A hole-collapse prevention mechanism for ultra-deep rotary pile construction and its use method

Abstract

The present invention relates to the technical field of rotary pile construction, and discloses a hole-collapse prevention mechanism for ultra-deep rotary pile construction, comprising: a plurality of steel casings connected in sequence along the vertical direction; and a cutting device, which comprises a cutting sleeve, cutting teeth, a force storage assembly and a reset assembly, wherein the cutting sleeve is slidably connected to the lowest steel casing along the vertical direction, the force storage assembly is used to selectively drive the cutting teeth to pass through the bottom of the cutting sleeve, and the reset assembly is used to drive the cutting teeth to embed into the cutting sleeve. In addition, the present invention also discloses a method for using the hole-collapse prevention mechanism for ultra-deep rotary pile construction. The present invention utilizes the process of synchronously lowering the drilling hole and the cutting sleeve to achieve the effect of real-time protection of the drilling hole, and can also realize the process of multiple-stage and multiple-time release of the steel casing, effectively avoiding the deformation of the steel casing during long-distance release, and at the same time achieving the protection effect of the ultra-deep rotary pile construction drilling hole, effectively avoiding the occurrence of the hole-collapse phenomenon.

Description

Technical Field

[0001] The invention relates to the technical field of rotary drilling pile construction, and in particular to an anti-collapse hole mechanism for ultra-deep rotary drilling pile construction and a use method thereof. Background Art

[0002] In construction projects, drilling and burying piles are common foundation treatment methods. However, due to the pressure of the land or poor geological conditions, the drilled holes are prone to collapse, which poses a challenge to the burying of piles.

[0003] For foundations with complex geological conditions, such as deep bearing layer, loose surface soil, uneven soil distribution, and silty soil interlayers, pile holes are prone to collapse and necking, and it is difficult to control the collapse, necking, and verticality of the pile holes during construction. In this case, steel casings are required to protect the holes, and the steel casings are used to pass through the loose soil layer to avoid the occurrence of collapse. However, for pile foundations with extremely long construction lengths, such as pile foundations with a length of 80m, due to the long distance and complex geological conditions, it is impossible to achieve a one-time steel casing application process, which can easily cause sleeve deformation and other phenomena, and the steel casing application process is extremely difficult.

[0004] In view of this, for complex geological environments, how to achieve the placement and installation of steel casings during the construction of ultra-deep rotary bored piles to avoid hole collapse has become a technical problem that technical personnel in this field urgently need to solve. Summary of the invention

[0005] The present invention aims to provide a hole-collapse prevention mechanism for ultra-deep rotary pile construction and a method of using the same, so as to overcome the above-mentioned shortcomings.

[0006] In order to achieve the above-mentioned object, the first aspect of the present invention provides a hole-collapse prevention mechanism for ultra-deep rotary pile construction, comprising:

[0007] A plurality of steel casings connected in sequence in a vertical direction; and

[0008] The cutting device includes a cutting sleeve, cutting teeth, a force storage assembly and a reset assembly. The cutting sleeve is slidably connected to the steel casing at the lower end along the vertical direction. The force storage assembly is used to selectively drive the cutting teeth to pass through the bottom of the cutting sleeve. The reset assembly is used to drive the cutting teeth to embed into the cutting sleeve.

[0009] Further, a cutting cavity is arranged at the bottom end of the cutting sleeve, a cutting tooth is slidably connected in the cutting cavity, and the cutting tooth selectively penetrates the bottom end of the cutting sleeve;

[0010] The power storage component comprises:

[0011] A plurality of first magnets and second magnets arranged in a one-to-one correspondence in the cutting sleeve are slidably connected in a vertical direction, the first magnets and the second magnets have the same magnetic poles on opposite surfaces, and the first magnets are fixedly connected to the cutting teeth, and

[0012] An annular cavity is arranged in the cutting sleeve and located above the cutting cavity. A driving ring is rotatably connected in the annular cavity. The upper surface of the driving ring protrudes upward to form a plurality of driving plates. The plurality of driving plates are distributed on the driving ring at intervals on the circumference. Rotating the driving ring can drive the second magnet to selectively slide with the driving plate and move upward, or slide down to the driving ring by its own gravity and slide with the driving ring.

[0013] Furthermore, the outer edge of the driving plate includes an ascending section, a horizontal section and a vertical section connected in sequence, and the ascending section and the vertical section are respectively connected in sequence to the upper surface of the driving ring, and when the ascending section is slidably connected to the second magnet, it drives it to move upward.

