Deep and collapsible hole cast-in-place pile rotary excavating full casing drilling, sinking and pulling integrated construction method

Abstract

This invention relates to the technical field of cast-in-place pile construction and discloses an integrated construction method for drilling, sinking, and extracting casing in rotary drilling of deep, easily collapsible cast-in-place piles. The method includes the following steps: 1) Determining the pile location; 2) The power head drives the drive cylinder through the connecting sleeve to drill the casing towards the pile location, and soil is extracted into the casing using the drilling tool; 3) Concrete is poured into the pile hole through the guide pipe; 4) The casing extraction clamping mechanism is fitted onto the casing, and the power head extracts the casing through the drive cylinder; The rotary drilling rig outputs torque and pressure to the casing through the power head, connecting sleeve, and drive cylinder, causing the casing to sink to a set depth at the pile location via the casing shoe, and soil is extracted into the casing using the drilling tool, forming a pile hole inside the casing; After the pile hole is completed and concrete pouring is finished, the power head extracts the casing again through the drive cylinder. This construction method integrates casing drilling, sinking, and extraction using a rotary drilling rig, solving the problems of complex construction procedures and low drilling efficiency.

Description

Technical Field

[0001] This invention relates to the technical field of cast-in-place pile construction, and more specifically, to an integrated construction method for rotary drilling, sinking, and extraction of deep, easily collapsible cast-in-place piles. Background Technology

[0002] When constructing rotary bored piles in deep, easily collapsible strata, it is usually necessary to drive deep and long casings for wall protection, and to pass through the easily collapsible strata to ensure the stability of the borehole wall.

[0003] Currently, there are three main methods for constructing long and deep casings: one is to use a full-casing rotary drilling rig to lower the long casing and use a grab bucket for soil removal; the second is to use a full-casing rotary drilling rig to lower the long casing and use a rotary drilling rig for soil removal; and the third is to use a vibratory hammer to sink an ultra-long casing and then use a rotary drilling rig for soil removal. All three methods require the use of two large pieces of equipment, which makes the process complex and the drilling efficiency low. Summary of the Invention

[0004] The purpose of this invention is to provide an integrated construction method for rotary drilling, sinking, and extraction of deep, easily collapsed bored piles, aiming to solve the problems of complex construction procedures and low drilling efficiency in the existing technology.

[0005] This invention is implemented as follows: a complete rotary drilling, driving, and extraction method for deep, easily collapsible cast-in-place piles, comprising the following construction steps:

[0006] 1) Level the construction site and determine the pile positions for construction; arrange a rotary drilling rig on the construction site. The rotary drilling rig includes a power head and drilling tools. The power head is equipped with a drive cylinder. The drive cylinder is connected to the power head through a connecting cylinder. The top of the connecting cylinder is arranged axially around the bottom of the power head. The bottom of the connecting cylinder is detachably connected to the top of the drive cylinder. A sleeve is installed at the bottom of the drive cylinder. The bottom of the sleeve is equipped with a shoe with cutting teeth.

[0007] 2) The center of the casing is arranged concentrically with the center of the pile position using the rotary drilling rig; the power head drives the drive cylinder through the connecting cylinder to drill the casing toward the pile position and presses it down until the casing sinks to the set depth. Then, the drive cylinder is separated from the casing, and soil is taken into the casing through the drilling tool until a pile hole is formed inside the casing.

[0008] 3) After cleaning the pile hole, lower the steel cage into the pile hole, then lower the guide pipe into the pile hole, and pour concrete into the pile hole through the guide pipe until the concrete fills the pile hole.

[0009] 4) The orifice sleeve pulling clamping mechanism is sleeved on the sleeve, the sleeve has an outer tube body exposed to the ground, and the orifice sleeve pulling clamping mechanism is arranged around the bottom outer periphery of the outer tube body; the power head pulls out the sleeve through the drive cylinder.

[0010] Furthermore, in the construction step 1), the connecting cylinder has a hollow cavity that runs vertically through the interior and exterior, and the hollow cavity is arranged longitudinally; the drill bit is located in the hollow cavity, and the outer side wall of the drill bit is spaced apart from the inner side wall of the hollow cavity.

[0011] Furthermore, the connecting cylinder has an upwardly protruding connector that is clamped and connected to the power head. The top of the connector is exposed outside the connecting cylinder, and the bottom of the connector is located in the hollow cavity. There is a gap between the inner wall of the hollow cavity and the outer wall of the connector, and the gap forms an annular clamping groove with an external opening.

[0012] Furthermore, the outer periphery of the connector extends outward with an outer ring located in the interval region; the outer periphery of the outer ring abuts against the inner wall of the hollow cavity, and the inner wall of the hollow cavity, the top of the outer ring, and the outer wall of the connector enclose to form the annular clamping groove.

[0013] Furthermore, the connector is provided with multiple outward-facing clamping plates, which are arranged at intervals around the top circumference of the connector. Each clamping plate is connected to a fixing ring, the bottom of which abuts against the clamping plate. A fastening groove is formed between adjacent clamping plates for the power head to engage and clamp.

[0014] Furthermore, the connector has a through-cavity that extends vertically, and the through-cavity is connected to the hollow cavity and the fastening groove, respectively.

