US2403002A - Apparatus for undisturbed overburden sampling - Google Patents

Description

July 2, 1946. H. L. JOHNSON 2,403,002

APPARATUS FOR UNDISTURBED OVERBURDEN SAMPLING Filed March-6, 1940 4 Sheets-Sheet 1 Fly. 1

ATTORNEY.

July 2, 1946. JOHNSON APPARATUS FOR UI ID'.[STURB]:'1D OVERBURDEN SAMPLING Filed March 6, 1940 4 Sheets-Sheet 2 L... 4 I h 30 INVENTOR. 'f/en Lrjbknsrm Q ATTORNEY.

July 2, 1946. H. L. JOHNSON ,00

APPARATUS FOR UNDISTURBED OVERBURDEN SAMPLING Filed March 6, 1940 4 Sheets-Sht 3 IIIIHIIIII Henry .L.J 07zns0n y 1946- H. L. JOHNSON A A 2,

APPARATUS FOR UNDISTURBED OVERBURDEN SAMPLING sampling operations.

Patented July 20, 1946 UNITED STATES PATENT omos APPARATUS roe UNDISTURBED OVERBURDEN SAMPLING Henry L. Johnson, Denison, Tex. Application March 6, 1940, Serial No. 322,545

(Granted under the act of March 3, 1883, as

This invention described herein may bemanufactured and used by or for the Government for v governmental purposes, without the payment to me of any royalty thereon.

This invention relates generally tothe art ofamended April 80, 1928; 370 '0. G. 757) date the conditions met in the natural deposits below the'wat'er table, and to provide for the renewal of shoe cutting teeth, when they become worn, dull, or broken, and the extracting of the sample in such manner that it is undisturbed.

Another object of theinvention is to provide a sampling device which i of simple, economical, and durable construction, and one which may be easily and quickly attached to standard drill rods and operated with a standard rotary-type coredrilling rig of suitable size, and easily cleaned.

Another object of the invention i to provide a means of carrying away cuttings by use of a circulated mud or viscous and thixotropic fluids, which form a filler and support the drill hole walls to prevent caving and contamination oi the sample, and eliminates the needof casing to maintain the hole in an open condition. durin r A further object of the invention is to provide means for obtaining a continuous and undisturbed sample uncontaminated by drilling mud or cuttings of overburden or similar materials, from deposits of such materials in situ.

' The invention which forms the subject matter of this application relates. to means for sampling gravels, sand, silts, and mixtures thereof, in which the drilling mud, or viscous and thixotropic fluid, is introduced and .clrculated in the drill hole and sampling device in such a manner as to carry away the cuttings from the materials being cut by suspension in said mud or fluid without contaminating the sample. I

Certain classes of overburden or similar materials in situ are very dimcult to sample. The difflculty arises in deposits below the natural water being sampled to overcome this dimculty.

The improved apparatus for efiecting sampling operations may be utilized in the following forms of engineering work:

Sampling of natural foundation materials in situ. for all types of structures; fOr foundation studies; and

Sampling .of materials placed in earth'dams, dam levees, and dikes for test purposes.

Referring. more particularly to the accompanying drawings in which corresponding P rts are indicated by similar reference characters:

, Figures 1 and 2, together, comprise a side sectionalized view of the sampling device.

Fig. l is a side, centrally sectionalized elevation of the top portion of the sampling .device; and fits above Fig. 2 which is a side centrally sectionalized elevation of the bottom portion of the sampling device: a

Fig. 3 is an end elevation of a standard rota ytype core-drilling ri provided with a pump for circulating the drill mud .or viscous and thixotropic fluid, and fitted with standard drill rod connecting the drill rigwi-th the sampling device;

and

Fig. 4 is an enlarged sectionalized view or the sampler, and indicates the circulation of the drill mud in the sampler, all shown in Fig. 3.

The sampling device consists of an outer drill barrel head I, with threaded hole at 4 to take standard drill rods, and an outer core barrel 20, which are coupled to an inner barrel head 18 and an inner barrel It by means of a hollow spindle shaft H to permit the inner barrel is to remain stationary while the outer barrel 20 is rotated. The inner barrel i9 is equipped with a L check valve 22 having a soft rubber facing 23 toprovide a tight seal, a valve seat 24 having valve guides 25 welded to the valve seat 24 as shown at M, a sample catcher ring 3| fitted with flexible springs 32, a sample cutting shoe 29, and

rotary drill forces the sampler downward into table which are ina quick or semi-quick conditi ne sampling device may be fitted with the material being sampled and the drill imparts a rotary motion to the outer barrel 2!! and it cuttingshoes of variable lengths to accommo as shoe 28 and cutting teeth '30 while drilling mud or fluid is being circulated through the sampler via the hollow drill rods by means of a slush pump. In operation, the device is forced downward into the material to be sampled while the drill is rotating and drilling fluid or mud is circulated. l

The downward thrust of the drill rod is transmitted through the outer barrel headto the inner barrel l9 and the sample cutting shoe 29 by means .of the hollow spindle shaft I5 attached to the inner barrel head I6 and secured by lock nut I8. To permit the inner barrel l9 and the spindle shaft Hi to remain stationary while the outer barrel 20 is rotating, the spindle shaft is equipped with a ball thrust bearing 8 and a bronze ring bearing Ill. To prevent water, drilling fluids, grit, etc., from gaining access to bearings 8 and III, the outer barrel head i is recessed to take four felt grease retainers 9 which fit around the upper end of the hollow spindle shaft i5, and is equipped with a packing box l4, containing packing l3, which is automatically compensated for wear by means of packing washer I2, upon which the coil spring exerts a continuous pressure. The outer barrel head I is also provided with a grease port 5 which is closed by stud bolt 6 seated against a copper' washer l to make a tight seal.

