JP2001323771A - Core sampling method and core sampling device - Google Patents

Abstract

(57) [Summary] A core sampling device and a core sampling method capable of sampling a wide range of soil and bedrock such as sedimentary soil and soft rock with a single system at a high speed and a high sampling rate. SOLUTION: A foam is generated, and the foam is mixed with fresh water so that the volume ratio of the foam to the fresh water at 1 atm is 5: 1 to 1: 1.
A foam mixing apparatus 3 for producing foam water of 1: 3, an excavator 5 having a rotatable tubular rod 40 having a bit 37 at a tip and an inner tube 43 arranged at a lower end inside thereof; For pumping the drill into the rod of the excavator 3
5, the rod is provided such that the bubbled water pumped into the rod passes between the inner surface of the rod and the outer surface of the inner tube 43 from the inside of the rod, and is ground along the outer surface of the rod via the tip of the rod. With a path that is discharged to

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an apparatus and a method for collecting cores for geological surveys and moisture geological surveys and for drilling for survey boring.

[0002]

2. Description of the Related Art Conventionally, a muddy water boring method is known as one method of collecting cores for geological survey. Although this method is widely used, it has the following problems.

In the core extraction method using mud drilling, sand flows out of the sand layer due to inconsistency in the flow rate and flow velocity of the mud, and similarly, fine particles flow out of the gravel layer, resulting in the conversion of gravel. There was a problem that the sample could not be collected due to movement and biting of the tip of the sampler, or exclusion of pore wall soil.

[0004] In this method, when excavating hard rocks or collecting all cores, when the crushed portion or the weathered zone is approached, the fine-grained portion, which is an interposed object, flows out, and the crushed portion is accordingly discharged. High quality core samples could not be collected at high recovery rates due to disturbances and other reasons.

[0005] Furthermore, in the coring method using muddy water boring, it is necessary to increase the excavation speed to take the sample and to take it into the sampler before the sample does not run off. This was difficult.

Therefore, as a method of compensating for the above-mentioned drawbacks of the muddy water boring, a hard foam is produced by a high-pressure jet, and this is pressed into a boring hole at a high speed and excavated while cutting a soil layer, unconsolidated rock, etc. There is a method of collecting samples. However, this method also has some problems as follows.

That is, when the tip is located in a very deep part, it is difficult to maintain the bubble state, so that the excavation depth cannot be extended. In addition, there is a problem of operational safety because it is necessary to increase the pressure resistance of the foaming / air supply device.

[0008] In addition, due to the limitations of the survey area due to the underground environment due to water quality and groundwater volume, foams are formed in strata containing salt water that is common in San'in and the Hokuriku region, or in coastal strata where seawater is mixed with groundwater. There is a problem that does not occur. In addition, there is another problem that the excavation speed is extremely low, and it is not suitable for collecting all-core samples from the ground surface to an extremely deep depth.

[0009] As another conventional method, there is known a method called "rotary percussion" or "hammer excavation", in which a rotary bit is excavated using muddy water while applying a hitting force to a bit at the tip. The core sample was taken while excavating by vibration or impact. However, this method also has the following problems.

[0010] In other words, in this method, the core is loosened or compacted by vibration in soil or unconsolidated sedimentary rock in order to apply a striking force to the bit, and a good core sample for core identification and physical property test is obtained. It becomes difficult to obtain. Also, this method uses muddy water and is not suitable for investigations that dislike pore wall contamination by highly adsorbent bentonite.

Furthermore, in this construction method, slime generated during excavation is not smooth even in hard rock, unconsolidated rock, and soil, and a large amount of circulating It was necessary to carry out an operation for washing and removing the slime together with the injection of the slime (and also by injecting the inside of the hole with a digging device). In extreme cases, vacuum action when collecting the inner tube causes obstacles such as the introduction of groundwater from surrounding soil and bedrock and boiling, which disrupts the soundness of unconsolidated rock and soil pore walls and bottoms. Was causing it. Also, in the case of hard rock, the fine particles in the crushed part and weathered zone were washed away and the hole wall was also damaged.