[0014] Furthermore, the power storage component also includes a plurality of third magnets fixedly connected in the annular cavity and arranged one-to-one with the plurality of second magnets. The third magnets are located above the second magnets, and the magnetic poles of the third magnets and the opposite surfaces of the second magnets are the same.

[0015] Furthermore, the power storage component also includes:

[0016] a gravity block fixedly connected to the second magnet;

[0017] A friction ring rotatably connected to the cutting sleeve and a connecting plate respectively connected to the friction ring and the driving ring, wherein the cross-sections of the friction ring and the connecting plate are in a "T"-shaped structure.

[0018] Furthermore, a plurality of driving blind holes are arranged at intervals on the circumference of the inner surface of the friction ring.

[0019] Furthermore, a connecting ring is slidably connected in the cutting cavity in the vertical direction, a plurality of cutting teeth are fixedly distributed at circumferential intervals below the connecting ring, and a through hole for the cutting teeth to pass through is arranged at the lower end of the cutting cavity.

[0020] Furthermore, the reset assembly includes an elastic member installed between the cutting chamber bottom plate and the connecting ring, and the elastic force of the elastic member is smaller than the repulsive force between the first magnet and the second magnet when the second magnet slides to the driving ring.

[0021] Furthermore, adjacent steel casings are provided with annular grooves and annular protrusions respectively, and the annular protrusions are inserted into the annular grooves and fixed by positioning screws.

[0022] Compared with the prior art, the anti-collapse hole mechanism for ultra-deep rotary pile construction and the use method thereof of the present invention have the following advantages:

[0023] During the drilling process, the force storage component and the reset component alternately apply force to the cutting teeth, so that the cutting teeth repeatedly penetrate or embed into the cutting sleeve, thereby realizing impact cutting of the soil layer, and further driving the cutting sleeve to gradually extend downward into the lower soil layer. The cutting sleeve can protect the borehole during the drilling process. When the length of the borehole penetrating the steel casing is equal to the maximum length of the cutting component extending out of the steel casing, the next steel casing is sequentially connected above the uppermost steel casing, and the steel casing is installed in the soil layer using a vibrating hammer. At this time, the cutting sleeve slides into the lowermost steel casing under the effect of the supporting force of the soil layer, and the process of drilling and connecting the next steel casing is cyclic until the steel casing penetrates all loose soil layers, and then the borehole is drilled to the designed depth. The present invention utilizes the process of synchronously lowering the drilling and cutting sleeves to achieve the effect of real-time protection of the borehole, and can realize the multi-stage and multiple release process of the steel casing, effectively avoiding the deformation of the steel casing during long-distance release, and at the same time achieves the protection effect of the ultra-deep rotary pile construction drilling, effectively avoiding the occurrence of hole collapse.

[0024] A second aspect of the present invention provides a method for using an anti-collapse hole mechanism for ultra-deep rotary pile construction, comprising the following steps:

[0025] The first step is to find out the underground structure and soil conditions, level the site, stake out the pile positions, and bury cross guard piles. The cross guard piles should be higher than the top surface of the casing, and the pile positions and axis lines should be checked.

[0026] The second step is to use a vibrating hammer to install the bottom of the steel casing and the cutting assembly in the soil layer, ensuring that the axis of the steel casing is located on the intersection line of the cross guard piles, and the buried height of the steel casing should be 50cm above the ground;

[0027] The third step is to drill a hole in the steel casing and penetrate it, and the cutting assembly simultaneously realizes soil layer cutting. When the length of the hole through the lower end of the steel casing is equal to the maximum length of the cutting assembly extending out of the steel casing, the next steel casing is sequentially connected to the top of the uppermost steel casing, and the steel casing is installed in the soil layer using a vibrating hammer, and the buried height of the next steel casing is ensured to be 50 cm above the ground. The above operation is repeated until the steel casing penetrates all the loose soil layers;

[0028] Step 4: Drill to the designed depth.

[0029] The method of using the anti-hole collapse mechanism for ultra-deep rotary pile construction is the same as the advantages of the anti-hole collapse mechanism for ultra-deep rotary pile construction over the prior art, and will not be repeated here. BRIEF DESCRIPTION OF THE DRAWINGS

[0030] In order to more clearly illustrate the embodiments of the present invention or the technical solutions in the prior art, the drawings required for use in the embodiments will be briefly introduced below. Obviously, the drawings described below are only some embodiments of the present invention. For ordinary technicians in this field, other drawings can be obtained based on these drawings without paying creative labor.

