Expanded-base precast pile

Abstract

The utility model discloses an expanded-base precast pile. The expanded-base precast pile comprises a precast pile body, a pile tip assembly and a penetrating rib plate, a third rib plate and a fourth rib plate are formed at the two ends of the penetrating rib plate respectively; the pile tip assembly comprises a first pile tip assembly, a second pile tip assembly and a mounting plate, and the mounting plate is fixed to the lower end of the precast pile body; the first pile tip assembly comprises a first hinge plate and a first rib plate, and the second pile tip assembly comprises a second hinge plate and a second rib plate; the first hinge plate and the second hinge plate are hinged to the mounting plate; when the first pile tip assembly and the second pile tip assembly are in a first state, the first hinge plate and the second hinge plate are parallel to the axial direction of the precast pile body; when the first pile tip assembly and the second pile tip assembly are in the second state, the first hinge plate abuts against the lower edge of the third rib plate, and the second hinge plate abuts against the lower edge of the fourth rib plate. According to the utility model, the resistance at the pile end is improved, the pile length or the number of piles can be reduced, and a large amount of construction cost and construction period are saved.

Description

Technical Field

[0001] This utility model relates to an enlarged-base precast pile, belonging to the field of precast pile technology. Background Technology

[0002] Precast piles (represented by prestressed concrete pipe piles and hollow square piles) have significant advantages over traditional cast-in-place piles in terms of pile integrity, construction period, and economy, and are widely promoted and applied in the engineering industry. However, when the overburden layer on the bedrock is thin, the short pile length results in lower single-pile bearing capacity and poor economic efficiency. Furthermore, under heavy loads (such as high-rise buildings), pile placement becomes difficult, rendering this type of pile unfeasible. In geological conditions with deep overburden layers, the thickness of the soft soil layer is very large, making it difficult to achieve the required pile driving conditions (design-required hammer penetration or static pressure pile final driving force), leading to excessively long piles and higher costs.

[0003] Because the mainstream precast pile type has a small cross-sectional area, with the pile bottom area equal to the pile body cross-sectional area, the pile end resistance is low, resulting in a relatively low single pile bearing capacity. In my country's inland hilly areas, the geological strata are highly varied, and most building foundations are located in geological conditions with thin overburden layers, making it difficult to fully utilize the advantage of the larger bearing capacity of precast piles. At the same time, there are also many geological conditions with deep overburden layers, leading to excessively long piles and higher costs. The main reason for this is that the commonly used pile tip (flat-bottomed cross-shaped pile tip) of existing precast piles has a very small end-resistance area, and the contribution of pile end resistance to the pile foundation bearing capacity is relatively small.

[0004] The applicant's prior Chinese invention patent application (application number: 202411358496X) and Chinese utility model patent application (application number: 2024223743101) both describe precast piles with enlarged base devices and precast pile construction methods. This utility model application is a further improvement and perfection based on the original scheme. Utility Model Content

[0005] In order to overcome the problem of low end resistance of precast piles in the prior art, this utility model provides an enlarged base precast pile, and the specific technical solution is as follows.

[0006] An enlarged-base precast pile, characterized in that it comprises: a precast pile body, a pile tip assembly, and a through rib plate;

[0007] The lower end of the precast pile body is provided with the through rib plate, the through rib plate is parallel to the axial direction of the precast pile body, and the two ends of the through rib plate protrude from the outer surface of the precast pile body to form the third rib plate and the fourth rib plate respectively.

[0008] The pile tip assembly includes a first pile tip assembly, a second pile tip assembly, and a mounting plate, the mounting plate being fixed to the lower end of the precast pile body; the first pile tip assembly includes a first hinge plate and a first rib plate, the first rib plate being perpendicular to the first hinge plate; the second pile tip assembly includes a second hinge plate and a second rib plate, the second rib plate being perpendicular to the second hinge plate.

[0009] Both the first hinge plate and the second hinge plate are hinged to the mounting plate, and the hinge axis of the first hinge plate and the mounting plate is parallel to the hinge axis of the second hinge plate and the mounting plate.

[0010] The first rib and the second rib are located in the same plane. The first rib has a first hole and the second rib has a second hole.

