Guide hole expanding implantable precast pile mechanism convenient to mount and mounting method

Abstract

The invention relates to the technical field of pile foundation construction, and discloses a guide hole expanding implantable precast pile mechanism convenient to install and an installation method.The mechanism comprises a pile body vertically arranged in a guide hole, an inner grouting cavity is formed in the top end of the pile body in the length direction of the pile body, a reducing area is arranged in the middle of the pile body, and a conical guide shoe is arranged at the bottom end of the pile body; telescopic grooves are formed in the four sides of the outer wall of the bottom end of the pile body, supporting and locking mechanisms are arranged in the telescopic grooves, lateral supporting wings are inserted into the telescopic grooves, the supporting and locking mechanisms lock the relative positions of the lateral supporting wings and the pile body, the outer walls of the lateral supporting wings on the four sides abut against the hole wall of the guide hole, and the pile body is kept in a vertical state all the time. Through the arrangement of the lateral supporting wings and the supporting locking mechanism, under the complex geological condition that frozen soil is mixed with an ice layer, the pile body keeps vertical penetration in the whole process, the pile head is complete and free of fragmentation, the stress distribution of the pile body is balanced, and the construction problems of pile breakage, deflection and the like in the cold region are thoroughly solved.

Description

TECHNICAL FIELD

[0001] The present application relates to the field of pile foundation construction, more particularly, it relates to an expansion hole implantation type prefabricated pile mechanism and installation method convenient to install. BACKGROUND

[0002] The cold regions in China are widely distributed, and the foundation engineering construction in the cold regions mainly uses bored piles and traditional prefabricated pile construction technology. The expansion hole implantation prefabricated pile construction technology is an innovative pile foundation construction method, which has many advantages compared with the traditional prefabricated pile construction technology and the bored pile construction technology. In some complex geological conditions in the cold regions, by pre-expanding a hole, the pile is constructed by using the hammering method, which can effectively reduce the damage of the pile body, better penetrate the medium-coarse sand layer, improve the single pile bearing capacity, speed up the construction progress, and ensure the engineering quality.

[0003] In the construction in the cold regions, the pile body is affected by the ice layer in the frozen soil during the hammering of the pile body, causing the pile body to be deflected, and when the pile head part is impacted, the pile head may be broken. Meanwhile, the traditional steel pile cap and the concrete pile head joint have a stiffness mutation, and when the ice layer is mixed in the frozen soil, the hammering stress will form a shear force at the interface, causing the problem of broken pile. SUMMARY

[0004] The present application provides an expansion hole implantation type prefabricated pile mechanism and installation method convenient to install, which solves the technical problem of pile body breakage caused by the ice layer in the process of implanting the pile body in the construction in the cold regions in the related art.

[0005] The present application provides an expansion hole implantation type prefabricated pile mechanism convenient to install, which comprises a pile body vertically arranged in an expansion hole, an inner grouting cavity is formed in the pile body from the top end along the length direction of the pile body, a variable diameter zone is arranged at the middle part of the pile body, and a conical guide shoe is arranged at the bottom end of the pile body. Expansion slots are formed on the four sides of the outer wall of the bottom end of the pile body, a support locking mechanism is arranged in the expansion slots, a lateral support wing is inserted into the expansion slots, a connecting column is connected to the inner wall of the lateral support wing, a push plate is arranged on the side of the connecting column close to the inner grouting cavity, and the outer edge of the push plate is slidingly connected in the expansion slot. The support locking mechanism comprises a pushing ring, a support spring and a pin column, a columnar groove is formed in the groove wall of the telescopic groove, the support spring is sleeved on the end of the pin column, and the support spring and the pin column are both inserted into the columnar groove; a ring of guide grooves is arranged on the periphery of the pushing ring, the guide grooves are in the shape of right-angled trapezoidal structure, in the initial state, the end of the pin column away from the support spring abuts against the groove bottom of the guide groove, a column hole is formed on the periphery of the push plate, the hole diameter of the column hole is consistent with the outer diameter of the pin column, when the push plate drives the pushing ring to move, the pin column continuously slides along the groove shape of the guide groove until the pin column is inserted into the column hole, the relative position between the locking lateral support wing and the pile body is locked, and the outer wall of the lateral support wing on four sides abuts against the hole wall of the lead hole, so that the pile body always maintains a vertical state. A prestressed steel strand is arranged on the inner wall of the pile body, and the prestressed steel strand is distributed in the pile body in a double helix structure; and a self-temperature-control electric heating wire is embedded in the prestressed steel strand.

