Limited micro-space pile foundation construction method based on multifunctional pile machine

Abstract

The invention discloses a limited micro-space pile foundation construction method based on a multifunctional pile machine, and belongs to the technical field of constructional engineering pile foundations. The limited micro-space pile foundation construction method comprises the following construction steps that S1, a matched drilling tool is selected according to the type of a pile foundation, wherein the type of the pile foundation at least comprises one of a cast-in-situ bored pile, a stirring pile, a high-pressure jet grouting pile and a threaded expanding body steel pile; s2, pile machine equipment is assembled and placed in place, wherein the pile machine equipment comprises a main machine assembly, a drilling rig assembly, a power head assembly and a multi-channel telescopic drilling rod; and S3, pile foundation construction is conducted, specifically, corresponding pile machine equipment and auxiliary equipment are started according to different pile foundation technologies to conduct pile foundation construction. According to the multifunctional pile machine, various pile foundation types can be constructed on one pile machine, the power head with the multi-channel flow divider and the multi-channel telescopic drill rod are matched, so that the pile machine can achieve efficient and environment-friendly pile foundation construction in a limited space, the adaptability and the integration degree of equipment are improved, continuous work in construction is reduced, and the construction efficiency is improved. And the construction efficiency is improved, and various geological conditions and construction requirements can be met.

Description

Technical Field

[0001] The invention relates to a pile foundation construction technology, and more specifically, to a limited micro-space pile foundation construction method based on a multifunctional pile driver. Background Art

[0002] The low-headroom drilling rig construction method is a technology developed to adapt to pile foundation construction in densely built areas, under viaducts or in limited space environments. With the acceleration of urbanization, traditional pile foundation construction methods are no longer applicable in these special environments due to problems such as large equipment size, low construction efficiency, and great impact on the surrounding environment. In order to solve these problems, low-headroom drilling rigs and their construction methods came into being.

[0003] At present, there are related technologies of low-headroom drilling rigs and their construction methods, such as the "low-headroom double-rotary drilling rig and its construction method" disclosed in Chinese patent number ZL201711385608.0 (authorization announcement date is April 9, 2024), the "front and rear displacement low-headroom drilling rig" disclosed in Chinese patent number ZL201610702344.6 (authorization announcement date is October 25, 2019), and the "a low-headroom rotary drilling rig" disclosed in Chinese patent number ZL202111556090.9 (authorization announcement date is March 1, 2024). These existing patent technologies show the possibility of efficient and environmentally friendly construction in limited space.

[0004] However, although these technologies have improved construction efficiency and safety to a certain extent, there are still some problems and shortcomings in conventional construction methods:

[0005] (1) Construction efficiency: In traditional construction methods, drill rods need to be connected section by section, which not only increases the complexity of construction, but also significantly reduces construction efficiency;

[0006] (2) Equipment adaptability issues: Existing low-headroom drilling rigs may lack the ability to adapt to different geological conditions. The equipment may not be able to effectively cope with the changing underground environment;

[0007] (3) Space limitation: In a small space, the size of the equipment and the scope of construction are limited, which may affect the construction quality or fail to complete the scheduled construction tasks;

[0008] (4) Lack of versatility: The existing construction methods may be too single and unable to meet the diverse construction needs. There is a lack of a multifunctional pile driver that can adapt to a variety of foundation processes;

[0009] (5) Equipment integration problem: In a small space, the equipment needs to have a smaller size and higher integration, but the existing equipment may be too large, which is not conducive to flexible operation in a limited space;

[0010] The difficulties encountered in solving the above problems include the difficulty of technological innovation, the pressure of cost control, the limitations of existing manufacturing processes, etc. In order to overcome these problems, it is necessary to develop more flexible, efficient and multifunctional construction equipment and methods. Summary of the invention

[0011] 1. Technical problem to be solved by the invention

[0012] The purpose of the present invention is to overcome the above-mentioned shortcomings of the existing limited micro-space pile foundation construction process, and to provide a limited micro-space pile foundation construction method based on a multi-functional pile driver. By adopting the technical solution of the present invention, a multi-functional pile driver is used to realize the construction of various types of pile foundations on one pile driver. In combination with a power head with a multi-channel diverter and a multi-channel telescopic drill rod, the pile driver can realize efficient and environmentally friendly pile foundation construction in a limited space, improve the adaptability and integration of the equipment, reduce the follow-up work during construction, improve the construction efficiency, and be able to adapt to various geological conditions and construction requirements.

[0013] 2. Technical solution

[0014] In order to achieve the above object, the technical solution provided by the present invention is:

[0015] A limited micro-space pile foundation construction method based on a multifunctional pile driver of the present invention comprises the following construction steps:

[0016] S1. Select the matching drilling tools according to the pile foundation type:

[0017] The pile foundation type includes at least one of bored cast-in-place piles, mixing piles, high-pressure rotary jet piles and threaded enlarged steel piles, and the supporting drilling tools include corresponding process drill bits, which correspond to drilling drill bits, mixing pile drill bits, high-pressure rotary jet drill bits and threaded enlarged steel pile drill bits;

[0018] S2. Assembly and positioning of pile driver equipment:

[0019] The pile driver equipment comprises a mainframe assembly, a drill frame assembly, a power head assembly and a multi-channel telescopic drill rod, wherein the drill frame assembly is arranged on the mainframe assembly, the power head assembly is mounted on the drill frame assembly, the multi-channel telescopic drill rod is detachably mounted on the power head assembly, and the process drill bit is mounted on the power head assembly directly or through the multi-channel telescopic drill rod; wherein,

[0020] The power head assembly has a multi-channel flow divider, and independently driven drill pipe rotary joints and telescopic drive joints, wherein the drill pipe rotary joint is used to drive the process drill bit to rotate, and the telescopic drive joint is used to control the telescopic movement of the multi-channel telescopic drill pipe. The multi-channel flow divider is arranged at the upper end of the telescopic drive joint and is used to connect to the surface fluid system;

[0021] The multi-channel telescopic drill rod comprises a plurality of sections of telescopic rod bodies which are sleeved together step by step from the outside to the inside, a transmission screw for controlling the telescopic movement of the telescopic rod body, and a corrugated telescopic tube for establishing a channel. The transmission screw is located inside the telescopic rod body, and the transmission screw located in the center is provided with a plurality of fluid channels which are connected to the corresponding flow diversion channels in the multi-channel diverter. The corrugated telescopic tube is sleeved together from the inside to the outside to form a plurality of pipe channels. The upper end of the corrugated telescopic tube is connected to the transmission screw located in the center through a multi-channel rotary joint, so that the corresponding pipe channels are connected to the fluid channels one by one.

[0022] It also includes auxiliary equipment. The pile driver equipment and auxiliary equipment are transported to the designated construction location and connected to various pipelines and lines. At the same time, the main machine assembly is fixed, and the process drill bit is adjusted to the construction angle through the drill frame assembly;

[0023] S3. Pile foundation construction:

[0024] After installing the corresponding process drill bit, perform centering and debugging, and start the corresponding pile driver equipment and auxiliary equipment according to different pile foundation processes to carry out pile foundation construction.

[0025] Furthermore, the construction process of bored piles in step S3 is as follows:

[0026] S3-1, install the multi-channel telescopic drill rod on the power head assembly, connect the drill rod rotary joint of the power head assembly with the telescopic rod body of the multi-channel telescopic drill rod, and connect the telescopic drive joint of the power head assembly with the transmission screw of the multi-channel telescopic drill rod; and install the drilling drill bit at the lower end of the multi-channel telescopic drill rod, so that the tube cavity in the drilling drill bit is connected with the corresponding tube channel in the multi-channel telescopic drill rod;

[0027] S3-2. After the casing is installed, the power head assembly is used to drive the drilling bit to rotate, and the drilling bit is driven to drill by extending the multi-channel telescopic drill rod and moving the power head assembly downwards through the drill frame assembly. At the same time, the drilling mud circulation is started through auxiliary equipment. After reaching the set drilling depth, the drilling bit is controlled to reverse and lift to the ground.

[0028] S3-3, after removing the drilling bit, install the grouting conduit at the lower end of the multi-channel telescopic drill rod; and hang the steel cage in the pile hole;

[0029] S3-4. After the steel cage is installed in place, the grouting conduit is lowered by extending the multi-channel telescopic drill rod and driving the power head assembly downward by the drill frame assembly, and the concrete pump is connected through the multi-channel diverter to pour concrete from the bottom of the pile hole upward;

[0030] S3-5. After the grouting is completed, lift the multi-channel telescopic drill rod and grouting pipe and rinse them with clean water.

[0031] Furthermore, the drilling bit has two fluid inlets and outlets arranged in an upper and lower manner, the two fluid inlets and outlets are respectively connected to the corresponding cavities, and the fluid inlet and outlet located at the lower part is arranged at the spiral wing plate of the drilling bit; the drilling mud circulation has the following two modes:

[0032] A. The fluid inlet and outlet at the lower part are closed with a plug, and the circulating mud enters through the multi-channel diverter, passes through the pipe channel in the multi-channel telescopic drill rod and the corresponding pipe cavity in the drilling drill bit in turn, and is ejected from the bottom of the drilling drill bit; the drilling drill bit cuts the soil and mixes it with the circulating mud to form a debris mud mixture, which enters through the fluid inlet and outlet at the upper part, passes through the corresponding pipe cavity in the drilling drill bit, the pipe channel in the multi-channel telescopic drill rod and the multi-channel diverter in turn, and is sucked to the ground by a vacuum pump;

[0033] B. Seal the fluid inlet and outlet at the top with a plug, and input the circulating mud into the borehole by reverse circulation. The debris-mud mixture enters through the bottom of the drilling bit at the bottom of the borehole, and is sucked to the ground by a vacuum pump after passing through the corresponding tubular cavity in the drilling bit, the tubular channel in the multi-channel telescopic drill rod and the multi-channel diverter in turn; at the same time, high-pressure gas is sprayed through the multi-channel diverter, the tubular channel in the multi-channel telescopic drill rod, the corresponding tubular cavity in the drilling bit and the fluid inlet and outlet at the bottom by a high-pressure air compressor to assist the spiral wing plate in cutting the soil and prevent the drill from getting stuck.

