Precast pile and pile end mechanism thereof

Abstract

The utility model discloses a pile end mechanism of a precast pile, which comprises an end plate and a sleeve, and one end of the sleeve is fixedly connected with the end plate; a plurality of through holes are formed in the side wall of the sleeve; the area of the end plate is larger than the cross sectional area of the sleeve. The utility model further relates to the precast pile with the pile end mechanism, the pile end mechanism is fixed at the lower end of the precast pile main body, and the inner cavity of the sleeve is communicated with the cavity of the precast pile main body. The utility model further relates to a precast pile. The bearing capacity of the precast pile can be improved, the construction procedure can be simplified, and the construction efficiency can be improved.

Description

Technical Field

[0001] This utility model relates to a precast pile and its pile end mechanism, belonging to the field of pile foundation engineering technology. Background Technology

[0002] The traditional precast pile installation process mainly includes the following steps: 1. Drilling to the designed depth using mechanical drilling equipment 6; 2. Injecting cement grout, cement mortar, or fine stone concrete (collectively referred to as grout 4) into the lower half of the hole; 3. Inserting the precast pile into the hole, with the diameter of the precast pile slightly smaller than the diameter of the drilled hole, and the mortar in the hole filling the gap between the precast pile and the hole wall under the pressure of the precast pile; 4. Pressing or hammering the precast pile into the bearing layer at the bottom of the hole using pile driving machinery 5.

[0003] The bearing capacity of precast piles relies primarily on two aspects: the end (bottom) resistance of the pile and the friction between the side surface of the precast pile and the borehole wall. Current technology uses mechanical drilling equipment, which can only produce circular holes, and since precast piles are also circular, the limited surface area of ​​the precast pile results in relatively low friction between the side surface of the precast pile and the borehole wall, failing to fully utilize the bearing capacity of the precast pile. Furthermore, in softer soils, the drilled holes are prone to collapse, requiring repeated drilling operations, which is detrimental to improving construction efficiency. Simultaneously, the use of mechanical drilling equipment and the removal of excavated soil not only increases construction steps but also increases construction costs. Utility Model Content

[0004] This utility model provides a precast pile and its pile end mechanism, which helps to reduce construction procedures and improve the bearing capacity of precast piles. The specific technical solution is as follows.

[0005] A pile end mechanism for a precast pile, characterized in that it comprises: an end plate and a sleeve, one end of the sleeve being fixedly connected to the end plate; a plurality of through holes are provided on the side wall of the sleeve; and the area of ​​the end plate is larger than the cross-sectional area of ​​the sleeve.

[0006] Furthermore, a first rib is fixedly provided inside the sleeve, the first rib being perpendicular to the end plate and fixedly connected to both the end plate and the sleeve. By providing the first rib, the overall strength of the pile end mechanism is improved, preventing significant deformation.

[0007] Furthermore, a second rib is provided below the end plate, the second rib being perpendicular to the end plate and fixedly connected to it; preferably, four second ribs are distributed in a cross shape below the end plate. By providing the second ribs, the rigidity of the end plate is improved, which helps prevent or reduce bending at the end; furthermore, the generally vertical second ribs help ensure that the entire precast pile remains vertical when pressed into the soil, preventing or reducing tilting. Preferably, the lower outer end of the second rib is chamfered.

[0008] Furthermore, the pile end mechanism is made of metal. Preferably, it is made of welded steel.

[0009] Based on the same inventive concept, this utility model also relates to a precast pile, including a precast pile body, characterized in that the precast pile body has a cavity inside, and the above-mentioned pile end mechanism is fixedly provided at the lower end of the precast pile body.

[0010] The upper end of the sleeve of the pile end mechanism is fixedly connected to the lower end of the precast pile body, and the lower end of the sleeve is fixedly connected to the end plate; the inner cavity of the sleeve is connected to the cavity; the area of ​​the end plate is larger than the cross-sectional area of ​​the sleeve and also larger than the cross-sectional area of ​​the precast pile body.

[0011] Using the above technical solution, during on-site construction, only the pile end mechanism needs to be fixed to the lower end of the precast pile body. No modifications to the existing precast pile body are required. The precast pile is then driven into the soil using pile driving machinery. Because the end plate's area is larger than the cross-sectional area of ​​the precast pile body, the end plate is pushed into the soil during the driving process, creating a pile hole with a cross-sectional area larger than that of the precast pile body. Simultaneously, grout is placed in the cavity of the precast pile body. As the precast pile is continuously driven into the soil, the grout fills the gap between the precast pile body and the pile hole through the through-hole of the sleeve. On the one hand, it eliminates the need for separate mechanical drilling equipment, reducing construction steps; on the other hand, it increases the bearing capacity of the precast pile. The larger area of ​​the end plate compared to the cross-sectional area of ​​the precast pile body not only increases the pile end resistance but also helps to expand the sidewall area of ​​the pile hole, thereby increasing the friction between the side surface of the precast pile and the hole wall.