When a sample is taken, the protruding sample cutting shoe 29 enters the material being sampled and is prevented from rotating by its downward pressure and friction between the shoe and the material, thus causing the inner barrel l9 and all of its parts to remain stationary. Meanwhile the outer barrel 20, its shoe 28 of varying lengths depending on the material cut, and the cutting teeth 30 are rotated and drilling mud or fluid circulated to remove material through which the sample cutting shoe 29 has passed. The drilling mud or fluid is pumped down the hollow drill rods and enters the sampler by way of the inlet ports 3-in the outer barrel head I and passes downward between the inner barrel l9 and outer barrel 20 and their shoes 29 and 28, escaping under the edge of the outer barrel shoe 28, returning upward to the surface between the outer barrel 20 and the side of the drill hole, carrying the material loosened by the cutting teeth 30 up with it.

As the sampler penetrates the material being sampled, the sample cutting shoe 29 cuts the sample, which enters the shoe 29 and passes upward through the core catcher ring 3|, forcing the springs 32, which retain the sample in the sampler when it is extracted from the hole, to open and allow the sample to pass up into the thin sheet metal sample tube 21, which is inserted in the inner barrel l9 prior to inserting the core catcher ring 3| with its attached springs 32 and attaching the sample cutting shoe 29 preparatory to taking the sample. As the sample enters the inner barrel, the drilling fluid entrapped therein, when the sampling device is lowered into the hole which is kept full of drilling fluid to prevent caving, is forced upward through the valve seat 24 inserted in the inner barrel l9 and held in place by studs 26, lifting the check valve 22 which is faced with soft rubber 23 to provide a tight seal when the valve is closed.

The check valve is kept in proper alignment by r the guides 25 which are welded 2| to the valve seat 24.

After passing through the valve, the drilling fluid escapes from the inner barrel l9 outlet ports 2 into the drill hole above the sampler.

Drilling muds or fluids of a thixotropic nature are used because they plaster and support the sides of the hole to prevent caving and thereby eliminate the need of casing, and because by their consistency they readily carry cuttings to the surface and do not penetrate the materials being sampled for more than a fraction of an inch.

For-facilitating assembly and disassembly, the inner barrel head I6 is provided with spanner wrench sockets H.

In operation the undisturbed overburden sampler described above is actuated-by means of a rotary core drill rig using hollow drill rods and equipped with a suitable slush pump. One type of such rig and the general setup of the apparatus is diagrammatically shown by Figure 3.

In practice the top three or four feet of material are sampled with an ordinary drive sampler, the hole 34 reamed out and a short length of casing 33 inserted to protect the top of the hole 34, The undisturbed overburden sampler Figures 1 and 2 is then attached to the hollow drill rods 43 which pass through the chuck 38 and the Kelly stem 40 of the drill rig. The sampling device is lowered to the bottom of the hole 34, the drill rods clamped into the chuck 38 and a downward pressure exerted by hydraulic cylinders 4| which is transmitted by the hollow drill rods 43 to the sampling device. Rotary motion is imparted to the sampling device by the rotary table 39 via the Kelly stem 40 and the hollow drill rods 43. As soon as downward thrust and rotation are imparted to the sampling device the slushpump 59 is put in operation. The pump 50 picks up the drilling fluid 38 from the tank 48 by means of intake 49 and forces it through hose 46 to water swivel 44 and thence through the hollow drill rods 43 to the sampling device. The drilling fluid 36 enters and passes through the sampling device as shown by enlarged Figure 4 and escapes by rising upward in the hole 34 in the overburden 35, through the casing 33 to the overflow trough 41 and thence back to tank 48.

As the sample 31 enters the sample tube 21 of the sampling device, the drilling fluid 36 entrapped therein when the sampling device is lowered to bottom of the hole 34, which is kept full of drilling fluid 36 at all times, vents into the hole 34 as shown in Figures 3 and 4, by arrows.

The drill rig shown in Figure 3 is of the truck 3lmounted type, equipped with a folding mast 42 to permit hoisting of the tool by means of line 45.

I am aware that prior-to my invention double core barrels connected by a bearing swivel have been used for coring rock. I therefore do not claim such a, combination broadly; but I claim:

An undisturbed soil sampling apparatus comprising a drill barrel, a drill head at one end of the barrel and a drilling shoe at the other, a core barrel within the drill barrel, said barrel including a. displaceable liner for facilitating removal of the core adapted to be formed in said liner, means associated with the core and drill barrels for hydraulically removing drill cuttings and loose material from the operating zone of the drilling shoe, means connecting the barrels so as to permit the drill barrel to be rotated relative to. the core barrel, said means including a passage establishing communication between the interior of the core barrel and conduits formed in the drill head and opening to its exterior, valve means within the upper portion of "the core barrel, said valve means being normally closed but operable to efl'ect communication between the space below said valve means and the lower end of said passage, whereby fluid entrapped in the core barrel will be vented to the exterior of the drill barrel without exposure to the pressure of the circulating drill fluid, means in connection with said barrel head for simul- 6 taneously imparting movement to the drill barrel and a downward soil penetrating movement to the core barrel; and means in connection with l the lower end of the core barrel and enacting '5 with said barrel to seal the interior of the barrel against the entrance of the drilling fluid.

HENRY L. JOHNSON.

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