[0034] Furthermore, the construction process of the mixing pile in step S3 is as follows:

[0035] S3-1, install the multi-channel telescopic drill rod on the power head assembly, connect the drill rod rotary joint of the power head assembly with the telescopic rod body of the multi-channel telescopic drill rod, and connect the telescopic drive joint of the power head assembly with the transmission screw of the multi-channel telescopic drill rod; and install the mixing pile drill bit at the lower end of the multi-channel telescopic drill rod, so that the tube cavity in the mixing pile drill bit is connected with the corresponding tube channel in the multi-channel telescopic drill rod;

[0036] S3-2, the mixing pile drill bit is driven to rotate by the power head assembly, and the multi-channel telescopic drill rod is extended, and the drill frame assembly drives the power head assembly to move downward to drive the mixing pile drill bit to drill, and at the same time, the curing agent high-pressure pump and the high-pressure air compressor are turned on, and after passing through the multi-channel diverter, the pipe channel in the multi-channel telescopic drill rod, and the corresponding pipe cavity in the mixing pile drill bit, the curing agent and high-pressure air are sprayed from the corresponding fluid nozzle of the mixing pile drill bit to perform rotary mixing drilling; after reaching the set depth, the mixing pile drill bit is controlled to reverse and lift, and at the same time, the curing agent high-pressure pump and the high-pressure air compressor are continued to be turned on to spray to form a mixing pile;

[0037] S3-3. After the mixing pile drill bit is lifted to the designed pile top, continue mixing to reinforce the pile head;

[0038] S3-4. After the mixing is completed, lift the multi-channel telescopic drill rod and the mixing pile drill bit and rinse them with clean water.

[0039] Furthermore, the construction process of the high-pressure jet grouting pile in step S3 is as follows:

[0040] S3-1, install the multi-channel telescopic drill pipe on the power head assembly, connect the drill pipe rotary joint of the power head assembly with the telescopic rod body of the multi-channel telescopic drill pipe, and connect the telescopic drive joint of the power head assembly with the transmission screw of the multi-channel telescopic drill pipe; and install the high-pressure jet grouting drill bit at the lower end of the multi-channel telescopic drill pipe, so that the tube cavity in the high-pressure jet grouting drill bit is connected with the corresponding tube channel in the multi-channel telescopic drill pipe;

[0041] S3-2, the high-pressure jet grouting drill bit is driven to rotate by the power head assembly, and the high-pressure jet grouting drill bit is driven to drill by the extension of the multi-channel telescopic drill rod and the downward movement of the power head assembly driven by the drill frame assembly, and the curing agent high-pressure pump and the high-pressure air compressor are turned on at the same time, and the curing agent and high-pressure air are sprayed from the corresponding high-pressure nozzle of the high-pressure jet grouting drill bit through the multi-channel diverter, the pipe channel in the multi-channel telescopic drill rod, and the corresponding pipe cavity in the high-pressure jet grouting drill bit to perform rotary cutting and drilling of the soil; after reaching the set depth, the high-pressure jet grouting drill bit is controlled to reverse and lift, and the curing agent high-pressure pump and the high-pressure air compressor are continued to be turned on to spray to form a high-pressure jet grouting pile;

[0042] S3-3, after the high-pressure jet grouting drill bit is lifted to the designed pile top, continue cutting and mixing to reinforce the pile head;

[0043] S3-4. After cutting and mixing, lift the multi-channel telescopic drill rod and high-pressure rotary jet drill bit and rinse them with clean water.

[0044] Furthermore, the construction process of the threaded enlarged steel pile in step S3 is as follows:

[0045] S3-1, install the thread enlarged steel pile drill bit on the power head assembly through the steel pile joint, so that the drill pipe rotary joint of the power head assembly can drive the thread enlarged steel pile drill bit to rotate;

[0046] S3-2, the threaded enlarged steel pile drill bit is driven to rotate and drill by the power head assembly, and the power head assembly is driven to move downward in coordination with the drill frame assembly to drive the threaded enlarged steel pile drill bit to drill and implant into the soil;

[0047] S3-3. After the first section of the threaded enlarged steel pile drill bit is implanted, a steel pile extension section or extension rod is installed between the threaded enlarged steel pile drill bit and the steel pile joint, so that the steel pile extension section or extension rod is quickly connected to the threaded enlarged steel pile drill bit, and drilling is continued until the designed pile length and designed depth are reached.

[0048] Furthermore, when the designed pile top is deeper from the bottom plate or the ground, the multi-channel telescopic drill rod is installed on the power head assembly, the drill rod rotating joint of the power head assembly is connected to the telescopic rod body of the multi-channel telescopic drill rod, and the telescopic drive joint of the power head assembly is connected to the transmission screw of the multi-channel telescopic drill rod; and the last section of the steel pile extension section or extension rod is connected to the multi-channel telescopic drill rod, and the multi-channel telescopic drill rod is extended to rotate and deliver the pile, so as to deliver the threaded expanded body steel pile to the specified design position.

[0049] Furthermore, the power head assembly also includes a box body, and a telescopic drive hydraulic motor and a drill rod drive hydraulic motor are respectively placed flat on the side walls of the box body. The telescopic drive hydraulic motor is connected to the telescopic drive joint through a telescopic drive transmission mechanism, and the drill rod drive hydraulic motor is connected to the drill rod rotary joint through a drill rod drive transmission mechanism.

[0050] Furthermore, the telescopic rod body of the multi-channel telescopic drill rod comprises a primary fixed rod body, an intermediate telescopic rod body and a final telescopic rod body, and the transmission screw of the multi-channel telescopic drill rod comprises a primary screw and an intermediate transmission screw, the primary fixed rod body, the intermediate telescopic rod body and the final telescopic rod body are sleeved together step by step from the outside to the inside, and the telescopic rod bodies of each stage are axially locked relative to the primary fixed rod body; the primary screw and the intermediate transmission screw are arranged on the inner side of the primary fixed rod body, the intermediate telescopic rod body and the final telescopic rod body, and the primary screw and the intermediate transmission screws of each stage are threadedly sleeved together step by step from the inside to the outside; the intermediate transmission screws of each stage are relatively rotatably connected with the intermediate telescopic rod body of the corresponding stage through an annular relay, and the primary screw and ... The first-stage screw and the intermediate transmission screws of each stage are all threadedly matched with the corresponding next-stage intermediate telescopic rod body and the final telescopic rod body; the upper end of the first-stage fixed rod body can be connected to the drill rod rotary joint to drive the multi-channel telescopic drill rod to rotate; the upper end of the first-stage screw can be connected to the telescopic drive joint to drive the multi-channel telescopic drill rod to telescopic movement; the first-stage screw is provided with a plurality of fluid channels connected to the corresponding diversion channels in the multi-channel diverter; the upper end of the corrugated telescopic tube is connected to the lower end of the first-stage screw through the multi-channel rotary joint, and the corrugated telescopic tube is formed from the inside to the outside of the ring sleeve to form a pipe channel corresponding to the above-mentioned fluid channel, and each pipe channel is connected to the corresponding channel opening at the lower end of the final telescopic rod body.

[0051] Furthermore, the mainframe assembly includes a walking mechanism, a working platform, a leg assembly, a hydraulic drive system and a background control system, the working platform is installed on the walking mechanism, the hydraulic drive system and the background control system are respectively integrated on the working platform, the drilling frame assembly is installed on the front side of the working platform, and the leg assembly is installed on the outside of the working platform;

[0052] The leg assembly includes a cylinder bracket, a telescopic cylinder, a support plate and a hole-opening fixture, wherein the cylinder bracket is fixed on a working platform, the telescopic cylinder is vertically mounted on the cylinder bracket, the support plate is fixed on the lower end of the telescopic cylinder, and the hole-opening fixture is mounted on the support plate; the hole-opening fixture includes a rotating cylinder and a rotating anchoring claw fixed on the lower end of an output shaft of the rotating cylinder, the output shaft of the rotating cylinder has a dust suction channel, and a dust suction pipe joint connected to the dust suction channel is provided on the upper part of the cylinder body of the rotating cylinder.

[0053] 3. Beneficial effects

[0054] Compared with the existing known technologies, the technical solution provided by the present invention has the following significant effects:

[0055] (1) A limited micro-space pile foundation construction method based on a multifunctional pile driver of the present invention utilizes a multifunctional pile driver to realize construction of various types of pile foundations on one pile driver. With a power head with a multi-channel diverter and a multi-channel telescopic drill rod, the pile driver can realize efficient and environmentally friendly pile foundation construction in a limited space, thereby improving the adaptability and integration of the equipment, reducing the follow-up work during construction, improving the construction efficiency, and being able to adapt to various geological conditions and construction requirements;

[0056] (2) The invention provides a limited micro-space pile foundation construction method based on a multifunctional pile driver. During the construction of bored piles, a multi-channel telescopic drill rod can be used in conjunction with a grouting conduit to perform concrete pouring, thereby reducing the need to disassemble and assemble the conduit section by section, thereby reducing the difficulty of grouting from the bottom of the pile hole upward in a limited micro-space and improving construction efficiency.

[0057] (3) A limited micro-space pile foundation construction method based on a multifunctional pile driver of the present invention, during the construction process of bored piles, the drilling drill bit is provided with two fluid inlets and outlets arranged in an upper and lower manner, the two fluid inlets and outlets are respectively connected to corresponding cavities, and the fluid inlet and outlet located at the lower portion is arranged at the spiral wing plate of the drilling drill bit. By blocking different fluid inlets and outlets, different drilling mud circulation processes can be realized. When the lower fluid inlet and outlet are blocked, the mud reverse circulation can be realized, the hole forming speed is fast, and the problem of instability and collapse of the hole wall caused by mud scouring can be avoided. When the upper fluid inlet and outlet are blocked, the lower fluid inlet and outlet can be used to spray high-pressure gas under the reverse circulation process to assist in cutting the soil, avoid the soil wrapping the drill bit, and improve the drilling efficiency.

[0058] (4) The invention discloses a limited micro-space pile foundation construction method based on a multifunctional pile driver, wherein the power head adopts a horizontally placed dual-drive hydraulic motor, which reduces the size of the power head in the height direction, and can further reduce the overall height of the pile driver while ensuring the effective travel space of the pile driver. In combination with a multi-channel telescopic drill rod, efficient and accurate construction operations can be achieved in a limited space. The dual hydraulic motors are used for propulsion, and the mechanical structure is simple and maintenance is convenient.

