Foundation cast-in-place pedestal pile
By burying spiral stirrups in the expanded base part of the expanded base pile section and combining them with steel strands and vibrating equipment, the problem of loose connection between the expanded base pile section and the main part is solved, and the integrity and bearing capacity of the cast-in-place expanded base pile are improved.
Patent Information
- Application Number
- CN202422867755.3
- Authority / Receiving Office
- CN · China
- Patent Type
- Utility models(China)
- Current Assignee / Owner
- Filing Date
- 2024-11-23
- Publication Date
- 2025-09-23
- Estimated Expiration
- 2034-11-23
AI Technical Summary
The lack of steel bars connecting the expanded bottom part and the main body of the cast-in-place expanded bottom pile results in poor integrity and affects the bearing capacity.
Spiral stirrups are buried in the expanded bottom part of the expanded bottom pile section, and the position of the spiral stirrups is fixed by steel strands. The concrete is vibrated with vibrating equipment to improve the connection strength and integrity between the expanded bottom part and the main part.
The integrity and bearing capacity of the expanded base pile section are improved, and the shear resistance and concrete structure strength of the expanded base pile are enhanced.
Smart Images
Figure CN223373706U_ABST
Abstract
Description
Technical Field
[0001] The present application relates to the technical field of building foundations, and in particular to a foundation cast-in-place expanded bottom pile. Background Art
[0002] A cast-in-place pile with an enlarged base is a pile with a bottom diameter larger than the diameter of the upper pile body. The bearing capacity of a single cast-in-place pile with an enlarged base is higher than that of a straight pile with the same pile body diameter.
[0003] The construction process of cast-in-place expanded-base piles is as follows: first, a pile hole is drilled in the ground, with the bottom diameter of the pile hole larger than the top diameter of the pile hole; then, a steel cage is placed in the pile hole; finally, concrete is injected into the pile hole to form a cast-in-place expanded-base pile.
[0004] Because the diameter of the expanded base section of a cast-in-place expanded-base pile is larger than that of the upper straight section, there's a lack of steel reinforcement connecting the expanded base section to the main body of the pile. Consequently, when the cast-in-place expanded-base pile is subjected to significant external forces, the lack of steel reinforcement restrains the concrete in the expanded base section, leading to cracks that easily form between the expanded base section and the main body. This compromises the integrity of the expanded base section and reduces the pile's bearing capacity. Utility Model Content
[0005] In order to improve the integrity of the expanded bottom pile section in the cast-in-place expanded bottom pile and improve the bearing capacity of the cast-in-place expanded bottom pile, the present application provides a foundation cast-in-place expanded bottom pile.
[0006] This application provides a foundation cast-in-place expanded bottom pile, which adopts the following technical solution:
[0007] A foundation cast-in-place expanded-bottom pile, comprising, in a vertical downward direction, a straight pile section and an expanded-bottom pile section integrally cast with concrete, wherein the diameter of the expanded-bottom pile section is larger than that of the straight pile section, and the expanded-bottom pile section comprises an integrally cast main body portion and an expanded-bottom portion, wherein the main body portion is located inside the vertical projection of the straight pile section, and the expanded-bottom portion is located outside the vertical projection of the straight pile section;
[0008] The cast-in-place expanded base pile includes a steel cage and spiral stirrups, and the diameter of the spiral stirrups is larger than the diameter of the straight pile section; when the steel cage is processed, the bottom section of the spiral stirrups is fixedly connected to the bottom of the steel cage, the spiral stirrups are stretched, and the other end of the spiral stirrups is detachably connected to the steel cage, at which time the diameter of the spiral stirrups is smaller than the diameter of the straight pile section; when the cast-in-place expanded base pile is cast, the steel cage is buried in the main part of the straight pile section and the expanded base pile section, and the main body of the spiral stirrups is arranged in the expanded base part of the expanded base pile section.
[0009] By adopting the above technical solution, spiral stirrups are embedded in the expanded bottom part of the expanded bottom pile section, so that the spiral stirrups have a restraining effect on the concrete of the expanded bottom part, thereby improving the integrity of the main part and the expanded bottom part in the expanded bottom pile section and improving the bearing capacity of the cast-in-place expanded bottom pile.
[0010] Optionally, the cast-in-place expanded base pile further includes a steel strand, one end of the steel strand is fixedly connected to the steel cage, and the other end of the steel strand is fixedly connected to the spiral stirrup.