[0011] When the first pile tip assembly and the second pile tip assembly are in the first state, the first hinge plate and the second hinge plate are parallel to the axial direction of the precast pile body; when the first pile tip assembly and the second pile tip assembly are in the second state, the first hinge plate abuts against the lower edge of the third rib, and the second hinge plate abuts against the lower edge of the fourth rib.

[0012] Using the above technical solution, the first rib and the second rib are respectively provided with a first hole and a second hole, which can be used to install a locking mechanism. When the first pile tip assembly and the second pile tip assembly are in the first state, the locking mechanism locks the relative position between the first pile tip assembly and the second pile tip assembly, preventing them from rotating relative to the mounting plate. When the locking mechanism is unlocked, the first pile tip assembly and the second pile tip assembly can rotate relative to the mounting plate, rotating from the first state to the second state. When the first pile tip assembly and the second pile tip assembly are in the second state, the bearing area at the bottom of the precast pile is increased, significantly increasing the pile end resistance. The first rib and the second rib, on the one hand, enhance the structural strength of the first hinge plate and the second hinge plate, and on the other hand, provide an installation position for the locking mechanism, achieving the purpose of reliably locking the relative position of the first pile tip assembly and the second pile tip assembly. Furthermore, when in the first state, the upper ends of the first rib and the second rib are pressed against the bottom of the mounting plate, and the relative positional relationship of the first rib and the second rib is fixed by the locking mechanism. In the early stage of the pile driving process, this helps to prevent the pile tip assembly from rotating or tilting as a whole, thus preventing the precast pile body from tilting during the pile driving process. Furthermore, the third and fourth ribs provide reliable support for the first and second pile tip assemblies, preventing them from becoming unstable cantilever structures relative to the mounting plate in the second state. Additionally, this invention cleverly places the through rib at the lower end of the precast pile body, which not only improves the strength of the lower end of the precast pile body but also reduces the amount of steel used compared to the applicant's prior art mentioned in the background section.

[0013] Furthermore, grooves are provided on both sides of the lower end of the third rib and the fourth rib. A claw is provided on the side of the first hinge plate opposite to the first rib, and a claw is also provided on the side of the second hinge plate opposite to the second rib. The claws correspond to the grooves. When the first pile tip assembly and the second pile tip assembly are in the second state, the claws can engage in the grooves, thereby fixing the first pile tip assembly to the third rib and the second pile tip assembly to the fourth rib, thus improving the pull-out bearing capacity of the precast pile. By setting the third and fourth ribs, not only the compressive bearing capacity of the precast pile is improved, but also its pull-out bearing capacity. Preferably, the groove is a toothed groove extending vertically, and the claw is a toothed claw. The advantage of setting the toothed groove is that even if affected by slag or other factors, not all the teeth of the toothed claw can engage in the toothed groove, but at least some teeth can engage in the corresponding toothed groove, improving the reliability and fault tolerance of the entire device.

[0014] Furthermore, the lower end of the precast pile body has an end plate, and the mounting plate is fixedly connected to the end plate. Preferably, the end plate has screw holes, and the mounting plate is fixedly connected to the end plate by bolts. Existing precast pile bodies already have metal end plates, and these end plates have pre-drilled screw holes. Therefore, the solution of this utility model does not require significant modifications to existing precast piles. It should be noted that the mounting plate and the end plate can also be fixedly connected by welding.

[0015] Furthermore, it also includes a locking mechanism having a rope passing through the first hole and the second hole, the rope extending to the top of the precast pile body. When the rope simultaneously crosses the first hole and the second hole, the relative position between the first pile tip assembly and the second pile tip assembly is locked. When unlocking is required, the relative position between the first pile tip assembly and the second pile tip assembly can be unlocked simply by withdrawing the rope from the first hole and / or the second hole.

[0016] Furthermore, both the first and second hinge plates employ variable thickness sections, meaning the thickness in the middle is greater than the thickness at the edges. The smaller edge thickness of the first and second hinge plates reduces end-face resistance and pile driving resistance during the pile driving process, while also reducing the material usage and cost of the hinge plates.

