CN111504689A - Jet type in-situ soil sampler - Google Patents

Abstract

A jet type in-situ soil extractor for acquiring a soil sample and maintaining its in-situ characteristics, comprising: a cutting mechanism capable of moving downward along a longitudinal axis to cut into the soil sample, and at a direction perpendicular to the longitudinal axis A soil sample collection chamber (S1) is defined on the first radius, and the soil sample entering the soil sample collection chamber (S1) is coated with a gel solution to maintain its in-situ characteristics; The longitudinal axis exerts downward force on the cutting mechanism and is provided with a waterjet assembly (6) rotating about the longitudinal axis, the waterjet assembly (6) at a second radius greater than the first radius The soil sample was cut along the circumference to reduce the cutting resistance of the cutting mechanism. The invention adopts high-pressure jet to cut the soil, drills to clear the hole, wraps the soil sample with a gel solution before the soil sample enters the connecting inner cylinder, greatly reduces the friction between the soil sample and the side wall of the connecting inner cylinder, and greatly reduces the impact on the soil sample. The disturbance of the soil sample can maintain the in-situ characteristics of the soil sample to the greatest extent.

Description

A jet type in-situ earth extractor

technical field

The invention relates to the field of engineering geological drilling, in particular to a jet type in-situ earth borrower, which can be used for type I sampling of soft soil and sandy soil. test sample.

Background technique

Engineering geological survey is a geological survey and research work carried out to identify the geological factors affecting engineering buildings, and to provide a basis for determining the protective measures to ensure the stability and normal use of buildings. With the demand and development of my country's economic construction and the increase of various large and medium-sized geotechnical engineering projects in recent years, the research and development of new borrowers has become an important issue for workers in the field of engineering geological exploration. In order to obtain various physical and mechanical properties of soil, in addition to the expensive in-situ test, the main method is to conduct indoor geotechnical experiments after drilling and sampling. The soil borrower is a tool used to collect soil samples from the engineering site. The obtained soil samples are transported back to the laboratory, and the basic physical and mechanical parameters of the site are determined through indoor tests, including density, void ratio, moisture content, specific gravity, internal friction angle, and cohesion. Force, consolidation coefficient, unconfined compressive strength, etc., provide parameters for subsequent engineering design. The sampling quality of the soil borrower directly determines whether these basic physical and mechanical parameters are accurate or not. If the sampling quality is poor, the measured basic physical and mechanical parameters will be inaccurate, which will lead to an overly conservative design and increase the project cost, or the design is dangerous and easy to use. Cause engineering accidents, so it is very necessary to obtain high-quality soil samples.

In engineering geological survey, soft clay or sandy soil is mainly encountered. Soft clay is a kind of soil often encountered in engineering geological exploration. The main characteristics of soft clay are high natural water content, large natural void ratio, high compressibility, low shear strength, small consolidation coefficient, long consolidation time, High sensitivity, large disturbance, poor water permeability, etc. In the geotechnical engineering investigation of strata with soft soil distribution, it is often necessary to sample soft clay and conduct indoor geotechnical tests. The degree of disturbance directly affects the reliability of the physical and mechanical characteristics of the indoor test, that is, when the soil sample is disturbed very little, the indoor physical and mechanical indicators can truly reflect the physical and mechanical properties of the natural soil layer; when the soil sample is greatly disturbed, the indoor The physical and mechanical indexes of the soil layer cannot reflect the physical and mechanical properties of the natural soil layer, and the gap between the two is too large. For sandy soils, sampling is difficult because there is almost no cohesion between particles.

At present, the soil borrowers on the market perform well in soft clay sampling, but in terms of sand sampling, it is difficult to obtain high-quality sand samples. The change of the relative compactness and the destruction of the structure are caused by the high friction between the sand sample and the inner tube wall, or the soil sample is loosened due to the diameter of the sampling tube being larger than the diameter of the cutting shoe; ② effective stress recovery and related changes, which in turn lead to the deformation of soil samples; ③ the sand samples are easy to fall off when they are taken out from the borehole, resulting in soil sample defects.

The current earth borrower cannot reduce the disturbance to the soil sample very well in the process of borrowing. Disturbances caused by friction of the walls.

For example, the patent document CN101140201A designs a hydraulic thin-walled earth extractor. The earth extractor is a hollow drill rod with a water-separating head connected to the lower end. The water-separating head is connected to the piston rod and the outer cylinder. A movable piston seal slides on the piston rod and seals and slides with the inner wall of the outer cylinder. The movable piston is connected to a soil The lower end of the piston rod is connected to a fixed piston. When the water pressure is passed from the drill pipe to the movable piston, the movable piston is pressed down to force the soil sample cylinder into the soil. The fixed piston cannot move. When the soil sample cylinder is pressed down, the fixed piston will rise relatively, resulting in a closure, so that the soil sample will not fall off. When pulling up, the outer cylinder is lifted together with the soil sample cylinder. When the cutting shoe penetrates the soil layer, this kind of soil extractor has obvious effect of squeezing the soil, causing great disturbance to the soil sample, and excessive friction between the soil sample and the sampling inner pipe wall will cause soil sample disturbance and lead to Structural damage to soil samples.