[0031] Figure 1 It is a schematic diagram of the overall structure of the anti-collapse hole mechanism for ultra-deep rotary pile construction of the present invention;

[0032] Figure 2 It is a cross-sectional view of the anti-collapse mechanism for ultra-deep rotary pile construction of the present invention;

[0033] Figure 3 For the present invention Figure 2 A partial enlarged view of the middle A area;

[0034] Figure 4 It is a schematic diagram of assembling components such as a drive ring, a drive plate, a connecting ring, a cutting tooth and an elastic member of the present invention;

[0035] Figure 5 A cross-sectional view of the anti-hole collapse mechanism for ultra-deep rotary pile construction of the present invention from another perspective;

[0036] Figure 6 For the present invention Figure 5 A partial enlarged view of the middle B area;

[0037] Figure 7 For the present invention Figure 5 A partial enlarged view of the middle C area.

[0038] Figure numerals: 1. steel casing; 2. cutting sleeve; 3. cutting teeth; 4. cutting chamber; 5. first magnet; 6. second magnet; 7. annular chamber; 8. driving ring; 9. driving plate; 10. rising section; 11. horizontal section; 12. vertical section; 13. third magnet; 14. gravity block; 15. connecting plate; 16. friction ring; 17. driving blind hole; 18. connecting ring; 19. elastic member; 20. annular groove; 21. annular protrusion; 22. positioning screw; 23. sliding bolt; 24. sliding hole. DETAILED DESCRIPTION

[0039] The following will be combined with the drawings in the embodiments of the present invention to clearly and completely describe the technical solutions in the embodiments of the present invention. Obviously, the described embodiments are only part of the embodiments of the present invention, not all of the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field without creative work are within the scope of protection of the present invention.

[0040] In order to make the above-mentioned objects, features and advantages of the present invention more obvious and easy to understand, the present invention is further described in detail below with reference to the accompanying drawings and specific embodiments.

[0041] Reference Figure 1 , Figure 2 , Figure 3 , Figure 4 , Figure 5 and Figure 7 The first aspect of the present invention provides an anti-collapse hole mechanism for ultra-deep rotary pile construction, comprising a steel casing 1 and a cutting device. Among them, multiple steel casings 1 can be installed and connected in sequence along the vertical direction, and the overall length of the steel casing 1 is determined according to the geological conditions to ensure that the total length of the steel casing 1 can penetrate all loose soil layers; the cutting assembly includes a cutting sleeve 2, a cutting tooth 3, a power storage assembly and a reset assembly. The cutting sleeve 2 is slidably connected to the lowermost steel casing 1 along the vertical direction (i.e., the axial direction of the steel casing 1), and the power storage assembly is used to selectively drive the cutting tooth 3 to pass through the bottom of the cutting sleeve 2 to achieve impact cutting of the soil layer, and the reset assembly is used to drive the cutting tooth 3 to embed into the cutting sleeve 2.

[0042] During the drilling process, the force storage component and the reset component alternately apply force to the cutting teeth 3, so that the cutting teeth 3 repeatedly penetrate or embed into the cutting sleeve 2, and achieve impact cutting of the soil layer, and further drive the cutting sleeve 2 to gradually extend downward into the lower soil layer. It can be achieved that as the drilling process progresses, the cutting sleeve 2 can simultaneously achieve the effect of protecting the drilling hole. When the length of the drilled hole penetrating the steel casing 1 is equal to the maximum length of the cutting component extending out of the steel casing 1, the next steel casing 1 is sequentially connected above the uppermost steel casing 1, and the steel casing 1 is installed in the soil layer using a vibrating hammer. At this time, the cutting sleeve 2 slides to the lowermost steel casing 1 under the effect of the supporting force of the soil layer, and the process of drilling and connecting the next steel casing 1 is cyclic until the steel casing 1 penetrates all the loose soil layers, and then the hole is drilled to the specified depth. The present invention utilizes the process of synchronously lowering the drilling and cutting sleeves 2 to realize the multi-stage and multiple release processes of the steel casing 1, effectively avoiding the deformation of the long-distance steel casing 1 during release, and at the same time achieving the protective effect on the ultra-deep rotary pile construction drilling, effectively avoiding the occurrence of hole collapse.