[0006] Further, the variable-diameter zone comprises a stress buffer cavity and a variable-diameter reinforcing rib, the variable-diameter reinforcing rib is arranged on the inner wall of the cavity at both ends of the stress buffer cavity, the variable-diameter reinforcing rib is in an annular structure, and a plurality of groups of variable-diameter reinforcing ribs are arranged in parallel on the variable-diameter zone.

[0007] Further, the lateral support wing is in an arc-shaped plate structure, the bottom end of the lateral support wing is a pointed end, the pointed end is provided with a cutting edge, the connection angle between the lateral support wing and the connecting column is between 5° and 10°, and the pointed end of the lateral support wing faces the conical guide shoe.

[0008] Further, an inner support cylinder is arranged at the corresponding position of the stress buffer cavity of the inner grouting cavity, and is used for compensating for the cross-section loss of the pile body in the variable-diameter zone.

[0009] Further, an insulating layer is arranged outside the embedded self-temperature-control electric heating wire, and the end of the prestressed steel strand extends out of the cavity of the inner grouting cavity.

[0010] Further, the pile cap further comprises a detachable pile cap, an anti-shearing key is arranged in the middle of the inner wall of the bottom end of the pile cap, the anti-shearing key is a four-way support, and the anti-shearing key is inserted into the port of the inner grouting cavity of the pile body.

[0011] Further, the top end of the pile body is provided with a pile head ring, and a buffer layer is arranged at the connection position of the pile head ring and the pile body.

[0012] Further, the pile cap comprises a pile cap top layer and a pile cap middle layer, the pile cap middle layer is embedded in the pile cap top layer, the pile cap top layer is used for absorbing instantaneous impact, and the pile cap middle layer is a honeycomb steel plate and is used for uniformly dispersing stress.

[0013] Further, a hard alloy cutting edge is annularly arranged on the conical guide shoe, and the hard alloy cutting edge is in a zigzag shape.

[0014] The application further provides a method for installing the expanding-hole implantation type prefabricated pile mechanism, which comprises the following steps: S100, hole positioning: a hole is formed by using a rotary drilling machine, and the soil in the pit is continuously cleaned from the hole; and after forming, a gravel layer is laid at the bottom of the hole; S200, pile hoisting and sinking: the hoisting point is arranged on the pile body, a double-hook balance system is adopted, the conical guide shoe is aligned with the hole position and then uniformly sunk, the cutting edge of the conical guide shoe is used to cut the soil layer, and the verticality is monitored in real time; S300, lateral support wing unfolding: the cement slurry is injected into the inner grouting cavity at high pressure, the liquid level of the cement slurry is below the variable-diameter area, the slurry pushes the push plate to displace outward, and the slurry drives the connecting column to pop out and fit to the hole wall of the hole; The push plate is first combined with the end surface of the push ring, then the continuous displacement of the push plate extrudes the push ring, the inclined surface of the guide groove forces the pin column to compress the support spring, when the push plate moves to the position where the column hole is aligned with the pin column, the support spring releases the push pin column to be inserted into the column hole, and mechanical self-locking is formed; S400, pile cap installation: after the floating slurry on the top of the pile is removed, the epoxy interface agent is brushed, and the shear-resistant key is pressed into the inner grouting cavity port; S500, graded hammer sinking: the hammering energy is buffered by the top elastic body of the pile cap, transmitted to the honeycomb steel plate and uniformly dispersed, and then transmitted through the shear-resistant key; S600, pile end grouting reinforcement: cement slurry is injected through the reserved hole between the hole wall of the hole and the outer wall of the pile body, and a bearing layer is formed at the variable-diameter area; the slurry leaks out from the root of the lateral support wing, and is solidified to form a pull-out rib plate; micro-expanding slurry is continuously injected through the inner grouting cavity to fill the internal inner support cylinder; S700, intelligent temperature control system starts: after the pile sinking is completed, the self-control temperature electric heating wire is immediately started, is automatically started at-5 DEG C, maintains the temperature of the soil around the pile, and continuously monitors until the slurry is finally set.