[0015] Furthermore, in the construction step 1), the top of the drive cylinder is provided with multiple locking holes, which are arranged at intervals around the outer periphery of the drive cylinder; the bottom of the drive cylinder is provided with multiple connecting pins for fixing sleeves, which are arranged at intervals around the outer periphery of the drive cylinder; the bottom of the drive cylinder has a positioning groove that is recessed inward to form an external opening; the drive cylinder is provided with multiple vent holes, which are arranged at intervals around the outer periphery of the drive cylinder.

[0016] The top of the sleeve is provided with a plurality of pin holes through which connecting pins pass. The plurality of pin holes are arranged at intervals around the outer periphery of the sleeve. A positioning block is provided on the outer periphery of the sleeve facing outward. The sleeve is fixed to the drive cylinder by the connecting pins passing through the pin holes. The bottom inner wall of the drive cylinder abuts against the top outer wall of the sleeve. The outer periphery of the positioning block abuts against the inner wall of the positioning groove.

[0017] Furthermore, in the construction step 4), the orifice sleeve pulling clamping mechanism includes a clamping platform and an annular wall with a protrusion arranged around the inner end of the clamping platform. The clamping platform is provided with a plurality of oppositely arranged screw locks and a plurality of cam locks. The plurality of cam locks and the plurality of screw locks are respectively arranged at intervals around the annular wall. The screw locks and cam locks respectively abut against the outer periphery of the outer tube body.

[0018] The screw lock includes a screw that reciprocates toward the center of the outer tube and a support plate. The support plate is fixed to the annular wall. The screw and the support plate are connected by threads so that at least part of the screw can abut against the outer tube.

[0019] The cam lock includes a support and a cam. The support is fixedly connected to the annular wall, and the cam is rotatably connected to the support so that the cam at least partially abuts against the outer tube. The side of the cam facing the outer tube is arc-shaped and has multiple serrations.

[0020] Furthermore, the annular wall is provided with a friction ring that generates resistance by rubbing against the outer tube. The friction ring is arranged circumferentially around the inner sidewall of the annular wall, and there is an annular region between the inner sidewall of the annular wall and the outer sidewall of the outer tube, and the friction ring is located in the annular region.

[0021] The friction ring has an inner end face facing the outer tube body, the inner end face being inclined from bottom to top, and a plurality of balls being provided at the lower part of the inner end face. The plurality of balls are arranged at intervals around the inner end face in a circumferential direction, and the balls abut against the outer side wall of the outer tube body. The middle part of the inner end face abuts against the outer side wall of the outer tube body, and the upper part of the inner end face is spaced apart from the outer side wall of the outer tube body. The bottom of the friction ring presses against the ground.

[0022] In construction step 4), as the outer pipe body sinks, the middle part of the inner end face of the friction ring rubs against the outer pipe body, causing the inner end face to be arranged inclined from top to bottom, increasing the contact area between the inner end face and the outer pipe body, and generating frictional resistance.

[0023] As the outer tube is pulled out upwards, the inner end face of the friction ring reduces the frictional resistance between itself and the outer wall of the outer tube through the ball bearings.

[0024] Furthermore, in the construction step 2), the drilling tool includes a drill barrel for drilling soil, a clamping ring is provided on the drill barrel, the clamping ring is arranged around the outer periphery of the drill barrel, the clamping ring is provided with a plurality of arc-shaped scrapers that swing up and down, the plurality of arc-shaped scrapers are arranged around the outer periphery of the clamping ring, a limiting strip is provided on the outer periphery of the clamping ring to position the swing range of the arc-shaped scrapers, the limiting strip is arranged around the outer periphery of the clamping ring, the limiting strip is located below the arc-shaped scrapers, and the outer side wall of the limiting strip is spaced apart from the inner side wall of the casing, there is a soil scraping area spaced apart between the inner side wall of the casing and the outer side wall of the drill barrel, and the arc-shaped scrapers are located in the soil scraping area;

[0025] The arc-shaped scraper has a scraping section that bends and abuts against the inner wall of the sleeve. The outer wall of the arc-shaped scraper abuts against the inner wall of the sleeve to form a connecting edge. The scraping section extends along the length of the connecting edge.

[0026] In the construction step 2), as the drill bit moves downward to extract soil inside the casing, the arc-shaped scraper moves downward inside the casing. When the arc-shaped scraper is obstructed by the clay on the inner wall of the casing, the arc-shaped scraper flips upward.

[0027] As the drill bit moves upwards inside the casing to extract soil, the arc-shaped scraper moves upwards inside the casing. When the arc-shaped scraper is obstructed by the clay on the inner wall of the casing, the limiting strip supports the bottom of the arc-shaped scraper so that the arc-shaped scraper moves upwards in conjunction with the scraping section to scrape away the clay on the inner wall of the casing.

[0028] Compared with existing technologies ， This invention provides a method for integrated drilling, sinking, and extraction of casing for deep, easily collapsible bored piles using rotary drilling rigs. The rotary drilling rig, through its power head, connecting cylinder, and drive cylinder, outputs torque and pressure to the casing, causing it to sink to a set depth at the pile location via the casing shoe. Soil is then extracted into the casing using the drilling tool, forming a pile hole. After the pile hole is completed and concrete is poured, the power head, through the drive cylinder, extracts the casing. This method integrates casing drilling, sinking, and extraction using a rotary drilling rig, solving the problems of complex construction procedures and low drilling efficiency. Furthermore, a casing extraction clamping mechanism at the borehole opening prevents the casing from slipping back into the pile location during extraction. Attached Figure Description

[0029] Figure 1 This is a schematic diagram of the construction process of the integrated drilling, sinking, and extraction method for rotary drilling of deep, easily collapsible cast-in-place piles provided by the present invention.

