Construction method of prefabricated hollow core reinforced pile with stretching wing

Abstract

This invention provides a construction method for precast hollow rigid piles with extendable wings, belonging to the field of precast hollow rigid pile construction. The method includes a rigid pile body, a hammer-limiting device, an impact bullet, and several extendable wings arranged in a circular array along the centerline of the rigid pile body. During construction, a hole is drilled in the ground, and grout is injected into the hole. The impact bullet is then inserted from the bottom of the rigid pile body upwards to the hollow bottom of the rigid pile body. The extendable wings are then temporarily fixed in an undeployed state. The rigid pile body with the temporarily fixed extendable wings is placed in the hole, with the grout covering the outer side of the rigid pile body. The hammer-limiting device is then used to repeatedly hammer the impact bullet at the bottom of the rigid pile body, causing the impact bullet to push the extendable wings located at the bottom of the rigid pile body to expand towards the outer wall of the rigid pile body, thereby achieving bottom expansion.

Description

Technical Field

[0001] This invention belongs to the field of precast hollow stiffened pile construction, and in particular relates to a construction method for precast hollow stiffened piles with extension wings. Background Technology

[0002] Pile foundations are a widely used form of deep foundation in civil engineering, used to transfer the load of the superstructure to deep soil or rock layers with good bearing capacity. Among the many types of piles, precast hollow piles (such as prestressed concrete pipe piles, PHC piles, hollow square piles, etc.) have been widely used in industrial and civil buildings, bridges, docks and other projects due to their significant advantages such as stable quality from factory production, fast construction speed, no mud pollution, and relatively economical cost.

[0003] In order to significantly improve the end bearing capacity of a single pile, reduce settlement, and make full use of the bearing capacity of deep bearing strata, the technology of enlarged-base piles is often used in engineering practice. Enlarged-base piles increase the pile-soil contact area by forming an enlarged head at the pile end with a diameter larger than that of the pile body, thereby greatly increasing the pile end resistance (which can be 50% or even higher than that of a straight pile of the same diameter).

[0004] However, existing enlarged-base piles are usually enlarged using mechanical reaming drill bits. Specifically, a special reaming drill bit (such as a hydraulic reaming drill bit or a mechanical linkage reaming drill bit) installed at the bottom of the drill rod is used to form an enlarged cavity at the bottom of the hole under the drive of the drilling rig. However, this method integrates the complex and cumbersome reaming mechanism into the precast pile or sinks it with the pile, which greatly increases the complexity of the pile structure and manufacturing cost, and may even affect the integrity of the pile structure. Summary of the Invention

[0005] In view of the shortcomings of the prior art described above, the purpose of this invention is to provide a construction method for precast hollow rigid piles with extension wings, which solves the problem that the base expansion mechanism in the prior art increases the complexity of the pile structure and the manufacturing cost.

[0006] To achieve the above and other related objectives, the present invention provides a construction method for precast hollow core reinforced piles with extendable wings, the construction method comprising:

[0007] Hole-forming steps: Drill holes in the ground and inject slurry into the holes;

[0008] Piling steps: Place the precast hollow rigid pile in the hole, wrap the precast hollow rigid pile with grout on the outside, and keep the hollow part of the precast hollow rigid pile dry.

[0009] Expansion step: Use a hammer limiting device to repeatedly hammer the impact bullet head at the bottom of the precast hollow rigid pile, so that the impact bullet head pushes the extension wing located at the bottom of the precast hollow rigid pile to unfold towards the outer wall of the precast hollow rigid pile.

[0010] As an optional solution, the precast hollow reinforced piles in the pile driving step include:

[0011] The rigid pile body has a first through hole penetrating its upper and lower end faces;

[0012] An expanded base unit is disposed at the bottom of the rigid pile body. The expanded base unit includes several extension wings, which are arranged in a circular array along the center line of the rigid pile body. The extension wings are triangular prisms in shape, and each extension wing is hinged to the lower end face of the rigid pile body. The rotation axis at the hinge of the extension wing is perpendicular to the center line of the rigid pile body.

[0013] When the extendable wings are not deployed, the lower end faces of the first through holes are closed by the plurality of the extendable wings;

[0014] During the process of the extension wing rotating to the unfolded state, the extension wing opens the lower end face of the first through hole, and the extension wing forms an enlarged bottom at the bottom end of the stiff pile body.