Furthermore, in this method, the removal of slime is not smooth, so in the case of unconsolidated rock or soil containing a viscous component, the slime in the core is taken in, for example, by taking in the slime in the core.
Apparent core elongation occurred, which hindered core identification and analysis using the core.

Further, soil and soft rock excavation by this method
The inherent disadvantage of core extraction is that the method of crushing and excavating rock by hitting was originally adopted.If the gravel in the soil or soft rock is equal to or smaller than the diameter of the bit used for excavation, Rocks or gravel cannot be broken in situ properly, and by pushing them out of the bit, they become trapped in the less resistant bit. For this reason, although the core is apparently elongated, a core sample that is actually greatly disturbed is provided.

[0014]

SUMMARY OF THE INVENTION The present invention has been made to solve at least a part of the problems of the above-mentioned conventional method, and is applicable to a wide area such as sedimentary soil or soft rock regardless of the level of the groundwater level. An object of the present invention is to provide a core collecting apparatus and a core collecting method that can collect a sample at a high speed and a high collection rate with a single system for soil and rock in a range.

[0015]

In order to achieve the above-mentioned object, a method of collecting cores according to the present invention comprises a method of mixing foams such that the volume ratio of foam to fresh water at 1 atm is 5: 1 to 1: 3. The step of preparing water, the step of preparing a tubular rod and an inner tube disposed at the lower end inside the rod, and excavating the ground by applying a rotational force to a bit attached to the tip of the rod, A step of collecting a core in the inner tube, and while excavating the ground, passing the foamed water from the inside of the rod to between the inner surface of the rod and the outer surface of the inner tube; And discharging the rod to the ground along the outer surface of the rod.

In the above invention, the component of the foam may be α-paraffinsulfonic acid or a salt thereof. In the above invention, the step of excavating the underground may include a step of applying vibration to the bit.

Further, in the above invention, the volume ratio of the foam to the fresh water in the foam water at 1 atm may be 3: 1 to 1: 3. Further, in the above invention, the volume ratio of the foam to the fresh water in the foam water at 1 atm may be 3: 1.

Further, the core collecting apparatus of the present invention generates foam and mixes the foam with fresh water to produce foam water in which the volume ratio of foam to fresh water at 1 atm is 5: 1 to 1: 3. And a drilling machine comprising a rotatable tubular rod with a bit at the tip and an inner tube located at the lower inside of the rod, and means for pumping the foamed water into the rod of the drilling machine Wherein the foamed water pumped into the rod passes between the inner surface of the rod and the outer surface of the inner tube from the inside of the rod, and the rod of the rod passes through the tip of the rod. It has a path to be discharged to the ground along the outer surface.

In the above invention, the bubble water may have a volume ratio of the bubble to the fresh water at 1 atm of 3: 1 to 1: 3. Further, in the above invention, the bubble water may have a volume ratio of bubble to fresh water of 3: 1 at 1 atm.

In the above invention, the component of the foam is α.
-It may be paraffinsulfonic acid or a salt thereof.
Further, in the above invention, a casing provided with a casing bit at a distal end is provided outside the rod, and a path discharged along an outer surface of the rod is formed by a lower end surface of the bit, an outer surface of the rod, and an inner surface of the casing. May be formed between them.

[0021] In the above invention, the excavator may include a device for applying vibration while rotating the bit, and a wire connected to the inner tube for lifting the inner tube.

[0022]

Embodiments of the present invention will be described below with reference to the drawings. FIG. 1 shows a coring device 1 according to the present invention, which comprises a foaming and mixing device 3 and an excavator 5 as main members. Hereinafter, each of these components will be described.

As shown in FIG. 2, the foaming / mixing apparatus 3 includes two foaming agent tanks 9 each having a capacity of 30 L, and a foaming liquid supply pump 7 is connected downstream thereof. A foaming gun 15 is connected downstream of the foaming liquid supply pump 7 via a foaming liquid flow meter 13. The foaming gun 15 is also connected to a compressor 17 and is set on a control panel 31 via a dry filter 19, a pressure regulating valve 21, a solenoid valve 23, a flow meter 25, a flow regulating valve 27 and a solenoid flow meter 29. The predetermined pressure and air amount can be applied to the foaming gun 15. The foam generated by the foam gun 15 is mixed with the fresh water supplied from the fresh water tank 32 in the static mixer 33 to become foam water, and sent to the foam water supply nozzle 55 of the excavator 5 by the foam water supply pump 35. It has become.