[0012] Furthermore, the edge of the end plate is serrated. Compared to a circular end plate, the serrated end plate has a significantly increased perimeter, thereby increasing the borehole wall area and thus improving the friction between the precast pile and the borehole wall. In contrast, traditional construction methods using mechanical drilling equipment can only form circular boreholes, not serrated (irregular) boreholes.

[0013] Furthermore, the end plate comprises a square main body and four right-angled isosceles triangles located in the same plane, with the four right-angled isosceles triangles respectively fixed to the center of the four edges of the square main body. The end plate is typically formed from steel plate, which helps save steel consumption. The four right-angled isosceles triangles can be cut from a square steel plate and then welded to the square main body to form a complete end plate. Preferably, each corner of the end plate is machined with a right-angled notch. The right-angled notch helps prevent (or reduce) bending (warping) of the end plate when it is pressed into the soil, without reducing the perimeter of the end plate.

[0014] Compared with the prior art, this utility model has the following beneficial effects.

[0015] 1. Traditional mechanical drilling produces round holes, which are difficult to form serrated holes. Serrated holes have a larger perimeter and greater lateral friction for the same cross-sectional area. The solution of this utility model is beneficial to improving the bearing capacity of precast piles.

[0016] 2. Traditional mechanical drilling is prone to hole collapse. This utility model of precast piles can be grouted while drilling, eliminating the risk of repeated drilling caused by hole collapse.

[0017] 3. The construction method of the precast pile of this utility model belongs to the complete soil displacement pile formation, the soil at the pile bottom is squeezed and compacted, and the resistance at the pile end is greater;

[0018] 4. When it is required that the surface of the precast pile body be coated with anti-corrosion material, the end plate with a larger area can reduce the friction between the soil and the pile body during the pile driving process, which is beneficial to protect the anti-corrosion coating and improve the anti-corrosion performance of the precast pile.

[0019] 5. It does not require changing the existing structure of the precast pile body; it only requires fixing the pile end mechanism to the lower end of the precast pile body, making it highly operable.

[0020] 6. During construction, the top of the pile is higher than the ground. The grout can be automatically injected into the pile hole through the cavity inside the precast pile body under the action of gravity, without the need to apply additional grouting pressure. Compared with the traditional post-grouting method of precast piles (injecting grout into the pile hole through pre-embedded grouting pipes), it is simpler, more efficient, saves construction time and costs.

[0021] 7. The chemical reactions such as cement hydration in the grout solidify the precast pile body and the soil of the pile hole wall into a whole. The soil of the hole wall does not experience stress relaxation. That is, the pile hole wall is filled and protected by the grout, which effectively improves the friction of the pile side. In contrast, traditional pile planting technology is prone to stress relaxation of the hole wall.

[0022] 8. Because the voids on the pile side are filled with fluid slurry during the pile driving process, the contact between the pile side and the surrounding soil is lubricated, which greatly reduces the pile side friction during the pile driving process, reduces the pile driving side resistance and the difficulty of pile driving construction.

[0023] 9. Since the pile hole is slightly larger than the pile body, if the verticality of the pile body is found to be insufficient during the pile driving process, it can be adjusted immediately and the pile driving can continue. The verticality is relatively controllable, which is conducive to improving the verticality of the precast pile. Attached Figure Description

[0024] Figure 1 This is a schematic diagram of the existing precast pile construction process;

[0025] Figure 2 This is a partial schematic diagram of the precast pile of this utility model;

[0026] Figure 3 This is a cross-sectional schematic diagram of the pile end mechanism (the cross-section passes through the through hole);

[0027] Figure 4 This is a schematic diagram of a pile end mechanism with serrated end plates;

[0028] Figure 5 This is a bottom view of the pile end mechanism;

[0029] Figure 6 This is a schematic diagram of the precast pile construction process of this utility model;

[0030] Figure 7 yes Figure 6 A magnified view of region A in the middle.