[0015] As an optional feature, the sidewalls of the extendable wing include a first sidewall, a second sidewall, and a third sidewall;

[0016] When the extension wing is not deployed, the third sidewall on the extension wing is flush with the outer sidewall corresponding to the rigid pile body, the first sidewall on one of the extension wings is in contact with the second sidewall on another adjacent extension wing, and the second sidewall on one of the extension wings is in contact with the first sidewall on another adjacent extension wing.

[0017] As an optional solution, a reinforcing bar is embedded at the junction of the first and second sidewalls of the extendable wing, with the upper end face of the reinforcing bar flush with the upper end face of the extendable wing and the lower end face of the reinforcing bar extending beyond the lower end face of the extendable wing.

[0018] As an optional feature, when the extendable wing is not deployed, the axis of rotation at the hinge of the extendable wing is at the same height as the upper surface of the extendable wing.

[0019] As an optional solution, in the bottom expansion step, the sidewall of the impact bullet head is sealed to the inner sidewall of the rigid pile body by a sealing ring, the head of the impact bullet head is conical, and the head of the impact bullet head is located at the lower end of the impact bullet head.

[0020] As an optional solution, in the bottom expansion step, the hammering limiting device includes a mounting block, a spring, a sliding block, an inner hammer, a connecting rope, and a hammer lifting block.

[0021] The mounting block is fixedly installed on the upper end face of the rigid pile body. The upper and lower end faces of the mounting block have a second through hole. The cross-sectional area of ​​the second through hole is the same as that of the first through hole, and the second through hole is connected to the first through hole.

[0022] The mounting block has a circular array of several springs along the center line of the rigid pile body. The lower end face of each spring is fixed to the upper end face of the mounting block. The lower end face of the sliding block has a groove. The upper end face of each spring is fixed to the upper end face of the groove. The mounting block is located in the groove. The sliding direction of the sliding block is consistent with the extension and retraction direction of the spring.

[0023] The upper and lower end faces of the sliding block are perforated by a third through hole. The cross-section of the third through hole is the same size as the cross-section of the second through hole, and the third through hole is connected to the second through hole.

[0024] One end of the connecting rope is fixedly connected to the upper end face of the inner hammer, and the other end of the connecting rope is fixedly connected to the lower end face of the hammer lifting block. When the inner hammer strikes the bullet head inside the rigid pile body, the hammer lifting block contacts the upper end face of the pressing sliding block.

[0025] As an option, the cross-section of the inner hammer is smaller than the cross-section of the first through hole.

[0026] As an optional solution, when the lifting hammer block contacts and presses against the sliding block, the outer wall of the lifting hammer block is flush with the outer wall of the sliding block.

[0027] As an optional configuration, when the inner hammer strikes the extension wing to the deployed state, the upper end face of the groove is in contact with the upper end face of the mounting block, the lower end face of the sliding block is flush with the lower end face of the mounting block, the distance from the upper end face of the impact bullet to the upper end face of the sliding block is a, the length of the connecting rope is b, the height of the inner hammer is c, and a = b + c.

[0028] As described above, the construction method of precast hollow stiffened piles with extension wings of the present invention has at least the following beneficial effects:

[0029] 1. The extension wings of the present invention are arranged in a circular array along the center line of the rigid pile body. After the rigid pile body with the extension wings temporarily fixed is placed in the hole, the extension wings rotate to the unfolded state when the base of the extension wings is expanded to increase the pile end resistance of the rigid pile body. The structure design is simple, the manufacturing cost is low, and the rigid pile body has good stability after construction.

[0030] 2. When sealing the lower end face of the first through hole, the present invention can first fill the bottom of the first through hole with the impact bullet head to seal the bottom of the first through hole, and then tie several steel bars together with iron wire so that all the extension wings are temporarily fixed in the state of sealing the lower end face of the first through hole. This ensures that when the extension wings are put into the hole with the stiff pile body, the extension wings extend into the hole with less resistance. After extending in, the inside of the first through hole remains dry, which facilitates the subsequent expansion of the bottom of the extension wings under the hammering of the inner hammer.