Here, the mixing ratio between foam and fresh water will be described. In the present invention, one of the bubbles before entering the static mixer 33 is used.
The ratio at 1 atm between the volume at atmospheric pressure and the volume of fresh water mixed with foam by the static mixer 33 is 5: 1 to 1: 3.
And This volume ratio can be appropriately changed in this range according to the excavation depth, the geology, or to adjust the density of foam water. FIG. 6 shows the geology and the mixing ratio of foam and fresh water suitable for the geology.

In FIG. 6, for example, a line is drawn at a depth of about 50 m in the alluvium, but this is a rough guide because viscosity, sand, and gravel in the alluvium are often found at a depth of 50 m or more. I just drew a line. This line is not drawn to limit the invention, as alluvial deposits may actually be at other depths. This line is also drawn on the Kozumi, the Tertiary Formation, the Shatter Zone, and the hard rock, but not to limit the invention in the same way as above.

In FIG. 6, for example, the indication of 3: 1 in the column of alluvial gravel means that it is preferable that the mixing ratio of bubbles and fresh water is 3: 1 in alluvial gravel. means. Of course, this ratio number should not be interpreted restrictively, but rather to a certain extent. Here, since the mixing ratio of foam and fresh water is shown in each column of geology in FIG. 6, it is considered that the mixing ratio of foam and fresh water in each geology is disclosed in this specification.

According to the present invention, foam and clear water having a mixing ratio as shown in FIG. 6 are used in alluvial and dip gravel, tertiary conglomerate and crush zone where it was conventionally difficult to collect cores. Is particularly significant in that a good core can be collected. That is, in the alluvial and glacial gravel and crush zones, a 3: 1 mixture of foam and Shimizu was used, and in the Tertiary conglomerate, a 2: 1-3: 1 mixture of foam and Shimizu was used. It is preferred to use foam water.

Bubble water in which foam and fresh water are mixed at a mixing ratio of 5: 1 to 1: 3 contains soft and small bubbles, and is advantageous in the following points, unlike solid foam in conventional foam boring. (1) In conventional foam boring, since water is pumped up together with air, the sand particles are also pumped up and the pores may be broken. There is no boiling at the wall or the bottom of the hole, so that there is no adverse effect such as outflow of the core sample or breaking of the hole. (2) In the conventional bubble boring, bubbles disappear when there is a large amount of flowing water in the underground water vein, but bubbles do not disappear in the bubble water of the above-described mixing ratio and fresh water. (3) In the conventional bubble boring, when the foam rises, the wall of the hole may be broken because the foam expands rapidly. Absent. (4) Since the bubble water used in the present invention contains soft and small bubbles, it can be easily guided to the bit periphery only by applying a small pressure and press-fitting. In addition, the lubricating property of the foam water allows smooth excavation, and generates appropriate air bubbles at the tip of the bit, which will be described later. It becomes possible. (5) Since the foam water contains a small amount of foam, it is possible to very easily remove the foam component from the pore wall by rinsing the inside of the pore after the operation is completed. Incidentally, removal of the foam component can be confirmed by confirming the foaming property of the washing wastewater.

When the mixing ratio of foam to fresh water is 1: 3 or less, a lubricating action as a foaming agent can be expected, but it is difficult to obtain a remarkable slime removing effect. Also, when the mixing ratio of foam to fresh water is 5: 1 or more (for example, about 10: 1), it is caused by conventional foam boring such as high pressure in a deep underground (about 60 m or less), mine wall destruction, and extreme pumping. Problems arise.

As the foam component, a conventionally known foaming agent can be used, but α-paraffinsulfonic acid or a salt thereof is preferable. Here, α-paraffin contains 8 to 14 carbon atoms in one molecule of the main component of the foaming agent, and the cation constituting the salt is preferably a monovalent or divalent cation. Most preferred is a sodium salt containing 10 to 12 carbon atoms in one molecule of the component.