[0043] In one embodiment of the present invention, the maximum length of the cutting sleeve 2 extending from the steel casing 1 should be greater than or equal to the length of a single steel casing 1 to ensure that when a single steel casing 1 is added and deployed, the friction force of the steel casing 1 at the cutting sleeve 2 is minimized.

[0044] In order to enable the cutting sleeve 2 to slide along the axial direction of the steel casing 1, the lowermost steel casing 1 is fixedly connected with a sliding bolt 23 along its radial direction. The cutting sleeve 2 is provided with a sliding hole 24 along its axial direction, and the sliding bolt 23 is slidably connected along the sliding hole 24.

[0045] Preferably, a cutting cavity 4 is arranged at the bottom end of the cutting sleeve 2, and a cutting tooth 3 is slidably connected in the cutting cavity 4, and the cutting tooth 3 selectively penetrates the bottom end of the cutting sleeve 2. The power storage component includes a first magnet 5, a second magnet 6, an annular cavity 7, a driving ring 8 and a driving plate 9. A plurality of groups of vertical slide grooves are arranged in the cutting sleeve 2, and the first magnet 5 and the second magnet 6 are slidably connected along the vertical slide grooves. The first magnet 5 is located below the second magnet 6, and a plurality of first magnets 5 and a plurality of second magnets 6 are arranged one by one in the vertical direction. The magnetic poles of the opposite surfaces of the first magnet 5 and the second magnet 6 are the same. When the first magnet 5 and the second magnet 6 are close to each other, a repulsive force can be formed, and the first magnet 5 is fixedly connected to the cutting tooth 3. In addition, an annular cavity 7 is arranged in the cutting sleeve 2, and the annular cavity 7 is located above the cutting cavity 4. A driving ring 8 is rotatably connected in the annular cavity 7. The upper surface of the driving ring 8 protrudes upward to form a plurality of driving plates 9, and the plurality of driving plates 9 are distributed on the driving ring 8 at intervals on the circumference. Rotating the driving ring 8 can drive the second magnet 6 to selectively slide and connect with the driving plate 9 and move upward, or slide down to the driving ring 8 by its own gravity and slide and connect with the driving ring 8. When the second magnet 6 slides downward by its own gravity, a repulsive force is formed between the first magnet 5 and the second magnet 6, driving the cutting tooth 3 to pass through the bottom of the cutting sleeve 2.

[0046] Reference Figure 4 The outer edge of the driving plate 9 includes a rising section 10, a horizontal section 11 and a vertical section 12 connected in sequence, and the rising section 10 and the vertical section 12 are respectively connected in sequence to the upper surface of the driving ring 8. The rising section 10 is preferably connected to an inclined line segment. When the rising section 10 is slidably connected to the second magnet 6, it will drive it to move upward. After the driving plate 9 misses the vertical section 12, it will slide downward by its own gravity.

[0047] In order to increase the speed of the second magnet 6 when sliding downward, and thus improve the impact cutting ability of the cutting teeth 3 on the soil layer. The power storage component of the present invention also includes a third magnet 13 fixedly connected in the annular cavity 7, and multiple third magnets 13 are arranged one-to-one with multiple second magnets 6, and the magnetic poles of the third magnet 13 and the opposite surface of the second magnet 6 are the same. In addition, the power storage component also includes a gravity block 14 fixedly connected to the second magnet 6, and the gravity block 14 cooperates with the second magnet 6 to increase the downward repulsive force on the first magnet 5. The further power storage component also includes a friction ring 16 rotatably connected in the cutting sleeve 2 and a connecting plate 15 respectively connected to the friction ring 16 and the drive ring 8. The cross-section of the friction ring 16 and the connecting plate 15 is a "T"-shaped structure.

[0048] Preferably, the inner surface of the friction ring 16 is provided with a plurality of driving blind holes 17 at intervals. A connecting ring 18 is slidably connected in the cutting cavity 4 in the vertical direction, and a plurality of cutting teeth 3 are circumferentially spaced below the connecting ring 18. The lower end of the cutting cavity 4 is provided with a through hole for the cutting teeth 3 to pass through.