[0059] (5) The invention provides a limited micro-space pile foundation construction method based on a multifunctional pile driver, wherein the telescopic rod body of the multi-channel telescopic drill rod comprises a primary fixed rod body, an intermediate telescopic rod body and a final telescopic rod body, and the transmission screw of the multi-channel telescopic drill rod comprises a primary screw and an intermediate transmission screw. The synchronous telescopic movement of the telescopic drill rod is achieved by threaded transmission between the screw and the rod bodies at each level, thereby ensuring the control accuracy and stability of the telescopic movement of the telescopic drill rod and improving the verticality and precision of the construction drill rod. A multi-fluid channel is constructed in the telescopic drill rod by using a corrugated telescopic tube sleeved together. Not only is the structure simple and compact, and the manufacture and implementation are convenient, but also the establishment of the multi-fluid channel in the telescopic drill rod makes it possible to cooperate with a variety of process drill bits, thereby greatly improving the applicability of the telescopic drill rod.

[0060] (6) A limited micro-space pile foundation construction method based on a multifunctional pile driver of the present invention, wherein the main engine assembly includes a walking mechanism, a working platform, a leg assembly, a hydraulic drive system and a background control system, wherein the hydraulic drive system and the background control system are respectively integrated on the working platform, and have a compact structure and occupy a small space, and have the advantages of flexible movement, diverse application scenarios, and convenient construction in a limited space; and a perforated fixture is provided on the leg assembly, and the main engine can be firmly fixed on the ground by the perforated fixture, which can effectively overcome the torque generated by the large torque power head, effectively improve the output torque of the pile driver, improve the construction efficiency, and solve the contradiction between the existing small space pile driver and the large torque demand;

[0061] (7) The present invention provides a limited micro-space pile foundation construction method based on a multifunctional pile driver, wherein the leg assembly includes a cylinder bracket, a telescopic cylinder, a support plate and a hole-opening fixture, wherein the cylinder bracket is fixed on a working platform, the telescopic cylinder is vertically mounted on the cylinder bracket, the support plate is fixed on the lower end of the telescopic cylinder, and the hole-opening fixture is mounted on the support plate. The telescopic leg structure can facilitate the control of the legs, and the support plate can increase the ground contact area and improve the support stability; further, the hole-opening fixture includes a rotating cylinder and a rotating anchoring claw fixed on the lower end of the output shaft of the rotating cylinder, which can enable the rotating anchoring claw to quickly break through and anchor into the stratum, thereby increasing the grip of the main machine; the output shaft of the rotating cylinder has a dust suction channel, and the upper part of the cylinder body of the rotating cylinder is provided with a dust suction pipe joint connected to the dust suction channel, which can suck out and collect dust while the anchoring claw breaks through the stratum, thereby reducing the environmental pollution problem caused by dust at the construction site. BRIEF DESCRIPTION OF THE DRAWINGS

[0062] Figure 1 A schematic diagram of a construction scene of a limited micro-space pile foundation construction method based on a multifunctional pile driver of the present invention;

[0063] Figure 2 It is a three-dimensional structural schematic diagram of a multifunctional pile driver in the limited micro-space pile foundation construction method of the present invention;

[0064] Figure 3 It is a three-dimensional structural schematic diagram of the leg assembly of the multifunctional pile driver in the present invention;

[0065] Figure 4 It is a schematic diagram of the three-dimensional structure of the opening fixture of the leg assembly in the present invention;

[0066] Figure 5 It is a schematic cross-sectional view of the open hole fixing device of the leg assembly in the present invention;

[0067] Figure 6 It is a three-dimensional structural schematic diagram of a power head assembly of a multifunctional pile driver in the present invention from an angle;

[0068] Figure 7 It is a three-dimensional structural schematic diagram of the power head assembly of the multifunctional pile driver in the present invention from another angle;

[0069] Figure 8 It is a cross-sectional structural schematic diagram of the power head assembly of the multifunctional pile driver in the present invention;

[0070] Fig. 9 It is a schematic diagram of the three-dimensional structure of the multi-channel telescopic drill rod in the extended state in the present invention;

[0071] Fig.10 It is a schematic cross-sectional structure diagram of the multi-channel telescopic drill rod in the present invention in an extended state;

[0072] Fig.11 It is a schematic cross-sectional structure diagram of the multi-channel telescopic drill rod in the present invention in a contracted state;

[0073] Fig.12 It is a three-dimensional structural schematic diagram of the multifunctional pile driver in the present invention used in conjunction with a drilling drill bit;

[0074] FIG. 13( a) is a construction state diagram of construction step 1 of bored piles in the present invention;

[0075] FIG13( b) is a construction state diagram of the construction step 2 of the bored pile in the present invention;

[0076] FIG. 13( c ) is a construction state diagram of the construction step three of the bored pile in the present invention;

[0077] FIG13( d ) is a construction state diagram of the construction step 4 of the bored pile in the present invention;

[0078] FIG13( e) is a construction state diagram of the construction step five of the bored pile in the present invention;

[0079] Fig.14 It is a schematic diagram of the reverse circulation of mud in the drilling bit of the present invention;

[0080] Fig.15 It is a schematic diagram of mud reverse circulation + gas assisted cutting of the drilling drill bit in the present invention;

[0081] Fig.16 It is a three-dimensional structural schematic diagram of the multifunctional pile driver in the present invention used in conjunction with a mixing pile drill bit;

[0082] FIG. 17( a ) is a construction state diagram of the construction step 1 of the mixing pile in the present invention;

[0083] FIG. 17( b ) is a construction state diagram of the second construction step of the mixing pile in the present invention;

[0084] FIG. 17( c ) is a construction state diagram of the construction step 3 of the mixing pile in the present invention;

[0085] FIG. 18( a ) is a schematic diagram of a three-dimensional structure of a multi-channel telescopic drill rod used in conjunction with a mixing pile drill bit in the present invention;

[0086] FIG18( b ) is a cross-sectional view of the multi-channel telescopic drill rod used in conjunction with a mixing pile drill bit in the present invention;

[0087] Fig.19 It is a three-dimensional structural schematic diagram of the multifunctional pile driver in the present invention used in conjunction with a high-pressure jet jet drill bit;

[0088] FIG. 20( a) is a construction state diagram of the construction step 1 of the high-pressure jet grouting pile of the present invention;

[0089] FIG. 20( b ) is a construction state diagram of the second construction step of the high-pressure jet grouting pile of the present invention;

[0090] FIG. 20( c ) is a construction state diagram of the construction step three of the high-pressure jet grouting pile of the present invention;

[0091] FIG21( a ) is a schematic diagram of a three-dimensional structure of a multi-channel telescopic drill rod used in conjunction with a high-pressure jet jet drill bit in the present invention;

[0092] FIG21( b ) is a cross-sectional view of the multi-channel telescopic drill rod used in conjunction with a high-pressure jet jet drill bit in the present invention;

[0093] Fig. 22 It is a three-dimensional structural schematic diagram of the multifunctional pile driver of the present invention used in conjunction with a thread-enlarged steel pile drill bit;

[0094] FIG. 23( a ) is a construction state diagram of the construction step 1 of the threaded enlarged steel pile of the present invention;

[0095] FIG23( b ) is a construction state diagram of the second construction step of the threaded enlarged steel pile of the present invention;

[0096] FIG23( c ) is a construction state diagram of the construction step 3 of the threaded enlarged steel pile of the present invention;

[0097] FIG23( d ) is a construction state diagram of the fourth construction step of the threaded enlarged steel pile of the present invention;

[0098] FIG23( e) is a construction state diagram of the construction step 5 of the threaded enlarged steel pile of the present invention;

[0099] Fig.24 It is a three-dimensional structural schematic diagram of a multifunctional pile driver using a foldable mechanical arm in the present invention;

[0100] Fig.25 This is a schematic diagram of a construction scene of a multifunctional pile driver using a foldable mechanical arm in the present invention.

[0101] Explanation of the symbols in the schematic diagram:

[0102] 100, main machine assembly; 11, walking mechanism; 12, working platform; 13, outrigger assembly; 131, cylinder bracket; 132, telescopic cylinder; 133, support plate; 134, hole fixing device; 1341, rotating cylinder; 1342, rotating anchor claw; 1343, dust suction channel; 1344, dust suction pipe joint; 14, hydraulic drive system; 15, backstage control system; 200, mast drilling assembly; 200', foldable mechanical arm assembly; 300, power head assembly ; 31, box; 32, telescopic drive hydraulic motor; 33, drill rod drive hydraulic motor; 34, multi-channel diverter; 34-1, rotary diverter seat; 34-2, channel tube; 34-3, diversion channel; 35, drill rod rotary joint; 36, telescopic drive joint; 37, drill rod drive transmission mechanism; 38, telescopic drive transmission mechanism; 400, multi-channel telescopic drill rod; 41, first-stage fixed rod body; 42, intermediate telescopic rod body; 42-1, intermediate rod body connection part; 43, final stage Telescopic rod body; 43-1, channel opening; 44, anti-rotation guide rib; 45, primary screw; 45-1, fluid channel; 46, intermediate transmission screw; 46-1, screw connection; 47, annular relay; 48, corrugated telescopic tube; 48-1, multi-channel rotary joint; 500, process drill bit; 510, drilling drill bit; 510A, grouting catheter; 511, drilling drill tip; 512, spiral wing plate; 513, fluid inlet and outlet; 514, plug; 520, mixing pile drill bit ; 520A, extended drill rod for mixing pile; 521, mixing drill tip; 522, mixing blade; 523, fluid nozzle; 530, high-pressure jet grouting drill bit; 530A, extended drill rod for jet grouting; 531, jet grouting drill tip; 532, high-pressure nozzle; 540, threaded enlarged steel pile drill bit; 540A, steel pile extension section; 540B, steel pile joint; 540C, extension rod; 600, high-pressure pump; 700, wireless remote control; 800, multi-functional pump station; 900, high-pressure air compressor. DETAILED DESCRIPTION

[0103] In order to further understand the content of the present invention, the present invention is described in detail in conjunction with the accompanying drawings and embodiments.