[0030] Figure 2 This is a structural schematic diagram of the rotary drilling rig provided by the present invention;

[0031] Figure 3 This is a three-dimensional schematic diagram of the power head, connecting cylinder, drive cylinder, and sleeve provided by the present invention;

[0032] Figure 4 This is a three-dimensional schematic diagram of the connecting cylinder provided by the present invention;

[0033] Figure 5 This is a three-dimensional schematic diagram of the drive cylinder provided by the present invention;

[0034] Figure 6 This is a three-dimensional schematic diagram of the sleeve provided by the present invention;

[0035] Figure 7 This is a top view of the orifice sleeve pulling and clamping mechanism provided by the present invention.

[0036] Figure 8 This is a schematic diagram of the structure of the orifice sleeve pulling clamping mechanism and the sleeve provided by the present invention;

[0037] Figure 9 This is a schematic diagram of the structure of the drilling tool and casing provided by the present invention.

[0038] The diagram shows: rotary drilling rig 100, power head 200, drilling tool 300, connecting cylinder 400, drive cylinder 500, casing 600, casing shoe 700, borehole casing lifting and clamping mechanism 800, drill barrel 301, clamping ring 302, arc-shaped scraper 303, limiting strip 304, scraping section 305, joint 401, annular groove 402, outer ring 403, clamping plate 404, fixing ring 405, fastening groove 406, connecting cavity 407, locking hole 501, connecting pin 502, positioning groove 503, vent hole 504, pin hole 601, positioning block 602, clamping platform 801, annular wall 802, screw lock 803, screw 804, support plate 805, cam lock 806, support 807, cam 808, friction ring 809, inner end face 810, ball bearing 811. Detailed Implementation

[0039] To make the objectives, technical solutions, and advantages of this invention clearer, the invention will be further described in detail below with reference to the accompanying drawings and embodiments. It should be understood that the specific embodiments described herein are merely illustrative and not intended to limit the invention.

[0040] The implementation of the present invention will be described in detail below with reference to specific embodiments.

[0041] In the accompanying drawings of this embodiment, the same or similar reference numerals correspond to the same or similar components. In the description of this invention, it should be understood that if terms such as "upper," "lower," "left," and "right" indicate the orientation or positional relationship based on the orientation or positional relationship shown in the drawings, they are only for the convenience of describing this invention and simplifying the description, and do not indicate or imply that the device or element referred to must have a specific orientation, or be constructed and operated in a specific orientation. Therefore, the terms used to describe positional relationships in the drawings are only for illustrative purposes and should not be construed as limiting this invention. For those skilled in the art, the specific meaning of the above terms can be understood according to the specific circumstances.

[0042] Reference Figure 1-9 The image shown is a preferred embodiment of the present invention.

[0043] The integrated construction method for rotary drilling, driving, and extraction of deep, easily collapsible bored piles includes the following steps:

[0044] 1) Level the construction site and determine the pile positions for construction; arrange a rotary drilling rig 100 on the construction site. The rotary drilling rig 100 includes a power head 200 and a drilling tool 300. The power head 200 is equipped with a drive cylinder 500. The drive cylinder 500 and the power head 200 are driven by connecting cylinder 400. The top of the connecting cylinder 400 is arranged axially around the bottom of the power head 200. The bottom of the connecting cylinder 400 is detachably connected to the top of the drive cylinder 500. A sleeve 600 is installed at the bottom of the drive cylinder 500. The bottom of the sleeve 600 is equipped with a shoe 700 with cutting teeth.

[0045] 2) The center of the casing 600 is arranged concentrically with the center of the pile position using the rotary drilling rig 100; the power head 200 drives the drive cylinder 500 through the connecting cylinder 400 to drill the casing 600 into the pile position and press down until the casing 600 sinks to the set depth. Then, the drive cylinder 500 is separated from the casing 600, and soil is taken into the casing 600 through the drilling tool 300 until a pile hole is formed inside the casing 600.

[0046] 3) After cleaning the pile hole, lower the steel cage into the pile hole, then lower the guide pipe into the pile hole and pour concrete into the pile hole through the guide pipe until the concrete fills the pile hole.

[0047] 4) The orifice casing pulling clamping mechanism 800 is fitted onto the casing 600, which has an outer tube body exposed to the ground. The orifice casing pulling clamping mechanism 800 is arranged around the bottom outer periphery of the outer tube body; the power head 200 pulls out the casing 600 through the drive cylinder 500.