[0011] By adopting the above technical solution, the position of the bolt stirrups is fixed by the steel strands, so that a certain distance can be maintained between adjacent coils of the spiral stirrups to allow concrete to pass through, thereby facilitating the workers to pour concrete.
[0012] Optionally, there are a plurality of steel strands, which are spaced apart along the length of the steel cage, and the plurality of steel strands are fixedly connected to coils of the spiral stirrups at different heights.
[0013] By adopting the above technical solution, a plurality of steel strands are fixedly connected to coils of spiral stirrups at different heights, thereby improving the uniformity of the coil spacing in the spiral stirrups.
[0014] Optionally, after the grouting of the cast-in-place expanded-base pile is completed, the coil diameter of the spiral stirrup decreases in a direction away from the expanded-base pile section.
[0015] By adopting the above technical solution, the coil diameter of the spiral stirrup decreases in the direction away from the expanded bottom pile section, thereby further improving the connection strength between the expanded bottom part and the main part, and the expanded bottom part and the straight part in the expanded bottom section, and further improving the bearing capacity of the cast-in-place pile.
[0016] Optionally, the spiral stirrups are ribbed steel bars.
[0017] By adopting the above technical solution, the spiral stirrups are ribbed steel bars, so as to improve the bite effect between the spiral stirrups and concrete.
[0018] Optionally, along the direction away from the straight pile section, the expanded bottom pile section includes a first pile section and a second pile section; and along the direction away from the straight pile section, the diameter of the first pile section increases gradually.
[0019] By adopting the above technical solution, the diameter of the first pile segment increases gradually, thereby facilitating the arrangement of the spiral stirrups at the expanded bottom portion of the expanded bottom pile segment.
[0020] Optionally, a plurality of vibrating plates are welded to the spiral stirrups, and the plurality of vibrating plates are arranged at intervals along the length direction of the spiral stirrups.
[0021] By adopting the above technical solution, when the vibrating equipment drives the spiral stirrups to vibrate, the vibrating plates on the spiral stirrups can drive the concrete to vibrate in a wider range, thereby further improving the structural strength of the concrete in the expanded bottom part.
[0022] Optionally, the vibrating plate is further provided with a plurality of connecting holes.
[0023] By adopting the above technical solution, the communicating holes on the vibrating plate improve the vibrating effect of the vibrating plate on the concrete, thereby further improving the structural strength of the concrete in the expanded bottom portion.
[0024] In summary, this application includes at least one of the following beneficial technical effects:
[0025] 1. By embedding spiral stirrups in the expanded bottom part of the expanded bottom pile section, the spiral stirrups have a restraining effect on the concrete in the expanded bottom part, thereby improving the integrity of the main body and the expanded bottom part of the expanded bottom pile section and increasing the bearing capacity of the cast-in-place expanded bottom pile;
[0026] 2. Fixing the position of the bolt stirrups by steel strands can keep a certain distance between adjacent coils of spiral stirrups to allow concrete to pass through, making it easier for workers to pour concrete;
[0027] 3. When the vibrating equipment drives the spiral stirrups to vibrate, the vibrating plate on the spiral stirrups can drive the concrete to vibrate in a wider range, so as to further improve the structural strength of the concrete in the expanded bottom part. BRIEF DESCRIPTION OF THE DRAWINGS
[0028] Figure 1 Schematic diagram of the structure of the cast-in-place expanded base pile before grouting in Example 1.
[0029] Figure 2 Schematic diagram of the structure of the cast-in-place expanded base pile after grouting in Example 1.
[0030] Figure 3 It is a structural schematic diagram of the cast-in-place expanded base pile before grouting in Example 2.
[0031] Figure 4 It is a schematic diagram of the structure of the cast-in-place expanded base pile after grouting in Example 2.
[0032] Figure 5 yes Figure 4 Enlarged view of point A in the middle.
[0033] Explanation of the accompanying reference numerals: 1. Straight pile section; 2. Expanded bottom pile section; 21. Main body; 22. Expanded bottom part; 23. First pile section; 24. Second pile section; 3. Steel cage; 4. Spiral stirrups; 5. Steel strand; 6. Vibrating plate; 61. Connecting hole; 7. Pile hole; 71. Straight hole; 72. Expanded bottom hole; 8. Ground. DETAILED DESCRIPTION
[0034] The following is combined with Figure 1-5 This application is described in further detail.