[0104] [Example]

[0105] Combination Figure 1 and Figure 2 As shown, a limited micro-space pile foundation construction method based on a multifunctional pile driver in this embodiment includes the following construction steps:

[0106] S1. Select the matching drilling tools according to the pile foundation type:

[0107] The pile foundation types include at least one of bored cast-in-place piles, mixing piles, high-pressure rotary jet piles and threaded enlarged steel piles. The supporting drilling tools include the corresponding process drill bit 500, which corresponds to a drilling drill bit 510, a mixing pile drill bit 520, a high-pressure rotary jet drill bit 530 and a threaded enlarged steel pile drill bit 540. In this embodiment, the pile foundation types that can be implemented on the multifunctional pile driver include at least four types: bored cast-in-place piles, mixing piles, high-pressure rotary jet piles and threaded enlarged steel piles. The specific type of pile foundation to be used can be determined according to geological conditions and design technology.

[0108] S2. Assembly and positioning of pile driver equipment:

[0109] Reference Figure 2 As shown, the pile driver equipment includes a main engine assembly 100, a drill frame assembly, a power head assembly 300 and a multi-channel telescopic drill rod 400. The main engine assembly 100 serves as a basic platform for the pile driver and plays a supporting role. The drill frame assembly is arranged on the main engine assembly 100 and can construct pile foundations at a certain angle, mainly used for drilling or lifting drills. The power head assembly 300 is installed on the drill frame assembly and is used to drive the drill to rotate. The multi-channel telescopic drill rod 400 is detachably installed on the power head assembly 300 and can perform telescopic movements to cooperate with drilling or lifting drills, reducing or avoiding connecting rod operations. The process drill bit 500 is installed on the power head assembly 300 directly or through the multi-channel telescopic drill rod 400 to realize the construction of different pile driver processes. Whether the multi-channel telescopic drill rod 400 is needed can be determined according to the specific construction steps. Among them,

[0110] Reference Figures 6 to 8 As shown, the power head assembly 300 has a multi-channel flow divider 34, and an independently driven drill pipe rotary joint 35 and a telescopic drive joint 36. The drill pipe rotary joint 35 is used to drive the process drill bit 500 to rotate, and the telescopic drive joint 36 is used to control the telescopic movement of the multi-channel telescopic drill pipe 400. The multi-channel flow divider 34 is arranged at the upper end of the telescopic drive joint 36 and is used to connect to the ground fluid system.

[0111] Reference Figures 9 to 11As shown, the multi-channel telescopic drill pipe 400 includes a plurality of telescopic rod bodies which are sleeved together step by step from the outside to the inside, a transmission screw for controlling the telescopic movement of the telescopic rod body, and a bellows telescopic tube 48 for establishing a channel. The transmission screw is located inside the telescopic rod body, and the transmission screw located in the center is provided with a plurality of fluid channels 45-1 which are connected to the corresponding diversion channels 34-3 in the multi-channel diverter 34. The bellows telescopic tube 48 is sleeved together from the inside to the outside to form a plurality of pipe channels. The upper end of the bellows telescopic tube 48 is connected to the transmission screw located in the center through a multi-channel rotary joint 48-1, so that the corresponding pipe channels are connected to the fluid channels 45-1 one by one. The drill pipe rotary joint 35 of the power head assembly 300 can be connected to the outermost telescopic rod body to drive the multi-channel telescopic drill pipe 400 to rotate, and the telescopic drive joint 36 of the power head assembly 300 can be connected to the transmission screw to drive the multi-channel telescopic drill pipe 400 to telescopic movement.

[0112] It also includes transporting auxiliary equipment, pile driver equipment and auxiliary equipment to the designated construction location, and connecting various pipelines and lines; at the same time, fixing the main machine assembly 100, and adjusting the process drill bit 500 to the construction angle through the drill frame assembly. Figure 1 As shown, the auxiliary equipment mainly includes a high-pressure pump 600, a wireless remote controller 700, a multifunctional pump station 800 and a high-pressure air compressor 900. The multifunctional pump station 800 includes a hydraulic pump station and a vacuum pump station, which are integrated on a mobile platform; the wireless remote controller 700 can be used to remotely control the construction of the pile driver. Different auxiliary equipment can be selected for construction according to different construction processes. Before construction, the corresponding equipment should also be tested to check whether each equipment and pipeline is normal.

[0113] S3. Pile foundation construction:

[0114] After installing the corresponding process drill bit 500, the centering and debugging are carried out, and the corresponding pile driver equipment and auxiliary equipment are started according to different pile foundation processes to carry out pile foundation construction.

[0115] Reference Fig.12 , Figure 13(a) to Figure 13(e) , the construction process of bored piles is as follows:

[0116] S3-1, install the multi-channel telescopic drill rod 400 on the power head assembly 300, connect the drill rod rotary joint 35 of the power head assembly 300 with the telescopic rod body of the multi-channel telescopic drill rod 400, and connect the telescopic drive joint 36 of the power head assembly 300 with the transmission screw of the multi-channel telescopic drill rod 400; and install the drilling drill bit 510 at the lower end of the multi-channel telescopic drill rod 400, so that the tube cavity in the drilling drill bit 510 is connected with the corresponding tube channel in the multi-channel telescopic drill rod 400, forming the state shown in FIG. 13(a);

[0117] S3-2, as shown in FIG13(b), after the casing is installed, the drilling bit 510 is driven to rotate by the power head assembly 300, and the drilling bit 510 is driven to drill by the extension of the multi-channel telescopic drill rod 400 and the downward movement of the power head assembly 300 driven by the drill frame assembly, and the drilling mud circulation is started by the auxiliary equipment; after reaching the set drilling depth, the drilling bit 510 is controlled to reverse and lift to the ground; FIG13(c) shows the state of reaching the set drilling depth. If the movement amount of the multi-channel telescopic drill rod 400, the power head assembly 300, and the drill frame assembly still cannot meet the design pile length requirement, an extension rod can be added between the drilling bit 510 and the multi-channel telescopic drill rod 400;

[0118] S3-3, as shown in FIG. 13( d ), after the drilling is completed, the drilling bit 510 is disassembled and a grouting conduit 510A is installed at the lower end of the multi-channel telescopic drill rod 400 ; and a steel cage is suspended in the pile hole;

[0119] S3-4, after the steel cage is installed in place, the grouting conduit 510A is lowered by extending the multi-channel telescopic drill rod 400 and driving the power head assembly 300 downward by the drill frame assembly, and the concrete pump is connected through the multi-channel diverter 34 to pour concrete from the bottom of the pile hole upward, as shown in FIG. 13( e); the multi-channel telescopic drill rod 400 is used in conjunction with the grouting conduit 510A to pour concrete, which reduces the disassembly and assembly operations of the conduit section by section, reduces the difficulty of grouting from the bottom of the pile hole upward in a limited micro space, and improves the construction efficiency;

[0120] S3-5. After the grouting is completed, the multi-channel telescopic drill rod 400 and the grouting conduit 510A are lifted and flushed with clean water.

[0121] The subsequent construction steps are similar to those of the prior art. After the initial setting of the concrete, the casing can be pulled out and grouting can be used to fill the side gap between the bored pile and the soil.

[0122] Reference Fig.14 and Fig.15 As shown, in this embodiment, two fluid inlets and outlets 513 are specifically arranged on the drilling bit 510, and the two fluid inlets and outlets 513 are respectively connected to the corresponding lumens. The fluid inlet and outlet 513 located at the lower part is arranged at the spiral wing plate 512 of the drilling bit 510. The bottom of the spiral wing plate 512 has a drilling drill tip 511, and the bottom of the drilling drill tip 511 has a mud channel. The drilling mud circulation has the following two modes:

[0123] A. Fig.14As shown, the fluid inlet and outlet 513 at the bottom is closed with a plug 514, and the circulating mud enters through the multi-channel diverter 34, passes through the pipe channel in the multi-channel telescopic drill rod 400 and the corresponding pipe cavity in the drilling bit 510 in turn, and is ejected from the bottom of the drilling bit 510; the drilling bit 510 cuts the soil and mixes it with the circulating mud to form a debris-mud mixture, and the debris-mud mixture enters through the upper fluid inlet and outlet 513, passes through the corresponding pipe cavity in the drilling bit 510, the pipe channel in the multi-channel telescopic drill rod 400 and the multi-channel diverter 34 in turn, and is sucked to the ground by a vacuum pump; this mud circulation can be called "reverse circulation", which has a fast hole-making speed and can avoid the problem of instability and collapse of the hole wall caused by mud scouring.

[0124] B. Fig.15 As shown, the upper fluid inlet and outlet 513 is closed with a plug 514, and the circulating mud is input into the borehole by reverse circulation (reverse circulation is the mud flowing from the outer mud pool into the hole), and the debris mud mixture enters through the bottom of the drilling bit 510 at the bottom of the borehole, and is sucked to the ground by a vacuum pump after passing through the corresponding tube cavity in the drilling bit 510, the tube channel in the multi-channel telescopic drill rod 400 and the multi-channel diverter 34 in sequence; at the same time, high-pressure gas is sprayed through the multi-channel diverter 34, the tube channel in the multi-channel telescopic drill rod 400, the corresponding tube cavity in the drilling bit 510 and the lower fluid inlet and outlet 513 by a high-pressure air compressor to assist the spiral wing plate 512 in cutting the soil and prevent the drill from getting stuck. In the reverse circulation process, the lower fluid inlet and outlet are used to spray high-pressure gas to assist in cutting the soil, prevent the soil from wrapping the drill bit, and improve the drilling efficiency.