[0048] The aforementioned integrated drilling, sinking, and extraction method for deep, easily collapsible bored piles using rotary drilling rig 100 with a full casing 600 involves the rotary drilling rig 100 using a power head 200 in conjunction with a connecting cylinder 400 and a drive cylinder 500 to output torque and pressure to the casing 600. This causes the casing 600 to be driven to a set depth at the pile location via a shoe 700. Soil is then extracted into the casing 600 using a drilling tool 300, forming a pile hole within the casing 600. After the pile hole is completed and concrete is poured, the power head 200, via the drive cylinder 500, extracts the casing 600. This method integrates drilling, sinking, and extraction of the casing 600 using the rotary drilling rig 100, solving the problems of complex construction procedures and low drilling efficiency. Furthermore, a casing extraction clamping mechanism 800 at the borehole opening prevents the casing 600 from slipping back into the pile location during extraction.

[0049] The entire process of sinking the casing 600, rotary drilling for soil removal, and pulling out the casing 600 was carried out using only one rotary drilling rig 100, which achieved high construction efficiency, good pile quality, and low overall cost, resulting in good economic and social benefits.

[0050] In construction step 1), the connecting cylinder 400 has a hollow cavity that runs vertically through the interior and is arranged longitudinally; the drill bit 300 is located in the hollow cavity, and there is a gap between the outer wall of the drill bit 300 and the inner wall of the hollow cavity; thus, when the connecting cylinder 400 is installed on the power head 200, it will not affect the use of the drill bit 300.

[0051] In this embodiment, the connecting cylinder 400 has an upwardly protruding connector 401 that is clamped and connected to the power head 200. The top of the connector 401 is exposed outside the connecting cylinder 400, and the bottom of the connector 401 is located in the hollow cavity. There is a gap between the inner wall of the hollow cavity and the outer wall of the connector 401. The gap forms an annular groove 402 with an external opening.

[0052] The connecting cylinder 400 is clamped and installed by the power head 200 through the connector 401, and the bottom edge of the power head 200 is embedded in the annular clamping groove 402 formed between the connecting cylinder 400 and the connector 401. This can protect the top of the connecting cylinder 400 from damage when transmitting output torque and pressure, and can also increase the connection between the connecting cylinder 400 and the power head 200.

[0053] By connecting the connector 401 to the inside of the power head 200, the connecting diameter is gradually increased by the connecting cylinder 400 and the driving cylinder 500, so that the large-diameter sleeve 600 can be indirectly connected to the power head 200 and bear the output torque and pressure of the power head 200, thus solving the problem of mismatch between the power head 200 and the large-diameter sleeve 600.

[0054] In this embodiment, an outer ring 403 extends outward from the outer periphery of the connector 401 and is located in the interval region; the outer periphery of the outer ring 403 abuts against the inner wall of the hollow cavity, and the inner wall of the hollow cavity, the top of the outer ring 403, and the outer wall of the connector 401 enclose to form an annular groove 402.

[0055] The outer ring 403 restricts the bottom edge of the power head 200 from being embedded in the bottom of the annular groove 402, thus preventing the connecting cylinder 400 from shaking after being installed on the power head 200.

[0056] In this embodiment, the connector 401 is provided with a plurality of outwardly extending clamping plates 404. The plurality of clamping plates 404 are arranged at intervals around the top circumference of the connector 401. The plurality of clamping plates 404 are connected to fixing rings 405. The bottom of the fixing rings 405 abuts against the clamping plates 404. A fastening groove 406 is formed between adjacent clamping plates 404 for the power head 200 to fasten and clamp.

[0057] The connector 401 provides a fastening groove 406 formed by multiple clamping plates 404 and a fixing ring 405 for the power head 200 to fasten and hold, so that the power head 200 can output torque and pressure to the sleeve 600 through the connector 401 in conjunction with the connecting cylinder 400 and the drive cylinder 500.

[0058] The connector 401 has a through cavity 407 that runs vertically through the joint. The through cavity 407 is connected to the hollow cavity and the snap-fit ​​groove 406 respectively. In this way, the connector 401 will not affect the use of the drill bit 300.

[0059] In this embodiment, in construction step 1), the top of the drive cylinder 500 is provided with a plurality of locking holes 501, which are arranged at intervals around the outer periphery of the drive cylinder 500. The bottom of the drive cylinder 500 is provided with a plurality of connecting pins 502 for fixing sleeves 600, which are arranged at intervals around the outer periphery of the drive cylinder 500. The bottom of the drive cylinder 500 has a positioning groove 503 that is recessed inward to form an external opening. The drive cylinder 500 is provided with a plurality of exhaust holes 504, which are arranged at intervals around the outer periphery of the drive cylinder 500.

[0060] The top of the sleeve 600 is provided with a plurality of pin holes 601 through which connecting pins 502 pass. The plurality of pin holes 601 are arranged at intervals around the outer periphery of the sleeve 600. A positioning block 602 is provided on the outer periphery of the sleeve 600 protruding outward. The sleeve 600 is fixed to the drive cylinder 500 by the connecting pins 502 passing through the pin holes 601. The bottom inner side wall of the drive cylinder 500 abuts against the top outer side wall of the sleeve 600. The outer periphery of the positioning block 602 abuts against the inner side wall of the positioning groove 503.

[0061] The drive cylinder 500 is connected to the pin of the connecting cylinder 400 through the locking hole 501. The sleeve 600 is connected to the connecting pin 502 of the drive cylinder 500 through the pin hole 601. The positioning block 602 of the sleeve 600 is embedded in the positioning groove 503 of the drive cylinder 500, making the connection between the drive cylinder 500 and the sleeve 600 more stable, thereby improving the ability of the drive cylinder 500 to apply the output torque and pressure of the power head 200 to the sleeve 600.