[0031] 3. In this invention, after the impact bullet is filled, the head of the impact bullet is located at the lower end of the impact bullet. The head of the impact bullet is conical, so that when the inner hammer strikes the impact bullet, the impact bullet rotates with the conical head of the impact bullet in contact with the extension wing when pushing the extension wing to unfold. That is, the distance between the force point of the extension wing and the axis of rotation of the extension wing is relatively long, so that the impact bullet can push the extension wing to rotate smoothly with a smaller force.

[0032] 4. After the inner hammer of the present invention strikes the impact bullet, the impact bullet expands the extension wing and remains in the first through hole. After the extension wing forms an enlarged bottom, the side wall of the impact bullet is still sealed with the side wall inside the first through hole, so that the grout will not flow into the first through hole from the bottom of the rigid pile body. Moreover, the impact bullet can keep the extension wing in the unfolded state to expand the bottom, and the extension wing will not rotate back to the unfurled state. The structural design is ingenious.

[0033] 5. Before the impact bullet head expands to the extended wing, the connecting rope is not fully taut when the lower end face of the inner hammer contacts the upper end face of the impact bullet head. At this time, the force on the spring is the weight of the lifting block and the connecting rope. The lower end face of the sliding block is higher than the lower end face of the mounting block under the support of the spring. When the inner hammer strikes the impact bullet head to expand to the extended wing, the connecting rope is just fully taut in the first through hole. The spring is compressed under the combined weight of the lifting block, the connecting rope and the inner hammer until the lower end face of the sliding block is flush with the lower end face of the mounting block. The inner hammer will no longer strike the impact bullet head. Thus, during the process of the inner hammer striking the impact bullet head, it is possible to observe whether the lower end face of the sliding block is flush with the lower end face of the mounting block to determine whether the extended wing has been hammered to the extended state. It can also ensure that after the impact bullet head is hammered to the extended wing extended state, it will not continue to be hammered downward by the inner hammer to detach from the extended wing. Thus, the extended wing can always remain in the extended state under the support of the impact bullet head. Attached Figure Description

[0034] Figure 1 The diagram shown is a three-dimensional structural schematic of the present invention.

[0035] Figure 2 The view shown is a partial cross-sectional view related to the sliding block of the present invention.

[0036] Figure 3 The diagram shows the structural schematic of the length of the connecting rope and the height of the inner hammer of the present invention.

[0037] Figure 4 This is a schematic diagram showing the distance between the upper surface of the impact bullet head and the upper surface of the sliding block according to the present invention.

[0038] Figure 5 The diagram shown is a structural schematic of the present invention when the extendable wing is not deployed.

[0039] Figure 6 The diagram shown is a structural schematic of the extended wing of the present invention when it is deployed.

[0040] In the image: 101, impact bullet head;

[0041] 201. Extendable wing; 202. Reinforcing bar;

[0042] 301. Reinforced pile body; 302. First through hole;

[0043] 401. Mounting block; 402. Spring; 403. Sliding block; 404. Inner hammer; 405. Connecting rope; 406. Hammer lifting block; 407. Second through hole; 408. Groove; 409. Third through hole. Detailed Implementation

[0044] The following specific embodiments illustrate the implementation of the present invention. Those skilled in the art can easily understand other advantages and effects of the present invention from the content disclosed in this specification.

[0045] Please see Figures 1 to 6 It should be understood that the structures, proportions, sizes, etc., depicted in the accompanying drawings are merely for illustrative purposes to aid those skilled in the art and to facilitate understanding. They are not intended to limit the scope of the invention and therefore have no substantial technical significance. Any modifications to the structure, changes in proportions, or adjustments to size, without affecting the effectiveness and purpose of the invention, should still fall within the scope of the technical content disclosed herein. Furthermore, the terms "upper," "lower," "left," "right," "middle," and "one" used in this specification are merely for clarity and not intended to limit the scope of the invention. Changes or adjustments to their relative relationships, without substantially altering the technical content, should also be considered within the scope of the invention.

[0046] The following embodiments are for illustrative purposes only. These embodiments can be combined and are not limited to the content shown in any single embodiment below.

[0047] Please see Figures 1 to 6This invention provides a construction method for precast hollow core reinforced piles with extendable wings, the construction method comprising:

[0048] Hole-making steps: Drill a hole in the ground and inject slurry into the hole. After the hole is drilled, remove the drilling equipment from the hole.