[0017] Furthermore, the first rib and the second rib abut against each other. The first rib has several protrusions and / or recesses near the edge of the second rib, and the second rib has several recesses and / or protrusions near the edge of the first rib. The recesses and protrusions of the first and second ribs match each other. Through the mutual cooperation and abutment of the recesses and protrusions, the contact surface of the first and second ribs can effectively transmit shear force in the first state (locked state), avoiding the impact of the swaying of the pile tip assembly on the normal functioning of the locking mechanism and the verticality of the pile during the pile driving process.

[0018] Furthermore, stiffening plates are provided at the upper ends of both the first and second ribs. When the first and second pile tip assemblies are in the first state, the stiffening plates are in contact with the mounting plate. The stiffening plates can improve the stability and torsional resistance of the pile tip assembly. At the same time, the soil pressure exerted by the pile driving on the stiffening plates can offset part of the torque generated by the unbalanced soil pressure on the pile tip assembly and reduce the tension borne by the locking mechanism (this tension is directly proportional to the torque), thereby improving the reliability and operability of the locking mechanism.

[0019] Compared to existing technologies, this invention features a locked relationship between the first and second pile tip components during the precast pile driving process. The first and second pile tip components are roughly vertical, with a very small end-resistance area, resulting in minimal increase in driving resistance and construction difficulty. Once the relationship between the first and second pile tip components is unlocked, they automatically rotate outwards and open as the pile is driven (either by pressing down or hammering the precast pile). This results in an end-resistance area at the pile bottom that is much larger than the pile body area, significantly increasing the end resistance and effectively improving the single pile bearing capacity. This saves on pile length or the number of piles, resulting in substantial savings in construction costs and time. Furthermore, when the first pile tip component is fixed to the third rib and the second pile tip component is fixed to the fourth rib, an expanded-base pull-out structure is formed, further enhancing the pull-out bearing capacity of the precast pile. This superior pull-out bearing capacity makes precast piles more economical than anti-buoyancy anchors, simplifying construction and saving time.

[0020] In geological conditions with thin overburden, the advantage of the large bearing capacity of pipe piles can be fully utilized, making the pipe pile scheme feasible; in geological conditions with deep overburden, the pile length can be effectively controlled, the pile length can be optimized, and losses can be reduced. Attached Figure Description

[0021] Figure 1 This is a construction schematic diagram of the enlarged-base precast pile of this utility model;

[0022] Figure 2 This is a schematic diagram of the precast pile with enlarged base according to this utility model (the first pile tip assembly and the second pile tip assembly are in the first state);

[0023] Figure 3 This is a schematic diagram of the precast pile body and the through rib plate;

[0024] Figure 4 yes Figure 3 Schematic diagram of section AA;

[0025] Figure 5 This is a schematic diagram of the pile tip assembly;

[0026] Figure 6 This is an exploded view of the first pile tip assembly and the second pile tip assembly;

[0027] Figure 7 This is a bottom view of the pile tip assembly;

[0028] Figure 8 This is a schematic diagram of the precast pile with enlarged base according to this utility model (the first pile tip assembly and the second pile tip assembly are in the second state);

[0029] Figure 9This is a bottom view of the precast pile with enlarged base according to this utility model (the first pile tip assembly and the second pile tip assembly are in the second state);

[0030] Figure 10 This is a schematic diagram of the third rib and the groove;

[0031] Figure 11 This is a schematic diagram of the first hinge plate and the chuck;

[0032] Figure 12 This is a schematic diagram of the engagement between the third rib and the first hinge plate.

[0033] In the diagram: 1. Precast pile body, 1.1. Channel, 1.2. End plate, 2. Pile tip assembly, 2.1. Mounting plate, 2.2. First pile tip assembly, 2.2.1. First hinge plate, 2.2.2. Second rib, 2.3. Second hinge plate, 2.3.1. Second rib, 2.3.2. First hole, 2.4. Second hole, 2.5. Locking mechanism, 2.6. Protrusion, 2.7. Recess, 2.8. Stiffening plate, 2.9. Through rib, 3. Third rib, 3.1. Fourth rib, 3.2. Groove, 5. Toothed groove, 5.1. Claw, 6. Toothed claw, 6.1. Foundation soil layer, 7. Pile driving machinery, 8. Detailed Implementation

[0034] The present invention will now be described in further detail with reference to the accompanying drawings.