[0062] In this embodiment, in construction step 4), the orifice sleeve pulling clamping mechanism 800 includes a clamping platform 801 and an annular wall 802 arranged around the inner end of the clamping platform 801. The clamping platform 801 is provided with a plurality of oppositely arranged screw locks 803 and a plurality of cam locks 806. The plurality of cam locks 806 and the plurality of screw locks 803 are respectively arranged at intervals around the annular wall 802. The screw locks 803 and the cam locks 806 respectively abut against the outer periphery of the outer tube body.

[0063] The screw lock 803 includes a screw 804 that reciprocates toward the center of the outer tube and a support plate 805. The support plate 805 is fixed to the annular wall 802. The screw 804 and the support plate 805 are connected by threads so that the screw 804 can at least partially abut against the outer tube.

[0064] The cam lock 806 includes a support 807 and a cam 808. The support 807 is fixedly connected to the annular wall 802. The cam 808 is rotatably connected to the support 807 so that the cam 808 at least partially abuts against the outer tube. The side of the cam 808 facing the outer tube is arc-shaped and has multiple serrations.

[0065] The screw 804 abuts against the outer tube, and together with the cam 808 and multiple serrations, it forms abutment with the outer tube, thus fixing the sleeve 600 in place and preventing it from sinking. Therefore, the sleeve 600 is easy to disassemble and is safe and reliable.

[0066] In this embodiment, the annular wall 802 is provided with a friction ring 809 that generates resistance by friction with the outer tube. The friction ring 809 is arranged circumferentially around the inner sidewall of the annular wall 802. There is an annular region between the inner sidewall of the annular wall 802 and the outer sidewall of the outer tube, and the friction ring 809 is located in the annular region.

[0067] The friction ring 809 has an inner end face 810 facing the outer tube body. The inner end face 810 is inclined from bottom to top. A plurality of balls 811 are provided at the lower part of the inner end face 810. The plurality of balls 811 are arranged at intervals around the inner end face 810 in a circumferential direction. The balls 811 abut against the outer wall of the outer tube body. The middle part of the inner end face 810 abuts against the outer wall of the outer tube body. The upper part of the inner end face 810 is spaced apart from the outer wall of the outer tube body. The bottom of the friction ring 809 presses against the ground.

[0068] In construction step 4), as the outer pipe body sinks, the middle part of the inner end face 810 of the friction ring 809 rubs against the outer pipe body, causing the inner end face 810 to be arranged inclined from top to bottom, increasing the contact area between the inner end face 810 and the outer pipe body, and generating frictional resistance.

[0069] As the outer tube is pulled out upwards, the inner end face 810 of the friction ring 809 reduces the frictional resistance between itself and the outer wall of the outer tube through the ball bearings 811.

[0070] The friction ring 809 forms a friction section by abutting the middle of the inner end face 810 with the outer tube body, while the lower part of the inner end face 810 abuts with the outer tube body through the ball bearing 811. As the outer tube body moves upward, the friction causes the middle part of the inner end face 810 to swing upward, while the lower part of the inner end face 810 reduces the friction with the outer tube body through the ball bearing 811. Therefore, the friction ring 809 will not have a significant impact on the outer tube body during the upward movement of the outer tube body.

[0071] As the outer tube moves downward, the middle part of the inner end face 810 shifts downward due to friction with the outer tube, causing the upper part of the inner end face 810 to abut against the outer tube, thereby increasing the frictional resistance between the friction ring 809 and the outer tube. This friction prevents the sleeve 600 from sliding down when it is disassembled.

[0072] In this embodiment, in construction step 2), the drilling tool 300 includes a drill barrel 301 for drilling soil. The drill barrel 301 is provided with a clamping ring 302, which is arranged around the outer periphery of the drill barrel 301. The clamping ring 302 is provided with multiple arc-shaped scrapers 303 that swing up and down. The multiple arc-shaped scrapers 303 are arranged around the outer periphery of the clamping ring 302. A limiting strip 304 is provided on the outer periphery of the clamping ring 302 to position the swing range of the arc-shaped scrapers 303. The limiting strip 304 is arranged around the outer periphery of the clamping ring 302. The limiting strip 304 is located below the arc-shaped scrapers 303. The outer wall of the limiting strip 304 is spaced apart from the inner wall of the casing 600. There is a soil scraping area spaced apart between the inner wall of the casing 600 and the outer wall of the drill barrel 301. The arc-shaped scrapers 303 are located in the soil scraping area.

[0073] The arc-shaped scraper 303 has a scraping section 305 that bends and abuts against the inner wall of the sleeve 600. The outer wall of the arc-shaped scraper 303 abuts against the inner wall of the sleeve 600 to form a connecting edge. The scraping section 305 extends along the length of the connecting edge.

[0074] In construction step 2), as the drill bit 300 moves downwards to remove soil inside the casing 600, the arc-shaped scraper 303 moves downwards inside the casing 600. When the arc-shaped scraper 303 is obstructed by the clay on the inner wall of the casing 600, the arc-shaped scraper 303 flips upwards; in this way, the arc-shaped scraper 303 will not scrape the clay on the inner wall of the casing 600 downwards.