[0049] In the hole-making process, the diameter of the hole can be 700mm;

[0050] Piling steps: The impact bullet 101 is inserted from the bottom end of the precast hollow rigid pile upwards to the bottom of the hollow core of the precast hollow rigid pile. Then the bottom expansion unit seals the bottom end of the precast hollow rigid pile. After sealing, the precast hollow rigid pile is placed in the hole. The grout wraps the precast hollow rigid pile on the outside, and the hollow interior of the precast hollow rigid pile remains dry.

[0051] In the pile driving step, the bottom of the precast hollow rigid pile can be sealed by embedding steel bars 202 into each extension wing 201 and then binding all the steel bars 202 together with wire to temporarily fix several extension wings 201 to an unexpanded state, thereby sealing the bottom of the precast hollow rigid pile.

[0052] In the pile driving step, the cross-section of the precast hollow rigid pile can be a square with a side length of 400mm, and the central axis of the precast hollow rigid pile placed in the hole coincides with the central axis of the hole.

[0053] Expansion step: Use the hammer limiting device to repeatedly hammer the impact bullet head 101 at the bottom of the precast hollow rigid pile, so that the impact bullet head 101 pushes the extension wing 201 located at the bottom of the precast hollow rigid pile to open the wire and then continue to expand the extension wing 201 toward the outer wall of the precast hollow rigid pile.

[0054] Please see Figure 1 , Figure 5 and Figure 6 In the pile driving step, the precast hollow reinforced piles include:

[0055] The rigid pile body 301 has a first through hole 302 penetrating through its upper and lower end faces.

[0056] An expanding base unit is disposed at the bottom of the rigid pile body 301. The expanding base unit includes a plurality of extending wings 201, which are arranged in a circular array along the center line of the rigid pile body 301. The shape of the extending wings 201 is a triangular prism. Each extending wing 201 is hinged to the lower end face of the rigid pile body 301. The rotation axis of the extending wing 201 at the hinge is perpendicular to the center line of the rigid pile body 301.

[0057] When the extendable wing 201 is not deployed, a plurality of the extendable wings 201 close the lower end face of the first through hole 302;

[0058] When the extendable wing 201 is not deployed, several of the extendable wings 201 do not completely close the lower end face of the first through hole 302;

[0059] During the process of the extension wing 201 rotating to the unfolded state, the extension wing 201 opens the lower end face of the first through hole 302, and the extension wing 201 forms an enlarged bottom at the bottom end of the stiff pile body 301.

[0060] In this embodiment, when using precast hollow rigid piles for construction, the bottom of the rigid pile body 301 can be first filled with an impact bullet 101 from the bottom end of the rigid pile body 301 upwards to the bottom of the first through hole 302, so that the impact bullet 101 seals the bottom of the first through hole 302. Then, since each extension wing 201 is embedded with a steel bar 202, all the steel bars 202 are tied together with wire to temporarily fix several extension wings 201 to an undeployed state. At this time, several extension wings 201 seal the bottom of the first through hole 302. A hole is opened on the ground and grout is injected into the hole. Then, the rigid pile body 301 with the extension wings 201 temporarily fixed is placed in the hole. Afterwards, the extension wings 201 open the bottom of the first through hole 302 under repeated hammering by the hammering limiting device, and the extension wings 201 unfold toward the outer wall of the rigid pile body 301.

[0061] The extension wings 201 of the present invention are arranged in a circular array along the center line of the stiffened pile body 301. After the stiffened pile body 301 with the extension wings 201 temporarily fixed is placed in the hole, the extension wings 201 rotate to the unfolded state when the bottom of the extension wings 201 is expanded to increase the pile end resistance of the stiffened pile body 301. The structure design is simple, the manufacturing cost is low, and the stability of the stiffened pile body 301 after construction is good.

[0062] Please see Figure 5 and Figure 6 The sidewalls of the extendable wing 201 include a first sidewall, a second sidewall, and a third sidewall;

[0063] The number of the extension wings 201 can be four. When the extension wings 201 are not deployed, the third sidewall on the extension wing 201 is flush with the outer sidewall corresponding to the stiff pile body 301. The first sidewall on one of the extension wings 201 is in contact with the second sidewall on another adjacent extension wing 201, and the second sidewall on one of the extension wings 201 is in contact with the first sidewall on another adjacent extension wing 201.

