A device for expanding a bottom
By designing the pile end plate and the enlarged base unit, the enlarged base is achieved by rotating the extension wing at the hinge point between the extension wing and the pile end plate. This solves the problems of complex design and high maintenance cost of existing enlarged base piles, and achieves a low-cost and high-efficiency enlarged base effect.
Patent Information
- Authority / Receiving Office
- CN · China
- Patent Type
- Utility models(China)
- Current Assignee / Owner
- JIANGXI UNITED INSURANCE ENG CONSULTING CO LTD
- Filing Date
- 2025-08-22
- Publication Date
- 2026-05-29
AI Technical Summary
The existing underreaming mechanism for expanded-base piles is complex in design and has high manufacturing and maintenance costs.
The pile end plate and the base expansion unit are adopted. The base expansion unit consists of several extension wings. The base expansion is achieved by rotating the axis of rotation at the hinge of the pile end plate with the outer wall of the hollow pipe pile. The extension wings are fixed with steel bars and wires to control their expansion.
It achieves a simple structural design, low manufacturing and maintenance costs, a large enlarged base area, and a significantly improved pile end resistance.
Smart Images
Figure CN224299960U_ABST
Abstract
Description
Technical Field
[0001] This utility model belongs to the field of precast pile construction, and in particular relates to a base expansion device. Background Technology
[0002] As an important form of deep foundation, pile foundations are widely used in building engineering, bridge engineering, port terminals, large equipment foundations and other fields. They are mainly used to transfer the load of the superstructure to deep soil or rock layers with good bearing capacity. Their bearing capacity mainly comes from two parts: pile side friction and pile end resistance.
[0003] To significantly improve the end bearing capacity of a single pile, reduce settlement, and more effectively utilize the bearing capacity of deep bearing strata, enlarged-base piles (also known as large-head piles or enlarged-base cast-in-place piles) have emerged. Enlarged-base piles greatly increase the contact area between the pile tip and the foundation soil by forming an enlarged head at the bottom of the pile body with a diameter larger than that of the pile body, thereby multiplying the pile end resistance. Under the same pile length and diameter conditions, its bearing capacity can be increased by 20%-40% or even more than that of straight-hole piles, which has significant technical and economic advantages.
[0004] However, existing enlarged 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 type of reaming mechanism has disadvantages such as complex design and high manufacturing and maintenance costs. Utility Model Content
[0005] In view of the shortcomings of the prior art described above, the purpose of this utility model is to provide a bottom-expanding device to solve the problems of complex design, high manufacturing and maintenance costs of the bottom-expanding mechanism in the prior art.
[0006] To achieve the above and other related objectives, this utility model provides a bottom-expanding device, the bottom-expanding device comprising:
[0007] Pile end plate;
[0008] An expansion unit is provided at the lower end of the pile end plate. The expansion unit includes several extension wings arranged in a circular array along the center line of the pile end plate. The extension wings are triangular prisms in shape. Each extension wing is hinged to the lower end face of the pile end plate. The rotation axis at the hinge point between the extension wing and the pile end plate is perpendicular to the center line of the pile end plate.
[0009] As an optional solution, the upper and lower end faces of the pile end plate have through holes.
[0010] As an alternative, the lower end face of several of the extended wings is closed.
[0011] As an optional feature, the sidewalls of the extendable wing include a first sidewall, a second sidewall, and a third sidewall;
[0012] The third sidewall on the extension wing is flush with the outer sidewall corresponding to the pile end plate, and 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.
[0013] 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.
[0014] As an optional solution, the axis of rotation at the hinge point between the extension wing and the pile end plate is at the same height as the upper end surface of the extension wing.
[0015] As an optional solution, a portion of the upper surface of the extendable wing is fitted with the lower surface of the pile end plate.
[0016] As an optional feature, the extendable wing can rotate along the rotation axis at the hinge point between the extendable wing and the pile end plate to open the lower end face of the through hole.
