Full replacement process with precast pile implantation and expansion bottom integrated equipment and construction method

Abstract

The application provides a precast pile implantation and bottom expansion integrated equipment for full replacement process and a construction method, which comprises, from top to bottom along the same equipment axis, a main slide frame, a vibration isolation mechanism, a vibration mechanism, a centering and clamping mechanism, an extension mechanism, a secondary slide table and a drilling mechanism. The precast pile implantation and bottom expansion integrated equipment for full replacement process solves the problems that the traditional construction usually adopts independent equipment to respectively complete pile implantation and bottom expansion operation, repositioning and secondary installation are required, and pile body displacement, hole bottom disturbance and positioning deviation are easily caused in the process switching.

Description

TECHNICAL FIELD

[0001] The present application belongs to the technical field of precast piles, and particularly relates to a precast pile implanting and bottom-expanding integrated device for full replacement process and a construction method. BACKGROUND

[0002] In the current pile foundation construction field, as the main load-bearing component between the foundation and the upper structure, the implanting process (including pressing in, vibrating in or hammering in) of the precast pile is the core link to ensure the stability and bearing capacity of the pile body. Meanwhile, in order to further improve the vertical bearing capacity and horizontal resistance of the pile foundation, the in-hole bottom-expanding and mixing forming technology is widely used to form an enlarged head or an expanded diameter at the pile end or a specific position of the pile body, so as to increase the stress area and improve the compactness of the bearing layer at the pile end. Such bottom-expanding operation usually relies on a rotating mixing or radial expansion mechanism to form a regular bottom-expanding body around the pile end, so that the pile foundation can also obtain good bearing effect in soft ground.

[0003] However, in the traditional construction process, the pile implanting and bottom-expanding operations are usually completed by two independent devices. After the pile body is pressed into place, the bottom-expanding device needs to be reinstalled or the drill needs to be replaced in order to perform the bottom-expanding construction. Since the pile implanting device and the bottom-expanding mixing mechanism are independent of each other, not unified and lack of coaxial positioning reference in the related technology, the bottom-expanding construction cannot be continuously connected with the pile implanting process, the pile position needs to be rechecked, the bottom-expanding position precision and forming size are difficult to be stably controlled, and problems such as hole bottom disturbance and pile body deviation are prone to occur, thereby causing quality hidden troubles such as geometric deviation of the enlarged head, stress concentration at the pile end and reduction of the bearing capacity of the pile foundation. SUMMARY

[0004] Therefore, the present application aims to at least partially solve one of the problems in the related art.

[0005] To achieve the above-mentioned purposes, the technical solution of the present application is as follows:

[0006] A precast pile implanting and bottom-expanding integrated device for full replacement process, comprising a main slide frame, a vibration isolation mechanism, a vibration mechanism, a centering clamping mechanism, an extension mechanism, a secondary slide table and a drilling mechanism which are sequentially arranged from top to bottom along the same device axis.

[0007] The centering clamping mechanism is used for coaxially clamping and positioning the precast pile below the device axis, and the extension mechanism and the secondary slide table are linked to drive the drilling mechanism to switch between the retracted position and the working position in the axial position relative to the pile end under the condition that the pile position is kept unchanged by the centering clamping mechanism.

[0008] The drilling mechanism is coaxially arranged around the central through hole of the secondary slide table and is driven to rotate by the hollow rotating device below the secondary slide table, and the drilling mechanism performs hole / expanding operation around the pile end when in the working position.

[0009] Further, the drilling mechanism comprises a ring-shaped drilling ring, a hollow drill bit assembly, a protective sleeve, an output plate, a driven plate, a plurality of drill tooth assemblies and a plurality of variable-diameter reaming assemblies.

[0010] The output plate is connected to the output end of the hollow rotating device, the driven plate is located below the output plate, the plurality of variable-diameter reaming assemblies are uniformly arranged in a circumferential direction and are in sliding cooperation with the drilling ring, and the driving end of the variable-diameter reaming assembly is connected to the driven plate. The top of the protective sleeve is connected to the fixed part of the hollow rotating device, and the bottom of the protective sleeve is provided with a first bent edge.

[0011] A plurality of bent protrusions are uniformly arranged on the upper end surface of the driven plate in the circumferential direction, the first bent edge extends towards the bent protrusions and is located below the bent protrusions and maintains a sliding cooperation relationship therebetween.

[0012] The bent protrusions form an axial support surface of the driven plate above the first bent edge, so that the driven plate is axially limited and constrained in a freely rotatable state, thereby preventing the driven plate from moving along the axial direction under the action of force or vibration.

[0013] The plurality of drill tooth assemblies are uniformly arranged in a circumferential direction, the top of the drill tooth assembly is connected to the ring-shaped drilling ring, and the bottom of the drill tooth assembly is connected to the hollow drill bit assembly.

[0014] Further, the variable-diameter reaming assembly comprises a first sliding rod, a stop block, a shifting block, a return spring and a reaming drill tooth. The outer end of the first sliding rod is provided with the reaming drill tooth, and the inner end is provided with the stop block. An arc-shaped travel hole is arranged on the driven plate, the shifting block is connected to the output plate and located in the arc-shaped travel hole. When the output plate is driven in a forward direction, the shifting block is used to drive the first sliding rod to slide in a radial direction. One end of the return spring abuts against the stop block, and the other end abuts against the inner wall of the arc-shaped travel hole. When the output plate is driven in a reverse direction, the first sliding rod is reset and retracted.