[0064] In this embodiment, when the lower end face of the first through hole 302 is closed by the extendable wing 201, the first sidewall on one of the extendable wings 201 is attached to the second sidewall on another adjacent extendable wing 201, and the second sidewall on one of the extendable wings 201 is attached to the first sidewall on another adjacent extendable wing 201, so that the sidewalls between two adjacent extendable wings 201 in the four extendable wings 201 are attached to each other, so that the four extendable wings 201 are temporarily fixed in the undeployed state.

[0065] Please see Figure 5 and Figure 6 A steel bar 202 is embedded at the junction of the first sidewall and the second sidewall of the extendable wing 201. The upper end face of the steel bar 202 is flush with the upper end face of the extendable wing 201, and the lower end face of the steel bar 202 extends out of the lower end face of the extendable wing 201.

[0066] In this embodiment, when all the extendable wings 201 are rotated to the undeployed state, all the steel bars 202 are tied together with wire to temporarily fix several extendable wings 201 to the undeployed state.

[0067] When the lower end face of the first through hole 302 is closed, the present invention uses iron wire to tie several steel bars 202 together, so that all the extension wings 201 are temporarily fixed in an unexpanded state, thereby ensuring that the extension wings 201 will not open to open the lower end face of the first through hole 302 when the stiffened pile body 301 is put into the hole. The structure is ingeniously designed.

[0068] Please see Figure 5 When the extendable wing 201 is not deployed, the axis of rotation at the hinge of the extendable wing 201 is at the same height as the upper end surface of the extendable wing 201.

[0069] In this embodiment, when the extendable wing 201 rotates along the rotation axis at the hinge of the extendable wing 201, the upper end surface of the extendable wing 201 always maintains an attitude of rotating at a position not higher than the rotation axis at the hinge of the extendable wing 201.

[0070] Please see Figure 1 and Figure 3 In the bottom expansion step, the side wall of the impact bullet head 101 is sealed with the inner side wall of the rigid pile body 301 by a sealing ring. The head of the impact bullet head 101 is conical and located at the lower end of the impact bullet head 101.

[0071] In this embodiment, all the extension wings 201 are first rotated to the unfolded state. Then, the impact bullet head 101 is inserted from the bottom end of the stiff pile body 301 upwards into the bottom of the first through hole 302. During insertion, the side wall of the impact bullet head 101 and the side wall inside the first through hole 302 are sealed by a sealing ring to close the bottom of the first through hole 302. The head of the impact bullet head 101 is located at the lower end of the impact bullet head 101. After that, all the extension wings 201 are rotated to the unfurled state. Then, all the steel bars 202 are tied together with wire to temporarily fix all the extension wings 201 to the unfurled state, waiting for subsequent operations.

[0072] In this invention, after the impact bullet 101 is filled, the head of the impact bullet 101 is located at the lower end of the impact bullet 101. The head of the impact bullet 101 is conical, so that when the inner hammer 404 strikes the impact bullet 101, the impact bullet 101 rotates with the conical head of the impact bullet 101 in contact with the extension wing 201 when pushing the extension wing 201 to unfold. That is, the distance between the force point of the extension wing 201 and the axis of rotation of the extension wing 201 is relatively long, so that the impact bullet 101 can smoothly push the extension wing 201 to rotate with a small force. The structural design is ingenious.

[0073] Please see Figure 1 ,to Figure 4 In the bottom expansion step, the hammering limiting device includes a mounting block 401, a spring 402, a sliding block 403, an inner hammer 404, a connecting rope 405, and a hammer lifting block 406.

[0074] The mounting block 401 is fixedly installed on the upper end face of the rigid pile body 301. The upper and lower end faces of the mounting block 401 are provided with a second through hole 407. The cross-section of the second through hole 407 is the same size as the cross-section of the first through hole 302, and the second through hole 407 is connected to the first through hole 302.

[0075] The method by which the mounting block 401 is installed on the upper end face of the rigid pile body 301 is not limited here; it can be welded or connected by bolts.

[0076] The mounting block 401 has a plurality of springs 402 arranged in a circular array along the center line of the rigid pile body 301. The lower end face of each spring 402 is fixedly connected to the upper end face of the mounting block 401. The lower end face of the sliding block 403 has a groove 408. The upper end face of each spring 402 is fixedly connected to the upper end face of the groove 408. The mounting block 401 is located in the groove 408. The sliding direction of the sliding block 403 is consistent with the extension and retraction direction of the springs 402.