For example, the patent document CN105699118A designs a soil borrower directly used for the dynamic characteristic test of undisturbed sand samples. The upper outer cylinder and the lower outer cylinder of the soil borrower are screwed, the lower outer cylinder has chutes on both sides, and the lower part of the upper outer cylinder is installed. The inner spring is pressed against the top of the inner cylinder in the lower outer cylinder, the top of the inner cylinder has side ears, and there are hose holes on both sides of the inner cylinder under the side ears, and the inner cylinder is screwed on the waste soil pipe; The upper end of the incision shoe is connected, and the invention combines the traditional drilling collection process of the original sample with the laboratory processing and preparation process. The dynamic characteristics test of the undisturbed sand samples was carried out on the column instrument. However, the biggest problem is that when the cutting shoe penetrates, the soil-squeezing effect will cause excessive disturbance to the soil, and the soil-squeezing effect is obvious. When the sand sample enters the soil borrowing pipe, there is excessive frictional resistance with the pipe wall, and the natural structure of the sand sample has been destroyed. , is greatly disturbed.

On the whole, the current soil borrower will inevitably produce a soil squeeze effect in the process of penetrating the soil layer, which will cause great disturbance to the soil sample. Therefore, the soil sample is disturbed too much, the physical and mechanical indicators of the indoor geotechnical test are distorted, and the physical and mechanical properties of the in-situ soil cannot be reflected, which affects the engineering design and construction.

SUMMARY OF THE INVENTION

In order to solve the problems existing in the background technology, the present invention discloses a jet-type in-situ borrower for in-situ sampling on site, which is suitable for both soft clay and sandy soil sampling, and can simultaneously solve the problem that the earth-borrower is used for penetrating soil. The soil squeeze effect is obvious during the layering process, the friction between the soil sample and the inner wall of the sampling pipe is too large, the relative density of the soil sample changes during the sampling process, the structural damage and the soil sample is easy to fall off when the soil sample is taken out after the sampling is completed, resulting in defects, etc. question. Specifically, the high-pressure water column injected by the water jet assembly cuts the soil and drills into the hole to clear the hole, and there is almost no soil-squeezing effect, which avoids the defect that the traditional static pressure penetrates the soil and causes a large disturbance to the soil sample. Before the sample enters the connecting inner cylinder, the soil sample is wrapped by the polymer gel solution, which greatly reduces the friction of the side wall of the soil sample, keeps the original structure of the soil sample as much as possible, and obtains a high-quality soil sample.

The technical scheme adopted in the present invention is as follows:

A jet type in-situ soil extractor for acquiring soil samples and maintaining its in-situ characteristics, characterized in that it is provided with: a cutting mechanism, which can move down along the longitudinal axis to cut into the soil samples, and is perpendicular to the A soil sample collection chamber is defined on the first radius of the longitudinal axis, and the soil sample entering the soil sample collection chamber is coated with the gel solution to maintain its in-situ characteristics; An axis exerts downward force on the plunging mechanism and is configured with a waterjet assembly rotating about the longitudinal axis, the waterjet assembly circumferentially cutting the soil sample on a second radius greater than the first radius to reduce The cut-in resistance of the cut-in mechanism.

Further, the cutting mechanism includes a connecting outer cylinder and a cutting shoe fixedly connected to the connecting outer cylinder.

Further, the drilling mechanism includes a rotary head driven by a power source to rotate around the longitudinal axis, and an outer cylinder fixedly connected with the rotary head, and the water jet assembly is fixedly mounted on the outer cylinder.

Further, the drilling mechanism is connected to the cutting mechanism through a rotation stop assembly to transmit the displacement of the rotary head on the longitudinal axis to the non-rotatable connecting outer cylinder while the rotary head rotates.

Further, the anti-rotation assembly includes a force transmission ram and an axial bearing; wherein, the ring of the axial bearing is fixedly installed on the rotating head, and the shaft ring of the axial bearing is fixedly installed on the force transmission ram; wherein, all the The collar is disposed inside the collar and can move up and down along the longitudinal axis, and the collar or rotating head applies axial pressure to the collar through a loading spring to generate a loading force on the cutting shoe to cut the soil sample.

Further, the upper end of the loading spring is pressed against the rotating head, and the lower end thereof is pressed against the shaft ring.

Further, the anti-rotation assembly further includes at least one radial sliding bearing, the radial sliding bearing is fixedly connected to the ferrule, and the force transmission ram has a shaft portion passing through the radial sliding bearing.

