GB2480345A

GB2480345A - Soil sample scored liner

Info

Publication number: GB2480345A
Application number: GB1101975A
Authority: GB
Inventors: Ceri Copping
Original assignee: ARCADIS
Current assignee: ARCADIS
Priority date: 2010-05-12
Filing date: 2011-02-04
Publication date: 2011-11-16
Also published as: GB201007911D0; GB201101975D0; GB2480290A

Abstract

Soil sampler liner 2 comprising an outer wall 4 defining a longitudinally extending hollow body 6 arranged to retain a soil sample. The outer wall 4 of the sheath 2 has at least one line of weakness 16 extending longitudinally along the body 6. The outer wall 4 is separable for removal of the sample from sleeve 2. The liner can be tearable along the scored line of weakness. The wall 4 may have a living hinge so after the wall has been separated along a line of reduced thickness the wall may be folded about the hinge. Lines of weakness may be formed alongside one another to form a tear strip (30, Fig. 5). The liner may be made from a plastic materia The hollow body may have one or two open ends.

Description

SOIL SAMPLER LINER

This invention relates to soil sampler liners.

Soil samples are commonly obtained using a soil sampler having a cylindrical soil barrel. The soil barrel is inserted into the ground to cut a cylindrical core of soil from the ground. The soil barrel is then extracted from the ground with the core of soil contained therein. The soil barrel is typically fitted with a tubular sampler liner within which the core of soil is contained. The sampler liner facilitates removal of the sample from the soil barrel and reduces the likelihood of contamination of the sample during subsequent handling of the sample. Once the sampler liner containing the core has been removed from the soil barrel, the sampler liner is separated along its length and the sampler liner is forced apart to remove the sample.

A sampler liner must be sufficiently robust to withstand the forces applied to the liner as it is inserted into soil with the soil barrel, and retain the soil sample intact once removed from the soil barrel; for example, to prevent the sample from being damaged by excessive flexing of the sampler liner.

It is known to manufacture sampler liners from plastics such as polyvinyl chloride (PVC) because the material may be made sufficiently thick to provide the necessary rigidity, whilst being relatively low cost to manufacture. Such sampler liners are relatively tough and must be cut along their length in order to separate the sampler liner for removal of the sample. A user must therefore use a knife or similar cutting implement to remove the sample. This can be inconvenient and dangerous.

According to a first aspect of the invention there is provided a soil sampler liner comprising an outer wall defining a longitudinally extending hollow body arranged to retain a soil sample, the outer wall having at least one line of weakness extending in a longitudinal direction of the hollow body, the outer wall being separable along the line of weakness for removal of the sample from the hollow body.

The outer wall may be tearable along the line of weakness.

The outer wall may comprise a living hinge which extends in a longitudinal direction of the hollow body such that after the outer wall has been separated along the line of weakness it can be folded about the living hinge.

There may be first and second lines of weakness that extend in the longitudinal direction of the hollow body.

The first and second lines of weakness may be substantially parallel.

The first and second lines of weakness may be spaced from one another such that they define a first tear strip which may be torn away from the remainder of the outer wall. The width of the first tear strip may be not more than 10mm.

The outer wall may have a third line of weakness extending in the longitudinal direction of the hollow body.

The third line of weakness may be spaced from the first tear strip by not less than 90 degrees.

The third line of weakness may be spaced from the first tear strip by not less than 110 degrees and not more than 130 degrees.

The outer wall may have a fourth line of weakness extending in the longitudinal direction of the hollow body which is spaced from the third line of weakness such that they define a second tear strip which may be torn away from the remainder of the outer wall.

The width of the second tear strip may be not more that 10mm.

The second tear strip may be spaced from the first tear strip by not less than 90 degrees.

The second tear strip may be spaced from the first tear strip by not less than 110 degrees and not more than 130 degrees.

The, at least one or both of the tear strips, may comprise a tab portion for engagement by a tear strip removal tool.

The line of weakness, or at least one of the lines of weakness, may comprise a groove intheouterwall.

The groove, at least one of the grooves or all of the grooves may be formed in the outer surface of the outer wall.