[0035] Example 1
[0036] The present application discloses a foundation cast-in-place expanded bottom pile. Figure 1 and Figure 2 The cast-in-place expanded bottom pile is a reinforced concrete structure, and along the vertical downward direction, the foundation cast-in-place expanded bottom pile is integrally cast with a straight pile section 1 and an expanded bottom pile section 2, and the diameter of the expanded bottom pile section 2 is greater than that of the straight pile section 1.
[0037] The expanded-base pile segment 2 comprises an integrally cast main body 21 and an expanded base 22. The main body 21 is located within the vertical projection of the straight pile segment 1, while the expanded base 22 is located outside the vertical projection of the straight pile segment 1. In this embodiment, the expanded-base pile segment 2 comprises a first pile segment 23 and a second pile segment 24 as it moves away from the straight pile segment 1. The diameter of the first pile segment 23 increases as it moves away from the straight pile segment 1.
[0038] Reference Figure 1 and Figure 2 The cast-in-place expanded-base pile includes a reinforcement cage 3, spiral stirrups 4, steel strands 5, and a concrete body (in the accompanying drawings, the concrete body within the pile hole 7 is indicated by an inclined dashed line). The spiral stirrups 4 are composed of several coils and are sleeved around the outer periphery of the reinforcement cage 3. The reinforcement cage 3 is fixedly connected to the spiral stirrups 4 via the steel strands 5. The diameter of the spiral stirrups 4 is larger than that of the straight pile section 1. Therefore, when the cast-in-place expanded-base pile is completed, the spiral stirrups 4 are installed in the expanded base portion 22 of the expanded-base pile section 2, thereby improving the integrity of the expanded base portion 22 and the main body 21 of the expanded-base pile section 2.
[0039] Reference Figure 1 and Figure 2 The construction process for cast-in-place, expanded-base piles is as follows: Workers first drill a pile hole 7 in the ground 8, with the bottom diameter of the pile hole 7 larger than the top diameter. This means that, vertically downward, the pile hole 7 consists of a straight hole 71 and an expanded-base hole 72. Straight hole 71 corresponds to the straight pile section 1 of the cast-in-place, expanded-base pile, while expanded-base hole 72 corresponds to the expanded-base pile section 2. Next, workers place a reinforcement cage 3, spiral stirrups 4, and strands 5 into the pile hole 7. Finally, concrete is poured into the pile hole 7. Once the concrete solidifies into a concrete mass, the cast-in-place, expanded-base pile is formed.
[0040] The specific construction method of cast-in-place expanded pile is as follows:
[0041] Reference Figure 1After the steel cage 3 is processed on the ground 8, the staff will put the spiral stirrups 4 on the outer periphery of the steel cage 3, and fix the bottom section of the spiral stirrups 4 to the bottom of the steel cage 3. In this embodiment, the bottom of the spiral stirrups 4 is welded to the bottom of the steel cage 3.
[0042] Reference Figure 1 Subsequently, the staff stretches the spiral stirrups 4, causing the diameter of the coils in the spiral stirrups 4 to continuously decrease until the diameter of the spiral stirrups 4 is smaller than the diameter of the straight pile section 1. The staff then detachably connects the top end of the spiral stirrups 4 to the reinforcement cage 3. In this embodiment, the spiral stirrups 4 conform to the outer periphery of the reinforcement cage 3, facilitating the placement of the reinforcement cage 3 and the spiral stirrups 4 in the pile hole 7. The top end of the spiral stirrups 4 is securely connected to the reinforcement cage 3 using a rope with a removable knot, thereby securing the spiral stirrups 4 to the outer periphery of the reinforcement cage 3, allowing the spiral stirrups 4 and the reinforcement cage 3 to be placed in the pile hole 7 together.
[0043] Reference Figure 1 , then, the workers used steel strands 5 to connect the steel cage 3 and the spiral stirrups 4. Along the length direction of the steel cage 3, there are several steel strands 5, and several steel strands 5 are arranged at intervals, and one end of the steel strand 5 is fixedly connected to the steel cage 3, and different steel strands 5 are fixedly connected to the coils at different positions of the spiral stirrups 4. In this embodiment, nuts are welded on the steel cage 3 and the bolt stirrups, the ends of the steel strands 5 are passed through the nuts, and the ends of the steel strands 5 are fixedly connected by rope clips. It is worth noting that at this time, the steel strands 5 are in a relaxed state, that is, the straight line length between the connection points at both ends of the steel strands 5 is less than the length of the steel strands 5; thereby reserving space for the coils in the spiral stirrups 4 to fall.