Further, the connection outer cylinder is fixedly installed on the force transmission head, and the connection outer cylinder has a built-in gel storage chamber formed by the connection inner cylinder, the floating piston and the force transmission head; wherein, the connection The inner cylinder is fixedly installed on the force-transmitting pressure head, and there is a gap between it and the connecting outer cylinder to form a gel extrusion channel connecting the gel storage chamber and the soil sample collection chamber, and the upper part of the connecting inner cylinder has an opening. The hole is used to communicate the gel extrusion channel and the gel storage chamber; wherein, the floating piston is arranged in the connecting inner cylinder and the two are connected in a sealed sliding fit.

Further, the soil sample collection chamber is formed by a floating piston and a connecting inner cylinder, and when the floating piston moves upward, the soil sample collection chamber gradually increases, and the gel storage chamber gradually increases. decrease; a soil sample collection port for the soil sample to enter the soil sample collection chamber is formed inside the cutting shoe.

Further, the inner diameter of the soil sample collection chamber is slightly larger than the inner diameter of the soil sample collection port to form a glue injection gap for the gel to coat the soil sample between the inner wall of the connecting inner cylinder and the outer wall of the captured soil sample. ; wherein, the bottom of the connecting inner cylinder is provided with a glue injection hole connecting the soil sample collection chamber and the gel extrusion channel.

Further, the rotating head is provided with a gel discharge hole, and the gel storage chamber communicates with the gel discharge hole through a gel overflow pipe to discharge excess gel; wherein, the gel overflow pipe is fixed on the rotating head. and inserted into the gel storage chamber via the force-transmitting ram, and the gel overflow tube is in sealing contact with the force-transmitting ram.

Further, a multi-pass water distribution head is configured on the rotary head, and the multi-pass water distribution head is connected to the water jet assembly via the rotary head and the high-pressure water pipe, and the rotary head has a water distribution pipeline connecting the high-pressure water pipe and the multi-pass water distribution head.

The beneficial effects of the present invention are:

1) During the sampling process, the soil sample entering the cutting boot is coated and wrapped by the gel solution through the gel coating ring, which greatly reduces the friction when the soil sample enters the connecting inner cylinder, and causes less disturbance to the soil sample. Keep the original structure of the soil sample as much as possible.

2) The outer surface of the soil sample is covered with a polymer gel solution to avoid water loss during transportation and storage of the soil sample.

3) When the indoor soil sample needs to be pushed out of the soil sampler, since the soil sample is wrapped by the polymer gel solution, the friction between the soil sample and the inner wall of the soil sample pipe is very small, and the natural structure of the soil sample is preserved as much as possible.

4) The ultra-high pressure water column injected by the water jet is used to cut the soil and drill into the hole to clear the hole, with high efficiency, almost no soil squeeze effect, and little soil disturbance.

5) The whole borrowing device is of modular design and standardized structure, and each part is connected by screw thread, which is easy to disassemble.

6) Before borrowing soil, the floating piston is placed at the bottom of the borrower and is flush with the tip of the cutting shoe, which can completely prevent the mud in the borehole from entering the connecting inner cylinder and ensure a high sampling ratio of soil samples.

Description of drawings

FIG. 1 is a schematic cross-sectional structure diagram of the jet type in-situ earth borrower according to the present invention.

Fig. 2 is a schematic perspective view of the floating piston of the present invention.

Figure 3 is a schematic perspective view of the gel coating ring of the present invention.

Figure 4 is an exploded view of the water jet assembly of the present invention.

FIG. 5 is a schematic view of the working state of the jet type in-situ borrower according to the present invention.

In the figure: 1, cutting shoe; 2, jet shoe; 3, connecting inner cylinder; 4, connecting outer cylinder; 5, outer cylinder; 6, water jet assembly; 7, gel coating ring; 8, floating piston; 9, force transmission head; 10, rotary head; 11, multi-pass water distribution head; 12, loading spring; 13, transmission connecting cylinder; 14, axial bearing; 15, radial sliding bearing; 16, high pressure water pipe; 17, Air cylinder; 18, water switch; 19, high pressure water inlet; 20, connecting rod; 21, nozzle; 22, nut; 23, gel overflow pipe; 24, water distribution line; 25, high pressure elbow; 26, opening; 27, O-ring ring groove; 28, O-ring, 29, slot

Detailed ways

Further description will be given below in conjunction with the accompanying drawings and embodiments. The following examples are only used to illustrate the present invention and not to limit the scope of the present invention. In addition, it should be understood that after reading the teaching content of the present invention, those skilled in the art can make various changes or modifications to the present invention, and these equivalent forms also fall within the scope defined by the appended claims of the present application.