[0015] Further, the hollow drill bit assembly comprises a fixed ring, a hollow drill cylinder and a plurality of spiral protrusions. The upper end surface of the fixed ring is connected to the bottom of the drill tooth assembly. The hollow drill cylinder is coaxially sleeved outside the pile body and connected to the lower end surface of the fixed ring. A plurality of spiral protrusions are uniformly arranged on the outer wall of the hollow drill cylinder to achieve soil breaking and extrusion conveying.

[0016] The drill tooth assembly comprises an obliquely arranged drilling blade and a plurality of drilling cutter teeth arranged thereon.

[0017] Further, the centering and clamping mechanism comprises a driving plate, a guide plate, a plurality of fixed supports, a plurality of pile head clamping jaws and a plurality of rigid support rods; the driving plate is provided with an arc-shaped hole for driving the upper end of the pile head clamping jaw, the guide plate is provided with a strip-shaped hole matched with the upper part of the pile head clamping jaw, and the lower end of the pile head clamping jaw is provided with a second bent edge matched with the pile head;

[0018] The rigid support rod is located between the driving plate and the vibrating plate of the vibrating mechanism and is in sliding cooperation with the driving plate through a roller, so as to limit the non-axial deviation of the driving plate while centering and clamping.

[0019] Further, the vibrating mechanism comprises a vibrating plate, a plurality of electromagnetic vibrators and a plurality of limiting guide assemblies;

[0020] The plurality of electromagnetic vibrators and the plurality of limiting guide assemblies are circumferentially and uniformly arranged between the lower fixed plate of the vibration isolation mechanism and the vibrating plate, the electromagnetic vibrator fixing part is connected with the lower end surface of the lower fixed plate, and the output end of the electromagnetic vibrator is provided with a hammering block in the form of a first annular protrusion for hitting the upper end surface of the vibrating plate;

[0021] The limiting guide assembly comprises a second sliding rod and a limiting support, the limiting support is L-shaped, the second sliding rod is in sliding cooperation with the bent part of the limiting support, and the bottom of the second sliding rod is provided with a limiting block.

[0022] Further, the vibration isolation mechanism comprises an upper fixed plate, a lower fixed plate, a rubber buffer assembly, a plurality of hydraulic rods and a plurality of elastic buffer assemblies;

[0023] The rubber buffer assembly is arranged in the middle region between the upper fixed plate and the lower fixed plate and is arranged coaxially with the central axis of the device;

[0024] The rubber buffer assembly comprises an inner rubber sleeve, an outer rubber sleeve, a first pad plate, a second pad plate, a plurality of rubber pads and a plurality of steel plates;

[0025] The inner rubber sleeve is located at the central position of the rubber buffer assembly, the axis thereof is arranged coaxially with the driving shaft assembly, and the inner rubber sleeve is used for defining the inner diameter of the rubber buffer assembly and providing a channel for the driving shaft assembly to pass through;

[0026] The plurality of rubber pads and the plurality of steel plates are alternately and stacked around the outer wall of the inner rubber sleeve in the axial direction to form a buffer stack;

[0027] The outer rubber sleeve is sleeved outside the buffer stack, constitutes a circumferential containment constraint structure for limiting the outer diameter of the buffer stack, and enables the buffer stack to maintain a stable shape when compressed in the axial direction;

[0028] The first cushion plate is arranged at the top of the buffer stack and is attached to the lower end surface of the upper fixed plate, and the second cushion plate is arranged at the bottom of the buffer stack and is attached to the upper end surface of the lower fixed plate.

[0029] The hydraulic rod and the elastic buffer assembly are uniformly distributed along the circumference, and the elastic buffer assembly is sleeved outside the hydraulic rod.

[0030] Further, the telescopic mechanism includes a plurality of oil cylinders, the fixed ends of the oil cylinders are connected with the fixed supports of the centering and clamping mechanism respectively, and the telescopic ends of the oil cylinders are connected with the secondary sliding table, for adjusting the axial working position of the drilling mechanism relative to the pile end.

[0031] Further, the main sliding carriage is provided with a servo motor, the output end of the servo motor is connected with the driving plate of the centering and clamping mechanism through a driving shaft assembly, and the driving shaft assembly penetrates the vibration isolation mechanism in sequence.

[0032] The driving shaft assembly includes an output shaft, an output sleeve and a mounting sleeve, the output shaft is connected with the servo motor and is in sliding fit with the output sleeve, the output sleeve is connected with the driving plate through the mounting sleeve, and the output shaft and the driving plate are connected in spline or tooth shape.

[0033] A prefabricated pile implantation and bottom expansion construction method under a full replacement process, when the prefabricated pile implantation and bottom expansion integrated equipment under the full replacement process is used, the construction method includes the following steps:

[0034] Step one: align the main sliding carriage of the pile implantation and bottom expansion integrated equipment with the pile axis, and complete the perpendicularity correction through the column guide;

[0035] Step two: start the centering and clamping mechanism of the equipment to clamp the pile head, so that the pile shaft and the equipment axis coincide, and the coaxial clamping is maintained under the decoupling condition of the vibration mechanism and the vibration isolation mechanism;

[0036] Step three: drive the main sliding carriage to press down along the Z1 direction and drive the vibration mechanism to press in or vibrate in, so that the prefabricated pile enters the design depth interval;

[0037] Step four: keep the clamping and coaxial relationship unchanged, drive the telescopic mechanism to make the secondary sliding table descend along the Z2 direction to the bottom expansion working position outside the pile end, and the variable-diameter reaming assembly remains in the folded state;

[0038] Step five: start the hollow rotating device to drive the drilling mechanism to rotate, the drilling mechanism includes an annular drill ring, a hollow drill bit assembly, a protective sleeve, an output plate, a driven plate, a plurality of drill tooth assemblies and a plurality of variable-diameter reaming assemblies.