[0015] The application has the following beneficial effects: The conical guide shoe cooperates with the four-way unfolded lateral support wing to form mechanical self-locking anchoring, a stable guiding frame is constructed in the frozen soil, the pile body is ensured to vertically penetrate the ice layer during hammer sinking, the detachable pile cap absorbs the rigid impact of the frozen soil through the elastic top layer, the stress is uniformly dispersed in the middle layer of the honeycomb steel plate, the stiffness mutation at the junction of the traditional steel pile cap and the concrete is eliminated, the shear fracture is avoided, the double-helix electric heating system intelligently maintains the positive temperature of the pile-soil interface, blocks the path of the frost heaving force, guarantees the continuous and effective side friction resistance, the stress buffer cavity in the variable-diameter area absorbs the reflected stress wave, and the gradual pressure conversion mechanism of the shear-resistant key, so that the repeated hammering load in the frozen soil is smoothly conducted to the bearing layer.

[0016] In summary, under the complex geological conditions of frozen soil mixed with ice layer, the pile body keeps vertical penetration throughout the whole process, the pile head is complete without fragmentation, and the stress distribution of the pile body is balanced, thus completely solving the construction difficulties such as broken pile and deflection in cold regions. BRIEF DESCRIPTION OF DRAWINGS

[0017] Figure 1 is a structural schematic view of a convenient-to-install expanding hole implantation type precast pile mechanism of the present application; Figure 2 is a front view of the Figure 1 of the present application; Figure 3 is an A-A cross-sectional structural schematic view of the Figure 2 of the present application; Figure 4 is an enlarged view of partial B in the Figure 3 of the present application; Figure 5 is an installation flowchart of a convenient-to-install expanding hole implantation type precast pile mechanism of the present application (in the figure, a, b, c and d respectively correspond to S100, S300, S500 and S600 in the installation method); Figure 6 is a structural schematic view of a lateral support wing supporting in a hole wall of an expanding hole of a convenient-to-install expanding hole implantation type precast pile mechanism of the present application.

[0018] In the figure: 100, pile body; 110, stress buffer cavity; 120, variable-diameter reinforcing rib; 130, conical guide shoe; 140, pile head ring; 150, inner support cylinder; 160, inner grouting cavity; 170, prestressed steel strand; 200, lateral support wing; 210, connecting column; 220, push plate; 300, pile cap; 310, shear-resistant key; 400, support locking mechanism; 410, push ring; 420, support spring; 430, pin column; 440, column hole; 500, expanding hole; 600, bearing stratum. DETAILED DESCRIPTION

[0019] The subject matter described herein will now be discussed with reference to example implementations. It should be understood that the discussion of these implementations is merely meant to provide a better understanding of the subject matter described herein and can be changed in function and arrangement without departing from the scope of the present description. Various examples can omit, substitute, or add various procedures or components as appropriate. Also, features described with respect to some examples can be combined in other examples.