As shown in Fig. 1, the earth extractor includes a multi-pass distribution head 11, an earth extractor head 10, a transmission connection cylinder 13, a force transmission head 9, a connection outer cylinder 4, a connection inner cylinder 3, a gel coating ring 7, and a cutting shoe. 1. Floating piston 8, outer cylinder 5, high pressure water pipe 16, water jet assembly 6, jet shoe 2. Among them, the rotor end on the lower side of the multi-pass water distribution head 11 is connected with the earth extractor head 10 by bolts, the external thread of the side wall of the lower end of the earth extractor head 10 is connected with the inner thread of the upper end of the outer cylinder 5, and the inner concave hole at the lower end of the earth extractor head 10 The inner thread is connected with the outer thread on the upper end of the transmission connecting cylinder 13. The transmission connecting cylinder 13 is equipped with a loading spring 12, an axial bearing 14, a force transmission head 9 and a radial sliding bearing 15. The force transmission head 9 is subjected to axial The axial thrust transmitted by the bearing 14 and the radial force transmitted by the radial sliding bearing 15 are indirectly fixed in the transmission connecting cylinder 13, and the external thread of the side wall of the force transmission head 9 is connected with the internal thread connecting the upper end of the outer cylinder 4 , the outer thread of the lower end flange of the force transmission head 9 is connected with the inner thread connecting the upper end of the inner cylinder 3, the outer thread connecting the lower end of the inner cylinder 3 is connected with the inner thread of the upper end of the gel coating ring 7, the floating piston 8 is connected with the inner thread of the connection The barrel 3 is sealed and slidably arranged at the bottom, the outer thread connecting the lower end of the outer barrel 4 is connected with the inner thread at the upper end of the cutting shoe 1, the inner thread at the lower end of the outer barrel 5 is connected with the outer thread at the upper end of the jet shoe 2, and the inner thread of the jet shoe 2 is connected. The water jet assembly 6 is installed and fixed, and the two ends of the high pressure water pipe 16 are respectively connected to the earth extractor head 10 and the water jet assembly 6 .

The jet-type in-situ earth borrower of the present invention is used for acquiring soil samples and maintaining its in-situ characteristics. From the perspective of the overall structure, it has a cutting mechanism and a drilling mechanism. Wherein, the cutting mechanism can move down along the longitudinal axis to cut into the soil sample, and define a soil sample collection chamber S1 on a first radius perpendicular to the longitudinal axis, and the soil sample entering the soil sample collection chamber S1 is formed by The gel solution coats the outer peripheral surface to maintain its in-situ properties; the drilling mechanism exerts downward force on the cutting mechanism along the longitudinal axis, and is equipped with a water jet assembly 6 rotating about the longitudinal axis, the water The knife assembly 6 cuts the soil sample circumferentially on a second radius greater than the first radius to reduce the cutting resistance of the cutting mechanism. That is to say, the water jet assembly 6 is arranged on the outside of the cutting mechanism, and the connection between the soil sample and the outside world is cut off in advance, thereby reducing the cutting resistance of the cutting mechanism. In this embodiment, the first radius and the second radius are both fixed values, which are the pitch diameter of the cutting shoe 1 and the pitch diameter of the water jet head, respectively. In other embodiments, the first radius and the second radius may also be variable values.

Specifically, the cutting mechanism includes a connecting outer cylinder 4 and a cutting shoe 1 fixedly connected to the connecting outer cylinder 4 . The drilling mechanism includes a rotary head 10 driven by a power source to rotate around the longitudinal axis, and an outer cylinder 5 fixedly connected with the rotary head 10 , and the water jet assembly 6 is fixedly mounted on the outer cylinder 5 . Said drilling mechanism is connected to the cutting mechanism by means of the anti-rotation assembly to transmit the displacement of the rotary head 10 on the longitudinal axis to the non-rotatable connecting cylinder (4) while its rotary head 10 rotates.

Among them, the connecting outer cylinder 4 plays the role of resisting the penetration resistance during the penetration process of the earth borrower, preventing the connection inner cylinder 3 from being deformed and affecting the quality of the earth borrowing. The inner cylinder 3 is connected for actual borrowing and can be easily disassembled.

In the specific implementation, the inner diameter of the connecting inner cylinder 3 is 73.2 mm and the outer diameter is 77.2 mm; the inner diameter of the connecting outer cylinder 4 is 87.4 mm and the outer diameter is 95.4 mm; the inner diameter of the cutting edge of the cutting shoe 1 is 72.1 mm, which is slightly smaller than the inner diameter of the connecting inner cylinder 3. If the blade angle is 8°, the inner clearance ratio of the soil sampler is ICR=1.50%, which is close to 0. Since the side surface of the soil sample is covered by the gel solution when entering the soil sampler, the inner gap ratio is very small, and the soil sample is connected to the inner cylinder. The friction between the 3 is also very small.