[0039] During the rotation, the multiple variable-diameter reaming assemblies are expanded radially through the linkage of the output plate and the driven plate, driving the reaming drill teeth to cut, extrude and ream the soil around the pile end to obtain the enlarged head;

[0040] Step six: after stopping the rotation, the variable-diameter reaming assembly is radially reset to fold, the secondary sliding table is driven to move upwards and exit the bottom expansion area, then the clamping is released and the main sliding frame is lifted to complete the pile construction;

[0041] Step seven: during the whole process, the Z1 stroke, Z2 stroke and diameter expansion stroke, as well as the construction parameters such as rotation torque and speed, are recorded to confirm the compliance of the bottom expansion position and geometric size and used for quality acceptance;

[0042] Through the continuous operation of the above steps on the same device axis, the pile implantation and bottom expansion are completed under the unified geometric reference and positioning control, thereby reducing the pile position deviation, hole bottom disturbance and positioning deviation caused by process switching, and improving the consistency of the enlarged head formation and the bearing capacity of the pile foundation.

[0043] Compared with the prior art, the full replacement process of the precast pile implantation and bottom expansion integrated device and construction method has the following advantages:

[0044] 1. By integrating the implantation and bottom expansion functions coaxially on the same device base and using the centering clamping mechanism as the pile position geometric reference, the cumulative error caused by secondary positioning, repeated machine installation and repositioning is avoided during continuous operation, the pile body maintains consistency with the device axis during the conversion phase from penetration to bottom expansion, the probability of pile position deviation and hole bottom disturbance caused by device switching is reduced, the bottom expansion position is determined by the linkage of Z1 and Z2 strokes in the same coordinate system, and the geometric consistency and repeatability are significantly improved.

[0045] 2. By using a rubber buffer assembly with inner and outer sleeves and alternating stacked buffer layers, and forming a ring-shaped multi-point support with circumferentially distributed hydraulic rods and elastic buffer assemblies, the vibration load is absorbed and attenuated in stages before being transmitted to the upper guide structure, so that the guide and transmission components are not directly affected by high-frequency excitation and transient impact, the device can maintain the stability of the guide accuracy and assembly gap under long-time vibration working conditions, reduce looseness and wear, and improve the overall reliability and service life.

[0046] 3. By setting the variable-diameter reaming assembly driven by the output plate and the driven plate, and forming the sliding limit and axial support with the limiting bend of the protective sleeve bottom and the bent protrusion of the driven plate, the mechanical boundary control of the radial expansion stroke is implemented without affecting the free rotation of the driven plate, and the axial movement of the driven plate is prevented, so that the upper limit of the reaming radius and the boundary of the bottom expansion morphology are solidified and constrained by the mechanism body, and the geometric size and profile of the enlarged head are more stable, which is beneficial to obtain uniform and dense bottom expansion body and improve the stress state and bearing capacity of the pile end. BRIEF DESCRIPTION OF DRAWINGS

[0047] The accompanying drawings, which form a part of the present application, are intended to provide further understanding of the present application, and are used to interpret the illustrative embodiments of the present application and their descriptions, and do not constitute improper limitations on the present application. In the drawings:

[0048] Figure 1 The full replacement process described in the embodiment of the present application is an integrated equipment schematic diagram for precast pile implantation and bottom expansion;

[0049] Figure 2 The main carriage schematic diagram described in the embodiment of the present application;

[0050] Figure 3 The vibration isolation mechanism schematic diagram described in the embodiment of the present application;

[0051] Figure 4 The vibration mechanism schematic diagram described in the embodiment of the present application;

[0052] Figure 5 The centering and clamping mechanism schematic diagram described in the embodiment of the present application;

[0053] Figure 6 The drilling mechanism schematic diagram described in the embodiment of the present application;

[0054] Figure 7 The hollow rotating device schematic diagram described in the embodiment of the present application;

[0055] Figure 8 The variable-diameter reaming assembly schematic diagram described in the embodiment of the present application;

[0056] Figure 9 The hollow drill bit assembly schematic diagram described in the embodiment of the present application.

[0057] Explanation of reference signs:

[0058] 100, main slide; 110, driving block; 200, servo motor; 210, driving shaft assembly; 300, vibration isolation mechanism; 310, upper fixed plate; 320, lower fixed plate; 330, rubber buffer assembly; 340, elastic buffer assembly; 350, hydraulic rod; 400, vibration mechanism; 410, electromagnetic vibrator; 420, limiting support; 430, second sliding rod; 440, beating plate; 450, first annular protrusion; 500, centering and clamping mechanism; 510, driving plate; 520, fixed support; 530, guide plate; 540, pile head clamping jaw; 600, telescopic mechanism; 700, secondary slide; 800, hollow rotating device; 900, drilling mechanism; 910, drilling ring; 920, drilling tooth assembly; 930, hollow drill bit assembly; 940, variable-diameter reaming assembly; 941, first sliding rod; 942, reaming drill tooth; 943, shifting block; 950, protective sleeve; 960, output plate; 970, driven plate; 980, fixed ring. DETAILED DESCRIPTION

[0059] It should be noted that the embodiments in the present application and the features in the embodiments can be combined with each other without conflict.

