farctd fwo andtap in th fil in > 1981. * . .-.

a. Side view with square female end for connection to drill rod.

ifi

iff

b. Down-hole end with concave face and four internal spring pinsthat hold rod.

Figure 12. Rod retriever fabricated to retrieve a drill string that is acciden-tally dropped down a hole.

10

6i -.-. -.. .? . ' .-.. " < " • " .- - ; ".-.- 7 .. . " " " . . . . [

Figure I/. Core catcher of aluminum tube with internal spring clips to retain coresample. Head is removed to retrieve core from tube.

allow reverse rotation of the drill string. A third and pin, which rests upon either casing or timbershole was drilled through the tube and the rod for placed next to the drill hole (Fig. 10b). A handleuse with a fabricated pin and plate system (de- was attached to the plate to prevent fingers fromscribed below). A total of 33 m of rod, consisting accidentally being caught beneath it as the drillof 15 sections 2 m long, two sections 1 m long, and string is raised or lowered.2 sections 0.5 m long, were fabricated. To connect A core catcher (Fig. i1) (designed by H. Ueda)the drill rod directly to the coring auger a new is used to retrieve core from the bottom of a hole.head (designed by J. Rand) was fabricated. This The core catcher consists of an 80-mm-diam alu-simplified design eliminates binding of the internal minum tube with four spring steel teeth. The teethmechanisms of the original head by thawed silts. allow the core catcher to slip over the core. The

The components of the pin and plate system are teeth dig in as the catcher is raised. The head is re-shown in Figure 10. They are made from a 200- moved and the core sample is pushed through themm-square, 13-mm-thick aluminum plate with a catcher for retrieval.32-mm-wide and 100-mm-long slot cut to its cen- A rod retriever was designed and fabricated forter. The pin is a 200-mm-long, 13-mm-diam soft use in the event that the drill string is accidentallysteel rod bent to form an L-shaped pin. When low- dropped down the hole. The steel receiver has anering or raising the rod, sections are disconnected outside diameter of 102 mm, and centering of theby pushing the plate slot around the rod and inser- drill rod is automatic because of the concave shapeting the pin through the hole in the rod (Fig. 10a). (Fig. 12). Once it has been lowered into positionThe drill string is then suspended from the plate on top of the rod, two of the four spring bolts can

9

" -. " • -" " * - -" - .-- - . * .. . .. . . . . . .. , . -. • -*.--= :

Ja.

a. Inserting pin in rod hole below the rod-to-rod connection and Hartwell pin.

b. Drill st ring suspended from pin and plate, which is resting on casing.

Figure 10. Fabricated pin and plate systemn for systematically adding or removing drill rod indeep holes.

.?.8

-

TI "PO

Figure 8. Drill with small tires mounted for towing onroads. Arrow locates inverted 'V' hook for sling transport byhelicopter.

and installed to allow freedom of both hands dur- Drill accessoriesing coring and retrieval operations. The brake Sections of drill rod were manufactured frompedal release mechanism is attached to the throttle/ square steel tubing with a square cold drawn rodbrake lever (Fig. 5). Enough slack is provided at (Fig. 6c). Sections of rod were shimmed and weld-the connections to allow for unobstructed leveling ed into one end of the square tubing so that equalof the mast. portions of the solid rod were contained within the

A gasoline-powered winch was bolted onto a tube and protruded from it. Holes were drilled inframe that is welded to the drill platform and trail- both ends of the tube to interconnect the sectionser tongue (Fig. 8). This winch was originally used of rod by use of Hartwell pins (Fig. 9). Theseto raise and lower the drill rod and core barrel, but pins were selected because of their previous suc-was later replaced by a mast-mounted electric cessful use with the standard CRREL ice coringwinch described below. The tubular bracing on the auger (Ueda et al. 1975) and because they wouldplatform was reworked to 1) mount a lockingplate for nesting the drill rod and core barrel (Fig.8), 2) provide hand holds for maneuvering the drillin the field, and 3) allow for adequate space forthe winch frame.

An electric winch is now mounted on the backside of the mast (Fig. 4). This location provides

for a near-vertical pull and minimizes the lateralstrain on the mast extension that was produced wnwhen using the gas winch. The electric winch is op-erated from a control box on the end of a 3-m-longcable. The winch has a constant speed in both for-ward and reverse drive and has a trigger dynamicbrake that is automatically applied when the con-trol button is released. This winch was selectedprimarily for the safety provided by the constant Figure 9. Hartwell pin.speed and braking system.