[0044] Reference Figure 1 and Figure 2 After the steel cage 3 is placed in the pile hole 7, the main body of the spiral stirrup 4 is set in the expanded bottom hole 72, and the spiral stirrup 4 extends to the straight hole 71. Subsequently, the staff pulls the rope to release the connection between the top of the spiral stirrup 4 and the steel cage 3. Under the action of gravity and the deformation of the spiral stirrup 4 itself, the coils in the spiral stirrup 4 move vertically downward, and the coil diameter of the spiral stirrup 4 continues to increase; until the steel strand 5 between the steel cage 3 and the spiral stirrup 4 is straightened, the spiral stirrup 4 stops moving downward. At this point, the main body of the spiral stirrup 4 is set in the expanded bottom portion 22, and the top of the spiral stirrup 4 extends into the flat air; several steel strands 5 are fixedly connected to the coils of the spiral stirrup 4 at different heights, so that a certain distance is maintained between adjacent coils of the spiral stirrup 4 to allow for the passage of concrete. Finally, the staff pours concrete into the pile hole 7 and vibrates the concrete, thus forming a cast-in-place expanded bottom pile.
[0045] The expanded-base pile section 2 comprises a first section 23 and a second section 24. The gradually varying cross-sectional area of the first section 23 facilitates the collapse of the spiral stirrups 4, facilitating construction. Furthermore, the first section 23 facilitates force transfer between the straight pile section 1 and the expanded-base pile section 2, minimizing concrete damage at the edges of the cast-in-place expanded-base pile and further enhancing its bearing capacity.
[0046] That is, after the grouting of the cast-in-place expanded-base pile is completed, the steel cage 3 is buried in the main part 21 of the straight pile section 1 and the expanded-base pile section 2, and the main body of the spiral stirrup 4 is set in the expanded base part 22 of the expanded-base pile section 2.
[0047] The implementation principle of a foundation cast-in-place expanded bottom pile in the embodiment of the present application is as follows:
[0048] Reference Figure 1 and Figure 2 Since the spiral stirrups 4 are buried in the expanded bottom part 22 of the expanded bottom pile segment 2, the spiral stirrups 4 have a restraining effect on the concrete of the expanded bottom part 22, thereby improving the integrity of the main part 21 and the expanded bottom part 22 in the expanded bottom pile segment 2, and improving the bearing capacity of the cast-in-place expanded bottom pile.
[0049] Reference Figure 2 Since the spiral stirrups 4 are arranged in the expanded bottom part 22 of the expanded bottom pile segment 2 and the straight pile segment 1, there is a steel bar connection between the expanded bottom part 22 and the straight pile segment 1, which can improve the shear resistance of the expanded bottom part 22 in the cast-in-place expanded bottom pile, thereby further improving the bearing capacity of the cast-in-place expanded bottom pile.
[0050] In this embodiment, the spiral stirrups 4 are ribbed steel bars to enhance the engagement between the spiral stirrups 4 and the concrete, thereby fully utilizing the spiral stirrups 4, improving the integrity between the expanded base portion 22 and the main body portion 21 of the cast-in-place expanded base pile, and thereby increasing the bearing capacity of the cast-in-place expanded base pile. In other embodiments, the spiral stirrups 4 may also be plain round steel bars.
[0051] In addition, when the staff vibrates the concrete, the staff can contact the vibrating head of the vibrating equipment with the steel strand 5 and the spiral stirrups 4; thereby the vibrating head drives the steel strand 5 and the bolt stirrups to vibrate, so that the steel strand 5 and the spiral stirrups 4 vibrate the concrete of the expanded bottom part 22, so as to improve the structural strength of the concrete of the expanded bottom part 22, and further improve the bearing capacity of the cast-in-place expanded bottom pile.
[0052] Example 2
[0053] Reference Figures 3 to 5Several vibrating plates 6 are welded to the spiral stirrups 4. The vibrating plates 6 are spaced apart along the length of the spiral stirrups 4 and are provided with a plurality of connecting holes 61. Therefore, when the vibrating equipment drives the spiral stirrups 4 to vibrate, the vibrating plates 6 on the spiral stirrups 4 can drive the concrete to vibrate over a wider range. Furthermore, the connecting holes 61 on the vibrating plates 6 enhance the vibrating effect of the vibrating plates 6 on the concrete, thereby further improving the structural strength of the concrete in the expanded bottom portion 22.