[0077] The upper and lower end faces of the sliding block 403 are provided with a third through hole 409. The cross-section of the third through hole 409 is the same size as the cross-section of the second through hole 407, and the third through hole 409 is connected to the second through hole 407.

[0078] One end of the connecting rope 405 is fixedly connected to the upper end face of the inner hammer 404, and the other end of the connecting rope 405 is fixedly connected to the lower end face of the lifting hammer block 406. When the inner hammer 404 strikes the bullet head 101 inside the stiff pile body 301, the lifting hammer block 406 contacts and presses the upper end face of the sliding block 403.

[0079] In this embodiment, all the extendable wings 201 are first rotated to the extended state. Then, the impact bullet 101 is inserted from the bottom end of the stiffened pile body 301 upwards into the bottom of the first through hole 302. During insertion, the side wall of the impact bullet 101 is sealed to the inner side wall of the first through hole 302 by a sealing ring. The head of the impact bullet 101 is located at the lower end of the impact bullet 101. Afterwards, all the extendable wings 201 are rotated to the non-extended state. Then, all the reinforcing bars 202 are tied together with wire to temporarily fix all the extendable wings 201 to the non-extended state. Holes are made on the surface and grout is injected into the holes. Then, the rigid pile body 301, with the extension wing 201 temporarily fixed, is placed in the hole. The inner hammer 404 is driven by the lifting hammer block 406 to extend into the third through hole 409, the second through hole 407 and the first through hole 302 in sequence, and then repeatedly hammers the impact bullet head 101. After the extension wing 201 opens the wire, it continues to unfold towards the outer wall of the rigid pile body 301 to form an expanded bottom. After the hammering is completed, the inner hammer 404 is removed, and the impact bullet head 101 is left between several extension wings 201 to lock the extension wings 201 and prevent them from rotating.

[0080] After the inner hammer 404 of the present invention strikes the impact bullet head 101 and the extension wing 201 is opened, it remains in the first through hole 302. The side wall of the impact bullet head 101 after the extension wing 201 forms an enlarged bottom is still sealed with the side wall inside the first through hole 302, so that the grout will not flow into the first through hole 302 from the bottom of the stiff pile body 301. Moreover, the impact bullet head 101 can keep the extension wing 201 in the unfolded state to form an enlarged bottom. The extension wing 201 will not rotate back to the unfurled state. The structural design is ingenious.

[0081] Please see Figure 2 and Figure 5 The cross-section of the inner hammer 404 is smaller than the cross-section of the first through hole 302.

[0082] In this embodiment, when the inner hammer 404 is driven by the lifting hammer block 406 to repeatedly hammer the impact bullet head 101, since the cross-section of the inner hammer 404 is smaller than the cross-section of the first through hole 302, the inner hammer 404 can fall freely to hammer the impact bullet head 101.

[0083] When the inner hammer 404 strikes the impact bullet head 101, the inner hammer 404 can fall freely to strike the impact bullet head 101, so as to ensure that the impact bullet head 101 is successfully struck by the inner hammer 404 until the extension wing 201 is deployed.

[0084] Please see Figure 1 and Figure 4 When the lifting hammer block 406 contacts and presses against the sliding block 403, the outer side wall of the lifting hammer block 406 is flush with the outer side wall of the sliding block 403.

[0085] In this embodiment, when the inner hammer 404 is driven by the lifting hammer block 406 to repeatedly hammer the impact bullet head 101, the lifting hammer block 406 is blocked by the upper end surface of the sliding block 403 when it is lowered to the upper end surface of the sliding block 403, so that the lifting hammer block 406 and the sliding block 403 come into contact and press.

[0086] When the lifting hammer block 406 of the present invention is lowered to the upper end face of the sliding block 403, the outer side wall of the lifting hammer block 406 is placed flush with the outer side wall of the sliding block 403, so that the sliding block 403 can support the lifting hammer block 406 to prevent it from continuing to descend into the first through hole 302, thereby ensuring that the lifting hammer block 406 can be repeatedly raised and lowered so that the inner hammer 404 can be driven by the connecting rope 405 to hammer the impact bullet head 101.