[0060] In the description of the present application, it should be understood that the terms "center", "longitudinal", "transverse", "upper", "lower", "front", "rear", "left", "right", "vertical", "horizontal", "top", "bottom", "inner", "outer" and the like indicate the orientation or positional relationship based on the orientation or positional relationship shown in the drawings, and are only for the convenience of describing the present application and simplifying the description, and do not indicate or imply that the device or element referred to must have a particular orientation, be constructed and operated in a particular orientation, and therefore cannot be understood as a limitation on the present application. In addition, the terms "first", "second" and the like are only for descriptive purposes and cannot be understood as indicating or implying relative importance or implicitly indicating the number of the technical features indicated. Therefore, the features defined with "first", "second" and the like can explicitly or implicitly include one or more of the features. In the description of the present application, unless otherwise specified, the meaning of "a plurality of" is two or more.

[0061] In the description of the present application, it should be noted that unless otherwise explicitly specified and limited, the terms "mounting", "connection", "connection" should be understood broadly, for example, it can be fixedly connected, or it can be detachably connected, or integrally connected; it can be mechanically connected, or it can be electrically connected; it can be directly connected, or it can be indirectly connected through an intermediate medium; it can be the communication inside two elements. For those skilled in the art, the specific meaning of the above terms in the present application can be understood through specific circumstances.

[0062] The present application will be described in detail below with reference to the drawings and in conjunction with the embodiments.

[0063] The embodiment relates to a precast pile implantation and bottom expansion integrated equipment for a full replacement process, and belongs to the technical field of pile foundation construction equipment. In combination with the background art, two sets of equipment respectively used for pile implantation and bottom expansion are generally adopted in traditional construction, and the bottom expansion device needs to be repositioned and positioned and re-measured after pile implantation is completed on site, repeated equipment mounting not only increases operation time, but also easily causes pile body micro-displacement and hole bottom disturbance in the equipment switching and re-correction process, so that the bottom expansion position and geometric size control depend on manual experience and fluctuate. The embodiment integrates implantation and bottom expansion functions under the same geometric reference, so that two key processes are continuously connected and coaxially carried out, so as to improve bottom expansion position accuracy and forming consistency and reduce the uncertainty of process switching.

[0064] The integrated equipment of the embodiment sequentially comprises a main slide 100, a vibration isolation mechanism 300, a vibration mechanism 400, a centering and clamping mechanism 500, an extension mechanism 600, a secondary slide 700 and a drilling mechanism 900 along the same equipment axis from top to bottom, a servo motor 200 is installed on the main slide 100, the output end of the servo motor 200 is in transmission connection with the driving plate 510 of the centering and clamping mechanism 500 through a driving shaft assembly 210, the driving shaft assembly 210 is composed of an output shaft, an output sleeve and a mounting sleeve, the output shaft is coupled with the servo motor 200 and is in sliding fit with the output sleeve, the output sleeve is coaxially connected with the middle part of the driving plate 510 through the mounting sleeve, and the output shaft and the driving plate 510 are connected in the form of spline or tooth profile to realize anti-torsion and detachability; the main slide 100 is provided with a column guide and locking structure parallel to the equipment axis, so that the repeated maintenance and repair disassembly of the assembly reference can be facilitated, the driving shaft assembly 210 sequentially penetrates the vibration isolation mechanism 300 and the vibration mechanism 400 from top to bottom and forms a through channel in the center to reduce eccentric additional load. The main slide 100 is provided with a driving block 110 connected with the output end of the pile implantation and bottom expansion equipment.

[0065] The vibration isolation mechanism 300 comprises an upper fixed plate 310, a lower fixed plate 320, a rubber buffer assembly 330, a plurality of hydraulic rods 350 and a plurality of elastic buffer assemblies 340, the upper fixed plate 310 is connected with the lower end face of the main slide 100 in the form of high-strength bolt and positioning pin composite connection, the lower fixed plate 320 is located above the vibration mechanism 400 and is rigidly connected with the upper support surface thereof, the rubber buffer assembly 330 is arranged in the middle region between the upper fixed plate 310 and the lower fixed plate 320 and is coaxially arranged with the equipment central axis;

[0066] The rubber buffer assembly 330 specifically includes an inner rubber sleeve, an outer rubber sleeve, a first pad plate and a second pad plate, and a plurality of rubber pads and a plurality of steel plates. The inner rubber sleeve is located at the center of the assembly and is coaxially arranged with the drive shaft assembly 210 to define the inner diameter of the rubber buffer assembly 330 and provide a through passage. The plurality of rubber pads and the plurality of steel plates are alternately stacked around the outer wall of the inner rubber sleeve in the axial direction to form an annular buffer stack. The surfaces of each layer are in surface-to-surface contact to form a uniform pressure-bearing interface. The outer rubber sleeve is integrally sleeved outside the buffer stack to circumferentially contain the stack to limit radial bulging and maintain a stable stress state when axially compressed. The first pad plate and the second pad plate are respectively arranged at the upper and lower ends of the stack and are in contact with the lower end surface of the upper fixed plate 310 and the upper end surface of the lower fixed plate 320. The first pad plate and the second pad plate are fixed to the end surfaces of the corresponding fixed plates by bolts or limiting columns to define the flatness of the end surfaces of the stack and form an axial pressure-equalizing surface.