[0020] As Figures 1-6As shown, a convenient-to-install expanding-hole implantable precast pile mechanism, comprising a pile body 100, the pile body 100 is in a cylindrical structure, the pile body 100 is provided with an internal grouting cavity 160 along the length direction of the pile body 100 from the top end, the middle part of the pile body 100 is provided with a variable-diameter area, the variable-diameter area comprises a stress buffer cavity 110 and a variable-diameter reinforcing rib 120, the variable-diameter reinforcing rib 120 is arranged on the inner wall of both ends of the cavity of the stress buffer cavity 110, the variable-diameter reinforcing rib 120 is in an annular structure, a plurality of groups of variable-diameter reinforcing ribs 120 are arranged in parallel on the variable-diameter area, the plurality of groups of variable-diameter reinforcing ribs 120 are arranged in a trapezoidal shape, a conical guide shoe 130 is arranged at the bottom end of the pile body 100, the conical guide shoe 130 is annularly distributed with a hard alloy cutting edge, the hard alloy cutting edge is in a zigzag shape (the tooth depth is 5mm, and the tooth pitch is 20mm), the surface of the cutting edge is nitrided (the hardness is ≥1200HV), and the rock breaking capacity is improved by 3 times; It should be noted that the stress buffer cavity 110 absorbs the reflected energy of the hammering stress wave, the variable-diameter reinforcing rib 120 arranged in a trapezoidal shape is used for improving the circumferential strength of the variable-diameter area in the pile body 100, the variable-diameter area is used for reducing the risk of cracking of the pile body during hammering, providing space for grouting of the expanding head, and forming a bearing layer 600; A telescopic groove is arranged on each of the four sides of the outer wall of the bottom end of the pile body 100, a support locking mechanism 400 is arranged in the telescopic groove, a lateral support wing 200 is inserted into the telescopic groove, the inner wall of the lateral support wing 200 is connected with a connecting column 210, a push plate 220 is arranged on one side of the connecting column 210 close to the internal grouting cavity 160, and the outer edge of the push plate 220 is slidingly connected in the telescopic groove; A column hole 440 is arranged on the periphery of the push plate 220, and the hole diameter of the column hole 440 is consistent with the outer diameter of the pin column 430; The support locking mechanism 400 comprises a pushing ring 410, a support spring 420 and a pin column 430, a column groove is arranged in the groove wall of the telescopic groove, the support spring 420 is sleeved on the end of the pin column 430, and the support spring 420 and the pin column 430 are both inserted into the column groove, a guide groove is arranged on the periphery of the pushing ring 410, Figure 4 As shown, the guide groove is in a right-angled trapezoidal structure, in the initial state, the end of the pin column 430 away from the support spring 420 abuts against the groove bottom of the guide groove; When the push plate 220 is pushed, the pin column 430 slides along the groove shape of the guide groove, and finally the pin column 430 is inserted into the column hole 440; The groove shape of the guide groove is two stages. In the initial state, the bottom end of the pin column 430 abuts against the bottommost end. As the push ring 410 moves, the pin column 430 continuously compresses the supporting spring 420 and is inserted into the column groove. When the pin column 430 abuts against the end of the guide groove, the pin is completely compressed into the column groove. When the push ring 410 continues to move, the supporting spring 420 resets to push the pin column 430 out of the column hole 440, locking the structure of the push plate 220 connected by the pile body 100 and the lateral support wing 200. At this time, the outer wall of the lateral support wing 200 is tightly attached to the hole wall of the guide hole 500. The outer wall of the lateral support wing 200 is smooth, which facilitates the sliding of the lateral support wing 200 along the hole wall of the guide hole 500 downward when the pile body 100 is hammered, so as to maintain the perpendicularity when sliding along the hole wall during pile sinking; It needs to be supplemented that when the high-pressure grouting pushes the push plate 220, the push plate 220 extrudes the push ring 410. At this time, the pin column 430 slides along the slope on the groove shape of the guide groove to compress the spring. Finally, it is locked after aligning the column hole 440. There is no risk of hydraulic failure after locking. The polytetrafluoroethylene coating on the surface of the pin column 430 ensures smooth operation at low temperature; The lateral support wing 200 is an arc-shaped plate structure. The bottom end of the lateral support wing 200 is a sharp end, which is provided with a cutting edge. The connection angle between the lateral support wing 200 and the connecting column 210 is between 5° and 10°. The sharp end of the lateral support wing 200 faces the conical guide shoe 130, which facilitates the insertion of the lateral support wing 200 into the soil in the pit body to form a four-way anchoring structure, i.e., after unfolding, it forms an 80°-85° angle with the axis of the pile body 100 to form an optimal anti-pulling tooth key; The inner support cylinder 150 is arranged at the corresponding position of the stress buffer cavity 110 in the inner grouting cavity 160, which is used to compensate for the cross-sectional loss of the pile body 100 in the variable diameter area; The prestressed steel strand 170 is arranged on the inner wall of the pile body 100. The prestressed steel strand 170 is arranged in a double helix structure in the pile body 100. The self-controlled temperature electric heating wire is embedded in the prestressed steel strand 170, which is covered with an insulating layer. The end of the prestressed steel strand 170 extends out of the cavity of the inner grouting cavity 160, which is used to connect an external power supply. A waterproof socket (IP68 level) is pre-embedded, and an external 36V safe voltage is connected. The double helix structure makes the axial temperature difference ≤2℃ / m and the circumferential temperature difference ≤1℃; When the self-controlled temperature electric heating wire automatically starts heating below -5℃, it prevents the freezing of the soil around the pile and maintains the temperature of the pile-soil interface >0℃ to avoid the frost heaving force weakening the side friction; It also includes a detachable pile cap 300. The inner wall of the bottom end of the pile cap 300 is provided with an anti-shearing key 310 in the middle. The anti-shearing key 310 is a four-way support. The anti-shearing key 310 is inserted into the port of the inner grouting cavity 160 of the pile body 100. The top end of the pile body 100 is provided with a pile head ring 140. A buffer layer is arranged at the connection between the pile head ring 140 and the pile body 100; The pile cap 300 comprises a pile cap top layer and a pile cap middle layer, the pile cap middle layer is embedded in the pile cap top layer, the pile cap top layer is used for absorbing instantaneous impact, the pile cap top layer is made of elastic material, and the pile cap middle layer is a honeycomb steel plate and is used for uniformly dispersing stress and reducing the risk of concrete fragmentation of the pile head; In particular, the pile cap top layer can buffer the rigid impact of the frozen soil layer and avoid low-temperature brittle failure, and meanwhile, the pile cap 300 can be quickly replaced after damage, thereby reducing maintenance cost.

