CN206570792U - Prefabricated reinforced concrete under-reamed pile - Google Patents

Abstract

This patent discloses a prefabricated reinforced concrete pile with expanded bottom, which includes a pile body, the pile body is axially provided with a blind hole, and the bottom of the pile body is provided with a reserved hole, and the bottom of the pile body is evenly distributed from the center of the pile body to the outside. There are several bottom expansion chambers, the reserved holes communicate with the bottom expansion chamber, a piston is slidably connected to the bottom expansion chamber, and the side of the piston away from the reserved hole is provided with an expansion chamber that is slidably connected to the bottom expansion chamber. bottom plate. With this scheme, not only the bearing capacity of the concrete prefabricated pile is greatly improved, but also the bottom expansion is performed after the pile body is pre-buried, which reduces the radial width of the pre-drilled hole, thereby reducing the amount of filling side gaps and improving The efficiency of pre-embedded prefabricated piles is improved.

Description

Reinforced Concrete Expanded Bottom Prefabricated Pile

technical field

The utility model relates to prefabricated piles of various foundation bearing capacities such as construction engineering, in particular to a reinforced concrete prefabricated pile with expanded bottom.

Background technique

At present, the prefabricated piles used for various foundation bearing capacities such as construction projects are prefabricated by reinforced concrete, and have various shapes, usually including round piles and square piles, and the pile bodies are often of equal diameter. The quality of prefabricated piles is good, and the bearing capacity is also high. At present, the cost of prefabricated piles is relatively high, and they are generally used in buildings with higher safety levels.

In the prior art, Chinese Utility Model Patent No. CN201132955 discloses a synchronous grouting static pressure prefabricated pile sinking device, which belongs to the technical field of reinforced concrete prefabricated piles in the field of construction. The main technical features are: there are A certain length is reserved, and the lower end forms a grouting hole in the cone wall of the pile tip through the slurry-guiding bifurcation tube 3. Symmetrically distributed, the pile tip cone angle is 60°. The utility model can realize continuous grouting at the side of the pile and at the end of the pile, has simple and convenient operation, and is not easy to block the grouting hole, so that the grouting can be implemented smoothly in different stages of pile sinking. During the sinking process of the pile, the grout can be evenly distributed between the pile and the soil around the pile, so that a mud film can be formed around the pile. After the pile reaches the design depth, the pile end can form an enlarged head that wraps around the pile tip.

In the above scheme, during construction, the prefabricated piles are pressed into the foundation section by section with a static pile driver or the pile sections are driven into the foundation section by section by hammering, so that broken piles and necking may occur during continuous piling construction. phenomenon, and after the pile is driven into the foundation, the bearing capacity of the lower end of the pile is required to be higher. With the increase of service time, the contact area between the lower end of the pile and the soil is small, and the chassis of the pile is unstable, which also leads to The bearing capacity of the lower end cannot meet the requirements of use, and the pile body may break.

Utility model content

The utility model intends to provide a reinforced concrete prefabricated pile with enlarged bottom to solve the problem that the bearing capacity of the existing prefabricated pile with enlarged bottom cannot meet the use requirements.

The reinforced concrete prefabricated pile with expanded bottom in this scheme includes a pile body, the pile body is provided with a blind hole in the axial direction, and the bottom of the pile body is provided with a reserved hole, and the bottom of the pile body is evenly distributed from the center of the pile body to the outside. There are several bottom expansion chambers, the reserved holes communicate with the bottom expansion chamber, a piston is slidably connected to the bottom expansion chamber, and the side of the piston away from the reserved hole is provided with an expansion chamber that is slidably connected to the bottom expansion chamber. bottom plate.

The working principle and beneficial effects of the above-mentioned technical scheme are as follows: on the predetermined pile position, use a drilling rig to drill to a set depth, firstly drill according to the designed depth, and place the pile body by static pressure or vibration insertion, so as to avoid directly digging from the foundation soil. The continuous impact on the pile body caused by driving the pile body on the surface prevents the pile body from bursting during the sinking process or the pile length is inconsistent, and then injects liquid concrete into the blind hole, and the concrete flows into the bottom expansion cavity through the reserved hole. There is a piston slidingly connected in the bottom cavity, and the concrete pushes the piston to slide away from the center of the pile body, and the piston pushes the expanded base plate to slide away from the center of the pile body, so that the expanded base plate is inserted into the soil around the pile body, and the expanded base plate is distributed in The circumferential direction of the bottom plate of the pile body is expanded to realize the radial expansion of the bottom of the pile body, so that the bottom plate is directly supported on the soil layer, and the blind hole is also filled with concrete. The bottom plate not only increases the resistance at the bottom of the pile body and The friction resistance on the side of the pile can greatly increase the bearing capacity of the pile, and then fill the side gap with sand or artificial stones and compact it, so that the diameter of the upper section of the pile increases to the same diameter as the bottom of the pile . With this scheme, not only the bearing capacity of the concrete prefabricated pile is greatly improved, but also the bottom expansion is performed after the pile body is pre-embedded, which reduces the radial width of the pre-drilled hole, thereby reducing the amount of filling side gaps and improving The efficiency of pre-embedded prefabricated piles is improved.