[0067] A plurality of hydraulic rods 350 and a plurality of elastic buffer assemblies 340 are uniformly distributed between the upper fixed plate 310 and the lower fixed plate 320 in the circumferential direction, and the elastic buffer assembly 340 is sleeved outside the hydraulic rod 350. The hydraulic rod 350 is used to bear static load and cooperate with the integrated buffer element to control the displacement limit. The elastic buffer assembly 340 adopts a telescopic rod structure and a coaxial sleeve structure of a buffer spring to form secondary buffering and a return force when a predictable impact occurs. In this embodiment, the telescopic rod structure is composed of a light rod, a buffer spring, a sliding sleeve, a cover plate, and a limiting nut. The top end of the light rod is fixedly connected to the lower end surface of the upper fixed plate 310, and the bottom end is provided with external threads and mounted with a limiting nut. The sliding sleeve is fixedly arranged on the upper end surface of the lower fixed plate 320. The cover plate is fixed to the top end of the sliding sleeve. The light rod sequentially penetrates the buffer spring, the cover plate, and the inner cavity of the sliding sleeve, and forms a sliding fit with the cover plate. The buffer spring is coaxially sleeved on the light rod and located above the cover plate. The limiting nut is located inside the sliding sleeve. When impacted, the lower fixed plate 320 drives the sliding sleeve and the cover plate to slide upward relative to the light rod, compressing the buffer spring to achieve secondary buffering. When the impact disappears, the buffer spring releases the elastic force to push the entire assembly back to its original position to provide a return force.

[0068] The vibration mechanism 400 includes a beating plate 440, a plurality of electromagnetic vibrators 410, and a plurality of limiting guide assemblies. The plurality of electromagnetic vibrators 410 and the plurality of limiting guide assemblies are uniformly arranged between the lower fixed plate 320 and the beating plate 440 in the circumferential direction. The fixed part of the electromagnetic vibrator 410 is connected to the lower end surface of the lower fixed plate 320, and the output end of the electromagnetic vibrator 410 is provided with a hammering block to periodically hit the first annular protrusion 450 formed on the upper end surface of the beating plate 440.

[0069] The hammering block of the electromagnetic vibrator 410 directly acts on the first annular protrusion 450 on the vibrating plate 440. The direct impact here ensures that the vibration energy loss is minimal. A plurality of rigid support rods are arranged between the vibrating plate 440 and the driving plate 510 of the centering and clamping mechanism 500. The driving plate 510 transmits the reciprocating vibration force to the pile head clamping jaw 540 through the arc-shaped hole thereon and the guide plate 530, and finally transmits the vibration directly to the clamped precast pile head through the second bent edge at the lower end of the clamping jaw.

[0070] The limiting and guiding assembly includes a second sliding rod 430 and an L-shaped limiting support 420, the second sliding rod 430 is in sliding fit with the bent part of the limiting support 420, and the bottom of the second sliding rod 430 is provided with a limiting block to inhibit non-axial swing. The lower end surface of the vibrating plate 440 serves as the upper assembly base surface of the centering and clamping mechanism 500 and transmits vibration energy through rigid connecting members.

[0071] The centering and clamping mechanism 500 includes a driving plate 510, a guide plate 530, a plurality of fixed supports 520, a plurality of pile head clamping jaws 540, and a plurality of rigid support rods. The driving plate 510 is driven by the driving shaft assembly 210 and has arc-shaped driving holes formed thereon for the upper ends of the plurality of pile head clamping jaws 540. The guide plate 530 has strip-shaped holes arranged in cooperation with the upper parts of the pile head clamping jaws 540 and is axially limited by the fixed supports 520. The lower end of the pile head clamping jaw 540 has a second bent edge matched with the outer shape of the pile head to form a multi-point embrace when clamping. The plurality of rigid support rods are evenly arranged between the vibrating plate 440 and the driving plate 510. The top of the rigid support rod is welded to the vibrating plate 440, and the bottom of the rigid support rod is in sliding fit with the driving plate 510 through rollers (not shown in the figure) to limit the non-axial deviation of the driving plate 510 while centering and clamping. The rigid support rod constitutes the main framework for downward transmission of vibration. The fixed supports 520 are circumferentially and uniformly arranged at the outer edge of the vibrating plate 440 and have first bent edges formed at the bottom thereof for the guide plate 530 to inhibit the warping of the guide plate 530 during driving.

[0072] The top end and the two side surfaces of the upper part of the pile head clamping jaw 540 are respectively provided with similar notches. One of the notches is in sliding fit with the arc-shaped travel hole on the driving plate 510, and the other notch is in sliding fit with the strip-shaped hole on the guide plate 530 in the same way. This allows the pile head clamping jaw 540 to smoothly slide along a specific trajectory while adapting to the clamping action, and provides reliable rigid support for the pile head clamping jaw 540, thereby ensuring that the excitation force from the vibration mechanism 400 can be effectively transmitted to the pile head along the axial direction.

[0073] The telescopic mechanism 600 is arranged as a parallel structure of multiple oil cylinders, the fixed ends of which are connected with the fixed supports 520 of the centering and clamping mechanism 500 respectively, and the telescopic ends are connected with the secondary slide table 700 to form the Z2 axial feeding independent of the main slide carriage 100. The telescopic mechanism 600 can be judged to be in place and protected by force limiting through the stroke detection element and the pressure control element. The secondary slide table 700 is provided with a through hole in the middle for accommodating the pipe pile and is provided with a hollow rotating device 800 at the lower end surface. The output end of the hollow rotating device 800 is coaxially connected with the drilling mechanism 900 to drive the rotation of the drilling mechanism 900 and bear the axial load.