In the present invention, the use of α-paraffinsulfonic acid or a salt thereof as a foam component allows the use of metal soap in the presence of hard water or salt water such as old seawater as in the case of a conventional alkylcarboxylic acid-based foaming agent. , So that smooth foaming can be maintained. Therefore, even in an underground environment such as a coastal location, a good quality core can be collected without disappearing bubbles. In addition, unlike the alkyl ether sulfonic acid type foaming agent, there is an advantage that stable use is possible without causing a risk of hydrolysis of an ether bond in an alkaline or acidic formation, and defoaming after use is completed is easy. is there.

Next, the excavator 5 will be described. The excavator 5 according to the present embodiment is configured as shown in FIG.
Is provided. An excavator to which the triple-pipe type shown in FIG. 3A is applied is different from a self-propelled vehicle 36 in that an inner rod 39 having a bit 37 at the tip and a casing bit located outside the inner rod 39 are provided at the tip. A casing 41 having an inner tube 38 and an inner tube 43 provided inside the inner rod 39 and capable of accommodating a core therein are provided.

A drive section 45 is connected to the inner rod 39 and the casing 41. The drive section 45 acts to rotate the inner rod 39 and the casing 41 and, if necessary, the bit 37 and the casing bit 3
8 also has the function of imparting vibration. With such a structure, the inner rod 39 and the casing 41 can be driven by a vibration-free high-speed rotation, and on the other hand, the inner rod 39 and the casing 41 can be driven to rotate while applying vibration to the bit 37. in this case,
A step of changing the rotation speed of the bit may be provided.

Conventionally, when the core sampling is attempted by the latter method, the core is loosened or tightened due to vibration, and it has been difficult to obtain a good core sample for core identification and physical property test. In the present invention, since the bubble water is introduced into the bit 37 from between the inner rod 39 and the inner tube 43, the core is not loosened or compacted due to the lubricity of the bubble water, and a good core sample is collected. It becomes possible. FIG. 4 is an enlarged view of the vicinity of the bit showing a state in which foam water is being supplied to the tip of the bit (the bottom of the boring hole). FIGS. 4A and 4B show different types of bits.

On the other hand, in the excavator having the double-pipe type structure shown in FIG. 3B, there is no member corresponding to the casing 41, and the rod 40 and the inner tube 4 inside the rod 40 are not provided.
3 is provided. In the case of the double tube type, the rod 40 is connected to the drive unit 45, and similarly to the case of the triple tube type, the rod 40 is driven to rotate by the drive unit 45 and vibration is applied to the bit 37 as necessary. Can be provided.

The triple tube type is used when the hole wall is not self-supporting as in the case of alluvial stacking, and the double tube type is generally used at a depth lower than the depth at which the hole wall is self-supporting. In the case where a diluvial or Tertiary layer appears from the surface of the ground, a double pipe type excavator will be used.

FIG. 5 shows an excavator to which the double pipe type is applied.
(A) As shown in (b) and (c), the inner tube 4
3, a head 47 is formed at the upper end.
A grip portion 49 is formed on 7. The inner tube 43 containing the core can be lifted and collected by holding the holding portion 49 with the latch 48 connected to the tip of the wire 53 extending from the suspension mechanism 51 provided in the excavator 5.

Hereinafter, a core collecting method using the core collecting apparatus 1 of the present invention will be described. The excavator of FIG. 1 can use both methods appropriately, such as excavating with a triple tube type in a soft stratum, and then excavating with a double tube type in a stratum where the hole wall is independent. In other words, when the ground is soft and the surface layer is soft, the transition from the triple pipe type to the double pipe type is made.
Apply double tube type.

FIGS. 5 (a), 5 (b) and 5 (c) show the steps of collecting a core sample by applying the double tube method. First, as shown in FIG. 5A, a hole of a predetermined depth is excavated by the excavating action of the bit 37 by rotating the rod 40 by a conventional method. After excavation to the sampling depth, the inner tube 43 is inserted into the rod 40, and the rod 40 is extended as shown in FIG. 5B, and the drive unit 45 is connected to the upper end thereof.