[0075] As the drill bit 300 moves upward inside the casing 600 to remove soil, the arc-shaped scraper 303 also moves upward inside the casing 600. When the arc-shaped scraper 303 is obstructed by the clay on the inner wall of the casing 600, the limiting strip 304 supports the bottom of the arc-shaped scraper 303, so that the arc-shaped scraper 303 moves upward in conjunction with the scraping section 305 to scrape away the clay on the inner wall of the casing 600. In this way, the arc-shaped scraper 303 can scrape away the clay on the inner wall of the casing 600 in one direction.

[0076] Construction process steps:

[0077] 1. Opening a hole

[0078] 1) Hole opening can be achieved using a rotary drilling rig or directly using a casing with a sleeve shoe;

[0079] 2) When using a rotary drilling rig to drill holes, align the center of the rotary drilling rig with the center point of the pile location, lower the drilling rig to the ground, rotate and press down the drilling rig to start drilling. The drilling depth should be such that the hole opening does not collapse.

[0080] 2. The first section of steel casing with the boot sinks.

[0081] 1) Connect the first sleeve to the drive cylinder. Before installing the sleeve, first open the connecting pin of the drive cylinder clockwise to open it completely, and then install the sleeve. After the drive cylinder is fully inserted into the sleeve, turn the connecting pin counterclockwise to fix the sleeve.

[0082] 2) Slowly lower the casing of the connecting shoe into the pre-drilled hole, adjust the verticality of the casing using the power head of the rotary drilling rig, and confirm that the verticality of the casing meets the requirements.

[0083] 3) After the verticality meets the requirements, rotate the power head of the rotary drilling rig, rotate the drive cylinder and apply pressure, and the casing begins to cut the soil layer and sink into the ground.

[0084] 3. Casing orifice extension and sinking

[0085] 1) To facilitate the extension of the casing, when the first section of the casing is sunk to about 1m above the exposed ground, stop the sinking and start extending the casing.

[0086] 2) Turn the connecting pin of the drive cylinder clockwise to unlock the drive cylinder from the sleeve, and then lift the drive cylinder;

[0087] 3) Connect the drive cylinder to another casing section, move the rotary drilling rig to above the first casing section, adjust the power head so that the positioning groove below the casing is inserted into the positioning block above the first casing section, and slowly lower it;

[0088] 4) After the two sleeves are connected, before installing the bolts, clean the loose mud from the pin holes and column bolts with a high-pressure water gun. After installing the bolts, first tighten them manually with a wrench, and then tighten them with an electric wrench.

[0089] 5) After the casing connection is completed, use a horizontal straightedge to check the verticality of the casing and a ruler to check the pile position. If it does not meet the requirements, make adjustments in time.

[0090] 6) Rotate the power head of the rotary drilling rig and press down to sink the casing. When the top of the casing is about 1m from the ground, stop sinking and continue to repeat the casing extension steps.

[0091] 4. Soil extraction from inside the casing of a rotary drilling tool

[0092] 1) As the casing continues to sink, the frictional resistance on the casing increases. When the casing can no longer be sunk, a rotary drilling tool is used to remove soil inside the casing.

[0093] 2) After the rotary drilling tool has finished removing soil, turn the connecting pin of the drive cylinder counterclockwise to separate the connection between the drive cylinder and the casing, and lift the drive cylinder; when the connection between the drive cylinder and the casing is at a high position and the construction personnel cannot reach it by hand, a homemade long hook can be used to turn the connecting pin.

[0094] 3) Extend the drill rod of the rotary drilling rig, use the rotary drilling tool to remove soil from inside the casing, and temporarily store it in the slag box; the soil removal depth should be level with the bottom of the casing or slightly deeper than the bottom of the casing to ensure that the bottom of the hole does not collapse.

[0095] 4) Repeat the steps of casing insertion and rotary drilling to remove soil and unload slag inside the casing until the drilling depth penetrates the easily collapsible strata or meets the design pile bottom elevation.

[0096] 5. Rotary drilling inside casing

[0097] 1) After the casing passes through the easily collapsed strata and enters the rock surface, normal rotary drilling begins inside the casing;

[0098] 2) Disconnect the drive cylinder from the casing and allow the normal rotary drilling bit to perform drilling, soil extraction, and soil unloading operations until the drilling depth meets the design pile bottom elevation.

[0099] 6. Clean the hole, lower the reinforcing cage, install the grouting guide pipe, and pour the pile concrete.

[0100] 1) After drilling reaches the design requirements, use a hole cleaning and slag removal drill bit to sweep the bottom of the hole and clean the sediment at the bottom of the hole.

[0101] 2) When the crane lifts the steel cage into the hole, a designated person should be assigned to direct the operation, and the crane should rotate smoothly.

[0102] 3) After the steel cage is hoisted and qualified, install the grouting pipe. The pipe should be 250mm in diameter, with a firm joint and a sealing ring to ensure that it is leak-proof and watertight.

[0103] 4) After the secondary cleaning of the hole meets the requirements, the pile body concrete is poured. 12-hour super slow-setting concrete is used during the pouring to avoid the concrete solidifying before all the casing is pulled out, which would make it impossible to pull out the casing.