[0074] The drilling mechanism 900 comprises an annular drill ring 910, multiple drill tooth assemblies 920, a hollow drill bit assembly 930, a protective sleeve 950, an output plate 960, a driven plate 970 and multiple variable-diameter reaming assemblies 940. The output plate 960 is connected with the output end of the hollow rotating device 800 and serves as an upstream driving member of the poking member. The driven plate 970 is located below the output plate 960 and is connected with the driving ends of the multiple variable-diameter reaming assemblies 940. The multiple variable-diameter reaming assemblies 940 are uniformly distributed in the circumferential direction of the annular drill ring 910 and are in radial sliding fit with the drill ring 910. The top of the protective sleeve 950 is connected with the fixed part of the hollow rotating device 800, and the bottom thereof forms a first bent edge bent inward. The first bent edge extends towards the bent protrusions arranged in the circumferential direction on the upper end surface of the driven plate 970 and is located below the bent protrusions and in sliding fit relationship therebetween. The bent protrusions form an axial supporting surface of the driven plate 970 above the first bent edge, so that the driven plate 970 is axially limited and constrained in a freely rotatable state to prevent axial movement under the conditions of stress or vibration. The bent protrusions can be L-shaped, T-shaped or hook-shaped plate members, and in the embodiment, the L-shaped plate members are preferred. In order to simplify the drawing, the first bent edge and the bent protrusions are not shown in detail. The hollow rotating device 800 is a hollow shaft servo motor or an RVM series hollow hydraulic motor, and the hollow hole diameter is Ø650mm (for passing through a pipe pile with a diameter of Ø600mm).

[0075] The multiple drill tooth assemblies 920 are arranged in the circumferential direction. The top of the drill tooth assembly 920 is connected with the annular drill ring 910, and the bottom thereof is connected with the hollow drill bit assembly 930.

[0076] The variable-diameter reaming assembly 940 comprises a first sliding rod 941, a stop block, a poking block 943, a reset spring and a reaming drill tooth 942. The outer end of the first sliding rod 941 is provided with the reaming drill tooth 942, and the inner end thereof is provided with the stop block. An arc-shaped stroke hole is formed on the driven plate 970. The poking block 943 is connected with the output plate 960 and is located in the arc-shaped stroke hole. Under the forward driving condition of the output plate 960, the poking block 943 pokes the first sliding rod 941 along the arc-shaped stroke hole to complete the radial expansion. One end of the reset spring abuts against the stop block, and the other end thereof abuts against the inner wall of the arc-shaped stroke hole to reset the first sliding rod 941 under the reverse driving or shutdown of the output plate 960.

[0077] The hollow drill bit assembly 930 comprises a fixing ring 980, a hollow drill cylinder and a plurality of spiral protrusions, the upper end surface of the fixing ring 980 is connected with the bottom of the plurality of drill tooth assemblies 920, the hollow drill cylinder is coaxially sleeved outside the pile body and connected with the lower end surface of the fixing ring 980, the plurality of spiral protrusions are uniformly arranged along the circumference of the outer wall of the hollow drill cylinder to achieve soil crushing, lateral extrusion and upward feeding, the drill tooth assembly 920 adopts an inclined arrangement of drilling blades and a plurality of drilling teeth are uniformly arranged on the drilling blades to improve the cutting and crushing efficiency.

[0078] Working mode of the present example

[0079] “Z1 direction” is used to represent the downward pressing / lifting direction of the main slide 100 along the equipment axis, and “Z2 direction” is used to represent the feeding / retracting direction of the secondary slide 700 relative to the centering and clamping mechanism 500 along the equipment axis, both of which are parallel to the axis of the precast pile. As shown in FIG. 1, the positive directions of Z1 and Z2 respectively correspond to the movement directions of the main slide 100 pressing downward into the precast pile and the secondary slide 700 extending downward to the side of the pile end, and the corresponding “Z1 stroke” and “Z2 stroke” respectively represent the displacement amounts of the main slide 100 and the secondary slide 700 along the above directions. Figure 1

[0080] Step one: align the main slide 100 with the pile position axis, complete the equipment perpendicularity correction through the column guide, lock the reference, and make the equipment axis coincide with the designed pile position.

[0081] Step two: start the centering and clamping mechanism 500 to make the plurality of pile head clamping jaws 540 synchronously clamp the pile head along the arc-shaped hole of the driving plate 510, and realize guiding and limiting through the guide plate 530 and the first bent edge, and maintain coaxial clamping under the decoupling condition of the vibration mechanism 400 and the vibration isolation mechanism 300.

[0082] Step three: drive the main slide to press downward along the Z1 direction and link the vibration mechanism 400 to press in or vibrate in, so that the precast pile enters the designed depth interval and records the penetration force and stroke.

[0083] Step four: keep the clamping and coaxial relationship unchanged, drive the telescopic mechanism 600 to make the secondary slide 700 descend to the bottom expansion working position outside the pile end along the Z2 direction, and the plurality of variable-diameter reaming assemblies 940 are in the retracted state to avoid interference.

[0084] Step five: start the hollow rotating device 800 to drive the drilling mechanism 900 to rotate, the output plate 960 and the driven plate 970 are linked to make the plurality of variable-diameter reaming assemblies 940 synchronously expand along the radial direction, the reaming drill teeth 942 cut, extrude and ream the soil around the pile end, and the spiral protrusions on the outer wall of the hollow drill cylinder realize the lateral and upward feeding of the crushed materials, so as to obtain the enlarged head with the predetermined diameter and height.

[0085] ​Step six: after stopping rotation, the variable-diameter reaming assembly 940 is radially reset and retracted, the secondary slide 700 is driven to move upward and exit the bottom-expanding area, then the clamping is released and the main carriage 100 is lifted to complete the pile site construction.