[0031] In the diagram: 1. Precast pile body, 1.1. Pile end mechanism, 2. End plate, 2.1. Square body, 2.1.1. Right-angled isosceles triangle, 2.1.2. Right-angled notch, 2.1.3. Sleeve, 2.2. Through hole, 2.3. First rib, 2.4. Second rib, 2.5. Chamfer, 2.5.1. Pile hole, 3. Grout, 4. Pile driving machinery, 5. Mechanical drilling equipment, 6. Detailed Implementation

[0032] The present invention will now be described in further detail with reference to the accompanying drawings.

[0033] See Figures 2-7 A precast pile includes a precast pile body 1, the precast pile body 1 having a cavity 1.1 inside, and a pile end mechanism 2 fixedly installed at the lower end of the precast pile body 1.

[0034] The pile end mechanism 2 includes an end plate 2.1 and a sleeve 2.2. The upper end of the sleeve 2.2 is fixedly connected to the lower end of the precast pile body 1, and the lower end of the sleeve 2.2 is fixedly connected to the end plate 2.1. The inner cavity of the sleeve 2.2 communicates with the cavity 1.1 of the precast pile body 1. Several through holes 2.3 are provided on the side wall of the sleeve 2.2. Figure 3The image shows several through holes evenly distributed around the circumference of the sleeve 2.2; the area of ​​the end plate 2.1 is larger than the cross-sectional area of ​​the sleeve 2.2 and also larger than the cross-sectional area of ​​the precast pile body 1.

[0035] Preferably, such as Figure 4 As shown, the edge of end plate 2.1 is serrated. Compared with the circular end plate 2.1, the serrated end plate 2.1 has a significantly increased perimeter, thereby increasing the hole wall area of ​​the pile hole 3 and thus improving the friction between the precast pile and the hole wall. In contrast, traditional construction methods using mechanical drilling equipment can only form circular pile holes 3, and cannot form serrated (irregular) pile holes 3.

[0036] Preferably, such as Figure 3 As shown, the end plate 2.1 includes a square main body 2.1.1 and four right-angled isosceles triangles 2.1.2 located in the same plane. The four right-angled isosceles triangles 2.1.2 are respectively fixed to the center of the four edges of the square main body 2.1.1. The end plate 2.1 is usually formed from steel plate. This method helps to save steel. The four right-angled isosceles triangles 2.1.2 can be cut from a square steel plate and then welded to the square main body 2.1.1 to form a complete end plate 2.1. Preferably, as shown... Figure 4 , Figure 5 As shown, each corner of end plate 2.1 is machined with a right-angle notch 2.1.3. The right-angle notch 2.1.3 helps to prevent (or reduce) bending (warping) of end plate 2.1 when it is pressed into the soil, without reducing the perimeter of end plate 2.1. Figure 4 The end plate 2.1 is formed into a sawtooth end plate.

[0037] Preferably, such as Figure 3 As shown, a first rib 2.4 is fixedly installed inside the sleeve 2.2. The first rib 2.4 is perpendicular to the end plate 2.1 and is fixedly connected to both the end plate 2.1 and the sleeve 2.2. By setting the first rib 2.4, the overall strength of the pile end mechanism 2 is improved, and large deformation is prevented.

[0038] Preferably, such as Figure 2 , Figure 4As shown, a second rib 2.5 is provided below the end plate 2.1. The second rib 2.5 is perpendicular to the end plate 2.1 and is fixedly connected to the end plate 2.1. Preferably, four second ribs 2.5 are distributed in a cross shape below the end plate 2.1. By providing the second ribs 2.5, the rigidity of the end plate 2.1 is improved, which helps to prevent or reduce bending at the end. On the other hand, the generally vertical second ribs 2.5 help to ensure that the entire precast pile remains vertical when pressed into the soil, preventing or reducing tilting of the precast pile. Preferably, the lower outer end of the second rib 2.5 is provided with a chamfer 2.5.1.

[0039] Preferably, the pile end mechanism 2 is made of metal material, and more preferably it is made of welded steel.