[0035] See Figures 1-12 An enlarged-base precast pile includes a precast pile body 1, a pile tip assembly 2, and a through rib plate 3; wherein, the precast pile body 1 is the prior art, the precast pile body 1 is a concrete pipe pile or a hollow (or solid) square pile, and the cross-section of the precast pile body 1 is circular, square, or rectangular, etc.; the pile tip assembly 2 is fixed to the lower end of the precast pile body 1.

[0036] A through rib 3 is provided at the lower end of the precast pile body 1. The through rib 3 is parallel to the axial direction of the precast pile body 1. The two ends of the through rib 3 protrude from the outer surface of the precast pile body 1 to form the third rib 3.1 and the fourth rib 3.2 respectively. A through hole can be provided in the middle of the through rib 3, which is beneficial to make the concrete more evenly distributed when the precast pile body 1 is centrifugally manufactured.

[0037] like Figures 5-9As shown, the pile tip assembly 2 includes a first pile tip assembly 2.2, a second pile tip assembly 2.3, and a mounting plate 2.1. The mounting plate 2.1 is fixed to the lower end of the precast pile body 1. The first pile tip assembly 2.2 includes a first hinge plate 2.2.1 and a first rib plate 2.2.2, with the first rib plate 2.2.2 perpendicular to the first hinge plate 2.2.1. The second pile tip assembly 2.3 includes a second hinge plate 2.3.1 and a second rib plate 2.3.2, with the second rib plate 2.3.2 perpendicular to the first hinge plate 2.2.1. Two hinge plates 2.3.1; both the first hinge plate 2.2.1 and the second hinge plate 2.3.1 are hinged to the mounting plate 2.1, and the hinge axis of the first hinge plate 2.2.1 and the mounting plate 2.1 is parallel to the hinge axis of the second hinge plate 2.3.1 and the mounting plate 2.1; the first rib 2.2.2 and the second rib 2.3.2 are located in the same plane, the first rib 2.2.2 is provided with a first hole 2.4, and the second rib 2.3.2 is provided with a second hole 2.5.

[0038] like Figures 3-4 As shown, the lower end of the precast pile body 1 has an end plate 1.2, and an mounting plate 2.1 is fixedly connected to the end plate 1.2. The end plate 1.2 and the mounting plate 2.1 are adapted to the cross-sectional shape of the precast pile body 1, that is, the cross-sectional contours of the end plate 1.2 and the mounting plate 2.1 are the same as the cross-sectional contours of the precast pile body 1. Preferably, the end plate 1.2 has screw holes (not shown), and the mounting plate 2.1 is fixedly connected to the end plate 1.2 by bolts (not shown). The existing precast pile body 1 itself has a metal end plate 1.2, and the end plate 1.2 has pre-drilled screw holes. Therefore, the solution of this utility model does not require major modifications to the existing precast pile.

[0039] like Figures 1-9As shown, the first rib 2.2.2 and the second rib 2.3.2 are parallel to the third rib 3.1 and the fourth rib 3.2. When the first pile tip assembly 2.2 and the second pile tip assembly 2.3 are in the first state, the first hinge plate 2.2.1 and the second hinge plate 2.3.1 are parallel to the axial direction of the precast pile body 1, and the locking mechanism 2.6 locks the relative position between the first pile tip assembly 2.2 and the second pile tip assembly 2.3, so that the first pile tip assembly 2.2 and the second pile tip assembly 2.3 cannot rotate relative to the mounting plate 2.1. When the first pile tip assembly 2.2 and the second pile tip assembly 2.3 are in the second state, the first hinge plate 2.2.1 abuts against the lower edge of the third rib 3.1, and the second hinge plate 2.3.1 abuts against the lower edge of the fourth rib 3.2. The first state corresponds to the locked positional relationship between the first pile tip assembly 2.2 and the second pile tip assembly 2.3. In this state, the first pile tip assembly 2.2 (first hinge plate 2.2.1) and the second pile tip assembly 2.3 (second hinge plate 2.3.1) are approximately vertical, which facilitates pressing the entire precast pile into the foundation soil. The vertical state of the first pile tip assembly 2.2 and the second pile tip assembly 2.3 does not significantly increase the pile driving resistance. When the first pile tip assembly 2.2 and the second pile tip assembly 2.3 are in the second state, the first hinge plate 2.2.1 and the second hinge plate 2.3.1 are approximately horizontal. Projecting along the vertical direction, the projection range of the first hinge plate 2.2.1 and the second hinge plate 2.3.1 significantly exceeds the projection range of the precast pile body 1, thereby increasing the end-resistance area at the pile bottom and improving the bearing capacity of the precast pile. The number of third ribs 3.1 (fourth ribs 3.2) can be one or more, selected according to the specific stress conditions.