[0086] Step seven: during the whole process, the construction parameters such as the Z1 and Z2 strokes, the variable-diameter expansion stroke, the rotation torque, the rotating speed and the like are recorded, so as to confirm the compliance of the bottom-expanding position and geometric size and to be used for quality acceptance and record keeping.

[0087] The above is only a preferred embodiment of the present application, and is not used to limit the present application, any modification, equivalent replacement, improvement and the like within the spirit and principle of the present application should be included in the protection scope of the present application.

Claims

1. An integrated device for precast pile implantation and base enlargement in a full replacement process, characterized in that: The main slide (100), the vibration isolation mechanism (300), the vibration mechanism (400), the centering and clamping mechanism (500), the telescopic mechanism (600), the secondary slide (700) and the drilling mechanism (900) are arranged in sequence from top to bottom along the same equipment axis; The centering and clamping mechanism (500) is used for coaxially clamping and positioning the precast pile below the equipment axis, the telescopic mechanism (600) and the secondary slide (700) are linked to drive the drilling mechanism (900) to switch between the retracted position and the working position at the axial position relative to the pile end under the condition that the centering and clamping mechanism (500) keeps the pile position unchanged; The drilling mechanism (900) is coaxially arranged around the central through hole of the secondary slide (700) and is driven to rotate by the hollow rotating device (800) below the secondary slide (700), and the drilling mechanism (900) performs hole expansion / bottom expansion operation around the pile end in the working position; The drilling mechanism (900) includes an annular drill ring (910), a hollow drill bit assembly (930), a protective sleeve (950), an output plate (960), a driven plate (970), a plurality of drill tooth assemblies (920) and a plurality of variable-diameter hole expansion assemblies (940); The output plate (960) is connected with the output end of the hollow rotating device (800), the driven plate (970) is located below the output plate (960), a plurality of the variable-diameter hole expansion assemblies (940) are uniformly arranged in the circumferential direction and are in sliding fit with the drill ring (910), and the driving end of the variable-diameter hole expansion assembly (940) is connected with the driven plate (970); the top of the protective sleeve (950) is connected with the fixed part of the hollow rotating device (800), and the bottom of the protective sleeve (950) is provided with a first bent edge; The upper end surface of the driven plate (970) is uniformly provided with a plurality of bent protrusions in the circumferential direction, the first bent edge extends towards the bent protrusions and is located below the bent protrusions and in sliding fit relationship with the bent protrusions; The bent protrusions form an axial supporting surface of the driven plate (970) above the first bent edge, so that the driven plate (970) is axially limited and constrained in a freely rotatable state, preventing it from moving along the axial direction under the action of force or vibration; A plurality of the drill tooth assemblies (920) are uniformly arranged in the circumferential direction, the top of the drill tooth assembly (920) is connected with the annular drill ring (910), and the bottom of the drill tooth assembly (920) is connected with the hollow drill bit assembly (930); The variable-diameter reaming assembly (940) comprises a first sliding rod (941), a stop block, a shifting block (943), a return spring and a reamer tooth (942); the outer end of the first sliding rod (941) is provided with the reamer tooth (942), and the inner end is provided with the stop block; the driven plate (970) is provided with an arc-shaped stroke hole; the shifting block (943) is connected with the output plate (960) and located in the arc-shaped stroke hole; when the output plate (960) is driven in the forward direction, the shifting block (943) is used to drive the first sliding rod (941) to slide radially; one end of the return spring abuts against the stop block, and the other end abuts against the inner wall of the arc-shaped stroke hole; when the output plate (960) is driven in the reverse direction, the first sliding rod (941) is reset and retracted.

2. The integrated device for implanting and expanding the bottom of a precast pile for a total replacement process according to claim 1, wherein: The hollow drill bit assembly (930) comprises a fixing ring (980), a hollow drill cylinder and a plurality of spiral protrusions; the upper end surface of the fixing ring (980) is connected with the bottom of the drill tooth assembly (920); the hollow drill cylinder is coaxially sleeved outside the pile body and connected with the lower end surface of the fixing ring (980); and the plurality of spiral protrusions are uniformly arranged on the outer wall of the hollow drill cylinder to achieve soil crushing and external extrusion conveying. The drill tooth assembly (920) comprises obliquely arranged drilling blades and a plurality of drilling teeth arranged thereon.

3. The integrated equipment for precast pile implanting and bottom expanding of total replacement process according to any one of claims 1-2, characterized in that: The centering and clamping mechanism (500) comprises a driving plate (510), a guide plate (530), a plurality of fixed supports (520), a plurality of pile head clamping jaws (540) and a plurality of rigid supporting rods; the driving plate (510) is provided with an arc-shaped hole for driving the upper end of the pile head clamping jaw (540); the guide plate (530) is provided with a strip-shaped hole matched with the upper part of the pile head clamping jaw (540); and the lower end of the pile head clamping jaw (540) has a second bent edge matched with the pile head. The rigid supporting rod is located between the driving plate (510) and the vibrating plate (440) of the vibrating mechanism (400) and is in sliding cooperation with the driving plate (510) through a roller, so as to limit the non-axial deviation of the driving plate (510) while centering and clamping.