As shown in FIG. 1 , the earth extractor head 10 is provided with a water distribution pipeline 24. The upper end of the water distribution pipeline 24 is connected to the rotor end opening of the multi-pass water distribution head 11 through a high-pressure elbow 25, and the lower end of the water distribution pipeline 24 is connected by a high-pressure water pipe. 16 is connected with the water jet assembly 6, and the stator end of the multi-pass water distribution head 11 is connected with the pressurization system on the ground, thereby forming a complete jet system.

Among them, the multi-pass water distribution head 11 has a through hole, the through hole passes through the connecting pipe on the upper side of the borrower head 10, and is connected with the upper end face of the borrower head 10 by means of the bolt on the lower rotor end, and there is a certain distance between the through hole and the connecting pipe. Clearance. The drill pipe drives the earth extractor head 10 to rotate, thereby driving the rotor end of the multi-pass water distribution head 11 to rotate. The high-pressure liquid output from the rotor end passes through the water distribution pipeline 24 in the earth extractor head, passes through the high-pressure water pipe 16, and is input to the water jet assembly 6. The stator end of the multi-pass water distribution head 11 is fixed by a plurality of high-pressure water pipes connected to it, so that the high-pressure liquid is supplied into the rotating water jet assembly.

As shown in FIG. 1 , the two ends of the loading spring 12 are in extrusion contact with the inner wall of the concave hole of the earth extractor head 10 and the upper end face of the seat piece of the axial bearing 14 respectively. The shaft plate of the bearing 14 is fixedly connected with the upper end face of the force transmission pressure head 9, and the axial force is transmitted between the two through the rolling body. The inner ring of the bearing 15 is fixedly connected with the side wall of the force-transmitting indenter 9, and the radial force is transmitted between the two through the rolling elements, so as to isolate the connection between the outer cylinder 4 and the inner cylinder 3 connected to the force-transmission indenter 9. to prevent them from rotating.

Among them, the cutting shoe 1 and the connecting outer cylinder 4 are fixed by the axial bearing 14 and the radial sliding bearing 15 through the force transmission head 9. When the soil is extracted, the outer cylinder 5 rotates. The cutting shoe 1 and the connecting outer cylinder 4 have a bearing system due to the The isolation does not rotate, but only bears the axial pressure and radial force exerted by the drilling tool. While the water jet assembly 6 at the bottom of the outer cylinder 5 cuts the soil layer, the cutting shoe 1 connected to the inner cylinder 3 is pressed into the soil layer, and the The soil sample is pressed into the connecting inner cylinder 3 by the drilling of the earth borrower. The axial bearing 14 is loaded by the loading spring 12 to transmit the drilling pressure exerted by the drilling tool, so as to provide a more stable load for the cutting shoe 1 during the sampling process. Depending on the soil hardness or density, during the jet drilling process of the jet shoe 2, the distance between the cutting shoe 1 and the jet shoe 2 is not fixed. In soft soil, the cutting shoe 1 will penetrate relatively easily, so the cutting shoe 1 The distance from the jet shoe 2 will be close to the maximum spacing, however, in hard and dense soil, the cutting shoe 1 will retract and retreat, making the jet shoe 2 closer to the sampling surface, relying on the ultra-high pressure jet to help the cutting shoe 1 penetrate.

Among them, the axial bearing 14 is composed of a ferrule, a shaft washer, rolling elements and a cage holding the rolling elements. In the axial bearing 14, the ferrule and the shaft washer are arranged in parallel along the axial direction, and the rolling elements are sandwiched between the two Between the seat plate and the shaft plate, it is used to bear the axial load; the radial sliding bearing 15 is composed of the outer ring, the inner ring, the rolling body and the cage, and is used to bear the radial load.

That is to say, the anti-rotation assembly includes a force-transmitting ram 9 and an axial bearing 14; wherein, the ferrule of the axial bearing 14 is fixedly installed on the rotating head 10, and its shaft ring is fixedly mounted on the force-transmitting ram 9; wherein the collar is arranged inside the collar and can move up and down along the longitudinal axis, and the collar or rotary head 10 exerts an axial pressure on this collar by means of a loading spring 12 to generate an axial pressure on the cutting shoe 1 Loading force for cutting into soil samples.

More specifically, the upper end of the loading spring 12 is pressed against the rotating head 10, and the lower end thereof is pressed against the shaft ring. The anti-rotation assembly also includes at least one radial sliding bearing 15 fixedly connected to the ferrule, and the force-transmitting ram 9 has a shaft portion passing through the radial sliding bearing 15 .

The top of the connecting inner cylinder 3 is distributed with openings 26 along the circumference, and the openings 26 make the gel containing cavity formed by the inner wall of the connecting inner cylinder 3, the upper end face of the floating piston 8, and the lower end face of the force-transmitting pressure head 9 to connect with the inner cylinder. 3. The outer wall and the annular cavity connecting the inner wall of the outer cylinder 4 are communicated.