[0049] Optionally, the reset assembly includes an elastic member 19 installed between the bottom plate of the cutting chamber 4 and the connecting ring 18. The elastic member 19 is preferably a compression spring, and the elastic force of the elastic member 19 is smaller than the repulsive force between the first magnet 5 and the second magnet 6 when the second magnet 6 slides to the driving ring 8. And under the action of the gravity block 14 and the third magnet 13, the second magnet 6 can be slidably connected to the upper surface of the driving ring 8.

[0050] When drilling, it is necessary to pour mud into the borehole. The drilling process will disturb the mud, and the mud disturbance process will drive the friction ring 16 to rotate. The drive blind hole 17 can increase the contact range between the mud and the friction ring 16. At this time, the drive ring 8 and the drive plate 9 will rotate accordingly, and the upper surface of the drive ring 8, the rising section 10, the horizontal section 11 and the vertical section 12 will contact the second magnet 6 in sequence. When the second magnet 6 contacts the rising section 10, the second magnet 6 will slide upward with the vertical slide groove. At this time, the magnetic force between the second magnet 6 and the first magnet 5 is gradually increased. Gradually shrinking, under the action of the elastic member 19, the cutting tooth 3 is gradually embedded in the cutting cavity 4, and then the horizontal section 11 and the vertical section 12 slide with the second magnet 6. The second magnet 6 moves downward rapidly under the action of gravity and the repulsive force of the third magnet 13, and gradually approaches the first magnet 5. The magnetism between the second magnet 6 and the first magnet 5 gradually increases until it overcomes the elastic force of the elastic member 19 and quickly passes through the bottom of the cutting sleeve 2. The above process is repeated, and the cutting tooth 3 gradually impacts downward, gradually driving the cutting sleeve 2 to move downward.

[0051] Reference Figure 6 Adjacent steel casings 1 are respectively provided with annular grooves 20 and annular protrusions 21, and the annular protrusions 21 are inserted into the annular grooves 20 and fixed by positioning screws.

[0052] The present invention provides a second aspect, which provides a method for using the above-mentioned anti-hole collapse mechanism for ultra-deep rotary pile construction, comprising the following steps:

[0053] The first step is to find out the underground structure and soil conditions, level the site, stake out the pile positions, and bury cross guard piles. The cross guard piles should be higher than the top surface of the casing, and the pile positions and axis lines should be checked.

[0054] The second step is to use a vibrating hammer to install the lower end of the steel casing 1 and the cutting assembly in the soil layer, ensuring that the axis of the steel casing 1 is located on the intersection line of the cross guard piles, and the buried height of the steel casing 1 should be 50 cm above the ground;

[0055] The third step is to drill and penetrate the steel casing 1, and the cutting assembly simultaneously realizes soil layer cutting. When the length of the drilled hole through the lower end of the steel casing 1 is equal to the maximum length of the cutting assembly extending out of the steel casing 1, the next steel casing 1 is sequentially connected to the top of the uppermost steel casing 1, and the steel casing 1 is installed in the soil layer by using a vibrating hammer, and the buried height of the next steel casing 1 is ensured to be 50 cm above the ground. The above operation is repeated until the steel casing 1 penetrates all the loose soil layers;

[0056] Step 4: Drill to the designed depth.

[0057] In the description of the present invention, it should be understood that the terms "longitudinal", "lateral", "up", "down", "front", "back", "left", "right", "vertical", "horizontal", "top", "bottom", "inside" and "outside" etc., indicating orientations or positional relationships, are based on the orientations or positional relationships shown in the accompanying drawings, and are only for the convenience of describing the present invention, and do not indicate or imply that the device or element referred to must have a specific orientation, be constructed and operated in a specific orientation, and therefore should not be understood as a limitation on the present invention.

[0058] The embodiments described above are only descriptions of the preferred modes of the present invention, and are not intended to limit the scope of the present invention. Without departing from the design spirit of the present invention, various modifications and improvements made to the technical solutions of the present invention by ordinary technicians in this field should all fall within the protection scope determined by the claims of the present invention.