4. The integrated device for pile implanting and expanding bottom of full replacement process according to claim 3, characterized in that: The vibrating mechanism (400) comprises a vibrating plate (440), a plurality of electromagnetic vibrators (410) and a plurality of limiting guide assemblies. The plurality of electromagnetic vibrators (410) and the plurality of limiting guide assemblies are circumferentially and uniformly arranged between the lower fixed plate (320) of the vibration isolation mechanism (300) and the vibrating plate (440); the fixed part of the electromagnetic vibrator (410) is connected with the lower end surface of the lower fixed plate (320); and the output end of the electromagnetic vibrator (410) is provided with a hammering block for hitting the first annular protrusion (450) of the upper end surface of the vibrating plate (440); The limiting guide assembly comprises a second sliding rod (430) and a limiting support (420); the limiting support (420) is L-shaped; the second sliding rod (430) is in sliding cooperation with the bent part of the limiting support (420); and the bottom of the second sliding rod (430) is provided with a limiting block.

5. The integrated precast pile implanting and expanding device for total replacement process according to claim 3, characterized in that: The vibration isolation mechanism (300) comprises an upper fixed plate (310), a lower fixed plate (320), a rubber buffer assembly (330), a plurality of hydraulic rods (350) and a plurality of elastic buffer assemblies (340); The rubber buffer assembly (330) is arranged in the middle region between the upper fixed plate (310) and the lower fixed plate (320), and is coaxially arranged with the central axis of the device; The rubber buffer assembly (330) comprises an inner rubber sleeve, an outer rubber sleeve, a first pad plate, a second pad plate, a plurality of rubber pads and a plurality of steel plates; The inner rubber sleeve is located at the center of the rubber buffer assembly (330), and its axis is coaxially arranged with the driving shaft assembly (210) to define the inner diameter of the rubber buffer assembly (330) and provide a channel for the driving shaft assembly (210) to pass through; A plurality of rubber pads and a plurality of steel plates are alternately stacked around the outer wall of the inner rubber sleeve in the axial direction to form a buffer stack; The outer rubber sleeve is sleeved outside the buffer stack to form a circumferential containment constraint structure for limiting the outer diameter of the buffer stack, so that the buffer stack maintains a stable shape when compressed in the axial direction; The first pad plate is arranged at the top of the buffer stack and is attached to the lower end surface of the upper fixed plate (310), and the second pad plate is arranged at the bottom of the buffer stack and is attached to the upper end surface of the lower fixed plate (320); The hydraulic rods (350) and the elastic buffer assemblies (340) are uniformly distributed along the circumference, and the elastic buffer assemblies (340) are sleeved outside the hydraulic rods (350).

6. The integrated device for pile implanting and expanding bottom of full replacement process according to claim 3, characterized in that: The telescopic mechanism (600) comprises a plurality of oil cylinders, the fixed ends of the oil cylinders are respectively connected with the fixed supports (520) of the centering and clamping mechanism (500), and the telescopic ends of the oil cylinders are connected with the secondary sliding table (700) for adjusting the axial working position of the drilling mechanism (900) relative to the pile end.

7. The integrated precast pile implanting and expanding device for total replacement process according to claim 1, characterized in that: The main carriage (100) is provided with a servo motor (200), the output end of the servo motor (200) is connected with the driving plate (510) of the centering and clamping mechanism (500) through a driving shaft assembly (210), and the driving shaft assembly (210) penetrates the vibration isolation mechanism (300) in sequence; The driving shaft assembly (210) comprises an output shaft, an output sleeve and a mounting sleeve, the output shaft is connected with the servo motor (200) and is in sliding fit with the output sleeve, the output sleeve is connected with the driving plate (510) through the mounting sleeve, and the output shaft and the driving plate (510) are connected in spline or toothed connection.

8. A method for precast pile implantation and bottom expansion under the full replacement process, characterized in that: When using the full replacement process precast pile implantation and expansion integrated device according to any one of claims 1-7, the construction method comprises the following steps: Step one: align the main carriage (100) of the pile implantation and expansion integrated device with the pile axis, and complete the perpendicularity correction through the column guide; Step two: start the centering and clamping mechanism (500) of the device to clamp the pile head, so that the pile shaft is coaxial with the device axis, and the coaxial clamping is maintained under the decoupling condition of the vibration mechanism (400) and the vibration isolation mechanism (300); Step three: drive the main carriage (100) to press down along the Z1 direction and drive the vibration mechanism (400) to press in or vibrate, so that the precast pile enters the design depth interval; Step four: keep the clamping and coaxial relationship unchanged, drive the telescopic mechanism (600) to make the secondary slide table (700) go down along the Z2 direction to the bottom expansion working position outside the pile end, and the variable diameter reaming assembly (940) remains in the folded state; Step five: start the hollow rotating device (800) to drive the drilling mechanism (900) to rotate, which includes an annular drill ring (910), a hollow drill bit assembly (930), a protective sleeve (950), an output plate (960), a driven plate (970), a plurality of drill tooth assemblies (920), and a plurality of variable diameter reaming assemblies (940); During rotation, through the linkage of the output plate (960) and the driven plate (970), the plurality of variable diameter reaming assemblies (940) are radially expanded, driving the reaming teeth (942) to cut, extrude and ream the soil around the pile end to form an enlarged head; Step six: after stopping rotation, make the variable diameter reaming assembly (940) radially reset and fold, drive the secondary slide table (700) to go up and exit the bottom expansion area, then release the clamping and lift the main carriage (100) to complete the pile construction; Step seven: record the Z1 travel, Z2 travel, and expansion travel, as well as construction parameters such as rotation torque and speed, to confirm the compliance of the bottom expansion position and geometric size and for quality acceptance; Through the continuous operation of the above steps on the same device axis, the pile implantation and bottom expansion are completed under unified geometric reference and positioning control, thereby reducing the pile position deviation, hole bottom disturbance and positioning deviation caused by process switching, and improving the consistency of the enlarged head formation and the pile foundation bearing performance.

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