[0104] 5) The amount of concrete poured in the first batch should meet the requirement of the initial burial depth of the guide pipe being more than 1.0m, and continuous pouring should be maintained; during the pouring process, a dedicated person should regularly measure the concrete surface inside the casing and the rising height of the concrete inside the guide pipe, and remove the guide pipe in a timely manner, with the burial depth controlled between 2 and 6m.

[0105] 7. Install the orifice sleeve lifting and clamping mechanism

[0106] 1) After the concrete pouring is completed, begin pulling out the sleeve;

[0107] 2) Before pulling out the casing, separate the drive cylinder of the rotary drilling rig from the casing, slowly lower it from above the casing, and put the casing pulling clamping mechanism into the casing.

[0108] 3) After the orifice sleeve pulling clamping mechanism is in place, use pads to place the orifice sleeve pulling clamping mechanism stably and keep the clamping platform plane horizontal.

[0109] 8. Pull out the sleeve section by section.

[0110] 1) Position the rotary drilling rig, align it with the center of the casing, lower the drive cylinder to connect with the casing at the borehole opening, and fasten the connection with bolts;

[0111] 2) The power head of the rotary drilling rig outputs torque to rotate the connecting cylinder and the drive cylinder, while applying an upward pulling force to gradually pull the casing out of the borehole.

[0112] 3) When the upper section of the sleeve is completely pulled out and the lower section of the sleeve is pulled out about 1m above the ground, turn the screw of the screw lock clockwise to unscrew it and lock the short steel bar welded to the sleeve. Control the cam lock to clamp the sleeve and work together with the screw lock to fix the extra-long sleeve in the hole and prevent the sleeve from sinking.

[0113] 4) Use a high-pressure water gun to flush the pin hole position, loosen the connecting pins symmetrically and one by one, and loosen the two sleeve sections; lift the drive cylinder, and when the upper sleeve section and the lower sleeve section are completely separated, start the rotary drilling rig to move the first sleeve section to the side of the pile position or the next pile hole.

[0114] 5) Repeat the above steps to pull out the entire casing, including the first section with the sleeve shoe.

[0115] The above description is only a preferred embodiment of the present invention and is not intended to limit the present invention. Any modifications, equivalent substitutions, and improvements made within the spirit and principles of the present invention should be included within the protection scope of the present invention.

Claims

1. A method for integrated drilling, driving, and extraction of deep, easily collapsible bored piles using rotary drilling with a complete casing, characterized by: The construction steps include the following: 1) Level the construction site and determine the pile positions for construction; arrange a rotary drilling rig on the construction site. The rotary drilling rig includes a power head and drilling tools. The power head is equipped with a drive cylinder. The drive cylinder is connected to the power head through a connecting cylinder. The top of the connecting cylinder is arranged axially around the bottom of the power head. The bottom of the connecting cylinder is detachably connected to the top of the drive cylinder. A sleeve is installed at the bottom of the drive cylinder. The bottom of the sleeve is equipped with a shoe with cutting teeth. 2) The center of the casing is arranged concentrically with the center of the pile position using the rotary drilling rig; the power head drives the drive cylinder through the connecting cylinder to drill the casing into the pile position and presses the casing down until the casing sinks to the set depth. Then, the drive cylinder is separated from the casing, and soil is taken into the casing through the drilling tool until a pile hole is formed inside the casing. 3) After cleaning the pile hole, lower the steel cage into the pile hole, then lower the guide pipe into the pile hole, and pour concrete into the pile hole through the guide pipe until the concrete fills the pile hole. 4) The orifice sleeve pulling and clamping mechanism is sleeved on the sleeve, which has an outer tube body exposed to the ground. The orifice sleeve pulling and clamping mechanism is arranged around the bottom outer periphery of the outer tube body; the power head pulls out the sleeve through the drive cylinder. In the construction step 4), the orifice sleeve pulling clamping mechanism includes a clamping platform and an annular wall arranged around the inner end of the clamping platform with a protrusion. The annular wall is provided with a friction ring that generates resistance by rubbing against the outer tube. The friction ring is arranged circumferentially around the inner sidewall of the annular wall. There is an annular region between the inner sidewall of the annular wall and the outer sidewall of the outer tube, and the friction ring is located in the annular region. The friction ring has an inner end face facing the outer tube body, the inner end face being inclined from bottom to top, and a plurality of balls being provided at the lower part of the inner end face. The plurality of balls are arranged at intervals around the inner end face in a circumferential direction, and the balls abut against the outer side wall of the outer tube body. The middle part of the inner end face abuts against the outer side wall of the outer tube body, and the upper part of the inner end face is spaced apart from the outer side wall of the outer tube body. The bottom of the friction ring presses against the ground. In construction step 4), as the outer pipe body sinks, the middle part of the inner end face of the friction ring rubs against the outer pipe body, causing the inner end face to be arranged inclined from top to bottom, increasing the contact area between the inner end face and the outer pipe body, and generating frictional resistance. As the outer tube is pulled out upwards, the inner end face of the friction ring reduces the frictional resistance between itself and the outer wall of the outer tube through the ball bearings.

2. The integrated construction method for rotary drilling, sinking, and extraction of deep, easily collapsible bored piles as described in claim 1, characterized in that... In the construction step 1), the connecting cylinder has a hollow cavity that runs vertically through the cylinder, and the hollow cavity is arranged longitudinally; the drill bit is located in the hollow cavity, and there is a gap between the outer wall of the drill bit and the inner wall of the hollow cavity.