In this state, the inner tube 43 is driven again to excavate further. At this time, the foamed water is supplied from the foamed water supply nozzle 55 into the rod 40 while the pressure is applied by the mixed water supply pump 35. In FIG. 3B, as indicated by the arrow, the foam water is supplied into the rod 40 from the foam water supply nozzle 55 connected to the upper end of the rod 40, and passes between the inner tube 43 and the inner wall of the rod 40. After that, it wraps around the rod 40 via the bit 37,
It rises along the outer surface of the rod 40 and is finally discharged to the ground.

As a result, the lubricating property of the bubble water enables smooth excavation, and at the same time, a suitable amount of bubbles are generated at the tip of the bit as shown in FIG. 4 to cool the bit. In addition, slime generated during excavation can be attached to air bubbles and discharged. At the time of the above excavation, vibration may be applied to the bit 37 in order to improve workability.

During the excavation, the core enters the inner tube 43. Next, as shown in FIG. 5C, the grip portion 49 of the inner tube 43 is gripped by the latch 48 provided at the tip of the wire 53, and the inner tube 43 is lifted to collect the core.

The above description is of the case where the double tube type is applied. However, when the triple tube type is applied, the bubble water is supplied from the bubble water supply nozzle 55 connected to the upper end of the inner rod 39 to the inner rod. 39 into the inner tube 43
After passing between the inner rod 39 and the inner wall of the inner rod 39, the outer surface of the inner rod 39 and the casing 4
1 rises through the outer surface and is finally discharged to the ground.

[0044]

According to the invention as set forth in claim 1 or claim 6, there is no boiling at the hole wall and the hole bottom due to foam water.
Therefore, there is no adverse effect such as outflow of the core sample or breakage of the hole.
Also, even in a place where there is a large amount of flowing water in the groundwater vein, the foam bubbles do not disappear, and when the foam bubbles rise, they do not expand rapidly and break the wall of the hole.

Further, since the bubble water used in the present invention contains soft and small bubbles, it can be easily guided to the periphery of the bit only by applying a small pressure and press-fitting. In addition, the lubricating properties of the bubble water enable smooth excavation, generate appropriate air bubbles at the tip of the bit, cool the bit, and discharge the slime generated by excavation by attaching it to the air bubbles. Become. Furthermore, since the foam water contains a small amount of foam, it is possible to very easily remove the foam component from the pore wall by washing the inside of the pore with water after the work is completed.

Furthermore, it is possible to collect a sound core even at a level lower than the groundwater level of a soft alluvium where it is normally difficult to obtain a sound core. Also, it is possible to collect a sound core even at a depth of several hundred meters deeper than 50 m deep underground where it is usually difficult to remove slime (crushed rock fragments and crushed rock powder).

According to the second or ninth aspect of the present invention, unlike the conventional alkylcarboxylic acid-based blowing agent, metal soap is not produced in the presence of hard water or salt water such as old seawater. Therefore, smooth foaming can be maintained. Therefore, even in an underground environment such as a coastal site or a stratum containing old salt water (hard water), a high-quality core can be collected without disappearing bubbles.

According to the third aspect of the present invention, high-speed and efficient core sampling can be realized. According to the invention described in claim 4, 5, 7, or 8, it is also good in alluvial gravel, dip gravel, Tertiary conglomerate, and crushed zone where it was conventionally difficult to collect cores. It becomes possible to collect cores.

According to the tenth aspect of the present invention, since the discharge path of the bubble water is secured between the outer surface of the rod and the inner surface of the casing, the circulation of the bubble water is smooth,
Drilling will be smoother and slime removal will be easier.

According to the eleventh aspect of the present invention, the vibration is applied to the bit, so that the excavation speed is increased, and the hard rock can be excavated relatively easily while breaking. Also, by providing a wire for lifting the inner tube, the core can be easily obtained by simply lifting the inner tube with the wire after collecting the core with the inner tube.

[Brief description of the drawings]

FIG. 1 is a schematic view showing an entire core collecting apparatus of the present invention.

FIG. 2 is a flowchart showing a foam mixing apparatus.