[0087] Please see Figure 1 , Figure 2 , Figure 3 , Figure 4 and Figure 6 When the inner hammer 404 strikes the extension wing 201 to the unfolded state, the upper end face of the groove 408 is in contact with the upper end face of the mounting block 401, the lower end face of the sliding block 403 is flush with the lower end face of the mounting block 401, the distance from the upper end face of the impact bullet head 101 to the upper end face of the sliding block 403 is a, the length of the connecting rope 405 is b, the height of the inner hammer 404 is c, and a = b + c.

[0088] In this embodiment, a hole is drilled in the ground and grout is injected into the hole. The impact bullet head 101 is inserted from the bottom end of the rigid pile body 301 upwards to the bottom of the first through hole 302. After the extension wing 201 is temporarily sealed in the undeployed state of the rigid pile body 301 and placed into the hole, the inner hammer 404 is driven by the lifting hammer block 406 to repeatedly hammer the impact bullet head 101. Before the inner hammer 404 hammers the extension wing 201 to the deployed state, the impact bullet head 101 has not descended to the designated position. The connecting rope 405 is not fully straightened when the lower end face of the inner hammer 404 contacts the upper end face of the impact bullet head 101. At this time, the lower end face of the sliding block 403 is higher than the lower end face of the mounting block 401. When the inner hammer 404 repeatedly hammers the extension wing 201 through the impact bullet head 101 until the sliding block 403 is observed to be deployed, the impact bullet head 101 is inserted into the hole. When the lower end face of the sliding block 403 is flush with the lower end face of the mounting block 401, the impact bullet head 101 descends to the designated position, the connecting rope 405 is fully taut, and the spring 402 is compressed under the combined gravity of the lifting hammer block 406, the connecting rope 405 and the inner hammer 404 until the lower end face of the sliding block 403 is flush with the lower end face of the mounting block 401. This indicates that the inner hammer 404 has hammered the extension wing 201 to the unfolded state. At this time, the impact bullet head 101 is stuck between several extension wings 201 and blocks the lower end face of the first through hole 302. When it is observed that the lower end face of the sliding block 403 is flush with the lower end face of the mounting block 401, the connecting rope 405 and the inner hammer 404 are pulled out of the stiff pile body 301 by lifting the lifting hammer block 406, thereby completing the expansion work of the extension wing 201.

[0089] Before the impact bullet head 101 expands the extension wing 201 to the unfolded state, the connecting rope 405 is not fully taut when the lower end face of the inner hammer 404 contacts the upper end face of the impact bullet head 101. At this time, the force on the spring 402 is the weight of the lifting block 406 and the connecting rope 405. The lower end face of the sliding block 403 is higher than the lower end face of the mounting block 401 under the support of the spring 402. When the inner hammer 404 strikes the impact bullet head 101 to expand the extension wing 201 to the unfolded state, the connecting rope 405 is not fully taut. The rope 405 is fully stretched inside the first through hole 302. The spring 402 is compressed under the combined gravity of the lifting hammer block 406, the connecting rope 405 and the inner hammer 404 until the lower end face of the sliding block 403 is flush with the lower end face of the mounting block 401. Thus, during the process of the inner hammer 404 hammering and impacting the bullet head 101, it can be observed whether the lower end face of the sliding block 403 is flush with the lower end face of the mounting block 401 to determine whether the extension wing 201 has been hammered into the unfolded state. The structure is cleverly coordinated.

[0090] The above embodiments are merely illustrative of the principles and effects of the present invention and are not intended to limit the invention. Any person skilled in the art can modify or alter the above embodiments without departing from the spirit and scope of the present invention. Therefore, all equivalent modifications or alterations made by those skilled in the art without departing from the spirit and technical concept disclosed in the present invention should still be covered by the claims of the present invention.