3. The integrated construction method for rotary drilling, sinking, and extraction of deep, easily collapsible bored piles as described in claim 2, characterized in that... The connecting cylinder has an upwardly protruding connector that is clamped and connected to the power head. The top of the connector is exposed outside the connecting cylinder, and the bottom of the connector is located in the hollow cavity. There is a gap between the inner wall of the hollow cavity and the outer wall of the connector, and the gap forms an annular clamping groove with an external opening.

4. The integrated construction method for rotary drilling, sinking, and extraction of deep, easily collapsible bored piles as described in claim 3, characterized in that... The connector has an outer ring extending outward from its outer periphery, which is located in the interval region; the outer periphery of the outer ring abuts against the inner wall of the hollow cavity, and the inner wall of the hollow cavity, the top of the outer ring, and the outer wall of the connector enclose the annular clamping groove.

5. The integrated construction method for rotary drilling, sinking, and extraction of deep, easily collapsible bored piles as described in claim 4, characterized in that... The connector is provided with multiple outward-facing clamping plates, which are arranged at intervals around the top circumference of the connector. Each clamping plate is connected to a fixing ring, the bottom of which abuts against the clamping plate. A fastening groove is formed between adjacent clamping plates for the power head to engage and clamp.

6. The integrated construction method for rotary drilling, sinking, and extraction of deep, easily collapsible bored piles as described in claim 5, characterized in that... The connector has a through cavity running vertically through it, which is connected to the hollow cavity and the fastening groove, respectively.

7. The integrated construction method for rotary drilling, sinking, and extraction of deep, easily collapsible bored piles as described in any one of claims 1 to 6, characterized in that... In construction step 1), the top of the drive cylinder is provided with multiple locking holes, which are arranged at intervals around the outer periphery of the drive cylinder; the bottom of the drive cylinder is provided with multiple connecting pins for fixing sleeves, which are arranged at intervals around the outer periphery of the drive cylinder; the bottom of the drive cylinder has a positioning groove that is recessed inward to form an external opening; the drive cylinder is provided with multiple vent holes, which are arranged at intervals around the outer periphery of the drive cylinder. The top of the sleeve is provided with a plurality of pin holes through which connecting pins pass. The plurality of pin holes are arranged at intervals around the outer periphery of the sleeve. A positioning block is provided on the outer periphery of the sleeve facing outward. The sleeve is fixed to the drive cylinder by the connecting pins passing through the pin holes. The bottom inner wall of the drive cylinder abuts against the top outer wall of the sleeve. The outer periphery of the positioning block abuts against the inner wall of the positioning groove.

8. The integrated construction method for rotary drilling, sinking, and extraction of deep, easily collapsible bored piles as described in any one of claims 1 to 6, characterized in that... The clamping platform is provided with a plurality of oppositely arranged screw locks and a plurality of cam locks, the plurality of cam locks and the plurality of screw locks being arranged at intervals around the annular wall; the screw locks and cam locks respectively abut against the outer periphery of the outer tube; The screw lock includes a screw that reciprocates toward the center of the outer tube and a support plate. The support plate is fixed to the annular wall. The screw and the support plate are connected by threads so that at least part of the screw can abut against the outer tube. The cam lock includes a support and a cam. The support is fixedly connected to the annular wall, and the cam is rotatably connected to the support so that the cam at least partially abuts against the outer tube. The side of the cam facing the outer tube is arc-shaped and has multiple serrations.

9. The integrated construction method for rotary drilling, sinking, and extraction of deep, easily collapsible bored piles as described in any one of claims 1 to 6, characterized in that... In construction step 2), the drilling tool includes a drill barrel for drilling soil. The drill barrel is provided with a clamping ring, which is arranged circumferentially around the outer periphery of the drill barrel. The clamping ring is provided with multiple arc-shaped scrapers that swing up and down. The multiple arc-shaped scrapers are arranged circumferentially around the outer periphery of the clamping ring. A limiting strip is provided on the outer periphery of the clamping ring to position the swing range of the arc-shaped scrapers. The limiting strip is arranged circumferentially around the outer periphery of the clamping ring. The limiting strip is located below the arc-shaped scrapers, and the outer wall of the limiting strip is spaced apart from the inner wall of the casing. There is a soil scraping area spaced apart between the inner wall of the casing and the outer wall of the drill barrel. The arc-shaped scrapers are located in the soil scraping area. The arc-shaped scraper has a scraping section that bends and abuts against the inner wall of the sleeve. The outer wall of the arc-shaped scraper abuts against the inner wall of the sleeve to form a connecting edge. The scraping section extends along the length of the connecting edge. In the construction step 2), as the drill bit moves downward to extract soil inside the casing, the arc-shaped scraper moves downward inside the casing. When the arc-shaped scraper is obstructed by the clay on the inner wall of the casing, the arc-shaped scraper flips upward. As the drill bit moves upwards inside the casing to extract soil, the arc-shaped scraper moves upwards inside the casing. When the arc-shaped scraper is obstructed by the clay on the inner wall of the casing, the limiting strip supports the bottom of the arc-shaped scraper so that the arc-shaped scraper moves upwards in conjunction with the scraping section to scrape away the clay on the inner wall of the casing.

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