[0040] like Figure 5 , Figure 6 As shown, the lower ends (offset ends) of the first hinge plate 2.2.1 and the second hinge plate 2.3.1 away from the mounting plate 2.1 are provided with inclined guide surfaces. These guide surfaces are inclined relative to the first hinge plate 2.2.1 and the second hinge plate 2.3.1, and the guide surfaces help to apply an outward rotational torque to the first hinge plate 2.2.1 and the second hinge plate 2.3.1. Of course, the lower ends of the first hinge plate 2.2.1 and the second hinge plate 2.3.1 may not have inclined guide surfaces; that is, the lower ends may be provided with horizontal end faces.

[0041] In a preferred embodiment, such as Figures 10-12As shown, grooves 5 are provided on both sides of the lower end of the third rib 3.1 and the fourth rib 3.2. A claw 6 (arranged in pairs) is provided on the side of the first hinge plate 2.2.1 opposite to the first rib 2.2.2. A claw 6 is also provided on the side of the second hinge plate 2.3.1 opposite to the second rib 2.3.2. The claws 6 correspond to the grooves 5. When the first pile tip assembly 2.2 and the second pile tip assembly 2.3 are in the second state, the claws 6 can engage in the grooves 5, thereby fixing the first pile tip assembly 2.2 to the third rib 3.1 and the second pile tip assembly 2.3 to the fourth rib 3.2, thus improving the pull-out bearing capacity of the precast pile. By setting the third rib 3.1 and the fourth rib 3.2, not only is the compressive bearing capacity of the precast pile improved, but also its pull-out bearing capacity. Preferably, as shown... Figures 10-12 As shown, groove 5 is a toothed groove 5.1 extending vertically (i.e., a groove with multiple intervals along a certain direction), and claw 6 is a toothed claw 6.1 (i.e., a protrusion (claw) with multiple intervals along a certain direction). The advantage of setting toothed groove 5 is that even if affected by soil or other factors, not all the claws of the toothed claw 6.1 can be engaged in toothed groove 5.1, but at least some of the claws can be engaged in the corresponding toothed groove 5, thus improving the reliability and fault tolerance of the entire pile tip assembly. Since the groove 5 is located on both sides of the third rib 3.1 and the fourth rib 3.2, which are roughly in a vertical plane, the groove 5 is not easily jammed by gravel during the pressing of the third rib 3.1 and the fourth rib 3.2 into the foundation soil layer, making it easier for the claw 6 to be engaged. At the same time, the claw 6 is a plate-shaped structure that extends in the vertical plane. During the pressing of the first hinge plate 2.2.1 and the second hinge plate 2.3.1 into the foundation soil layer, the two claws 6 are also not easily jammed by gravel, making it easier for the claw 6 to be engaged in the groove 5.

[0042] In this invention, the first rib 2.2.2 and the second rib 2.3.2 serve two purposes: firstly, to enhance the structural strength of the first hinge plate 2.2.1 and the second hinge plate 2.3.1; secondly, to provide an installation position for the locking mechanism 2.6, thus reliably locking the relative positions of the first pile tip assembly 2.2 and the second pile tip assembly 2.3. Furthermore, the third rib 3.1 and the fourth rib 3.2 not only provide reliable support for the first pile tip assembly 2.2 and the second pile tip assembly 2.3, but also utilize a locking structure to fix the first pile tip assembly 2.2 to the third rib 3.1 and the second pile tip assembly 2.3 to the fourth rib 3.2, thereby improving the pull-out bearing capacity of the precast pile.