The thickness of the outer wall in the vicinity of the groove, at least one of the grooves or all of the grooves may be such that the outer wall can be torn along the groove or grooves.

The thickness of the outer wall along the length of the groove, or at least one of the grooves, may be not more than 0.4mm.

The soil sampler liner may be made of a plastics material, such as polyvinyl chloride (PVC). The soil sampler liner may be extruded.

The hollow body may have at least one open end. The or at least one of the lines of weakness may extend from the open end. The hollow body may have first and second open ends. The or at least one of the lines of weakness may extend from the first open end to the second open end.

The or at least one of the lines of weakness may extend parallel with the hollow body.

According to a second aspect of the invention there is provided a method of manufacturing a soil sampler liner in accordance with any one of the preceding claims, comprising the steps: (a) heating a plastics material until molten; (b) extruding the molten plastics material through a die to produce the outer wall; and (c) producing at least one line of weakness in the outer wall.

The line of weakness may be produced by scouring a groove in the outer wall.

Step (b) may comprise allowing the plastics material to cool once it has been extruded.

The plastics material is water cooled. Step (c) may be performed during cooling.

The plastics material may be polyvinyl chloride (PVC). The PVC may be heated to at least 260 degrees.

In order to better understand the present invention and to show more clearly how it may be carried into effect, reference shall be made, by way of example, to the following drawings of which:-Figure 1 is a schematic representation of a first embodiment of a sampler liner; Figure 2 is a partial sectional view of the sampler liner shown in Figure 1; Figure 3 is a perspective view of the sampler liner shown in Figure 1 during use; Figure 4 is a schematic representation of a second embodiment of a sampler liner; Figure 5 is a schematic representation of a third embodiment of a sampler liner; Figure 6 is a partial view of the sampler liner shown in Figure 5 during use; Figure 7 is a schematic representation of a fourth embodiment of a sampler liner; Figure 8 is a partial view of the sampler liner shown in Figure 7 during use; Figure 9 is a partial view of the sampler liner shown in Figure 7 following separation; and Figure 10 is a schematic representation of a soil sampler.

Figure 1 shows a soil sampler liner 2 comprising a cylindrical outer wall 4 which defines a tubular hollow body 6. The cylindrical outer wall 4 has an inner surface 8 and an outer surface 10. The tubular body 6 is open at first and second ends 12, 14. The outer wall 4 is made from polyvinyl chloride (PVC), such as uPVC, which may be transparent or translucent. The outer wall 4 has a substantially constant thickness.

The nominal thickness of the outer wall 4 is between 0.5mm and 2mm, and may be between 1mm and 1.5mm, for example 1.2mm. The nominal thickness of the outer wall 4 should be such that the outer wall 4 is rigid. In one embodiment, the outer wall 4 is sufficiently rigid to resist excessive deformation of the sampler liner 2 which could damage a sample contained within the sampler liner 2.

In this embodiment, the tubular body 6 has an outer diameter of 52.5mm, 87mm, 97mm or 124mm. However, it will be appreciated that the outer diameter of the tubular body 6 may be sized according to purpose and is not limited to these dimensions.

A line of markers in the form of a scoured groove 16 extends longitudinally along the outer surface 10 of the outer wall 4 from the first end 12 to the second end 14. The groove 16 is substantially parallel with the axial direction of the tubular body 6.

However, in other embodiments groove 16 may have a circumferential component therefore is not parallel with the axial direction of the tubular body.

As shown in Figure 2, the groove 16 has side walls 18, 20 and a bottom 22. The groove 16 defines a minimum wall thickness of the outer wall 4 between the bottom 22 and the inner surface 8, and so provides a line of weakness in the outer wall 4 which extends from the first end 12 to the second end 14. In this embodiment, the minimum wall thickness defined by the groove 16 is between 0.1mm and 1mm, and may be between 0.2 and 0.6mm, for example 0.4 mm. In the embodiment shown, the outer waIl 4 has a nominal thickness of 1.2mm and a groove 16 having a depth of 0.8mm, thereby defining a minimum wall thickness of 0.4mm.