[0017] As described above, the bottom-expanding device of this utility model has at least the following beneficial effects:
[0018] 1. The pile end plate of this utility model can be installed on the lower end face of the hollow pipe pile, so that after the hollow pipe pile is placed into the excavated hole, the extension wing can rotate along the rotation axis at the hinge point between the extension wing and the pile end plate towards the outer wall of the hollow pipe pile under the repeated hammering of the inner hammer inside the hollow pipe pile, thereby realizing the expansion of the bottom. The structure design is simple and the manufacturing and maintenance costs are low.
[0019] 2. Because the rotation axis at the hinge point between the extension wing and the pile end plate is located outside the pile end plate, the extension wing can expand to the maximum extent beyond the outer wall of the pile end plate when rotating along the rotation axis at the hinge point between the extension wing and the pile end plate, so as to ensure that the extension wing expands the bottom with a larger expansion area.
[0020] 3. In this utility model, the iron wire tied to the reinforcing bar can temporarily fix the extension wing to the lower end face of the through hole on the closed pile end plate when the extension wing rotates to the lower end face of the through hole on the closed pile end plate. When the inner hammer strikes the extension wing, the impact force of the inner hammer on the extension wing can open the iron wire, so that the extension wing can smoothly unfold towards the outer wall of the hollow pipe pile after the iron wire is opened. The structural design is ingenious. Attached Figure Description
[0021] Figure 1This is a structural schematic diagram of the extended wing closed pile end plate of this utility model;
[0022] Figure 2 The diagram shows the structure of the extended wing of this utility model when it is deployed.
[0023] Figure 3 The diagram shown is an exploded view of the pile end plate and extension wing of this utility model.
[0024] Figure 4 The image shown is a partial sectional view of the pile end plate of this utility model.
[0025] Figure 5 This is a structural schematic diagram of the extendable wing of this utility model from another perspective.
[0026] In the diagram: 101, pile end plate; 102, through hole;
[0027] 202. Extended wings;
[0028] 301. Reinforcing steel. Detailed Implementation
[0029] The following specific embodiments illustrate the implementation of this utility model. Those skilled in the art can easily understand other advantages and effects of this utility model from the content disclosed in this specification.
[0030] Please see Figures 1 to 5 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 are not intended to limit the scope of this invention. Therefore, they have no substantial technical significance. Any modifications to the structure, changes in proportions, or adjustments to size, without affecting the effectiveness and purpose of this invention, should still fall within the scope of the technical content disclosed in this invention. Furthermore, the terms such as "upper," "lower," "left," "right," "middle," and "one" used in this specification are merely for clarity and are not intended to limit the scope of this invention. Changes or adjustments to their relative relationships, without substantially altering the technical content, should also be considered within the scope of this invention.
[0031] 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.
[0032] Please see Figure 1 and Figure 2 This utility model provides a bottom-expanding device, the bottom-expanding device comprising:
[0033] Pile end plate 101;
[0034] An expanding base unit is disposed at the lower end of the pile end plate 101. The expanding base unit includes a plurality of extending wings 202, which are arranged in a circular array along the center line of the pile end plate 101. The shape of the extending wings 202 is a triangular prism. Each extending wing 202 is hinged to the lower end face of the pile end plate 101. The rotation axis of the extending wing 202 at the hinge point with the pile end plate 101 is perpendicular to the center line of the pile end plate 101.
[0035] In this embodiment, before the hollow pipe pile is placed into the excavated hole, the upper end of the pile end plate 101 is fixedly installed on the lower end face of the hollow pipe pile. The method of fixing the upper end of the pile end plate 101 to the lower end face of the hollow pipe pile is not limited here. It can be welded or connected by bolts. Then, grout is injected into the hole. After that, the pile end plate 101, along with the bottom expansion unit, is placed into the hole together with the hollow pipe pile, waiting for subsequent operations.
[0036] The bottom expansion unit of this utility model can be installed on the lower end face of the hollow pipe pile along with the pile end plate. After the hollow pipe pile is placed into the excavated hole, the extension wing 202 can rotate along the rotation axis at the hinge point between the extension wing 202 and the pile end plate 101 towards the outer wall of the hollow pipe pile under the repeated hammering of the inner hammer inside the hollow pipe pile, thereby realizing bottom expansion. The bottom expansion unit has a simple structural design and low manufacturing and maintenance costs.