As shown in FIG. 2 , an O-ring seal ring groove 27 is provided on the side wall of the floating piston 8 , and an O-ring seal ring 28 matching the width of the ring groove is installed in the O-ring seal ring groove 27 . The outer circumference of the type sealing ring 28 is in close contact with the inner wall of the connecting inner cylinder 3 .

As shown in FIG. 3 , the side of the gel coating ring 7 is provided with many slits 29 along the circumference, so that the gel solution flowing through the annular cavity between the inner cylinder 3 and the outer cylinder 4 can pass through, and then coat the The outer surface of the soil sample taken, and the inner diameter of the gel coating ring 7 is the same as the inner diameter of the connecting inner cylinder 3 . A gel overflow pipe 23 is installed in the extractor head 10, and the excess gel solution is discharged into the drilled hole along the gel overflow pipe 23 to avoid excessive hydraulic pressure inside the extractor.

The inner diameter of the gel coating ring 7 is the same as the inner diameter of the connecting inner cylinder 3 , and the inner diameter of the cutting shoe 1 is slightly smaller than the inner diameter of the connecting inner cylinder 3 . The gel solution of the present invention is a polymer gel solution, specifically a partially hydrolyzed polyacrylamide, commonly referred to as a PHP polymer, which has good lubricating properties and can be attached to the soil surface like lubricating oil to form lubricity. A very good film, greatly reducing the friction of soil samples entering the connecting inner cylinder 3.

That is to say, the connecting outer cylinder 4 is fixedly installed on the force-transmitting head 9, and the connecting outer cylinder 4 has a built-in gel storage formed by the connecting inner cylinder 3, the floating piston 8 and the force-transmitting head 9. Chamber S2; wherein, the connecting inner cylinder 3 is fixedly installed on the force-transmitting pressure head 9, and there is a gap between it and the connecting outer cylinder 4 to form a gel connecting the gel storage chamber S2 and the soil sample collection chamber S1 An extrusion channel, the upper part of the connecting inner cylinder 3 has an opening 26 to communicate with the gel extrusion channel and the gel storage chamber S2; wherein, the floating piston 8 is arranged in the connecting inner cylinder 3 and is sealed between the two slip-fit connection.

Specifically, the soil sample collection chamber S1 is formed by the floating piston 8 and the connecting inner cylinder 3 together, and when the floating piston 8 moves upward, the soil sample collection chamber S1 gradually increases, and the The gel storage chamber S2 is gradually reduced; a soil sample collection port C1 for supplying the soil sample into the soil sample collection chamber S1 is formed inside the cutting shoe 1 .

The inner diameter of the soil sample collection chamber S1 is slightly larger than the inner diameter of the soil sample collection port C1 to form a glue injection gap between the inner wall of the connecting inner cylinder 3 and the outer wall of the captured soil sample for the gel to coat the soil sample ; wherein, the bottom of the connecting inner cylinder 3 is provided with a glue injection hole connecting the soil sample collection chamber S1 and the gel extrusion channel. In other embodiments, the inner diameter of the soil sample collection chamber S1 may also be the same as the inner diameter of the soil sample collection port C1, and the soil sample is sealed by the pressure of the gel storage chamber S2.

The rotating head 10 is provided with a gel discharge hole, and the gel storage chamber S2 communicates with the gel discharge hole through a gel overflow pipe 23 to discharge excess gel; wherein, the gel overflow pipe 23 is fixed on the rotating head. 10 , and is inserted into the gel storage chamber S2 via the force-transmitting ram 9 , and the gel overflow tube is in sealing contact with the force-transmitting ram 9 .

As shown in FIG. 4 , the water jet assembly 6 is composed of a nut 22 , a nozzle 21 , a connecting rod 20 , a water switch 18 and an air cylinder 17 . The nozzle 21 is installed in the concave hole on the lower side of the connecting rod 20, and is connected and fixed with the external thread at the lower end of the connecting rod 20 through the inner thread of the nut 22. The inner thread of the concave hole is connected with the outer thread of the lower end of the cylinder 17 , the side of the water switch 18 is provided with an ultra-high pressure water inlet 19 , and the high pressure air inlet on the top surface of the cylinder 17 is connected to the high pressure water pipe 16 respectively.

Among them, the pressurization system located on the ground transports high-pressure water to the stator end of the multi-pass water distribution head 11 through the high-pressure water pipe, from the rotor end of the multi-pass water distribution head 11 through the high-pressure elbow 25, the water distribution pipeline 24, the high-pressure water pipe 16 and finally It is sent to the water jet assembly 6; the air cylinder 17 controls the opening and closing of the water switch 18. After the air cylinder 17 is vented, the cylinder piston pushes the ejector rod, so that the pressure on the valve needle is reduced, and the high-pressure water can pass through the small hole in the center of the spherical pad The gas reaches the nozzle 21 through the through hole in the center of the connecting rod. The gas passes from the ground through the stator end of the multi-pass water distribution head 11, and is output from the rotor end of the multi-pass water distribution head 11, and finally passes through the high-pressure elbow 25, the water distribution pipeline 24, and the high-pressure water pipe 16. It is sent to the air cylinder 17 of the water jet assembly 6 to control the opening and closing of the water jet.