7

1~

Figure 6. Close-up of front end of drill set up on site in northern Alaska in 1981. Jack standsand extension arms (A) located on boards to prevent sinking into thawed soil. Upper part of hole hasbeen augered and aluminum casing set (B) prior to coring operations. Square drill rod is on right side ofdrill platform in transport position (C).

Figure 7. Back end of drill with stock tires mounted on trailer tongue and gaso-line-powered winch mounted on frame welded to the tongue and drill plat-form. In this position, the winch was used for raising or lowering the drill string andlocal movements. Locking plate (A) is used to hold drill rod and 1.5-m-long core barrelon drill platform.

6

6

- .. '

a

!4

/-iure 4. Prototype drill in /983. Modifications to the Figure 5. Close-up sho wing fabricated foot brake re-Model 550 bawse Unit include a) tmast extension, b roller lease t echanism, with the foot brake pedal (A) and,uide and winch cable, c) electric winch, d) balloon tires, e) Upper loose connection (B) to allow vertical adjust-/ack.s and inount.s. and.l) two-twheel trailer tongue. inent of mast. Mast extension is bolted to ,as1tbr trns-

port (C).

a short safety chain is used to prevent it from acci- existing hubs with adapter plates (Fig. 6). Both ofdentally falling (Fig. 4). The addition of the mast the road tires are mounted to a fabricated hub andestension pro, ides a vertical clearance of 3.5 in, attached to the tongue jack stand (Fig. 7). [orcnough to pull a 2-n section of drill rod with a trailering over roads, the balloon tires must be re-1.5-n core barrel attached. moved and replaced with smaller road tires (liv.

Hand-operated, scre,-i ype implement jacks are 8) as the larger tires cannot be drawn at speed"mounlCted on extension arms, which are bolted to over 50 ki/hr. With four tires mounted, tile drillthe front of the drill platform (front refers to tile produces a ground pressure of 1.8 gfinin (2.6side of fle drill platform with the mast, moior and psi).cradle) (lig. 6). Each jack has a 0.38-m-travel and In addition, three skis were fabricated from9(X)-kg capacity. A third jack with a 0.25-ni travel 6.35-m-thick aluminum channel to permit mo-aed 9()-kg capacityv is mounted on tle trailer bility over snow. Two ,f the skis bolt to file hubstongue. lhese jacks are necessary to level the drill replacing the balloon tires; the other, a pivotal ski,and stabilie it wAhile it is operated. is inserted into a socket beneath tile trailer longue.

I \,%o bubble levels set at right angles to one an- With the three skis mounted, ground pressure isother are mounted on the rear face of tihe mast to 0.91 gf/mn (I.3 psi). An inverted V-shaped hookprovide visual control when les cling with Ile (Fig. 8) was welded at tile top ,f the mast for at-jacks, as well as for monitoring the drill posiliot taching tile drill to a choker and subsequent trans-during operaiion. port beneath a helicopter.

[wNo balloon tires are mouned directlv to the A brake release pedal (Fig. 5) was fabricated

5

0 01

c. Inserting pin in rod as drill string is progressive- d. After completion of coring, motor and cradlely lengthened and lowered, are swung away and sections of drill rod progres-

sively removed.

191

-°. "I T' - - -.-

head of the core barrel and agitating the antifreeze the end of the core. This method has proven suc-with a stream of air. The introduction of an air cessful and cores have been retrieved at depths ofcompressor to this system is currently being evalu- 20 m. Cores are only slightly damaged (e.g. withated. chipped edges) when using this method.

The most routine problem we encountered wasretrieving cores that did not break free from thehole bottom. This problem was commonly experi- CORE QUALITY AND COMPARISONenced in 1981 in frozen sediments with low icecontent. Successful retrieval of a core sample de- The most important feature of this drill systempends upon wedging cuttings between the inner is the quality of the core sample produced. Thiswalls of the core barrel and the core sample. This quality is produced by controlling the penetrationbinds the core in place and allows rotation to rate as physical conditions and material composi-break the sample at the toe of the barrel. In ice this tion change. The operator needs to gain experi-

. method works well; however, this method does ence in order to judge the progress of the cuttersnot work in frozen sediments with low ice content and respond to changes in the controlling factorsbecause of their resistance to shearing. Thinking by adjusting the speed or depth of cut. For exam-that the greater length of core within the barrel pie, penetration rates that are too aggressive canwould effectively increase the shear stress applied produce fractured and broken cores, while ratesto the base of the core, we tried first a 2-m- and that are too slow may cause melting or balling upsubsequently a 1.5-m-long version of the CRREL of the cuttings and produce refreezing problems.coring auger. These core barrels did not retrieve Incorrect positioning of the cutters will likewisecore any better than the original barrels, primarily produce an irregular and scored surface on thebecause the maximum speed of the drill motor core sample. In general, maintaining a consistent(144 rpm) is insufficient to transport cuttings up depth of cut per revolution as governed by mate-the full length of the flights to the top of the core rial and physical conditions will produce undis-barrel. The cuttings instead filled the lower por- turbed core samples from a variety of fine-grainedtion of the flights and they limited increase in sam- sediments (Fig. 24).