[0021] In the hammering stress concentration area, the pile cap 300 is arranged to solve the problem of insufficient tensile strength of concrete caused by stress wave reflection and superposition during hammering of the traditional flat pile, and the internal shear-resistant key 310 converts the destructive shear force into controllable pressure, thereby realizing reliable shear force transmission between the pile and the pile cap 300, and especially ensuring the safety of the structure under repeated loads of frost heaving in cold regions. In an embodiment of the present application, a method for installing the expanded-hole implantation type prefabricated pile mechanism is also provided, and the method comprises the following steps: S100, hole 500 positioning: a rotary drilling machine is used to form the hole 500, the hole diameter of the hole 500 needs to be greater than the pile diameter 100 mm (including the maximum outer diameter of the tapered boot 130), the soil in the pit is continuously cleaned during the formation of the hole 500, and a 200 mm thick graded gravel layer is laid at the bottom of the hole after the formation, so as to prevent damage of the hard alloy blade during pile sinking; S200, hoisting and pile sinking: the hoisting point is arranged at the upper 1 / 4 of the pile body 100, a double-hook balance system is adopted, the tapered boot 130 is aligned with the hole position and then is uniformly sunk, the blade is used to cut the soil layer, and the verticality is monitored in real time (deviation ≤0.5% of the pile length); S300, expansion of the lateral support wing 200: the cement slurry is high-pressure injected through the internal grouting cavity 160 (pressure ≥8MPa), the liquid level of the cement slurry is located below the variable-diameter area, the slurry pushes the push plate 220 to displace outward, drives the connecting column 210 to eject the lateral support wing 200 to be attached to the hole wall of the hole; When the push plate 220 is pushed, the push plate 220 is first combined with the end face of the push ring 410, then the continuous displacement of the push plate 220 extrudes the push ring 410, the inclined surface of the guide groove forces the pin column 430 to compress the support spring 420, when the push plate 220 moves to the position where the column hole 440 is aligned with the pin column 430, the support spring 420 releases the push pin column 430 to be inserted into the column hole 440, and mechanical self-locking (pull-out force ≥200kN) is formed; At this time, the pile body 100 is balanced and supported by the four lateral support wings 200, is always in a vertical structure, and is perpendicular to the horizontal plane and located in the plumb direction; S400, installation of the pile cap 300: after the pile top floating slurry is removed, the epoxy interface agent is brushed, the shear-resistant key 310 is pressed into the internal grouting cavity 160 port (fitting tolerance ≤0.3mm), and the hammering height of the pile cap top layer is controlled to be ≤1m (to avoid plastic deformation of the honeycomb steel plate). S500, hierarchical hammering pile sinking: hammering energy is buffered by the elastomer on the top layer of the pile cap, uniformly dispersed by the honeycomb steel plate, and then transmitted by the shear-resistant key 310; S600, pile tip grouting reinforcement: High-pressure grouting: cement slurry is injected through the reserved channel between the hole wall of the guide hole 500 and the outer wall of the pile body 100 (pressure 15 MPa), forming an enlarged head with a diameter ≥1.2m at the variable diameter area, and the enlarged head is the bearing layer 600 (slurry penetration radius 0.8m); Side wing grouting: the slurry covers the lateral support wing 200, and solidification forms a pull-out rib plate, the grouting pressure is reduced to 8MPa, and at the same time, internal compensation grouting is also carried out synchronously (to prevent the opening of the locking mechanism); Internal cavity compensation grouting: continuously inject micro-expanding slurry into the internal grouting cavity 160 to fill the internal support cylinder 150 (expansion rate 0.03%); S700, intelligent temperature control system starts: immediately after the pile sinking is completed, the self-controlled temperature electric heating wire is turned on, and it is automatically started at-5℃, maintaining the soil around the pile ≥2℃ (to prevent frost heaving from weakening the frictional resistance), the double helix structure of the prestressed steel strand 170 ensures uniform heat diffusion (temperature difference ≤3℃), and continuous monitoring is carried out until the slurry is finally set (generally 72 hours).