[0037] Please see Figure 1 and Figure 2 The pile end plate 101 has through holes 102 on its upper and lower end faces.
[0038] In this embodiment, when the upper end of the pile end plate 101 is fixedly installed on the lower end face of the hollow pipe pile, the cross-section of the through hole 102 is the same size as the cross-section of the hollow interior of the hollow pipe pile, and the through hole 102 is connected to the hollow interior of the hollow pipe pile. When the inner hammer strikes the extension wing 202, the inner hammer passes through the hollow interior of the hollow pipe pile and the through hole 102 in sequence before contacting and striking the extension wing 202.
[0039] Please see Figure 1 The lower end face of the through hole 102 is closed by several of the extended wings 202.
[0040] In this embodiment, a hole is drilled in the ground, and then the upper end of the pile end plate 101 is fixedly installed on the lower end face of the hollow pipe pile, so that the through hole 102 is connected to the hollow interior of the hollow pipe pile. At this time, several extension wings 202 are closed on the lower end face of the through hole 102. Grout is injected into the hole, and then the pile end plate 101 and the bottom expansion unit are placed into the hole together with the hollow pipe pile, waiting for subsequent operations.
[0041] When the hollow pipe pile is placed into the hole, the extension wing 202 of this utility model is placed into the hole with the lower end face of the through hole 102 on the pile end plate 101 closed, so that the hollow pipe pile can be placed into the hole with less resistance. The structure is ingeniously designed.
[0042] Please see Figures 1 to 5 The sidewalls of the extendable wing 202 include a first sidewall, a second sidewall, and a third sidewall;
[0043] The third sidewall on the extension wing 202 is flush with the outer sidewall corresponding to the pile end plate 101. The first sidewall on one of the extension wings 202 is in contact with the second sidewall on another adjacent extension wing 202. The second sidewall on one of the extension wings 202 is in contact with the first sidewall on another adjacent extension wing 202.
[0044] In this embodiment, the number of the extension wings 202 can be four. When the first sidewall of one of the extension wings 202 is in contact with the second sidewall of another adjacent extension wing 202, and the second sidewall of one of the extension wings 202 is in contact with the first sidewall of another adjacent extension wing 202, the four extension wings 202 together close the lower end face of the through hole 102 on the pile end plate 101.
[0045] Please see Figure 1 and Figure 2 A steel bar 301 is embedded at the junction of the first sidewall and the second sidewall of the extendable wing 202. The upper end face of the steel bar 301 is flush with the upper end face of the extendable wing 202, and the lower end face of the steel bar 301 extends out of the lower end face of the extendable wing 202.
[0046] In this embodiment, before the pile end plate 101 is installed, all the extension wings 202 are rotated to the state of closing the lower end face of the through hole 102 on the pile end plate 101, and then several steel bars 301 are tied together with iron wire, so that the extension wings 202 are temporarily fixed to the state of closing the lower end face of the through hole 102 on the pile end plate 101.
[0047] Before the pile end plate 101 is installed, several steel bars 301 can be tied together with wire, so that all the extension wings 202 are temporarily fixed to the lower end face of the through hole 102 on the closed pile end plate 101. This ensures that the extension wings 202 will not open to open the lower end face of the through hole 102 when the hollow pipe pile is put into the hole. The structure is ingeniously designed.
[0048] Please see Figure 1 and Figure 2 The axis of rotation at the hinge point between the extension wing 202 and the pile end plate 101 is at the same height as the upper end surface of the extension wing 202.
[0049] In this embodiment, when the extendable wing 202 rotates along the rotation axis at the hinge point between the extendable wing 202 and the pile end plate 101, the upper end surface of the extendable wing 202 always maintains an attitude that is not higher than the rotation axis at the hinge point between the extendable wing 202 and the pile end plate 101.