[0125] Reference Fig.16 , Figure 17(a) to Figure 17(c) , the construction process of mixing pile is as follows:

[0126] S3-1, install the multi-channel telescopic drill rod 400 on the power head assembly 300, so that the drill rod rotary joint 35 of the power head assembly 300 is connected to the telescopic rod body of the multi-channel telescopic drill rod 400, and the telescopic drive joint 36 of the power head assembly 300 is connected to the transmission screw of the multi-channel telescopic drill rod 400; and install the mixing pile drill bit 520 on the lower end of the multi-channel telescopic drill rod 400, so that the tube cavity in the mixing pile drill bit 520 is connected to the corresponding tube channel in the multi-channel telescopic drill rod 400, forming the state shown in Figure 17 (a); as shown in Figures 18 (a) and 18 (b), the mixing pile drill bit 520 has a mixing drill tip 521 and a plurality of mixing blades 522 distributed on the side of the mixing pile drill bit 520, and the mixing pile drill bit 520 is also provided with at least two fluid nozzles 523 arranged axially at intervals and connected to the corresponding tube cavities;

[0127] S3-2, as shown in FIG17(b), after centering and debugging, the pile mixing drill bit 520 is driven to rotate by the power head assembly 300, and the pile mixing drill bit 520 is driven to drill by the extension of the multi-channel telescopic drill rod 400 and the downward movement of the power head assembly 300 driven by the drill frame assembly. At the same time, the curing agent high-pressure pump and the high-pressure air compressor are turned on, and after passing through the multi-channel diverter 34, the pipe channel in the multi-channel telescopic drill rod 400, and the corresponding pipe cavity in the pile mixing drill bit 520, the curing agent and high-pressure air are sprayed from the corresponding fluid nozzle 523 of the pile mixing drill bit 520 to perform rotary stirring drilling; after reaching the set depth, the pile mixing drill bit 520 is controlled to reverse and lift, and at the same time, the curing agent high-pressure pump and the high-pressure air compressor are continued to be turned on to spray to form a pile mixing;

[0128] S3-3, after the mixing pile drill bit 520 is lifted to the designed pile top, continue mixing to reinforce the pile head;

[0129] S3-4. After the mixing is completed, the multi-channel telescopic drill rod 400 and the mixing pile drill bit 520 are lifted and rinsed with clean water.

[0130] If the movement of the multi-channel telescopic drill rod 400, the power head assembly 300, and the drill frame assembly still cannot meet the design mixing pile length requirements, a mixing pile extension drill rod 520A can be added between the mixing pile drill bit 520 and the multi-channel telescopic drill rod 400.

[0131] Reference Fig.19 , Figure 20(a) to Figure 20(c) , the construction process of high-pressure jet grouting piles is as follows:

[0132] S3-1, install the multi-channel telescopic drill rod 400 on the power head assembly 300, so that the drill rod rotary joint 35 of the power head assembly 300 is connected to the telescopic rod body of the multi-channel telescopic drill rod 400, and the telescopic drive joint 36 of the power head assembly 300 is connected to the transmission screw of the multi-channel telescopic drill rod 400; and install the high-pressure jet grouting drill head 530 at the lower end of the multi-channel telescopic drill rod 400, so that the tube cavity in the high-pressure jet grouting drill head 530 is connected to the corresponding tube channel in the multi-channel telescopic drill rod 400, forming the state shown in Figure 20 (a); as shown in Figures 21 (a) and 21 (b), the high-pressure jet grouting drill head 530 has a jet grouting drill tip 531 and at least one high-pressure nozzle 532 connected to the corresponding tube cavity;

[0133] S3-2, the high-pressure rotary jet drill bit 530 is driven to rotate by the power head assembly 300, and the high-pressure rotary jet drill bit 530 is driven to drill in coordination with the extension of the multi-channel telescopic drill rod 400 and the downward movement of the drill frame assembly to drive the high-pressure rotary jet drill bit 530, and at the same time, the curing agent high-pressure pump and the high-pressure air compressor are turned on, and after passing through the multi-channel diverter 34, the pipe channel in the multi-channel telescopic drill rod 400, and the corresponding pipe cavity in the high-pressure rotary jet drill bit 530, the curing agent and high-pressure air are sprayed from the corresponding high-pressure nozzle 532 of the high-pressure rotary jet drill bit 530 to perform rotary cutting and soil drilling; after reaching the set depth, the high-pressure rotary jet drill bit 530 is controlled to reverse and lift, and at the same time, the curing agent high-pressure pump and the high-pressure air compressor are continued to be turned on to spray to form a high-pressure rotary jet pile; Figure 20 (b) shows the state of the high-pressure rotary jet drill bit 530 after reaching the set depth, and Figure 20 (c) shows the state of the high-pressure rotary jet drill bit 530 after reaching the set depth.

[0134] S3-3, after the high-pressure jet grouting drill bit 530 is lifted to the designed pile top, cutting and mixing are continued to reinforce the pile head;

[0135] S3-4. After the cutting and mixing is completed, the multi-channel telescopic drill rod 400 and the high-pressure jet drilling head 530 are lifted and rinsed with clean water.

[0136] If the movement of the multi-channel telescopic drill rod 400, the power head assembly 300, and the drill frame assembly still cannot meet the design jet grouting pile length requirements, a jet grouting extension drill rod 530A can be added between the high-pressure jet grouting drill bit 530 and the multi-channel telescopic drill rod 400, as shown in Figures 20(b) and 20(c).

[0137] Reference Fig. 22 , Figure 23(a) to Figure 23(e) , the construction process of threaded enlarged steel pile is as follows:

[0138] S3-1, as shown in FIG. 23( a ), the threaded enlarged steel pile drill bit 540 is installed on the power head assembly 300 through the steel pile joint 540B, so that the drill pipe rotary joint 35 of the power head assembly 300 can drive the threaded enlarged steel pile drill bit 540 to rotate;

[0139] S3-2, as shown in FIG. 23( b ), the power head assembly 300 drives the threaded enlarged steel pile drill bit 540 to rotate and drill, and the drill frame assembly drives the power head assembly 300 to move downward to drive the threaded enlarged steel pile drill bit 540 to drill into the soil;

[0140] S3-3. After the first section of the threaded enlarged steel pile drill bit 540 is implanted, a steel pile extension section 540A or an extension rod 540C is installed between the threaded enlarged steel pile drill bit 540 and the steel pile joint 540B (as shown in Figure 23(c) , there are both a steel pile extension section 540A and an extension rod 540C), so that the steel pile extension section 540A or the extension rod 540C is quickly connected to the threaded enlarged steel pile drill bit 540, and drilling continues until the designed pile length and designed depth are reached.

[0141] 23(d) and 23(e), when the designed pile top is deeper from the bottom plate or the ground, the multi-channel telescopic drill rod 400 is installed on the power head assembly 300, so that the drill rod rotary joint 35 of the power head assembly 300 is connected to the telescopic rod body of the multi-channel telescopic drill rod 400, and the telescopic drive joint 36 of the power head assembly 300 is connected to the transmission screw of the multi-channel telescopic drill rod 400; and the last section of the steel pile extension section 540A or the extension rod 540C is connected to the multi-channel telescopic drill rod 400, and the multi-channel telescopic drill rod 400 is extended to rotate and deliver the pile, so that the threaded expanded body steel pile is delivered to the specified design position. In addition, two steel pipes can be installed in the threaded enlarged steel pile drill bit 540 and the corresponding steel pile extension section 540A, steel pile joint 540B and extension rod 540C according to design requirements to transport curing agent and high-pressure gas. While the threaded enlarged steel pile drill bit 540 is drilling, the curing agent high-pressure pump and high-pressure air compressor can be turned on to transport curing agent and high-pressure gas to enhance the strength of the threaded enlarged steel pile.

[0142] The threaded enlarged steel pile drill bit 540, the steel pile extension section 540A, the extension rod 540C and the steel pile joint 540B can be plug-in matched with a non-circular cross-section shaft hole, such as a regular hexagonal shaft hole, to achieve torque transmission while facilitating separation of the threaded enlarged steel pile drill bit 540 from the steel pile joint 540B after implantation.

[0143] catch Figures 6 to 8As shown, in this embodiment, the power head assembly 300 also includes a box body 31, and a telescopic drive hydraulic motor 32 and a drill rod drive hydraulic motor 33 are placed flat on the side walls of the box body 31, respectively. The telescopic drive hydraulic motor 32 is connected to the telescopic drive joint 36 through a telescopic drive transmission mechanism 38, and the drill rod drive hydraulic motor 33 is connected to the drill rod rotary joint 35 through a drill rod drive transmission mechanism 37. The box body 31 is installed on the drilling rig assembly, and the telescopic drive hydraulic motor 32, the drill rod drive hydraulic motor 33, the multi-channel diverter 34, the drill rod rotary joint 35 and the telescopic drive joint 36 are all arranged on the box body 31. The multi-channel diverter 34 is arranged at the upper end of the telescopic drive joint 36, and is used to connect the ground fluid pipeline to realize the input of fluid medium into the process drill bit 500 or discharge of fluid medium through the process drill bit 500 according to different pile foundation construction processes. The drill rod rotary joint 35 is located on the outside of the telescopic drive joint 36, and the two are preferably arranged coaxially. In this embodiment, the telescopic drive hydraulic motor 32 and the drill rod drive hydraulic motor 33 are respectively installed flat on the side walls of the box 31, and the telescopic drive hydraulic motor 32 and the drill rod drive hydraulic motor 33 are placed on both sides of the box 31. The hydraulic motor adopts a flat installation structure, which reduces the size of the power head in the height direction, and can further reduce the overall height of the pile driver while ensuring the effective stroke space of the pile driver. In conjunction with a multi-channel telescopic drill rod, efficient and accurate construction operations can be achieved in a limited space. Dual hydraulic motors are used for propulsion, with a simple mechanical structure and easy maintenance. The above-mentioned drill rod drive transmission mechanism 37 and telescopic drive transmission mechanism 38 both adopt planetary gear reduction mechanisms, which have a compact structure, high transmission efficiency, and can withstand large loads. The planetary gear reduction mechanism is an existing reduction mechanism, so its specific structural principle will not be described in detail again. Figure 8 As shown, the telescopic drive joint 36 is a hollow rotating shaft, the upper end of which extends out of the box body 31, and the multi-channel diverter 34 includes a rotary diverter seat 34-1 and a channel tube 34-2, the channel tube 34-2 is sleeved on the inner side of the telescopic drive joint 36 to form a concentric annular distribution of diverter channels 34-3, the rotary diverter seat 34-1 is rotatably mounted on the upper end of the telescopic drive joint 36, and the rotary diverter seat 34-1 is provided with a pipe joint connected to the corresponding diverter channel 34-3. A rotary sealed annular distribution cavity is also provided at the corresponding pipe joint, and each pipe joint can be connected to the corresponding diverter channel 34-3 through the corresponding annular distribution cavity, so that during the rotation of the telescopic drive joint 36, the rotary diverter seat 34-1 and the pipe joint thereon can be relatively fixed, so as to realize fluid diversion and prevent the fluid pipeline from being entangled.