Optimization scheme 1, as a further optimization of the foundation scheme, several diameter-expanding blocks are hinged on the side wall of the lower part of the pile body, and a chute is provided at the hinge joint between the diameter-expanding block and the side wall of the pile body. A through hole is provided, and a push rod is slidably connected to the through hole, and a slot for matching with the push rod is provided on the expanding block. Since a section of the expanded bottom plate is exposed outside the pile body, the expanded bottom plate can limit the expansion of the bottom plate. Before injecting concrete into the blind hole, a trapezoidal driving device with a large upper part and a smaller lower part is used to push the ejector rod to move to the outside of the pile body. Drive the expansion block to rotate along the hinge point, so that the expansion block expands outward, and the chute can ensure that the expansion block is not restricted when rotating, until the ejector rod is inserted into the slot on the expansion block and fixed, the expansion block can further Improve the bearing capacity of the pile.

The second optimization scheme, as a further optimization of the first optimization scheme, is provided with a reducing body in the middle of the pile body. The reducing body can further improve the bearing capacity of the upper part of the pile body and improve the overall stability of the pile body.

Optimization scheme three, as a further optimization of optimization scheme two, the longitudinal section of the variable diameter body is a semicircle. The side of the radius body away from the pile body is arc-shaped, and the arc side is easily staggered with other objects during transportation, so as to prevent the pile body from being damaged due to collision with other objects during transportation.

Optimization scheme four, as a further optimization of optimization scheme three, the cross-section of the pile body is square, and the number of expansion blocks is four. Under the premise of constant volume, the surface area of square piles is larger than that of circular piles, and the contact surface with the ground is also larger. The friction force between the pipe pile and the ground is increased, and the stability of the pile body is improved. To maintain the friction force between the pile body and the ground, the square pile uses less material, is more energy-efficient, and saves resources.

Optimization scheme five, as a further optimization of optimization scheme four, the diameter-expanding blocks are evenly arranged on the circumferential side wall of the pile body. The expansion blocks are evenly arranged on the circumferential side wall of the pile body, so that the bearing capacity of the pile body in all directions is the same, and a certain part of the pile body is prevented from being damaged due to overload.

Optimization scheme six, as a further optimization of optimization scheme five, a section of the expanded floor is exposed outside the pile body. Before the prefabricated pile is placed in the soil, one end of the expanded base plate is exposed outside the pile body. When liquid concrete is injected into the blind hole, the efficiency of the expanded base plate can be further improved.

Description of drawings

Fig. 1 is the structure schematic diagram before the piling of the prefabricated pile with expanded bottom of the utility model reinforced concrete;

Fig. 2 is a structural schematic diagram of the utility model reinforced concrete prefabricated pile with expanded bottom after pile installation.

detailed description

The utility model is described in further detail below by means of specific embodiments:

The reference signs in the drawings of the description include: pile body 1, blind hole 2, reserved hole 3, bottom expansion cavity 4, piston 5, bottom expansion plate 6, diameter expansion block 7, chute 8, ejector rod 9, card slot 10, reducing body 11, push head 12, push rod 13.

The embodiment is basically shown in accompanying drawing 1, Fig. 2: reinforced concrete prefabricated pile with enlarged bottom, comprises pile body 1, and the cross-section of pile body 1 is square, and pile body 1 is axially provided with blind hole 2, and pile body 1 bottom is provided with There are reserved holes 3, the bottom of the pile body 1 is evenly provided with several bottom expansion chambers 4 outward from the center of the pile body 1, the reserved holes 3 are connected to the bottom expansion chamber 4, and the piston 5 is slidably connected to the bottom expansion chamber 4. 5 The side away from the reserved hole 3 is connected with an expanded base plate 6, which is slidably connected in the expanded bottom cavity 4, and a section of the expanded base plate 6 is exposed outside the pile body 1, and the lower side wall of the pile body 1 is hinged with four expanded diameters Block 7, expansion block 7 is evenly arranged on the circumferential side wall of pile body 1, and the hinge joint of diameter expansion block 7 and pile body 1 side wall is all provided with chute 8, and the bottom of chute 8 is provided with through hole, through A push rod 9 is slidably connected in the hole, and a card slot 10 cooperating with the push rod 9 is provided on the expanding block 7, and a reducing body 11 is installed in the middle of the pile body 1, and the longitudinal section of the reducing body 11 is semicircular. , also includes a driving device, the driving device includes a push head 12, the longitudinal section of the push head 12 is a trapezoid with a large top and a small bottom, and a push rod 13 is connected above the push head 12.