. pie length to only 0.1 to 0.2 m. Further work on Cores of frozen sediments containing a range ofincreasing both the efficiency of core retrieval and ice from 10 to 90% by volume and pure ground icethe length of individual samples is continuing, obtained with the CRREL coring auger are intern-

In order to retrieve core samples that do not ally unaltered. Thin sections representative ofbreak free, a method was developed that minimiz- cores of frozen sediments and sediment-laden icees loss of sampling time. If the core barrel comes photographed under cross-polarized light illus-up without retaining the core, the drill rod is im- trate the quality of the core samples (Fig. 25).mediately reattached and a second, equally deep Each core typically has only a narrow annulus ofcut is made. If the core again does not break free, disturbed material on its outer I to 2 mm. Breaksa third cut is made. (Three cuts are all that are pos- in the core may sometimes result along planes ofsible-this is the full length of the interior of a weakness within the frozen materials, but adjacentI-m-long barrel.) If a core is again not retained in to these breaks the ice is basically unaltered. Forthe barrel, the core barrel is removed and a 2-m comparison, samples obtained in 1979 with alength of rod is attached to the end of the winch modified Shelby tube (Lawson and Brockett 1980)cable and lowered down the hole. When the top of at the same field sites are shown in Figure 26. This

. the core is reached, as can be determined by ob- comparison is important because a modified Shel-serving a slackening of the cable, another 0.3 m of by tube similar to the one used by us in 1979 iscable is played out, the rod is lifted by hand about commonly employed in obtaining core samples for0.3 m above the core, and then the rod is allowed geotechnical siting studies and laboratory testingto free-fall. (If the core breaks, the cable will be of the in-situ engineering properties of frozentaut.) Then the winch is reeled in, the rod is re- ground. These cores are often assumed to be un-moved and the rod retriever attached (Fig. 12). In disturbed.the rod retriever, the square to female round adap- The cores from the modified Shelby tube, par-ter is inserted (Fig. 19) and the core catcher is at- ticularly those of massive ice or ice-rich sediments,tached to the female round (Fig. 11). The hole is often have only a small part of the interior of thedescended to the bottom. Again 0.3 m of cable is core that is not disturbed and recrystallized (Fig.played out, and the core catcher is lifted, and al- 26). In some samples of ice we have examined, on-lowed to free-fall. The catcher should drop over ly about a 10-mm-diameter cylinder of material in

20

0,

.........................

a. Segregated ice in sill.

4?0 430 440- 450 460 470 480 490 510 520 530 540 j5Z56

b. Ice-rich clayey silt.

Figure 24. Examples of core samples of different grain size and ice content.

21

c. Ice-poor silt with small lenses of0c

0~ d IcePO~rsiltwithvery small pore ice.

Figure 24 (coflt'd). Examples of core samplso ifrn ri ieadiecnet

22

e. Ice lenses of 2- to 4-cm thickness in organic-rich silt.

f. Thin veins of ice in organic clay silt of frozen active layer.

Figure 24 (coni'd).

23

g. Tip of ice wedge in sand with pore ice.

401

h. Wdge ce ith oliaed trucure

Figre 4 (ont). xaple ofcor sapls o difernt rai sze nd ce ontnt

241

i. Bubble-rich pingo ice. j. Massive ice lens with suspended organic layer.

Figure 24 (cont 'd).

a. Ice-wedge ice.

Figure 25. Thin sections under ('rom polarized lightof representative cores obtained u.sing the (RRI-I

coring auger ana drill.

25

6 " .. c .- "

I IF

b. Ice veins in silt. c. Massive ground ice, with vari-able grain size, infilled cracks andrecrystallized natural fracturezones (same ice as Fig. 26c0.

Figure 25 (cont 'd). Thin sections under cross polarized light of representative cores obtained using theCRREL coring auger and drill.