The minimum wall thickness is such that the outer waIl 4 can be torn along the groove 16 when a portion of the outer waIl 4 adjacent the groove 16 is peeled away from the longitudinal direction of the body 6. It will be appreciated that and that this will depend on the strength of the PVC from which the outer waIl 4 is manufactured and the minimum thickness of the outer waIl 4. Furthermore, the ratio of the nominal wall thickness to the minimum wall thickness is sufficient to ensure that the outer waIl 4 tears along the groove 16 and not along another part of the outer waIl 4. For example, the ratio of the nominal wall thickness to the minimum wall thickness may be not less than 1.2:1, and may be not less than 1.5:1.

In use, the soil sampler liner 2 is placed into a soil barrel 102 of a soil sampler 100 such as that shown in Figure 10. The soil barrel 102 and liner 2 are then inserted into the ground and subsequently retrieved to remove a soil sample. The soil sampler liner 2 is then removed from the soil barrel 102 with the soil sample retained inside the liner 2.

Once the sampler liner 2 has been removed from the soil barrel, the region of the outer wall 4 adjacent the groove 16 and atone end 12, 14 of the sampler liner 2 is gripped by fingers, pliers or other suitable gripping means. The outer wall 4 is then peeled from the end 12, 14 at which it is gripped in a direction generally away from the groove 16 along the length of the tubular body 6. The shear force applied by the peeling action causes the outer wall 4 to separate along the line of weakness defined by the groove 16. The strength of the outer wall 4 along the line of weakness is such that the outer wall 4 can be separated along its length without the aid of cutting means. The outer wall 4 is then parted and the sample 24 removed from the sample liner 2, as shown in Figure 3.

Figure 4 shows a second embodiment of a sampler liner in which, in addition to a groove 16 such as that described with respect to the first embodiment, a hinge groove 26 or living hinge is provided in the outer surface 10 of the outer wall 4. The hinge groove 26 extends along the entire length of the tubular body 6 from the first end 12 to the second end 14. The hinge groove 26 is disposed diametrically opposite the groove 16 and is therefore spaced apart from it by approximately 180 degrees. The hinge groove 26 acts as a living hinge which, once the outer wall 4 has been separated along the groove 16, enables the outer wall 4 to be flexed apart or folded along the hinge groove 26. This improves the ease with which the sample can be removed.

Figure 5 shows a third embodiment of a sampler liner 2 in which a first line of weakness in the form of a first groove 16 and a second line of weakness in the form of a second groove 28 are provided in the outer wall 4. The second groove 28 is substantially identical to the first groove 16 in this embodiment. The second groove 28 is parallel with the first groove 16 and is angularly spaced apart from the first groove 16 about the longitudinal axis of the tubular body 6. The first and second grooves 16, 28 define an elongate tear strip 30 between them which extends from the first end 12 to the second 14 of the tubular body 6. The angular spacing of the grooves 16, 28 is such that the width of the tear strip 30, measured in the circumferential direction, is not more than 20mm, and may be not more than 10mm.

A hinge groove 26 or living hinge, such as that described with respect to the second embodiment, is also provided in the outer wall 4. The hinge groove 26 is angularly spaced apart from the tear strip 30, about the longitudinal axis of the tubular body 6, by not less than 90 degrees, and may be at about 120 degrees.

Referring to Figure 6, in order to remove a sample from the sampler liner 2, an end of the tear strip 30 is gripped by fingers, pliers or other suitable gripping means and the tear strip 30 is pulled away from the tubular body 6 to tear the outer wall 4 along the first and second grooves 16, 28 simultaneously. Removal of the tear strip 30 is therefore an unzipping action.

Once the tear strip 30 has been torn away from the remainder of the outer wall 4, the outer wall 4 is opened or folded about the hinge groove 26 and the sample is removed from the sample liner 2.

The hinge groove 26 may also provide a line of weakness along which the outer wall 4 can be further separated. For example, once the tear strip 30 has been removed, the portion of the outer wall 4 defined between the tear strip 30 and the hinge groove 26 can be torn away from the remainder of outer wall 4 along the hinge groove 26.