Claims

1. A construction method for precast hollow reinforced piles with extendable wings, characterized in that, The construction method for the precast hollow core reinforced piles includes: Hole-forming steps: Drill holes in the ground and inject slurry into the holes; Piling steps: The impact bullet is inserted from the bottom end of the precast hollow rigid pile upwards to the bottom of the hollow core of the precast hollow rigid pile. Then the bottom expansion unit seals the bottom end of the precast hollow rigid pile. After sealing, the precast hollow rigid pile is placed in the hole. The grout wraps the precast hollow rigid pile on the outside, and the hollow interior of the precast hollow rigid pile remains dry. Expansion step: Use a hammer limiting device to repeatedly hammer the impact bullet head at the bottom of the precast hollow rigid pile, so that the impact bullet head pushes the extension wing located at the bottom of the precast hollow rigid pile to unfold towards the outer wall of the precast hollow rigid pile. The pile driving step includes the following precast hollow reinforced piles: The rigid pile body has a first through hole penetrating its upper and lower end faces; An expanded base unit is disposed at the bottom of the rigid pile body. The expanded base unit includes several extension wings, which are arranged in a circular array along the center line of the rigid pile body. The extension wings are triangular prisms in shape, and each extension wing is hinged to the lower end face of the rigid pile body. The rotation axis at the hinge of the extension wing is perpendicular to the center line of the rigid pile body. When the extendable wings are not deployed, the lower end faces of the first through holes are closed by the plurality of the extendable wings; During the process of the extension wing rotating to the unfolded state, the extension wing opens the lower end face of the first through hole, and the extension wing forms an enlarged bottom at the bottom end of the stiff pile body. In the bottom expansion step, the hammering limiting device includes a mounting block, a spring, a sliding block, an inner hammer, a connecting rope, and a hammer lifting block. The mounting block is fixedly installed on the upper end face of the rigid pile body. The upper and lower end faces of the mounting block have a second through hole. The cross-sectional area of ​​the second through hole is the same as that of the first through hole, and the second through hole is connected to the first through hole. The mounting block has a circular array of several springs along the center line of the rigid pile body. The lower end face of each spring is fixed to the upper end face of the mounting block. The lower end face of the sliding block has a groove. The upper end face of each spring is fixed to the upper end face of the groove. The mounting block is located in the groove. The sliding direction of the sliding block is consistent with the extension and retraction direction of the spring. The upper and lower end faces of the sliding block are perforated by a third through hole. The cross-section of the third through hole is the same size as the cross-section of the second through hole, and the third through hole is connected to the second through hole. One end of the connecting rope is fixedly connected to the upper end face of the inner hammer, and the other end of the connecting rope is fixedly connected to the lower end face of the hammer lifting block. When the inner hammer strikes the bullet head inside the rigid pile body, the hammer lifting block contacts the upper end face of the pressing sliding block.

2. The construction method for a precast hollow stiffened pile with an extendable wing according to claim 1, characterized in that: The sidewalls of the extendable wing include a first sidewall, a second sidewall, and a third sidewall; When the extension wing is not deployed, the third sidewall on the extension wing is flush with the outer sidewall corresponding to the rigid pile body, the first sidewall on one of the extension wings is in contact with the second sidewall on another adjacent extension wing, and the second sidewall on one of the extension wings is in contact with the first sidewall on another adjacent extension wing.

3. The construction method for a precast hollow stiffened pile with an extendable wing according to claim 2, characterized in that: A reinforcing bar is embedded at the junction of the first and second sidewalls of the extendable wing. The upper end face of the reinforcing bar is flush with the upper end face of the extendable wing, and the lower end face of the reinforcing bar extends out of the lower end face of the extendable wing.

4. The construction method for a precast hollow reinforced pile with an extendable wing according to claim 3, characterized in that: When the extendable wing is not deployed, the axis of rotation at the hinge of the extendable wing is at the same height as the upper end surface of the extendable wing.

5. The construction method for a precast hollow stiffened pile with an extendable wing according to claim 1, characterized in that: In the expansion step, the sidewall of the impact bullet head is sealed to the inner sidewall of the rigid pile body by a sealing ring. The head of the impact bullet head is conical and located at the lower end of the impact bullet head.

6. The construction method for a precast hollow reinforced pile with an extendable wing according to claim 1, characterized in that: The cross-section of the inner hammer is smaller than the cross-section of the first through hole.

7. The construction method for a precast hollow stiffened pile with an extendable wing according to claim 1, characterized in that: When the lifting hammer block contacts and presses against the sliding block, the outer wall of the lifting hammer block is flush with the outer wall of the sliding block.

8. The construction method for a precast hollow stiffened pile with an extendable wing according to claim 1, characterized in that: When the inner hammer strikes the extension wing to the deployed state, the upper end face of the groove is in contact with the upper end face of the mounting block, the lower end face of the sliding block is flush with the lower end face of the mounting block, the distance from the upper end face of the impact bullet to the upper end face of the sliding block is a, the length of the connecting rope is b, the height of the inner hammer is c, and a = b + c.

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