[0144] catch Figures 9 to 11As shown, specifically in this embodiment, the telescopic rod body of the multi-channel telescopic drill rod 400 includes a primary fixed rod body 41, an intermediate telescopic rod body 42 and a final telescopic rod body 43, and the transmission screw of the multi-channel telescopic drill rod 400 includes a primary screw 45 and an intermediate transmission screw 46. The primary fixed rod body 41, the intermediate telescopic rod body 42 and the final telescopic rod body 43 are sleeved together from the outside to the inside, and the telescopic rod bodies of each level are axially fixed relative to the primary fixed rod body 41. That is, the intermediate telescopic rod bodies 42 and the final telescopic rod body 43 of each level can only be telescopically moved but not rotated relative to each other, and the diameter of each rod body is gradually reduced from the primary fixed rod body 41 to the final telescopic rod body 43; the primary screw 45 and the intermediate transmission screw 46 are arranged on the above-mentioned primary fixed rod body 41, the inner side of the intermediate telescopic rod body 42 and the final telescopic rod body 43, and the primary screw 45 and the intermediate transmission screws 46 of each level are threaded together from the inside to the outside, that is, the diameters of the primary screw 45 and the intermediate transmission screws 46 of each level are gradually increased; the intermediate transmission screws 46 of each level are relatively rotatably connected with the intermediate telescopic rod body 42 of the corresponding level through the annular relay 47, so that the intermediate transmission screws 46 and the intermediate telescopic rod body 42 of the corresponding level can rotate relatively but cannot move axially; the primary screw 45 and the intermediate transmission screws 46 of each level are threadedly matched with the corresponding intermediate telescopic rod body 42 of the next level and the final telescopic rod body 43, and the primary screw 45 is driven to rotate to drive the telescopic rod bodies of each level to synchronously axially telescopic movement relative to the primary fixed rod body 41. The primary screw 45 and the primary fixed rod body 41 can rotate relative to each other and the axial movement is also restricted. The upper end of the primary fixed rod body 41 can be connected to the drill rod rotating joint 35 to drive the multi-channel telescopic drill rod 400 to rotate; the upper end of the primary screw 45 can be connected to the telescopic drive joint 36 to drive the multi-channel telescopic drill rod 400 to telescopic movement. When the telescopic drive joint 36 drives the primary screw 45 to rotate, the secondary intermediate telescopic rod body 42 moves axially on the primary screw 45, driving the intermediate transmission screw 46 of the same level to move axially together. Since the secondary intermediate transmission screw 46 is threadedly matched with the primary screw 45, the secondary intermediate transmission screw 46 also rotates together at this time; the secondary intermediate transmission screw 46 rotates to drive the intermediate telescopic rod body 42 of the next level to move axially, and at the same time drives the intermediate transmission screw 46 of the next level to move axially and rotate at the same time, and the transmission is performed step by step until the final telescopic rod body 43 is driven to move axially. In this way, the intermediate telescopic rod bodies 42 of each level and the final telescopic rod body 43 can be synchronously axially telescopically moved relative to the primary fixed rod body 41, thereby ensuring the accuracy and stability of the telescopic movement control of the telescopic drill rod and improving the verticality and precision of the construction drill rod. The number of the intermediate telescopic rod bodies 42 and the intermediate transmission screw rods 46 is equal, and the specific number can be determined according to the telescopic stroke requirements.The primary screw 45 is provided with a plurality of fluid channels 45-1 connected with the corresponding flow diversion channels 34-3 in the multi-channel diverter 34; specifically, at least two fluid channels 45-1 are provided on the primary screw 45 from the inside to the outside, and each fluid channel 45-1 is distributed in an annular manner from the center to the outside. The upper end of the bellows expansion tube 48 is connected to the lower end of the primary screw 45 through a multi-channel rotary joint 48-1, so that the primary screw 45 can rotate freely relative to the bellows expansion tube 48 and maintain the connection and sealing of each channel. The bellows expansion tube 48 is formed from the inside to the outside of the ring sleeve to form a tube channel corresponding to the above-mentioned fluid channel 45-1, and each tube channel is connected with the corresponding channel opening 43-1 at the lower end of the final telescopic rod body 43. In other words, the central tube cavity of the innermost bellows expansion tube 48 is a fluid channel, and the annular interlayer between adjacent bellows expansion tubes 48 is a fluid channel. The number of fluid channels can be determined according to the number of ring sleeves of the bellows expansion tube 48. The bellows expansion tube 48 can be made of high-strength material to withstand the pressure of high-pressure fluid. The multi-channel rotary joint 48-1 is similar to the existing rotary joint, which realizes the relative rotation of the connected pipelines and can be used for the transportation of fluids such as gas and liquid. The bellows expansion tubes are used to construct multiple fluid channels in the telescopic drill rod, which is not only simple and compact in structure, easy to manufacture and implement, but also the establishment of multiple fluid channels in the telescopic drill rod makes it possible to cooperate with a variety of process drill bits, thereby improving the applicability of the telescopic drill rod.

[0145] Combination Fig.10As shown, in the above-mentioned multi-channel telescopic drill rod 400, the upper ends of the intermediate transmission screws 46 of each level are provided with screw connecting parts 46-1, and the upper ends of the intermediate telescopic rod bodies 42 of each level are provided with intermediate rod body connecting parts 42-1. The screw connecting parts 46-1 are sleeved on the outer sides of the corresponding intermediate rod body connecting parts 42-1, and the annular relay 47 is provided between the corresponding screw connecting parts 46-1 and the intermediate rod body connecting parts 42-1 to realize the axial connection and relative rotation of the screw connecting parts 46-1 and the intermediate rod body connecting parts 42-1. The diameter of the screw connecting part 46-1 is slightly larger than the diameter of the intermediate transmission screw 46, the cross section of the intermediate rod body connecting part 42-1 is inverted "U" shape, and the inner free end of the intermediate rod body connecting part 42-1 is sleeved on the inner side of the screw connecting part 46-1, so that the screw connecting part 46-1 and the intermediate rod body connecting part 42-1 are connected, and the inner free end of the intermediate rod body connecting part 42-1 can also be used to realize the threaded connection with the corresponding screw, so as to cleverly realize the synchronous telescopic movement of the telescopic rod body. The above-mentioned annular relay 47 is an annular structure, such as a steel ring, etc., and corresponding annular grooves are respectively provided between the screw connecting part 46-1 and the intermediate rod body connecting part 42-1. The annular relay 47 is located in the annular groove, so that the corresponding intermediate telescopic rod body 42 and the intermediate transmission screw 46 can be axially connected together to transmit axial force, while ensuring the free rotation of both. Of course, the annular relay 47 can also be a plurality of annularly distributed steel balls, etc. In addition, in this embodiment, the above-mentioned first-stage fixed rod body 41, intermediate telescopic rod body 42 and final telescopic rod body 43 are all cylindrical structures, and anti-rotation guide ribs 44 are provided between the first-stage fixed rod body 41 and the adjacent intermediate telescopic rod body 42, between the intermediate telescopic rod bodies 42 at each stage, and between the final telescopic rod body 43 and the adjacent intermediate telescopic rod body 42. The anti-rotation guide ribs 44 are slidably matched with the corresponding guide grooves, so that the rod bodies at each stage can move smoothly and prevent relative rotation. The first-stage screw 45 is a hollow screw, and the fluid channel 45-1 is composed of concentric tubes that are sleeved layer by layer on the inner side of the first-stage screw 45. The concentric tubes are separated and connected together by spacers from the inner wall of the first-stage screw 45 and between adjacent concentric tubes, so as to ensure the smooth flow of the annular fluid channel 45-1, and the formed fluid channel 45-1 is convenient for one-to-one correspondence with the tube channel formed by the corrugated telescopic tube 48 through the multi-channel rotary joint 48-1.

[0146] Reference Figures 2 to 5As shown, in the multifunctional pile driver of this embodiment, the main assembly 100 includes a walking mechanism 11, a working platform 12, a leg assembly 13, a hydraulic drive system 14 and a background control system 15. The working platform 12 is installed on the walking mechanism 11, and the walking mechanism 11 can drive the entire pile driver to move. The walking mechanism 11 preferably adopts a crawler walking structure and can move in a complex environment; the working platform 12 preferably adopts a rotating platform, which can be horizontally rotated relative to the walking mechanism 11 to facilitate the adjustment of the construction direction and improve the construction flexibility of the pile driver. The hydraulic drive system 14 and the background control system 15 are respectively integrated on the working platform 12. The hydraulic drive system 14 is mainly composed of a hydraulic oil tank, a hydraulic pump station, a hydraulic vacuum pump, a hydraulic control console and corresponding valve groups and pipelines, etc. The background control system 15 is mainly composed of an electrical control cabinet, etc. The hydraulic drive system 14 and the background control system 15 are respectively integrated on the working platform, which has a compact structure and occupies a small space. It has the advantages of flexible movement, diverse application scenarios, and convenient construction in a limited space. In addition, the drilling frame assembly is installed on the front side of the working platform 12, and the leg assembly 13 is installed on the outside of the working platform 12. Preferably, two sets of leg assemblies 13 are provided on the left and right sides of the working platform 12. Figure 3 As shown, the above-mentioned leg assembly 13 includes a cylinder bracket 131, a telescopic cylinder 132, a support plate 133 and a hole-opening fixture 134. The cylinder bracket 131 is fixed on the working platform 12, the telescopic cylinder 132 is vertically installed on the cylinder bracket 131, the support plate 133 is fixed to the lower end of the telescopic cylinder 132, and the hole-opening fixture 134 is installed on the support plate 133. By using the hole-opening fixture 134 on the leg assembly 13, the main machine can be firmly fixed on the ground, the torque generated by the high-torque power head can be effectively overcome, the output torque of the pile driver can be effectively increased, the construction efficiency is improved, and the contradiction between the existing small-space pile driver and the high-torque demand is solved. A plurality of hole-opening fixtures 134 can be provided on the support plate 133. As shown in FIG. Figure 4 and Figure 5The hole fixing device 134 includes a rotating oil cylinder 1341 and a rotating anchoring claw 1342 fixed at the lower end of the output shaft of the rotating oil cylinder 1341. The rotating anchoring claw 1342 has an alloy cutting tool. The rotating oil cylinder 1341 drives the rotating anchoring claw 1342 to rotate and break the ground. With the downward pressure of the telescopic oil cylinder 13, the rotating anchoring claw 1342 can be anchored into the ground, which can enable the rotating anchoring claw to quickly break and anchor into the formation, thereby increasing the grip of the main machine. The output shaft of the rotating oil cylinder 1341 has a dust suction channel 1343, and the upper part of the cylinder body of the rotating oil cylinder 1341 is provided with a dust suction pipe joint 1344 connected to the dust suction channel 1343. The upper part of the cylinder body of the rotating oil cylinder 1341 is sleeved on the output shaft, and the dust suction pipe joint 1344 is arranged on the upper part of the cylinder body, and has a certain distance from the upper end of the output shaft of the rotating oil cylinder 1341, so that the output shaft can rotate freely and keep the dust suction channel 1343 unobstructed. By adopting the above design, dust can be sucked out and collected while the anchor claw breaks the stratum, reducing the environmental pollution caused by dust at the construction site. The rotating anchor claw 1342 can adopt a four-petal structure. When working, the four-petal alloy rotating anchor claw 1342 is driven by the rotating cylinder 1341 (or hydraulic motor) to rotate and cut the ground at high speed. While cutting the bottom ground, the vacuum pump sucks away the debris formed by the rotating anchor claw 1342 through the dust suction channel 1343 to avoid polluting the environment. In addition, the above-mentioned hole fixing device 134 can also be provided with an expansion cylinder for driving the rotating anchor claw 1342 to expand. After the hole is formed, the expansion cylinder pushes downward to compress the four-petal rotating anchor claw 1342 to expand and tighten, thereby firmly fixing the main machine on the ground. In step S2 of the above-mentioned pile foundation construction method, after the main machine assembly 100 is in place, it can be supported on the ground by the leg assembly 13, and the hole fixing device 134 is used to firmly connect with the ground to overcome the large output torque of the power head. Similarly, after the construction is completed, the hole fixing device 134 is loosened and the entire support plate 133 is lifted to facilitate the mainframe assembly 100 to move to the next pile position for construction.