Consequently, a larger proportion of the outer wall 4 can be removed to facilitate removal of the sample. This may be advantageous in that deformation of the outer wall 4 by pressing apart the outer wall 4 is reduced, thereby lessening the likelihood of damage to the sample.

Figure 7 shows a fourth embodiment of a sampler liner 2 in which, in addition to a first tear strip 30, such as that described with respect to the third embodiment, a second tear strip 32 defined between a third line of weakness in the form of a third groove 34 and a fourth line of weakness in the form of a fourth groove 36. In this embodiment, the second tear strip 32 is similar to the first tear strip 30 and is parallel to the first tear strip 30. The first and second tear strips 30, 32 are angularly spaced apart from each other, about the longitudinal axis of the tubular body 6, by not less than 90 degrees, and may be by 120 degrees. The first and second tear strips 30, 32 define a panel 34 of the outer waIl 4 which subtends the angle between the tear strips 30, 32.

To remove a sample from the sampler liner 2, the first tear strip 30 is torn away from the outer wall 4. The panel 34 and the remainder of the outer wall 4 are then held firmly against the sample within the sampler liner 2 and the second tear strip 32 is torn away from between them, as shown in Figure 8. The panel 34 is then lifted away from the sample, as shown in Figure 9, and the sample removed through the opening which extends along the length of outer wall 4.

The first and/or second tear strip 30, 32 may comprise a tab portion (not shown) at one end. The tab portion may be a protrusion from the outer wall 4 in a radially outward direction or in a longitudinal direction. The tab portion is readily gripped by fingers, pliers or other gripping means without disturbing a sample within the sampler liner 2.

The tab portion is pulled to tear the tear strip 30, 32 from the remainder of the outer wall 4.

A key may be provided for gripping the tab portion. The key may, for example, have a lengthwise slot into which the tab portion is inserted. With the tab portion inserted through the slot, the key is wound along the length of the tear strip 30, 32 to wind the tear strip 30, 32 onto the key thereby tearing the tear strip 30, 32 away from the outer wall 4.

The embodiment described with respect to Figure 7 may be provided with a living hinge such as that described with respect to the embodiments shown in Figures 4 and 5.

The groove or grooves, including the hinge grooves, may be provided in the inner surface or the outer surface of the outer wall. Where there are two or more grooves in the outer wall, at least one of the grooves may be provided in the radially outer surface of the outer wall, and the other provided in the radially inner surface of the outer wall.

Other combinations are possible.

The body can be other forms of hollow elongate body, for example an elongate body having an elliptical cross-section, or a polygon-shaped cross-section such as, but not limited to, a triangular or quadrilateral cross-section.

The lines of weakness can be defined in the outer wall by other suitable means. For example, perforated lines could be provided in the outer wall. Alternatively, a portion of the outer wall can be made from a material having a lower tear strength, or from the same material formed to have a lower tear strength. It will be appreciated that a direct pulling or twisting action could be used to separate the outer wall along the line or lines of weakness.

A method of manufacturing a sample liner according to any one of the first to fourth embodiments comprises the steps of placing granules, or pellets, of PVC (e.g. uPVC) in a hopper. The granules of PVC are transported to a tool dye, for example by an Archimedes screw arrangement. The PVC is continually heated as it travels from the hopper to the tool die so that upon reaching the tool die the PVC is molten. Typically, the PVC is heated to a temperature of 260 degrees centigrade.

The tool dye has a cylindrical shape through which the molten PVC is extruded, for example by forcing the molten PVC through the dye using the Archimedes screw arrangement. As the PVC is extruded through the dye it is cooled so as to solidify the PVC to form the outer wall 4 of the tubular body 6. The PVC is cooled to a temperature at which the extruded outer wall 4 maintains its shape, but the PVC remains plastic. As the PVC exits the dye, the grooves 16, 26, 28, 34, 36 are formed in the outer surface by a scouring tool. The grooves 16, 26, 28, 34, 36 are therefore formed while the PVC is at the temperature at which the PVC is plastic. The PVC is then cooled further using a water cooling process to set the shape of the outer wall 4 and the grooves 16, 26, 28, 34, 36. It will be appreciated that the cooling of the PVC as it passes through the dye and during the subsequent formation of the grooves 16, 26, 28, 34, 36 may be a continual cooling process.