0 the core's center remains unaltered (Fig. 26). In samples off for retrieval), the ice and frozen sedi-ice-rich sediments, veins and lenses of ice are ments are also disturbed (Fig. 26). Clearly, thecrushed and refrozen, and in some, the sediments results of tests on those cores sampled with theare similarly modified with individual grains reori- modified Shelby tube would not be representativeented. In addition, breaks in the cores were com- of the in-situ properties of the perennially frozenmon and, adjacent to these breaks (including materials, whereas those sampled with the CRRELthose at the core base caused by snapping the core coring auger would be.

26

" • ". . - . *-, - ' %" % " * *. " .. . . * ." " " " " " " ' " . *" o ",. " . °. " ." - . .

-j

-- T-7 RZ' z'T C7

S

Tt

a. Ice- wedge ice, with only central, upper part of b. Ice-rich clayey silt, with individual ice veins andcore appearing to be unaltered. lenses (arrows) exhibiting crushing and refreezing.

MWi

c. Greatly disturbed massive ice, including alteredice along drilling-induced fractures. Only core cen-ter is undisturbed.

Figure 26. Thin sections under cross-polarizedlight of representative cores obtained using a mod-ified Shelby tube and MaYhew 200 rotary drill rig.

27

1---...

EFFECTS OF MATERIAL PROPERTIES, hole wall near the surface, the barrel froze inWEATHER AND WATER place.

In addition, the previous stress history of theWe have observed certain effects of the frozen materials, particularly of ice, is important. Layers

sediment's grain size, ice content and temperature that have apparently been affected by geologicon the depth of core sampling. Clean ice or sedi- stresses or recrystallization may act as planes ofment-rich ice were the easiest materials to core weakness and break into small sections or frag-sample. Similarly, ice-rich silt and ice-rich sand ments during coring.were easily cored and were the materials within Finally, in permafrost at temperatures of-I 0 towhich we attained the greatest hole depths. Sandy -1.5 'C, thaw zones were encountered. Slurries ofsediments dulled the cutters more rapidly than sil- supersaturated fine-grained material would flowty sediment, although ice-poor sand was found to from these zones into the holes, resulting in freeze-be operationally easy to core in comparison to ice- in of the core barrel and abandonment of thatpoor silt or clay. The noncohesive, granular na- hole.ture of the cuttings appears to be the reason forthis difference.

Difficulty was experienced in relatively dry fro- DEPTH AND HOLEzen silt or silty clay. In these materials, cuttings be- COMPLETION TIMEcame plastic, balled up, jammed between the holewall and core barrel and caused the barrel to stick Thus far, we have continuously core sampled ain the hole. The barrel often froze in place as soon total of 168 holes from which about 1092 m ofas rotation ceased. Although we have cored to core samples have been collected for research pro-depths of 15 m in these materials, excessive strains jects. In addition, two open holes to depths of 12on the drill were experienced. Dry frozen silts or m have been augered with the 57-mm augers.clays at temperatures above -5 'C should be con- Materials core sampled have ranged from clay-sidered a material limitation of the prototype to coarse-sand-size, with ice volumes ranging fromsystem. 10 to 10007o. Large bodies of massive ground ice

Casing must be used in near-surface highly or- have also been continuously cored, as have frozen,ganic-rich materials or peat that have been partly organic-rich materials and peat.thawed or contain a relatively large volume of un- The time necessary to complete each hole is gov-frozen water. Water in these materials seeps into erned by the material type sampled, condition ofthe hole, where it freezes and reduces the hole's di- the barrel, proficiency of the operators and coreameter, thereby preventing the core barrel from retrieval efficiency. Because these factors varybeing removed. from hole to hole, it is not possible to accurately

The coring auger cannot routinely cut cores in define the rate at which a given length of core cansediments with a grain-size larger than coarse be sampled. The first 10 m of core is typically ex-sand. When gravel is encountered, damage to one tracted in less than 5 hours. Sampling the 10- toor both carbide cutters is probable. The carbide 20-m depth increment will require additional timecutters are capable, however, of cutting through because of the increase in time needed to lowercalcareous gravel-rich sand. We have also augered and raise the drill string. We feel that the ability tothrough surface gravels to a depth of 2.4 m, both acquire I-m-long core samples will be forthcomingfrozen and unfrozen. Augering frozen gravel is and the time to continuously sample to depths ofnot recommended because of the adverse effects approximately 20 m reduced to less than one day.on the drill.