[0054] Reference Figure 3 and Figure 5 After the grouting of the cast-in-place expanded base pile is completed, the coil diameter of the spiral stirrup 4 decreases in the direction away from the expanded base pile section 2, thereby further improving the connection strength between the expanded base portion 22 and the main body portion 21, and between the expanded base portion 22 and the straight portion in the expanded base section, thereby further improving the bearing capacity of the cast-in-place pile. The change in the coil diameter of the spiral stirrup 4 is related to the drop height of the coil. The greater the drop height of the coil, the greater the change in the coil diameter. In this embodiment, the drop height of the coils at different positions of the spiral stirrup 4 can be achieved by the length of the steel strand 5 at different positions.
[0055] The above are all preferred embodiments of the present application, and are not intended to limit the scope of protection of the present application. Therefore, any equivalent changes made based on the structure, shape, and principle of the present application should be included in the scope of protection of the present application.
Claims
1. A foundation cast-in-place expanded-bottom pile, wherein the cast-in-place expanded-bottom pile comprises a straight pile section (1) and an expanded-bottom pile section (2) integrally cast with concrete in a vertical downward direction, wherein the diameter of the expanded-bottom pile section (2) is greater than the diameter of the straight pile section (1), and the expanded-bottom pile section (2) comprises an integrally cast main body portion (21) and an expanded-bottom portion (22), wherein the main body portion (21) is located inside the vertical projection of the straight pile section (1), and the expanded-bottom portion (22) is located outside the vertical projection of the straight pile section (1); and the characteristics are: The cast-in-place expanded-base pile comprises a steel cage (3) and spiral stirrups (4), wherein the diameter of the spiral stirrups (4) is larger than the diameter of the straight pile section (1); when the steel cage (3) is processed, the bottom section of the spiral stirrups (4) is fixedly connected to the bottom of the steel cage (3), the spiral stirrups (4) are stretched, and the other end of the spiral stirrups (4) is detachably connected to the steel cage (3), at which time the diameter of the spiral stirrups (4) is smaller than the diameter of the straight pile section (1); when the cast-in-place expanded-base pile is cast, the steel cage (3) is buried in the main body (21) of the straight pile section (1) and the expanded-base pile section (2), and the main body of the spiral stirrups (4) is arranged in the expanded-base part (22) of the expanded-base pile section (2).
2. The foundation cast-in-place expanded bottom pile according to claim 1, characterized in that: The cast-in-place expanded base pile further comprises a steel strand (5), one end of the steel strand (5) being fixedly connected to the reinforcement cage (3), and the other end of the steel strand (5) being fixedly connected to the spiral stirrup (4).
3. The foundation cast-in-place expanded bottom pile according to claim 2, characterized in that: A plurality of steel strands (5) are provided, and the plurality of steel strands (5) are spaced apart along the length direction of the reinforcement cage (3). The plurality of steel strands (5) are fixedly connected to coils of the spiral stirrups (4) at different heights.
4. The foundation cast-in-place expanded bottom pile according to claim 3, characterized in that: After the grouting of the cast-in-place expanded-base pile is completed, the coil diameter of the spiral stirrup (4) decreases in a direction away from the expanded-base pile section (2).
5. The foundation cast-in-place expanded bottom pile according to claim 1, characterized in that: The spiral stirrups (4) are ribbed steel bars.
6. The foundation cast-in-place expanded bottom pile according to claim 1, characterized in that: Along the direction away from the straight pile section (1), the expanded bottom pile section (2) comprises a first pile section (23) and a second pile section (24); and along the direction away from the straight pile section (1), the diameter of the first pile section (23) increases gradually.
7. The foundation cast-in-place expanded bottom pile according to claim 6, characterized in that: A plurality of vibrating plates (6) are further welded to the spiral stirrup (4), and the plurality of vibrating plates (6) are arranged at intervals along the length direction of the spiral stirrup (4).
8. The foundation cast-in-place expanded bottom pile according to claim 7, characterized in that: The vibrating plate (6) is also provided with a plurality of communicating holes (61).