The technical specifications of PVC from which the sampler liner is manufactured are as follows: Cell Classification: 12454 (ASTM D1784) Maximum Service Temp: 140°F Colour: Transparent Specific Gravity, (g/cu.cm @ 73°F): 1.33 (ASTM 0792) Hardness, Shore D: 84 (ASTM D2240) Hazen-Williams Factor: C = 150

MECHANICAL PROPERTIES

Tensile Strength, psi @ 73° F: 7,260 (ASTM D638) Tensile Modulus of Elasticity, psi @ 73°F: 392,000 (ASTM D638) Flexural Strength, psi @ 75°F: 12,000 (ASTM D790) Flexural Modulus, psi @ 75°F: 389,000 (ASTM D790) Compressive Strength, psi @ 75° F: 8,300 (ASTM D695) Compressive Modulus, psi @ 75°F: 307,000 (ASTM D695) Izod Impact notched -Method A, with Grain-Comp. Molded, .125 in. bars, 73°F 8.Oft-lbs./in. (ASTM D256) Izod Impact notched -Method A, against Grain-Comp. Molded, .125 in. bars, 73°F 2.0 ft-Ibs./in. (ASTM 0256)

THERMAL PROPERTIES

Coefficient of Linear Expansion (inlinl°F): 4.1 x 10-5 (ASTM D696) Heat Distortion Temp., Unannealed, 264 psi, .125 in. Bars: 154°F (ASTM D648) Glass Transition Temp.: 176°F

FIRE PERFORMANCE

Flammability Rating: V-0 (UL-94) Although PVC is the preferred material from which the sampler liner is manufactured, it will be appreciated that other types of material would be suitable provided a line of weakness can be formed in the outer wall of the sampler liner along which the outer wall is separable.

The sampler liner may be opened in a safe manner, and in accordance with health and safety requirements. The sampler liner aids in the sampling of soil and rock during site investigation activities without the need for knives, thus improving health and safety during sampling operations.

The sampler liner may comprise a 1.2mm thick UPVC wall with scour lines, 0.8mm in depth, pre marked into the sample liner. As such, a pair of pliers would be sufficient to pull the scoured strip back allowing sufficient access to the ground removed for sampling requirements.

The sampler liner may comprise a single scour line at 2 o'clock and a double scour line 10mm apart at 10 o'clock. The sampler liner may comprise a double scour line to be positioned on opposing sides, positioned 10mm apart. The sampler liner may comprise a sampler liner that is pre-scored for purposes of extracting samples without the need for knives.

The sampler liner may be a pre-scored sample liner for use sampling soils and rocks during drilling operations without the need for opening using tools with bladed properties.

The sampler liner may have a wall thickness 1.2mm. Scour lines may be cut to a depth of 08mm. Single scour line may be at 2 o'clock. Double scour lines may be at 10mm apart at 10 o'clock. The sampler liner may have a wall thickness 1.2mm. Scour line may be cut to a depth of 0.8mm. Double scour line may be on opposing sides 10mm wide.