[0147] In this embodiment, the drill frame assembly may be a mast drill lifting assembly 200 or a foldable mechanical arm assembly 200 ′, and drill frames of different structural forms may be selected according to the construction space. Figure 2 The structure shown is a mast drill lifting assembly 200, which has the advantages of small footprint, light and labor-saving use, and easy maintenance. It is mainly composed of a main mast, a main mast clamp, a clamp cylinder, and a hydraulic winch. The main mast clamp is installed on the working platform 12 through a boom and a cylinder. The boom and the cylinder can be used to control the pile angle. The main mast is installed on the main mast clamp, and the clamp cylinder clamps the main mast. The hydraulic winch is installed on the main mast and connected to the power head assembly 300. The box 31 of the power head assembly 300 is slidably arranged on the main mast and can be controlled to move up and down on the main mast by the hydraulic winch. Fig.24The structure shown is a foldable mechanical arm assembly 200'. Fig.24 The diagram shows a construction scene of a multifunctional pile driver using a foldable mechanical arm in a narrow and long space. The foldable mechanical arm assembly 200' can be extended into a narrow and long space for construction, meeting the construction needs of some special scenes. It is mainly composed of 2 to 3 foldable arms, and the rotation angle is controlled by a hydraulic cylinder. The structure is similar to the digging arm of an existing excavator. When the foldable mechanical arm assembly 200' is used, the box 31 of the power head assembly 300 is hinged at the free end of the foldable mechanical arm assembly 200', and the relative angle between the two can be controlled by a hydraulic cylinder. The above-mentioned mast drilling assembly 200 and foldable mechanical arm assembly 200' are similar to the prior art, and their specific structure and action principle will not be described in detail here.

[0148] The invention discloses a limited micro-space pile foundation construction method based on a multifunctional pile driver. The multifunctional pile driver is used to realize the construction of various types of pile foundations on one pile driver. The pile driver is matched with a power head with a multi-channel diverter and a multi-channel telescopic drill rod, so that the pile driver can realize efficient and environmentally friendly pile foundation construction in a limited space, improve the adaptability and integration of the equipment, reduce the follow-up work during construction, improve the construction efficiency, and can adapt to various geological conditions and construction requirements. The pile foundation construction method of the invention can effectively solve the problems existing in the existing construction methods, improve the construction efficiency and quality, reduce the impact on the environment, and provide more reliable support for urban construction and infrastructure construction.

[0149] The present invention and its embodiments are described schematically above, which is not restrictive. The drawings show only one embodiment of the present invention, and the actual structure is not limited thereto. Therefore, if a person skilled in the art is inspired by it and creatively designs a structure and an embodiment similar to the technical solution without departing from the purpose of the invention, they shall all fall within the protection scope of the present invention.

Claims

1. A limited micro-space pile foundation construction method based on a multifunctional pile driver, characterized in that: The construction steps include: S1. Select the matching drilling tools according to the pile foundation type: The pile foundation type includes at least one of bored cast-in-place piles, mixing piles, high-pressure rotary jet piles and threaded enlarged steel piles, and the matching drilling tools include corresponding process drill bits (500), and the process drill bits (500) correspond to drilling drill bits (510), mixing pile drill bits (520), high-pressure rotary jet drill bits (530) and threaded enlarged steel pile drill bits (540); S2. Assembly and positioning of pile driver equipment: The pile driver equipment comprises a main machine assembly (100), a drill frame assembly, a power head assembly (300) and a multi-channel telescopic drill rod (400), wherein the drill frame assembly is arranged on the main machine assembly (100), the power head assembly (300) is mounted on the drill frame assembly, the multi-channel telescopic drill rod (400) is detachably mounted on the power head assembly (300), and the process drill bit (500) is mounted on the power head assembly (300) directly or through the multi-channel telescopic drill rod (400); wherein: The power head assembly (300) comprises a multi-channel flow divider (34), and an independently driven drill pipe rotary joint (35) and a telescopic drive joint (36), wherein the drill pipe rotary joint (35) is used to drive the process drill bit (500) to rotate, and the telescopic drive joint (36) is used to control the telescopic movement of the multi-channel telescopic drill pipe (400), and the multi-channel flow divider (34) is arranged at the upper end of the telescopic drive joint (36) and is used to connect to a surface fluid system; The multi-channel telescopic drill rod (400) comprises a plurality of telescopic rod bodies which are sleeved together step by step from the outside to the inside, a transmission screw for controlling the telescopic movement of the telescopic rod body, and a bellows telescopic tube (48) for establishing a channel. The transmission screw is located inside the telescopic rod body, and the transmission screw located at the center is provided with a plurality of fluid channels (45-1) which are connected to the corresponding flow diversion channels (34-3) in the multi-channel diverter (34). The bellows telescopic tube (48) is sleeved together from the inside to the outside to form a plurality of pipe channels. The upper end of the bellows telescopic tube (48) is connected to the transmission screw located at the center through a multi-channel rotary joint (48-1), so that the corresponding pipe channels are connected to the fluid channels (45-1) in a one-to-one correspondence. It also includes auxiliary equipment. The pile driver equipment and the auxiliary equipment are transported to a designated construction location and connected to various pipelines and lines. At the same time, the main machine assembly (100) is fixed, and the process drill bit (500) is adjusted to a construction angle through the drill frame assembly. S3. Pile foundation construction: After the corresponding process drill bit (500) is installed, centering and debugging are performed, and corresponding pile driver equipment and auxiliary equipment are started according to different pile foundation processes to carry out pile foundation construction.

2. The limited micro-space pile foundation construction method based on a multifunctional pile driver according to claim 1 is characterized in that: The construction process of bored pile in step S3 is as follows: S3-1, installing the multi-channel telescopic drill rod (400) on the power head assembly (300), connecting the drill rod rotary joint (35) of the power head assembly (300) with the telescopic rod body of the multi-channel telescopic drill rod (400), and connecting the telescopic drive joint (36) of the power head assembly (300) with the drive screw of the multi-channel telescopic drill rod (400); and installing the drilling drill bit (510) at the lower end of the multi-channel telescopic drill rod (400), so that the tube cavity in the drilling drill bit (510) is connected with the corresponding tube channel in the multi-channel telescopic drill rod (400); S3-2, after the casing is installed, the power head assembly (300) is used to drive the drilling bit (510) to rotate, and the drilling bit (510) is driven to drill by the extension of the multi-channel telescopic drill rod (400) and the downward movement of the power head assembly (300) driven by the drill frame assembly, and the drilling mud circulation is started through the auxiliary equipment; after reaching the set drilling depth, the drilling bit (510) is controlled to reverse and be lifted to the ground; S3-3, after removing the drilling bit (510), install the grouting conduit (510A) at the lower end of the multi-channel telescopic drill rod (400); and hang the steel cage in the pile hole; S3-4, after the steel cage is installed in place, the grouting conduit (510A) is lowered by extending the multi-channel telescopic drill rod (400) and driving the power head assembly (300) downward by the drill frame assembly, and the concrete pump is connected through the multi-channel diverter (34) to pour concrete from the bottom of the pile hole upward; S3-5. After the grouting is completed, the multi-channel telescopic drill rod (400) and the grouting conduit (510A) are lifted and flushed with clean water.

3. The limited micro-space pile foundation construction method based on a multifunctional pile driver according to claim 2 is characterized in that: The drilling bit (510) has two fluid inlets and outlets (513) arranged one above the other. The two fluid inlets and outlets (513) are respectively connected to corresponding lumens. The lower fluid inlet and outlet (513) is arranged at the spiral wing plate (512) of the drilling bit (510). The drilling mud circulation has the following two modes: A. The fluid inlet and outlet (513) at the lower part is closed with a plug (514), and the circulating mud enters through the multi-channel diverter (34), passes through the pipe channel in the multi-channel telescopic drill rod (400), and the corresponding pipe cavity in the drilling drill bit (510) in sequence, and then is ejected from the bottom of the drilling drill bit (510); the drilling drill bit (510) cuts the soil and mixes it with the circulating mud to form a debris mud mixed liquid, and the debris mud mixed liquid enters through the fluid inlet and outlet (513) at the upper part, passes through the corresponding pipe cavity in the drilling drill bit (510), the pipe channel in the multi-channel telescopic drill rod (400), and the multi-channel diverter (34) in sequence, and then is sucked to the ground by a vacuum pump; B. The fluid inlet and outlet (513) at the upper part is closed with a plug (514), and the circulating mud is input into the borehole by reverse circulation. The debris mud mixture enters through the bottom of the drilling bit (510) at the bottom of the borehole, and is sucked to the ground by a vacuum pump through the corresponding tube cavity in the drilling bit (510), the tube channel in the multi-channel telescopic drill rod (400) and the multi-channel diverter (34) in sequence; at the same time, high-pressure gas is sprayed through the multi-channel diverter (34), the tube channel in the multi-channel telescopic drill rod (400), the corresponding tube cavity in the drilling bit (510) and the fluid inlet and outlet (513) at the lower part by a high-pressure air compressor to assist the spiral wing plate (512) in cutting the soil and prevent the drill from getting stuck.