When in use, use a drilling rig to drill to a set depth at the predetermined pile position, firstly drill the hole according to the design depth, and place the pile body 1 by static pressure or vibration insertion to avoid driving the pile body 1 directly from the surface of the foundation soil so that The continuous impact on the pile body 1 prevents the pile body 1 from bursting during the sinking process or the pile length is inconsistent. Since a section of the expanded bottom plate 6 is exposed outside the pile body 1, the expanded bottom plate 6 can limit the expanded bottom plate 6 and drive Put the device into the blind hole 2, use the push head 12 to push the ejector rod 9 to move to the outside of the pile body 1, and the ejector rod 9 drives the expansion block 7 to rotate along the hinge point, so that the four diameter expansion blocks 7 are all expanded outwards, The chute 8 can ensure that the expansion block 7 is not restricted when it rotates until the push rod 9 is inserted into the slot 10 on the expansion block 7 and fixed, and the variable diameter body 11 in the middle of the pile body 1 can further improve the bearing capacity of the upper part of the pile body 1 , and improve the overall stability of the pile body 1.

Then inject liquid concrete into the blind hole 2, and the concrete flows into the bottom expansion chamber 4 through the reserved hole 3. Since the piston 5 is slidably connected to the bottom expansion chamber 4, the concrete pushes the piston 5 to slide away from the center of the pile body 1. The piston 5 pushes the expanded base plate 6 to slide away from the center of the pile body 1, so that the expanded base plate 6 is inserted into the soil around the pile body 1, and the expanded base plate 6 is distributed in the circumferential direction of the expanded base plate 6 of the pile body 1, realizing the adjustment of the pile body. The radial expansion of the bottom of 1 makes the expanded bottom plate 6 directly supported on the soil layer, and at the same time fills the blind hole 2 with concrete. The expanded bottom plate 6 not only increases the resistance at the bottom of the pile body 1 and the frictional resistance on the side of the pile, so that The bearing capacity of the pile body 1 is greatly improved, and then the side gaps are filled with sand or artificial stones and compacted, so that the diameter of the upper section of the pile body is increased to the diameter equal to the bottom of the pile body.

What is described above is only the embodiment of the present utility model, and common knowledge such as the specific structure and/or characteristic known in the solution is not described too much here. It should be pointed out that for those skilled in the art, under the premise of not departing from the structure of the utility model, some deformations and improvements can also be made, and these should also be regarded as the protection scope of the utility model, and these will not affect the utility model. Effects of novel implementations and utility of patents. The scope of protection required by this application shall be based on the content of the claims, and the specific implementation methods and other records in the specification may be used to interpret the content of the claims.

Claims (7)

1. A reinforced concrete prefabricated pile with expanded bottom, comprising a pile body (1), characterized in that the pile body (1) is axially provided with a blind hole (2), and the bottom of the pile body (1) is provided with a prefabricated Holes (3), the bottom of the pile body (1) are uniformly provided with several bottom expansion cavities (4) from the center of the pile body (1), and the reserved holes (3) are connected to the bottom expansion cavities (4 ), the piston (5) is slidably connected to the bottom expansion chamber (4), and the side of the piston (5) away from the reserved hole (3) is provided with a bottom expansion plate (6) that is slidably connected to the bottom expansion chamber . 2. The reinforced concrete bottom-expanding prefabricated pile according to claim 1, characterized in that, the lower side wall of the pile body (1) is hinged with several diameter-expanding blocks (7), and the diameter-expanding blocks (7) and A chute (8) is provided at the hinge of the side wall of the pile body (1), and a through hole is provided under the chute (8), and a push rod (9) is slidably connected to the through hole, and the expanding block (7) is provided with a card slot (10) that cooperates with the ejector rod (9). 3. The reinforced concrete prefabricated pile with enlarged bottom according to claim 2, characterized in that, a diameter reducing body (11) is provided in the middle of the pile body (1). 4. The reinforced concrete prefabricated pile with expanded bottom according to claim 3, characterized in that, the longitudinal section of the reducing body (11) is semicircular. 5. The reinforced concrete prefabricated pile with enlarged bottom according to claim 4, characterized in that, the cross-section of the pile body (1) is square, and the number of the diameter-expanding blocks (7) is four. 6. The reinforced concrete prefabricated pile with enlarged bottom according to claim 5, characterized in that, the diameter-expanding blocks (7) are evenly arranged on the circumferential side wall of the pile body (1). 7. The reinforced concrete prefabricated pile with expanded bottom according to claim 6, characterized in that, a section of the expanded bottom plate (6) is exposed outside the pile body (1).