That is to say, the rotary head 10 is provided with a multi-pass water distribution head 11, and the multi-pass water distribution head 11 communicates with the water jet assembly 6 via the rotary head 10 and the high-pressure water pipe. The water distribution pipeline (24) of the universal water head 11.

It should be noted that the water jet assembly 6 of the present invention can also adopt the water jet structure in the prior art, and can be applied to the present invention after adaptive transformation. Component 6 does not require creative work.

Below, the working principle and process of the jet type in-situ borrower of the present invention will be described in detail below with reference to FIG. 5 .

When the earth extractor of the present invention is close to the bottom of the borehole, the drill pipe starts to rotate, the water jet system starts to run, and the high-pressure water column is ejected from the nozzles of a plurality of water jet assemblies 6 fixed on the jet shoe 2, so as to utilize the water jet assemblies 6 The rotation and the pressure of the high-pressure water column are used to cut the soil and realize the drilling and clearing.

As the earth extractor moves downward as a whole, when the cutting edge of the cutting shoe 1 of the earth extractor contacts with the bottom of the borehole, the cutting shoe 1 begins to penetrate the soil, and the floating piston 8 at the top of the collected soil sample is pushed by the soil sample below and is relatively opposite to the soil sample below. The connecting inner cylinder 3 moves upward, and during the upward movement of the floating piston 8 relative to the connecting inner cylinder 3, the polymer gel solution in the connecting inner cylinder 3 is forced to pass through the opening 26 and flow into the connecting inner cylinder 3 and the connecting outer cylinder 4 In the annular space between, the polymer gel solution finally flows out evenly from the slot 29 of the gel coating ring 7 connected to the lower end of the outer cylinder 4 and is applied to the soil passing through the gel coating ring 7. sample outer surface. At the same time, excess polymer gel solution can be drained along the gel overflow pipe 23 .

As the earth extractor continues to move downward, the soil sample whose outer surface has been uniformly coated with gel enters the connecting inner cylinder 3 upward. Since the outer surface of the soil sample has been uniformly coated with polymer gel, it can effectively reduce The friction force when the soil sample enters the connecting inner cylinder to avoid the soil sample being disturbed.

When the earth extractor moves down a predetermined distance (such as 1.05m), stop moving forward, the sampling is over, and then the whole earth extractor can be gently lifted out of the borehole.

During the specific implementation, during the soil borrowing process, the drill pipe rotates continuously at a moderate speed (40-80 rpm), driving the outer cylinder 5 and the jet shoe 2 to rotate, while the bearing system isolates the outer cylinder 4 and the inner cylinder 3. , to prevent them from rotating.

It can be seen from the above detailed description that the jet type in-situ earth extractor of the present invention drives the outer cylinder and the water jet assembly to rotate through the drill pipe, and uses the high-pressure water column to cut the soil to realize drilling and clearing, which not only has high drilling efficiency, but also There is almost no soil crowding effect, and the soil disturbance is small, which creates good conditions for the next cutting boot to borrow soil. During the sampling process, the top of the soil sample entering the cutting shoe pushes the floating piston upward, so as to extrude the gel solution connecting the inside of the inner cylinder to the annular gap between the inner cylinder and the outer cylinder, and finally pass through the gel The slot at the lower end of the coating ring is evenly coated to the outer surface of the soil sample to ensure that the outer surface of the soil sample forms a smooth gel coating layer before entering the connecting inner cylinder. When the soil sample continues to move upward and enters the connecting inner cylinder, the friction between the inner wall of the connecting inner cylinder and the soil sample is effectively reduced due to the existence of the gel coating layer, so that the soil sample is smooth and basically frictionless. Entering the connecting inner cylinder, the disturbance to the soil sample is very small, and the original structure of the soil sample can be maintained as much as possible, providing a real soil sample for the subsequent geotechnical test, and ensuring the accuracy of the soil sample test results in the later stage.