[0043] In a preferred embodiment, such as Figure 7As shown, both the first hinge plate 2.2.1 and the second hinge plate 2.3.1 adopt a variable thickness section, that is, the thickness in the middle is greater than the thickness at the edge. The smaller edge thickness of the first hinge plate 2.2.1 and the second hinge plate 2.3.1 can reduce the end face resistance and pile driving resistance during the pile driving process, and at the same time reduce the material usage and cost of the hinge plate.

[0044] In a preferred embodiment, such as Figure 2 , Figure 5 , Figure 6 As shown, the first rib 2.2.2 and the second rib 2.3.2 abut against each other. The first rib 2.2.2 has several protrusions 2.7 and / or recesses 2.8 near the edge of the second rib 2.3.2, and the second rib 2.3.2 has several recesses 2.8 and / or protrusions 2.7 near the edge of the first rib 2.2.2. The recesses 2.8 and protrusions 2.7 of the first rib 2.2.2 and the second rib 2.3.2 match each other. Through the mutual cooperation and abutment of the recesses 2.8 and protrusions 2.7, the contact surface of the first rib 2.2.2 and the second rib 2.3.2 can effectively transmit shear force in the first state (locked state), preventing the normal functioning of the locking mechanism and the verticality of the pile from being affected by the swaying of the pile tip assembly during pile driving.

[0045] Preferably, such as Figure 6 , Figure 7 As shown, stiffening plates 2.9 are provided at the upper ends of the first rib 2.2.2 and the second rib 2.3.2. When the first pile tip assembly 2.2 and the second pile tip assembly 2.3 are in the first state, the stiffening plates 2.9 are in contact with the mounting plate 2.1. The stiffening plates 2.9 can improve the stability and torsional performance of the pile tip assembly 2. At the same time, the soil pressure exerted by the pile driving on the stiffening plates can offset part of the torque generated by the unbalanced soil pressure on the pile tip assembly and reduce the tension borne by the locking mechanism (this tension is directly proportional to the torque), thereby improving the reliability and operability of the locking mechanism.

[0046] like Figure 5 As shown, the enlarged-base precast pile 2 also includes a locking mechanism 2.6. The locking mechanism 2.6 has a rope (not shown) passing through the first hole 2.4 and the second hole 2.5. The rope extends to the top of the precast pile body 1. When the rope crosses the first hole 2.4 and the second hole 2.5 at the same time, the relative position between the first pile tip assembly 2.2 and the second pile tip assembly 2.3 is locked. When unlocking is required, the rope only needs to be withdrawn from the first hole 2.4 and / or the second hole 2.5 to unlock the relative position between the first pile tip assembly 2.2 and the second pile tip assembly 2.3.

[0047] The rope, such as a steel wire rope or carbon fiber rope of a certain strength, provides locking force to secure the relative positions of the first pile tip assembly 2.2 and the second pile tip assembly 2.3. When unlocking is required, pulling the rope extending to the top of the precast pile body 1 opens the slip knot, allowing the rope to exit from the first hole 2.4 and / or the second hole 2.5, thus unlocking the relative positions of the first pile tip assembly 2.2 and the second pile tip assembly 2.3. To improve reliability, horizontal baffles (not shown) can be welded to the positions of the first rib plate 2.2.2 and the second rib plate 2.3.2 corresponding to the lower end of the slip knot. Small steel pipes are installed on the outside of the rope and welded to the corresponding rib plates to prevent the foundation soil layer from damaging the exposed rope or prematurely unlocking it during the pressing of the precast pile, thus affecting the planned construction steps. Of course, those skilled in the art will understand that even without a slip knot, the locking and unlocking functions can be achieved using a rope with appropriate selection. The function of the locking mechanism 2.6 is to lock and unlock the relative positional relationship between the first pile tip assembly 2.2 and the second pile tip assembly 2.3. Those skilled in the art will understand that there are various locking mechanisms in the prior art that can be applied to the embodiments of this utility model.