The temperature of the permafrost is an impor-tant factor that can vary considerably. For exam- SUMMARYpie, material with a temperature below about -3 'Cproduced few problems if the active layer was fro- A portable and lightweight drill system that canzen and air temperatures were below freezing. In auger and core-sample perennially frozen groundcontrast,coring of warm permafrost (-I to -0.5 'C) of clay- to coarse sand-size has been developedunder cold winter ambient temperatures caused through field use. Basically unaltered core samples --

problems because the sediment near the surface obtained with a modified CRREL coring auger arewas colder than the samples extracted from a useful for both chemical and physical analyses.greater depth. As soon as the warmer cuttings on The base unit for this drill is inexpensive and, withthe barrel flights came in contact with the colder total modifications described in this report, esti-

28

mated to cost about $10,000. It is designed for Lawson, D.E. (1982) Long-term modifications ofsafe use by persons with little or no experience in perennially frozen sediment and terrain at Eastdrilling operations, although as experience with Oumalik, northern Alaska. CRREL Report 82-36,the drill and CRREL coring auger is gained, the 30 pp.number of high quality core samples recovered Lawson, D. and B. Brockett (1980) Drilling andwill increase. Off-road transport can be accom- coring of frozen ground in northern Alaska, springplished with light plane, helicopter, tracked vehi- 1979. CRREL Special Report 80-12, 14 pp. ADAcle or snow vehicle, and the drill can be towed over 084277.roads. With the use of a winch, the drill is locally Lawson, D.E., J. Brown, K.R. Everett, A.W.self-mobile. Johnson, V. KomuirkovA, B.M. Murray, D.M.

Continuous samples have been acquired to a Murray and P.J. Webber (1978) Tundra distur-depth of 22.5 m and we anticipate being able to bances and recovery following the 1949 explora-reach depths around 30 m in ice-rich sediments, tory drilling, Fish Creek, northern Alaska. CRRELVarious external factors that affect the capabilities Report 78-28, 112 pp. ADA 065192.of the drill include the weather, local topography, Lawson, D.E. and J. Brown (1979) Human-sediment grain size, ice content of the sediment, induced thermokarst at old drill sites in northernground temperatures and presence of surface and Alaska. The Northern Engineer, 10(2): 16-23.ground water. The ideal materials for continuous- Mellor, M. and P. Sellmann (1975) General con-ly coring with this drill and coring auger are ice- siderations for drill system design. CRREL Techni-rich silt and ground ice, but high quality cores can cal Report 264. ADA 012646.be obtained of silty clay to coarse sand-size sedi- Nixon, M. (1977) ATV-Drill performance: A casement containing varying amounts of ice. Develop- study, Fort Simpson, District of Mackenzie. Sci-ment and refinement of the drill system are conti- entific and Technical Notes. In Current Research,nuing. Part B. Geological Survey of Canada, Paper

78-1B, pp. 212-214.Sellmann, P. and J. Brown (1965) Coring of fro-

LITERATURE CITED zen ground, Barrow, Alaska. Spring 1964. CRRELSpecial Report 81. AD 472341.

Davis, R.M. and F.F. Kitze (1967) Soil sampling Sellmann, P.V., R.I. Lewellen, H.T. Ueda, E.and drilling near Fairbanks, Alaska: Equipment Chamberlain and S.E. Blouin (1976) Operationaland procedures. USA Cold Regions Research and report: 1976 CRREL-USGS subsea permafrost pro-Engineering Laboratory, CRREL Technical Re- gram, Beaufort Sea, Alaska. CRREL Special Re-port 191. AD 816654. port 76-12. ADA 032440.Esch, D.C. (1982) Portable powered probe for Ueda, H., P. Sellmann and G. Abele (1975) USApermafrost. State of Alaska, Department of CRREL snow and ice testing equipment. CRRELTransportation and Public Facilities, Fairbanks, Special Report 146, 14 pp. ADA 01512.Report No. FHWA-AK-RD-83-12, 13 pp.

29

.- * , . . o .i :- .' - .

A facsimile catalog card in Library of Congress MARCformat is reproduced below.

Brockett, Bruce E.Prototype drill for core sampling fine-grained

perennially frozen ground /by Bruce E. Brockett andDaniel E. Lawson. Hanover, N.H.: Cold Regions Re-search and Engineering Laboratory; Springfield, Va.:available from National Technical Information Ser-vice, 1985.v, 34 p., illus.; 28 cm. (CRREL Report 85-1.)Bibliography: p. 29.1. Arctic regions. 2. Augers. 3. Core sampling.

4. Coring auger. 5. Drilling machines. 6. Fine-grained materials. 7. Frozen ground sampling.8. Ground ice. 9. Permafrost. I. Lawson, Daniel E.Il. United States. Army. Corps of Engineers.III. Cold Regions Research and Engineering Labora-tory, Hanover, N.H. IV. Series: CRREL Report 85-1.

FILMED

5-85

DTIC