Claims (10)

1. a jet type in-situ earth borrower, for obtaining soil sample and keeping its in-situ characteristics, it is characterized in that, possess: A cutting mechanism capable of moving downward along the longitudinal axis to cut into the soil sample, and defining a soil sample trapping chamber (S1) on a first radius perpendicular to the longitudinal axis, entering the soil sampling trapping chamber (S1) The soil samples were coated with a gel solution to maintain their in-situ properties; and, A drilling mechanism, which exerts downward force on the cutting mechanism along the longitudinal axis, and is equipped with a water jet assembly (6) that rotates around the longitudinal axis, the water jet assembly (6) being larger than the first The soil sample is cut circumferentially on a second radius of one radius to reduce the cutting resistance of the cutting mechanism; Preferably: the rotary head (10) is provided with a multi-pass water distribution head (11), the multi-pass water distribution head (11) is connected to the water jet assembly (6) via the rotary head (10) and the high-pressure water pipe, and the rotary head (10) is provided with a water distribution pipeline (24) that communicates with the high-pressure water pipe (16) and the multi-pass water distribution head (11). 2 . The jet type in-situ earth extractor according to claim 1 , wherein the cutting mechanism comprises a connecting outer cylinder ( 4 ) and a cutting shoe ( 1 ) fixedly connected to the connecting outer cylinder ( 4 ). 3 . 3. The jet type in-situ earth extractor according to claim 2, characterized in that: the drilling mechanism comprises a rotary head (10) driven by a power source to rotate around the longitudinal axis, and a rotary head (10). 10) A fixedly connected outer cylinder (5), the water jet assembly (6) is fixedly mounted on the outer cylinder (5). 4. The jet-type in-situ earth extractor according to claim 3, characterized in that: the drilling mechanism is connected to the cutting mechanism through a rotation stop assembly, so as to rotate the rotating head (10) at the same time as the rotating head (10). The displacement on the longitudinal axis is transmitted to the non-rotatable connecting cylinder (4). 5. jet type in-situ earth borrower according to claim 4 is characterized in that: The anti-rotation assembly includes a force transmission head (9) and an axial bearing (14); Wherein, the ferrule of the axial bearing (14) is fixedly installed on the rotating head (10), and the shaft ring thereof is fixedly installed on the force-transmitting pressure head (9); Wherein, the collar is arranged inside the collar and can move up and down along the longitudinal axis, and the collar or rotating head (10) applies axial pressure to the collar through a loading spring (12) in order to cut in the shoe (1). ) to generate the loading force that cuts into the soil sample. 6. The jet type in-situ earth extractor according to claim 5, characterized in that: the upper end of the loading spring (12) is pressed against the rotating head (10), and the lower end is pressed against the shaft ring superior. 7. The jet type in-situ earth extractor according to claim 5 or 6, wherein the anti-rotation assembly further comprises at least one radial sliding bearing (15), the radial sliding bearing (15) being fixedly connected to the On the ferrule, the force transmission head (9) has a shaft portion passing through the radial sliding bearing (15). 8. The jet type in-situ earth borrower according to claim 5 or 6 is characterized in that: The connecting outer cylinder (4) is fixedly installed on the force-transmitting pressure head (9), and the connecting outer cylinder (4) has a built-in connecting inner cylinder (3), a floating piston (8) and a force-transmitting pressure head (9). A gel storage chamber (S2) formed by a common enclosure; Wherein, the connecting inner cylinder (3) is fixedly installed on the force-transmitting pressure head (9), and there is a gap between it and the connecting outer cylinder (4) to form a communication gel storage chamber (S2) and soil sample collection The gel extrusion channel of the chamber (S1), the upper part of the connecting inner cylinder (3) has an opening (26) to communicate the gel extrusion channel and the gel storage chamber (S2); Wherein, the floating piston (8) is arranged in the connecting inner cylinder (3) and the two are connected in a sealed sliding fit; Preferably: the rotating head (10) is provided with a gel discharge hole, and the gel storage chamber (S2) communicates with the gel discharge hole through a gel overflow pipe (23) to discharge excess gel; Wherein, the gel overflow pipe (23) is fixed on the rotating head (10), and is inserted into the gel storage chamber (S2) through the force transmission head (9), and the gel overflow pipe is connected to the force transmission head (S2). 9) Sealed contacts. 9. jet type in-situ earth borrower according to claim 8 is characterized in that: The soil sample collection chamber (S1) is formed by a floating piston (8) and a connecting inner cylinder (3) together, and when the floating piston (8) moves upward, the soil sample collection chamber (S1) ) gradually increases, and the gel storage chamber (S2) gradually decreases; A soil sample collecting port (C1) for entering the soil sample into the soil sample collecting chamber (S1) is formed inside the cutting shoe (1). 10. The jet type in-situ earth borrower according to claim 8, characterized in that: the inner diameter of the soil sample collection chamber (S1) is slightly larger than the inner diameter of the soil sample collection port (C1) to connect the inner cylinder (S1). 3) A glue injection gap is formed between the inner wall of the trapped soil sample and the outer wall of the collected soil sample for the gel to coat the soil sample; Wherein, the bottom of the connecting inner cylinder (3) is provided with a glue injection hole connecting the soil sample collection chamber (S1) and the gel extrusion channel.

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