Claims

CLAIMS1. A soil sampler liner comprising an outer wall defining a longitudinally extending hollow body arranged to retain a soil sample, the outer wall having at least one line of weakness extending in a longitudinal direction of the hollow body, the outer wall being separable along the line of weakness for removal of the sample from the hollow body.
2. A soil sample liner as claimed in claim 1, wherein the outer wall is tearable along the line of weakness.
3. A soil sampler liner as claimed in claim 1 or 2, wherein the outer wall comprises a living hinge which extends in a longitudinal direction of the hollow body such that after the outer wall has been separated along the line of weakness it can be folded about the living hinge.
4. A soil sampler liner as claimed in any one of claims 1 to 3, wherein there are first and second lines of weakness that extend in the longitudinal direction of the hollow body.
5. A soil sampler liner as claimed in claim 4, wherein the first and second lines of weakness are substantially parallel.
6. A soil sampler liner as claimed in claim 4 or 5, wherein the first and second lines of weakness are spaced from one another such that they define a first tear strip which may be torn away from the remainder of the outer wall.
7. A soil sampler liner as claimed in claim 6, wherein the width of the first tear strip is not more than 10mm.
8. A soil sampler liner as claimed in claim 6 or 7, wherein the outer wall has a third line of weakness extending in the longitudinal direction of the hollow body.
9. A soil sampler liner as claimed in claim 8, wherein the third line of weakness is spaced from the first tear strip by not less than 90 degrees.
10. A soil sampler liner as claimed in claim 9, wherein the third line of weakness is spaced from the first tear strip by not less than 110 degrees and not more than 130 degrees.
11. A soil sampler liner as claimed in claim 8 to 10, wherein the outer wall has a fourth line of weakness extending in the longitudinal direction of the hollow body which is spaced from the third line of weakness such that they define a second tear strip which may be torn away from the remainder of the outer wall.
12. A soil sampler liner as claimed in claim 6, wherein the width of the second tear strip is not more that 10mm.
13. A soil sampler liner as claimed in claim 11 or 12, wherein the second tear strip is spaced from the first tear strip by not less than 90 degrees.
14. A soil sampler liner as claimed in claim 13, wherein the second tear strip is spaced from the first tear strip by not less than 110 degrees and not more than 130 degrees.
15. A soil sampler liner as claimed in any one of claims 6 to 14, wherein the, at least one or both of the tear strips, comprises a tab portion for engagement by a tear strip removal tool.
16. A soil sampler liner as claimed in any one of the preceding claims, wherein the line of weakness, or at least one of the lines of weakness, comprises a groove in the outer wall.
17. A soil sampler liner as claimed in claim 16, wherein the groove, at least one of the grooves or all of the grooves are formed in the outer surface of the outer wall.
18. A soil sampler as claimed in claim 16 or 17, wherein the thickness of the outer wall in the vicinity of the groove, at least one of the grooves or all of the grooves are such that the outer wall can be torn along the groove or grooves.
19. A soil sampler liner as claimed in claim 18, wherein the thickness of the outer wall along the length of the groove, or at least one of the grooves, is not more than 0.4mm.
20. A soil sampler liner as claimed in any one of the preceding claims, wherein the soil sampler liner is made of a plastics material, such as polyvinyl chloride (PVC).
21. A soil sampler liner as claimed in claimed in claim 20, wherein the soil sampler liner is extruded.
22. A soil sampler liner as claimed in any one of the preceding claims, wherein the hollow body has at least one open end.
23. A soil sampler liner as claimed in claim 22, wherein the or at least one of the lines of weakness extends from the open end.
24. A soil sample liner as claimed in claim 22 or 23, wherein the hollow body has first and second open ends.
25. A soil sample liner as claimed in claim 24, wherein the or at least one of the lines of weakness extends from the first open end to the second open end.
26. A soil sample liner as claimed in any one of the preceding claims, wherein the or at least one of the lines of weakness extends parallel with the hollow body.
27. A soil sampler liner substantially as described herein with reference to, and as shown in, the accompanying drawings.
28. A method of manufacturing a soil sampler liner in accordance with any one of the preceding claims, comprising the steps: (a) heating a plastics material until molten; (b) extruding the molten plastics material through a die to produce the outer wall; and (c) producing at least one line of weakness in the outer wall.
29. A method as claimed in claim 28, wherein the line of weakness is produced by scouring a groove in the outer wall.
30. A method of manufacturing a soil sampler liner as claimed in claim 28 or 29, wherein step (b) comprises allowing the plastics material to cool once it has been extruded.
31. A method of manufacturing a soil sampler liner as claimed in claim 30, wherein the plastics material is water cooled.
32. A method of manufacturing a soil sampler liner as claimed in claim 30 or 31, wherein step (c) is performed during cooling.
33. A method of manufacturing a soil sampler liner as claimed in any one of claims 28 to 32, wherein the plastics material is polyvinyl chloride (PVC).
34. A method of manufacturing a soil sampler liner as claimed in claim 33, wherein the PVC is heated to at least 260 degrees.