[0048] like Figure 1 As shown, the construction method of the precast pile of this utility model mainly includes the following steps:

[0049] The pile tip assembly 2 is installed at the lower end of the precast pile body 1. The fixed connection between the pile tip assembly 2 and the precast pile body 1 can be achieved by welding or fastener connection. The rope can pass through the end plate 2.1 and the channel 1.1 (not shown) inside the precast pile body 1, and the rope extends to the top of the precast pile body 1. The relative positional relationship between the first pile tip assembly 2.2 and the second pile tip assembly 2.3 is locked.

[0050] The precast pile is driven down using pile driving machinery 8 (such as hammering machinery or hydrostatic machinery) until the first pile tip assembly 2.2 and the second pile tip assembly 2.3 are fully driven into the foundation soil layer 7 to the predetermined depth. The relative positions of the first pile tip assembly 2.2 and the second pile tip assembly 2.3 are then unlocked using ropes. As the precast pile continues to be driven down, the lower soil is continuously squeezed into the gap between the first hinge plate 2.2.1 and the second hinge plate 2.3.1, creating a soil pressure difference. Specifically, the soil pressure inside the first hinge plate 2.2.1 and the second hinge plate 2.3.1 is greater than the soil pressure on the outer side. The force and soil pressure difference push the first hinge plate 2.2.1 and the second hinge plate 2.3.1 to automatically cut the soil outward and then rotate and unfold outward; the precast pile continues to be pressed down, and under the action of a large impact force or pile driving force, the claws 6 of the first hinge plate 2.2.1 and the second hinge plate 2.3.1 are engaged in the grooves 5 of the third rib plate 3.1 and the fourth rib plate 3.2, locking them together to form an enlarged-base precast pile. Under the action of impact force or pile driving force, the first hinge plate 2.2.1 and the second hinge plate 2.3.1 are tightly squeezed and pressed against the soil of the bearing layer below.

[0051] Those skilled in the art will understand that the fact that the first rib 2.2.2 is perpendicular to the first hinge plate 2.2.1 and the second rib 2.3.2 is perpendicular to the second hinge plate 2.3.1 does not mean that the first rib 2.2.2 and the first hinge plate 2.2.1 are absolutely perpendicular, but rather that the angle between them is approximately 90°. Similarly, the term "parallel" in this patent does not mean absolutely parallel, but rather that the angle between them is approximately 0°. The first pile tip assembly 2.2, the second pile tip assembly 2.3, the third rib 3.1, and the fourth rib 3.2 can all be made of steel, or other high-strength metals or alloys.

[0052] Furthermore, although the above embodiment has only one pair of first pile tip assembly 2.2 and second pile tip assembly 2.3, those skilled in the art will understand that two, three or more pairs of first pile tip assembly 2.2 and second pile tip assembly 2.3 can be provided at the lower end of the mounting plate 2.1.

[0053] In the above embodiments, both the first hinge plate 2.2.1 and the second hinge plate 2.3.1 are hinged to the bottom of the mounting plate 2.1. The common hinge method is to achieve the hinge connection between the two components through a hinge pin (similar to the hinge of a door). However, those skilled in the art will understand that the first hinge plate 2.2.1 and the second hinge plate 2.3.1 can also be hinged to the mounting plate 2.1 without using a hinge pin. For example, if the first hinge plate 2.2.1 and the second hinge plate 2.3.1 are made of steel plates, a notch is provided along the hinge axis. When the first hinge plate 2.2.1 and the second hinge plate 2.3.1 are subjected to torque, the first hinge plate 2.2.1 and the second hinge plate 2.3.1 can also rotate outward along the notch (hinge axis).

[0054] The embodiments of the present invention 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. The present invention is not limited to the specific embodiments described above; these embodiments are merely illustrative and not limiting. Those skilled in the art, under the guidance of the present invention, can make many modifications without departing from the spirit and scope of the claims, and all such modifications fall within the protection scope of the present invention.