FIG. 3A is an explanatory diagram showing a flow path of foam water when a triple pipe type is applied, and FIG. 3B is an explanatory view showing a flow path of foam water when a double pipe type is applied. FIG.

4 (a) and 4 (b) are examples of bits that can be used in the present invention, and are supplied through a bit tip (bottom of a boring hole).
It is an enlarged view of the periphery of the bit which shows the flow path structure of the bubble water discharged.

FIG. 5 is an explanatory diagram showing a step of collecting a core by applying a double pipe method.

FIG. 6 is a table showing the mixing ratio of foam and fresh water at 1 atm according to the geology.

[Explanation of symbols]

 REFERENCE SIGNS LIST 1 core sampling device 3 foam mixing device 5 excavator 7 foaming liquid supply pump 9 foaming agent tank 11 water tank 13 foaming liquid flow meter 15 foaming gun 17 compressor 19 dry filter 21 pressure regulating valve 23 solenoid valve 25 flow meter 27 flow rate regulating valve 29 Electromagnetic flow meter 31 Control panel 32 Fresh water tank 33 Static mixer 35 Mixed water supply pump 36 Self-propelled vehicle 37 Bit 38 Casing bit 39 Inner rod 40 Rod 41 Casing 43 Inner tube 45 Drive unit 47 Head 48 Latch 49 Grip unit 51 Wire suspension mechanism 53 Wire 55 Bubble water supply nozzle

 ────────────────────────────────────────────────── ─── Continuing on the front page (72) Inventor Shunsaku Nishie 3-13-5 Nishiwaseda, Shinjuku-ku, Tokyo F-term in Chuo Kaihatsu Co., Ltd. 2D043 BA07

Claims (11)

[Claims] 1. A step of preparing foamed water mixed so that the volume ratio of foam to fresh water at 1 atm is 5: 1 to 1: 3, and disposed at a lower end inside the tubular rod and the rod. Preparing an inner tube to be drilled, a step of collecting a core in the inner tube while excavating the ground by applying a rotational force to a bit attached to the tip of the rod, and excavating the ground. Passing the foamed water from inside the rod to between the inner surface of the rod and the outer surface of the inner tube, and discharging the foamed water to the ground along the outer surface of the rod via the tip of the rod. A core collection method characterized by the above-mentioned. 2. The composition according to claim 1, wherein the component of the foam is α-
A method for collecting cores, which is paraffin sulfonic acid or a salt thereof. 3. The method according to claim 1, wherein the step of excavating the ground includes a step of applying vibration to the bit. 4. The core collecting method according to claim 1, wherein a volume ratio of the foam to the fresh water in the foam water at 1 atm is 3: 1 to 1: 3. 5. The core collecting method according to claim 1, wherein a volume ratio of the foam to the fresh water in the foam water at 1 atm is 3: 1. 6. A foam is generated, and the foam is mixed with fresh water so that a volume ratio of the foam to the fresh water at 1 atm is 5: 1 to 1.
A foam mixing apparatus for producing foam water of 1: 3; a rotatable tubular rod having a bit at a tip thereof; and an excavator including an inner tube disposed at an inner lower end of the rod; Means for pumping into the rod of the excavator, wherein the rod is provided such that the foamed water pumped into the rod passes from inside the rod to between the inner surface of the rod and the outer surface of the inner tube, A coring device having a path that is discharged to the ground along an outer surface of the rod via a tip of the rod. 7. The coring apparatus according to claim 6, wherein the foamed water has a volume ratio of the foam to the fresh water at 1 atm of 3: 1 to 1: 3. 8. The coring apparatus according to claim 6, wherein the foamed water has a volume ratio of the foam to the fresh water at 1 atm of 3: 1. 9. The coring apparatus according to claim 6, wherein a component of the foam is α-paraffinsulfonic acid or a salt thereof. 10. The rod according to claim 6, wherein a casing provided with a casing bit at an end thereof is provided outside the rod, and a path discharged along the outer surface of the rod is a lower end surface of the bit. A core extracting device formed between an outer surface of the rod and an inner surface of the casing. 11. The method according to claim 6, wherein
The excavator includes a device for applying vibration while rotating the bit, and a wire connected to the inner tube for lifting the inner tube.