[0022] The embodiments of the present application are described above, but the present application is not limited to the above specific embodiments, and the above specific embodiments are only illustrative and not limiting, and those skilled in the art can make many forms under the inspiration of the present application, which all belong to the protection of the present application.

Claims

1. A prefabricated pile mechanism with expanded hole and implantable structure that is easy to install, characterized in that: The pile body comprises a pile body vertically arranged in a guide hole, an inner grouting cavity is opened along the length direction of the pile body from the top, a diameter-changing area is provided in the middle of the pile body, and a conical guide shoe is provided at the bottom end of the pile body; A telescopic groove is provided on all four sides of the outer wall of the bottom end of the pile body, a support locking mechanism is arranged in the telescopic groove, a lateral support wing is inserted in the telescopic groove, the inner wall of the lateral support wing is connected to a connecting column, and a push plate is provided on the side of the connecting column close to the inner grouting cavity, and the outer edge of the push plate is slidably connected in the telescopic groove; The support locking mechanism includes a pushing ring, a supporting spring and a pin. A cylindrical groove is opened in the groove wall of the telescopic groove. The supporting spring is sleeved on the end of the pin. The supporting spring and the pin are both inserted in the cylindrical groove. A circle of guide groove is provided on the periphery of the pushing ring. The groove shape of the guide groove is a right-angled trapezoidal structure. In the initial state, one end of the pin away from the supporting spring is abutted and connected to the groove bottom of the guide groove. A column hole is opened on the periphery of the push plate. When the push plate drives the pushing ring to move, the pin continuously slides along the groove shape of the guide groove until the pin is inserted into the column hole, locking the relative position between the lateral support wing and the pile body. The outer walls of the lateral support wings on the four sides abut against the hole wall of the guide hole, so that the pile body always maintains a plumb state. Prestressed steel strands are arranged on the inner wall of the pile body. The prestressed steel strands are distributed in the pile body in a double helix structure. Self-temperature-controlling electric heating wires are embedded in the prestressed steel strands.

2. The easy-to-install prefabricated pile mechanism with expanded hole implantation according to claim 1, characterized in that: The variable diameter area includes a stress buffer cavity and variable diameter reinforcement ribs. The variable diameter reinforcement ribs are arranged on the inner walls of the stress buffer cavity at both ends. The variable diameter reinforcement ribs are annular structures. Several groups of variable diameter reinforcement ribs are arranged in parallel on the variable diameter area.