Claims

1. A precast pile with an enlarged base, characterized in that, include: The precast pile body (1), pile tip assembly (2), and through rib plate (3); The lower end of the precast pile body (1) is provided with the through rib plate (3), the through rib plate (3) is parallel to the axial direction of the precast pile body (1), and the two ends of the through rib plate (3) protrude from the outer surface of the precast pile body (1) respectively to form the third rib plate (3.1) and the fourth rib plate (3.2). The pile tip assembly (2) includes a first pile tip assembly (2.2), a second pile tip assembly (2.3), and a mounting plate (2.1). The mounting plate (2.1) is fixed to the lower end of the precast pile body (1). The first pile tip assembly (2.2) includes a first hinge plate (2.2.1) and a first rib plate (2.2.2). The first rib plate (2.2.2) is perpendicular to the first hinge plate (2.2.1). The second pile tip assembly (2.3) includes a second hinge plate (2.3.1) and a second rib plate (2.3.2). The second rib plate (2.3.2) is perpendicular to the second hinge plate (2.3.1). Both the first hinge plate (2.2.1) and the second hinge plate (2.3.1) are hinged to the mounting plate (2.1), and the hinge axis of the first hinge plate (2.2.1) and the mounting plate (2.1) is parallel to the hinge axis of the second hinge plate (2.3.1) and the mounting plate (2.1). The first rib (2.2.2) and the second rib (2.3.2) are located in the same plane. The first rib (2.2.2) is provided with a first hole (2.4), and the second rib (2.3.2) is provided with a second hole (2.5). When the first pile tip assembly (2.2) and the second pile tip assembly (2.3) are in the first state, the first hinge plate (2.2.1) and the second hinge plate (2.3.1) are parallel to the axial direction of the precast pile body (1); when the first pile tip assembly (2.2) and the second pile tip assembly (2.3) are in the second state, the first hinge plate (2.2.1) abuts against the lower edge of the third rib (3.1), and the second hinge plate (2.3.1) abuts against the lower edge of the fourth rib (3.2).

2. The precast pile with enlarged base according to claim 1, characterized in that, The lower ends of the third rib (3.1) and the fourth rib (3.2) are provided with grooves (5) on both sides. The first hinge plate (2.2.1) is provided with a claw (6) on the side away from the first rib (2.2.2). The second hinge plate (2.3.1) is also provided with a claw (6) on the side away from the second rib (2.3.2). The claw (6) is provided corresponding to the groove (5). When the first pile tip assembly (2.2) and the second pile tip assembly (2.3) are in the second state, the claw (6) can be engaged in the groove (5).

3. A precast pile with an enlarged base according to claim 2, characterized in that, The groove (5) is a toothed groove extending in the vertical direction, and the claw (6) is a toothed claw.

4. A precast pile with an enlarged base according to claim 1, characterized in that, The lower end of the precast pile body (1) has an end plate (1.2), and the mounting plate (2.1) is fixedly connected to the end plate (1.2).

5. A precast pile with an enlarged base according to claim 4, characterized in that, The end plate (1.2) has screw holes, and the mounting plate (2.1) is fixedly connected to the end plate (1.2) by bolts.

6. A precast pile with an enlarged base according to claim 1, characterized in that, It also includes a locking mechanism (2.6) having a rope passing through the first hole (2.4) and the second hole (2.5) and extending to the top of the precast pile body (1).

7. A precast pile with an enlarged base according to claim 1, characterized in that, Both the first hinge plate (2.2.1) and the second hinge plate (2.3.1) adopt a variable thickness section, that is, the thickness in the middle is greater than the thickness at the edge.

8. A precast pile with an enlarged base according to claim 1, characterized in that, The first rib (2.2.2) and the second rib (2.3.2) abut against each other. The first rib (2.2.2) is provided with a plurality of protrusions (2.7) and / or recesses (2.8) near the edge of the second rib (2.3.2). The second rib (2.3.2) is provided with a plurality of recesses (2.8) and / or protrusions (2.7) near the edge of the first rib (2.2.2). The recesses (2.8) and protrusions (2.7) of the first rib (2.2.2) and the second rib (2.3.2) match each other.

9. A precast pile with an enlarged base according to claim 1, characterized in that, The upper end of the first rib (2.2.2) and the upper end of the second rib (2.3.2) are both provided with stiffening plates (2.9). When the first pile tip assembly (2.2) and the second pile tip assembly (2.3) are in the first state, the stiffening plate (2.9) is in contact with the mounting plate (2.1).

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