Claims

1. A hole-collapse prevention mechanism for ultra-deep rotary pile construction, characterized in that: include: A plurality of steel casings (1) connected in sequence in a vertical direction; and A cutting device, comprising a cutting sleeve (2), a cutting tooth (3), a force storage component and a reset component, wherein the cutting sleeve (2) is slidably connected to the steel casing (1) at the bottom in a vertical direction, the force storage component is used to selectively drive the cutting tooth (3) to pass through the bottom of the cutting sleeve (2), and the reset component is used to drive the cutting tooth (3) to embed into the cutting sleeve (2); A cutting cavity (4) is arranged at the bottom end of the cutting sleeve (2), a cutting tooth (3) is slidably connected in the cutting cavity (4), and the cutting tooth (3) selectively penetrates the bottom end of the cutting sleeve (2); The power storage component comprises: A plurality of first magnets (5) and second magnets (6) arranged in a one-to-one correspondence in the cutting sleeve (2) are slidably connected in a vertical direction, the magnetic poles of the opposing surfaces of the first magnets (5) and the second magnets (6) being the same, and the first magnets (5) being fixedly connected to the cutting teeth (3); and An annular cavity (7) is arranged in the cutting sleeve (2) and located above the cutting cavity (4), a driving ring (8) is rotatably connected in the annular cavity (7), the upper surface of the driving ring (8) protrudes upward to form a plurality of driving plates (9), and the plurality of driving plates (9) are circumferentially spaced and distributed on the driving ring (8), and the rotation of the driving ring (8) can drive the second magnet (6) to selectively slide with the driving plate (9) and move upward, or to slide down onto the driving ring (8) by its own gravity and slide with the driving ring (8); The outer edge of the driving plate (9) comprises an ascending section (10), a horizontal section (11) and a vertical section (12) which are connected in sequence, the ascending section (10) and the vertical section (12) being respectively connected in sequence to the upper surface of the driving ring (8), and the ascending section (10) drives the second magnet (6) to move upward when being slidably connected to the second magnet (6); The power storage component further comprises a plurality of third magnets (13) fixedly connected in the annular cavity (7) and arranged in one-to-one correspondence with the plurality of second magnets (6), the third magnets (13) being located above the second magnets (6), and the magnetic poles of the third magnets (13) and the second magnets (6) on the opposite sides thereof being the same; The power storage component also includes: A gravity block (14) fixedly connected to the second magnet (6); A friction ring (16) rotatably connected to the cutting sleeve (2), and a connecting plate (15) respectively connected to the friction ring (16) and the driving ring (8), wherein the cross-sections of the friction ring (16) and the connecting plate (15) are T-shaped structures; The inner surface of the friction ring (16) is provided with a plurality of driving blind holes (17) at intervals around the circumference; A connecting ring (18) is slidably connected in the cutting cavity (4) in a vertical direction, a plurality of the cutting teeth (3) are fixedly distributed at circumferential intervals below the connecting ring (18), and a through hole for the cutting teeth (3) to pass through is arranged at the lower end of the cutting cavity (4).

2. The anti-collapse mechanism for ultra-deep rotary pile construction according to claim 1 is characterized in that: The resetting assembly comprises an elastic member (19) installed between the bottom plate of the cutting chamber (4) and the connecting ring (18), wherein the elastic force of the elastic member (19) is smaller than the repulsive force between the first magnet (5) and the second magnet (6) when the second magnet (6) slides to the driving ring (8).

3. The anti-collapse hole mechanism for ultra-deep rotary pile construction and the use method thereof according to claim 1, characterized in that: An annular groove (20) and an annular protrusion (21) are respectively arranged on adjacent steel casings (1); the annular protrusion (21) is inserted into the annular groove (20) and fixed by a positioning screw (22).

4. A method for using the anti-collapse hole mechanism for ultra-deep rotary pile construction according to any one of claims 1 to 3, characterized in that: The following steps are involved: The first step is to find out the underground structure and soil conditions, level the site, stake out the pile positions, and bury cross guard piles. The cross guard piles should be higher than the top surface of the casing, and the pile positions and axis should be checked. The second step is to install the lower end of the steel casing (1) and the cutting assembly in the soil layer using a vibrating hammer, ensuring that the axis of the steel casing (1) is located on the intersection line of the cross guard piles, and the buried height of the steel casing (1) should be ensured to be 50 cm above the ground; The third step is to drill a hole in the steel casing (1) and penetrate it, and the cutting assembly simultaneously cuts the soil layer. When the length of the hole through the lower end of the steel casing (1) is equal to the maximum length of the cutting assembly extending from the steel casing (1), the next steel casing (1) is connected to the top of the uppermost steel casing (1) in sequence, and the steel casing (1) is installed in the soil layer using a vibrating hammer, and the buried height of the next steel casing (1) is ensured to be 50 cm above the ground. The above operation is repeated until the steel casing (1) penetrates all the loose soil layers. Step 4: Drill to the designed depth.

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