4. The limited micro-space pile foundation construction method based on a multifunctional pile driver according to claim 1 is characterized in that: The construction process of the mixing pile in step S3 is as follows: S3-1, installing the multi-channel telescopic drill rod (400) on the power head assembly (300), connecting the drill rod rotary joint (35) of the power head assembly (300) with the telescopic rod body of the multi-channel telescopic drill rod (400), and connecting the telescopic drive joint (36) of the power head assembly (300) with the drive screw of the multi-channel telescopic drill rod (400); and installing the mixing pile drill bit (520) at the lower end of the multi-channel telescopic drill rod (400), so that the tube cavity in the mixing pile drill bit (520) is connected to the corresponding tube channel in the multi-channel telescopic drill rod (400); S3-2, the mixing pile drill bit (520) is driven to rotate by the power head assembly (300), and the multi-channel telescopic drill rod (400) is extended and the drill frame assembly drives the power head assembly (300) to move downward to drive the mixing pile drill bit (520) to drill, and at the same time, the curing agent high-pressure pump and the high-pressure air compressor are turned on, and after passing through the multi-channel diverter (34), the pipe channel in the multi-channel telescopic drill rod (400), and the corresponding pipe cavity in the mixing pile drill bit (520), the curing agent and high-pressure air are sprayed from the corresponding fluid nozzle (523) of the mixing pile drill bit (520) to perform rotary mixing drilling; after reaching the set depth, the mixing pile drill bit (520) is controlled to reverse and rise, and at the same time, the curing agent high-pressure pump and the high-pressure air compressor are continued to be turned on to spray to form a mixing pile; S3-3, after the mixing pile drill bit (520) is lifted to the designed pile top, continue mixing to reinforce the pile head; S3-4. After the mixing is completed, the multi-channel telescopic drill rod (400) and the mixing pile drill bit (520) are lifted and rinsed with clean water.

5. The limited micro-space pile foundation construction method based on a multifunctional pile driver according to claim 1 is characterized in that: The construction process of high pressure jet grouting pile in step S3 is as follows: S3-1, installing the multi-channel telescopic drill rod (400) on the power head assembly (300), connecting the drill rod rotary joint (35) of the power head assembly (300) to the telescopic rod body of the multi-channel telescopic drill rod (400), and connecting the telescopic drive joint (36) of the power head assembly (300) to the transmission screw of the multi-channel telescopic drill rod (400); and installing the high-pressure jet grouting drill bit (530) at the lower end of the multi-channel telescopic drill rod (400), so that the tube cavity in the high-pressure jet grouting drill bit (530) is connected to the corresponding tube channel in the multi-channel telescopic drill rod (400); S3-2, the high-pressure jet grouting drill head (530) is driven to rotate by the power head assembly (300), and the high-pressure jet grouting drill head (530) is driven to drill by the extension of the multi-channel telescopic drill rod (400) and the downward movement of the power head assembly (300) driven by the drill frame assembly, and the high-pressure pump for curing agent and the high-pressure air compressor are turned on at the same time, and the curing agent and high-pressure air are sprayed from the corresponding high-pressure nozzle (532) of the high-pressure jet grouting drill head (530) through the multi-channel diverter (34), the pipe channel in the multi-channel telescopic drill rod (400), and the corresponding pipe cavity in the high-pressure jet grouting drill head (530), and the soil is drilled by rotation cutting; after reaching the set depth, the high-pressure jet grouting drill head (530) is controlled to reverse and rise, and the high-pressure pump for curing agent and the high-pressure air compressor are continued to be turned on to spray to form a high-pressure jet grouting pile; S3-3, after the high-pressure jet grouting drill bit (530) is lifted to the designed pile top, cutting and mixing are continued to reinforce the pile head; S3-4. After the cutting and mixing is completed, the multi-channel telescopic drill rod (400) and the high-pressure jet drilling head (530) are lifted and rinsed with clean water.

6. The limited micro-space pile foundation construction method based on a multifunctional pile driver according to claim 1 is characterized in that: The construction process of the threaded enlarged steel pile in step S3 is as follows: S3-1, installing the thread-enlarged steel pile drill bit (540) on the power head assembly (300) through the steel pile joint (540B), so that the drill pipe rotary joint (35) of the power head assembly (300) can drive the thread-enlarged steel pile drill bit (540) to rotate; S3-2, the power head assembly (300) drives the threaded enlarged steel pile drill bit (540) to rotate and drill, and the drill frame assembly drives the power head assembly (300) to move downward to drive the threaded enlarged steel pile drill bit (540) to drill into the soil; S3-3. After the first section of the threaded enlarged steel pile drill bit (540) is implanted, a steel pile extension section (540A) or an extension rod (540C) is installed between the threaded enlarged steel pile drill bit (540) and the steel pile joint (540B), so that the steel pile extension section (540A) or the extension rod (540C) is quickly connected to the threaded enlarged steel pile drill bit (540), and drilling is continued until the designed pile length and the designed depth are reached.

7. The limited micro-space pile foundation construction method based on a multifunctional pile driver according to claim 6 is characterized in that: When the designed pile top is at a relatively deep depth from the bottom plate or the ground, the multi-channel telescopic drill rod (400) is installed on the power head assembly (300), the drill rod rotary joint (35) of the power head assembly (300) is connected to the telescopic rod body of the multi-channel telescopic drill rod (400), and the telescopic drive joint (36) of the power head assembly (300) is connected to the driving screw of the multi-channel telescopic drill rod (400); and the last steel pile extension section (540A) or the extension rod (540C) is connected to the multi-channel telescopic drill rod (400), and the multi-channel telescopic drill rod (400) is extended to rotate and deliver the pile, so that the threaded expanded steel pile is delivered to the designated design position.

8. The limited micro-space pile foundation construction method based on a multifunctional pile driver according to any one of claims 1 to 7, characterized in that: The power head assembly (300) further comprises a box (31), on the side walls of which a telescopic drive hydraulic motor (32) and a drill rod drive hydraulic motor (33) are respectively placed horizontally, the telescopic drive hydraulic motor (32) being transmission-connected to a telescopic drive joint (36) via a telescopic drive transmission mechanism (38), and the drill rod drive hydraulic motor (33) being transmission-connected to a drill rod rotary joint (35) via a drill rod drive transmission mechanism (37).

9. The limited micro-space pile foundation construction method based on a multifunctional pile driver according to any one of claims 1 to 7, characterized in that: The telescopic rod body of the multi-channel telescopic drill rod (400) comprises a primary fixed rod body (41), an intermediate telescopic rod body (42) and a final telescopic rod body (43); the transmission screw of the multi-channel telescopic drill rod (400) comprises a primary screw rod (45) and an intermediate transmission screw rod (46); the primary fixed rod body (41), the intermediate telescopic rod body (42) and the final telescopic rod body (43) are sleeved together from outside to inside in stages, and the telescopic rod bodies of the stages are axially axially opposite to the primary fixed rod body (41). The first-stage screw (45) and the intermediate transmission screw (46) are arranged on the inner side of the first-stage fixed rod body (41), the intermediate telescopic rod body (42) and the final telescopic rod body (43), and the first-stage screw (45) and the intermediate transmission screws (46) of each stage are threadedly sleeved together from the inside to the outside; the intermediate transmission screws (46) of each stage are connected to the intermediate telescopic rod body (42) of the corresponding stage through the annular relay (47) for relative rotation, and the first-stage screw (45) and Each intermediate transmission screw rod (46) of each level is threadedly matched with the corresponding intermediate telescopic rod body (42) of the next level and the final telescopic rod body (43); the upper end of the first-level fixed rod body (41) can be connected to the drill rod rotating joint (35) to drive the multi-channel telescopic drill rod (400) to rotate; the upper end of the first-level screw rod (45) can be connected to the telescopic drive joint (36) to drive the multi-channel telescopic drill rod (400) to telescopic movement; the upper end of the first-level screw rod (45) can be connected to the telescopic drive joint (36) to drive the multi-channel telescopic drill rod (400) to telescopic movement. A plurality of fluid channels (45-1) are provided which are connected to the corresponding flow diversion channels (34-3) in the multi-channel diverter (34); the upper end of the bellows expansion tube (48) is connected to the lower end of the primary screw (45) via a multi-channel rotary joint (48-1), and the bellows expansion tube (48) is formed from the inside to the outside of the ring sleeve to form tube channels corresponding to the above-mentioned fluid channels (45-1), and each tube channel is connected to the corresponding channel opening (43-1) at the lower end of the final telescopic rod body (43).

10. The limited micro-space pile foundation construction method based on a multifunctional pile driver according to any one of claims 1 to 7, characterized in that: The main machine assembly (100) comprises a walking mechanism (11), a working platform (12), a leg assembly (13), a hydraulic drive system (14) and a background control system (15); the working platform (12) is mounted on the walking mechanism (11); the hydraulic drive system (14) and the background control system (15) are respectively integrated on the working platform (12); the drilling frame assembly is mounted on the front side of the working platform (12); and the leg assembly (13) is mounted on the outside of the working platform (12); The leg assembly (13) comprises a cylinder bracket (131), a telescopic cylinder (132), a support plate (133) and an opening fixture (134); the cylinder bracket (131) is fixed on the working platform (12); the telescopic cylinder (132) is vertically mounted on the cylinder bracket (131); the support plate (133) is fixed on the lower end of the telescopic cylinder (132); and the opening fixture (134) is mounted on the support plate (133); the opening fixture (134) comprises a rotating cylinder (1341) and a rotating anchoring claw (1342) fixed on the lower end of the output shaft of the rotating cylinder (1341); the output shaft of the rotating cylinder (1341) has a dust suction channel (1343); and a dust suction pipe joint (1344) connected to the dust suction channel (1343) is provided on the upper part of the cylinder body of the rotating cylinder (1341).

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