[0050] Please see Figure 1 and Figure 4 A portion of the upper surface of the extension wing 202 is in contact with the lower surface of the pile end plate 101.
[0051] In this embodiment, when the extension wing 202 closes the lower end face of the through hole 102 on the pile end plate 101, a part of the upper end face of the extension wing 202 is in contact with the lower end face of the pile end plate 101, and the other part closes the space corresponding to the lower end face of the through hole 102.
[0052] Please see Figure 2 The extendable wing 202 can rotate along the rotation axis at the hinge point between the extendable wing 202 and the pile end plate 101 to open the lower end face of the through hole 102.
[0053] In this embodiment, a hole is drilled in the ground, and then the upper end of the pile end plate 101 is fixedly installed on the lower end face of the hollow pipe pile. At this time, the extension wing 202 rotates to the state of closing the lower end face of the through hole 102 on the pile end plate 101. Several steel bars 301 are tied together with iron wire, so that all the extension wings 202 are temporarily fixed to the state of closing the lower end face of the through hole 102 on the pile end plate 101. Grout is injected into the hole, and then the hollow pipe pile with the extension wings 202 temporarily fixed is placed into the hole. When it is necessary to expand the bottom, the inner hammer is placed into the hollow interior of the hollow pipe pile. The inner hammer is used to hammer the extension wing 202 after passing through the hollow interior of the hollow pipe pile and the pile end plate 101 in sequence. After the inner hammer opens the iron wire tied to several steel bars 301, the extension wing 202 continues to unfold towards the outer wall of the hollow pipe pile to complete the expansion of the bottom of the hollow pipe pile.
[0054] In this invention, the wire tied to the reinforcing bar 301 can temporarily fix the extension wing 202 to the lower end face of the through hole 102 on the closed pile end plate 101 when the extension wing 202 rotates to the lower end face of the through hole 102 on the closed pile end plate 101. When the inner hammer strikes the extension wing 202, the impact force of the inner hammer on the extension wing 202 can open the wire, so that the extension wing 202 can smoothly unfold toward the outer wall of the hollow pipe pile after the wire is opened. The structural design is ingenious.
[0055] The above embodiments are merely illustrative of the principles and effects of this utility model and are not intended to limit the scope of this utility model. Any person skilled in the art can modify or alter the above embodiments without departing from the spirit and scope of this utility model. Therefore, all equivalent modifications or alterations made by those skilled in the art without departing from the spirit and technical concept disclosed in this utility model should still be covered by the claims of this utility model.
Claims
1. A bottom-expanding device, characterized in that, The bottom expansion device includes: Pile end plate; An expansion unit is provided at the lower end of the pile end plate. The expansion unit includes several extension wings arranged in a circular array along the center line of the pile end plate. The extension wings are triangular prisms in shape. Each extension wing is hinged to the lower end face of the pile end plate. The rotation axis at the hinge point between the extension wing and the pile end plate is perpendicular to the center line of the pile end plate.
2. The bottom expansion device according to claim 1, characterized in that: The top and bottom surfaces of the pile end plate have through holes.
3. The bottom expansion device according to claim 1, characterized in that: The lower end face of several of the aforementioned extended wing closed through holes.
4. The bottom expansion device according to claim 3, characterized in that: The sidewalls of the extendable wing include a first sidewall, a second sidewall, and a third sidewall; The third sidewall on the extension wing is flush with the outer sidewall corresponding to the pile end plate, and 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.
5. The bottom expansion device according to claim 4, 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 beyond the lower end face of the extendable wing.
6. The bottom expansion device according to claim 5, characterized in that: The axis of rotation at the hinge point between the extension wing and the pile end plate is at the same height as the upper end surface of the extension wing.
7. The bottom expansion device according to claim 5, characterized in that: A portion of the upper surface of the extension wing is in contact with the lower surface of the pile end plate.
8. The bottom expansion device according to claim 2, characterized in that: The extendable wing can rotate along the rotation axis at the hinge point between the extendable wing and the pile end plate to open the lower end face of the through hole.