3. The easy-to-install prefabricated pile mechanism with expanded hole implantation according to claim 2, characterized in that: The lateral support wing is an arc-shaped plate structure, the bottom end of the lateral support wing is a tip with a cutting edge, the connection angle between the lateral support wing and the connecting column is between 5° and 10°, and the tip of the lateral support wing faces the conical guide shoe.

4. The easy-to-install prefabricated pile mechanism with expanded hole implantation according to claim 3, characterized in that: An inner support cylinder is provided in the inner grouting cavity at a position corresponding to the stress buffer cavity, for compensating for the cross-sectional loss of the pile body in the diameter-changing area.

5. The easy-to-install prefabricated pile mechanism with expanded hole implantation according to claim 4, characterized in that: An insulating layer is covered on the pre-buried self-temperature-controlling electric heating wire, and the end of the prestressed steel strand extends out of the inner grouting cavity.

6. The easy-to-install prefabricated pile mechanism with expanded hole implantation according to claim 5, characterized in that: It also includes a detachable pile cap, with an anti-shear key provided in the middle of the inner wall of the bottom end of the pile cap. The anti-shear key is a four-way support member and is inserted into the port of the inner grouting cavity of the pile body.

7. The easy-to-install prefabricated pile mechanism with expanded hole implantation according to claim 6, characterized in that: A pile head ring is provided at the top of the pile body, and a buffer layer is provided at the connection between the pile head ring and the pile body.

8. The easy-to-install prefabricated pile mechanism with expanded hole implantation according to claim 7, characterized in that: The pile cap includes a top layer and a middle layer. The middle layer is embedded in the top layer and is used to absorb instantaneous impact. The middle layer is a honeycomb steel plate and is used to evenly disperse stress.

9. The easy-to-install prefabricated pile mechanism with expanded hole implantation according to claim 8, characterized in that: There are carbide cutting edges distributed in a ring on the conical guide shoe, and the carbide cutting edges are serrated.

10. A method for installing a precast pile mechanism of a hole expansion type that is easy to install, for installing a precast pile mechanism of a hole expansion type that is easy to install as claimed in claim 9, characterized in that: The following steps are involved: S100, pilot hole positioning: Use a rotary drilling rig to drill the pilot hole, continuously clean the soil in the pit from the pilot hole, and after the hole is formed, lay a gravel layer at the bottom of the hole; S200, hoisting pile sinking: The lifting point is set on the pile body, and a double-hook balancing system is used. The conical guide shoe is aligned with the hole position and then sinks at a uniform speed. The conical guide shoe is used to cut the soil layer, and the verticality is monitored in real time; S300, lateral support wings unfold: Cement slurry is injected into the inner grouting cavity under high pressure. The slurry level is below the diameter-changing zone. The slurry pushes the push plate outward, driving the connecting column to push the lateral support wings out and fit them against the hole wall. The push plate first engages with the end face of the push ring, and then the push plate continues to move and squeeze the push ring. The inclined surface of the guide groove forces the pin to compress the support spring. When the push plate moves until the column hole is aligned with the pin, the support spring releases and pushes the pin into the column hole, forming a mechanical self-locking. S400, pile cap installation: clean the floating slurry on the pile top and apply epoxy interface agent, align the anti-shear key with the port of the inner grouting cavity and press it in; S500, staged hammer pile driving: The hammer energy is buffered by the elastomer on the top layer of the pile cap, transferred to the honeycomb steel plate for uniform dispersion, and then conducted through the shear bond pressure; S600, pile tip grouting reinforcement: Cement slurry is injected through the reserved channel between the borehole wall and the outer wall of the pile body to form a bearing layer in the diameter change area. The slurry seeps through the root of the lateral support wing and solidifies to form an anti-pullout rib. Micro-expansion slurry is continuously injected through the internal grouting cavity to fill the internal support tube. S700, intelligent temperature control system starts: After the pile is sunk, the self-controlling temperature heating wire is immediately turned on, automatically starting at -5°C to maintain the temperature of the soil around the pile, and continuously monitoring until the slurry is finally set.

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