[0040] Using the technical solution of this utility model, during on-site construction, it is only necessary to fix the pile end mechanism 2 to the lower end of the precast pile body 1 without making any modifications to the existing precast pile body 1. The precast pile is pressed into the soil using pile driving machinery. Since the area of ​​the end plate 2.1 is larger than the cross-sectional area of ​​the precast pile body 1, the end plate 2.1 is squeezed out of the soil during the pressing process, thus forming a pile hole 3 with a cross-sectional area larger than that of the precast pile body 1. At the same time, grout is placed in the cavity 1.1 of the precast pile body 1. As the precast pile is continuously pressed into the soil, the grout is filled from the through hole 2.3 of the sleeve 2.2 into the gap between the precast pile body 1 and the pile hole 3. On the one hand, it eliminates the need for separate mechanical drilling equipment, reducing construction steps; on the other hand, it improves the bearing capacity of the precast pile. The area of ​​the end plate 2.1 is larger than the cross-sectional area of ​​the precast pile body 1, which not only increases the pile end resistance but also helps to expand the side wall area of ​​the pile hole 3, thereby increasing the friction between the side surface of the precast pile and the hole wall. The lower end of existing precast piles already has a metal sealing plate. When using the pile end mechanism 2 of this utility model, there is no need to change the structure of the existing precast pile, which greatly improves its practicality.

[0041] like Figure 6 , Figure 7 As shown, the construction process of the precast piles of this utility model mainly includes the following steps:

[0042] 1. The pile end mechanism 2 is fixed to the lower end of the precast pile body 1. The fixation between the two can be achieved by welding or fasteners.

[0043] 2. Using pile driving machinery, the precast pile is pressed into the soil, and the end plate 2.1 squeezes the soil to form the pile hole 3; during the process of forming the pile hole 3, the grout 4 in the cavity 1.1 of the precast pile body 1 continuously flows from the through hole 2.3 of the sleeve 2.2 into the gap between the precast pile body 1 and the pile hole 3.

[0044] 3. When the precast pile reaches the designed depth, the grout 4 fills the gap between the precast pile body 1 and the pile hole 3. After the grout 4 solidifies, the precast pile construction is completed.

[0045] The embodiments of this utility model have been described above with reference to the accompanying drawings. Unless otherwise specified, the embodiments and features described herein can be combined with each other. This utility model is not limited to the specific embodiments described above; the specific embodiments described above are merely illustrative and not limiting. Those skilled in the art, under the guidance of this utility model, can make many modifications without departing from the spirit and scope of the claims, and all such modifications fall within the protection scope of this utility model.

Claims

1. A pile end mechanism for a precast pile, characterized in that, include: An end plate (2.1) and a sleeve (2.2) are provided, one end of which is fixedly connected to the end plate (2.1); a plurality of through holes (2.3) are provided on the side wall of the sleeve (2.2); the area of ​​the end plate (2.1) is larger than the cross-sectional area of ​​the sleeve (2.2).

2. The pile end mechanism of a precast pile according to claim 1, characterized in that, The sleeve (2.2) is fixedly provided with a first rib (2.4), which is perpendicular to the end plate (2.1) and is fixedly connected to both the end plate (2.1) and the sleeve (2.2).

3. The pile end mechanism of a precast pile according to claim 1, characterized in that, A second rib (2.5) is provided below the end plate (2.1), the second rib (2.5) is perpendicular to the end plate (2.1), and the second rib (2.5) is fixedly connected to the end plate (2.1).

4. The pile end mechanism of a precast pile according to claim 3, characterized in that, The four second ribs (2.5) are arranged in a cross shape below the end plate (2.1).

5. The pile end mechanism of a precast pile according to claim 3, characterized in that, The lower outer end of the second rib (2.5) is provided with a chamfer (2.5.1).

6. The pile end mechanism of a precast pile according to claim 1, characterized in that, The pile end mechanism is made of metal.

7. A precast pile, comprising a precast pile body (1), characterized in that, The precast pile body (1) has a cavity (1.1) inside, and the lower end of the precast pile body (1) is fixedly provided with a pile end mechanism (2) as described in any one of claims 1-6; The upper end of the sleeve (2.2) of the pile end mechanism (2) is fixedly connected to the lower end of the precast pile body (1), and the lower end of the sleeve (2.2) is fixedly connected to the end plate (2.1); the inner cavity of the sleeve (2.2) is connected to the cavity (1.1); the area of ​​the end plate (2.1) is larger than the cross-sectional area of ​​the sleeve (2.2) and also larger than the cross-sectional area of ​​the precast pile body (1).

8. A precast pile according to claim 7, characterized in that, The edge of the end plate (2.1) is serrated.

9. A precast pile according to claim 7, characterized in that, The end plate (2.1) includes a square main body (2.1.1) and four right-angled isosceles triangles (2.1.2) located in the same plane. The four right-angled isosceles triangles (2.1.2) are respectively fixed to the middle of the four edges of the square main body (2.1.1).

10. A precast pile according to claim 9, characterized in that, Each corner of the end plate (2.1) is machined with a right-angle notch (2.1.3).

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