CN218712922U - Pile splicing device and expanding assembly for precast tubular pile - Google Patents

Abstract

The utility model discloses a pile extension device and hole enlargement subassembly for precast tubular pile belongs to the construction equipment field. The utility model discloses utilize this pile extension device to connect two sections precast tubular piles, adopted one kind in this pile extension device moreover and just formed the hole enlargement joint of hole enlargement structure after the pile sinking finishes, this hole enlargement joint has can follow the radial flexible variable diameter mechanism of pile body cross section, variable diameter mechanism has the contraction state of contracting in the pile body completely and stretches out the hole enlargement state of pile body, consequently, the pile sinking in-process can not additionally increase the resistance between the soil body of pile body and pile week. In addition, in order to cooperate this pile extension device that has the hole enlargement joint, the utility model also provides a hole enlargement subassembly that combines the enlarger, after all tubular piles were squeezed into the soil layer, put down the enlarger that all reaming end plates are in the state of gathering together to the hole enlargement joint position, can drive all reaming end plates and outwards extend to the expanded state in step, form the hole enlargement structure that improves pile foundation bearing capacity.

Description

Pile splicing device and expanding assembly for precast tubular pile

Technical Field

The utility model belongs to the construction equipment field, concretely relates to pile extension device and hole enlargement subassembly for precast tubular pile.

Background

The expanding method is a pile foundation construction method for improving the bearing capacity of a pile foundation by expanding the diameter of a pile body, and the method is widely applied to cast-in-place piles. For example, in the invention patent with the application number of CN202011628508.8, an expanding cast-in-place pile and a construction method thereof are disclosed, wherein the method comprises the following steps: 1. determining the number of pile bodies of the second expansion section; 2. embedding a protective cylinder; 3. the pile machine and the expanding drill rod are in place; 4. drilling; 5. drilling construction of the pile body of the expanded section; 6. lowering a reinforcement cage; 7. and (5) pouring concrete. The cast-in-place pile has the advantages that the pile body of the expanded section is arranged, the uplift resistance of the pile is increased, and the bearing capacity of the pile body can be greatly improved under the condition that the concrete consumption is only increased by a small amount. However, such a cast-in-place pile needs to be constructed on site, and has the problem that the quality of the pile body below the foundation is difficult to control and detect.

With the popularization of the precast pile, the method of adding expanding equipment outside the precast pile also appears in the prior art. For example, in the invention patent with the application number of CN201611100474.9, an external hoop sand-filled stone precast pile and a construction method thereof are disclosed. In the scheme, after the precast pile is formed into a pile, the pile body is connected with a pile body through an expanding hoop additionally arranged on the pile body and a pile tip expanded at the pile bottom to form a segmental interval expanding pile body. And filling sand and stone materials around the pile while pressing or driving the precast pile with the additional hoop into the foundation soil to finally form the composite foundation under the combined action of the precast pile with the additional hoop, the sand and stone materials around the pile and the foundation soil. However, in this method, because the pile body is additionally expanded, the resistance of the pile body is greatly increased in the pile sinking process, and the precast pile is driven into the soil layer by using higher static force or power. And after the soil layer is driven into, the sand and stone filling operation is needed to be additionally carried out, so that the labor cost, the time cost and the material cost of construction are increased.

Therefore, how to optimize the structure of the expanded precast pile to meet the coordination of the construction efficiency and the cost is a technical problem to be solved urgently at present.

Disclosure of Invention

An object of the utility model is to solve the complicated problem of hole enlargement precast pile sinking technology among the prior art to a pile extension device and hole enlargement subassembly for precast tubular pile are provided.

The utility model discloses the concrete technical scheme who adopts as follows:

in a first aspect, the utility model provides a pile extension device for precast tubular piles, which is used for connecting two sections of tubular piles, and comprises an expanding joint and a tubular pile joint;

the two sections of pipe piles are prefabricated pipe pile sections, and the pipe pile joints are respectively fixed on the respective connecting end surfaces;

the expanding joint comprises an upper end plate, a lower end plate, a connecting rib plate, expanding blades and connecting bolts; the upper end plate and the lower end plate are arranged in parallel at intervals, and a connecting structure capable of bearing loads in the direction vertical to the end plates is formed between the upper end plate and the lower end plate by clamping and fixing a plurality of connecting rib plates; the diameter-expanding blades and the connecting rib plates are assembled in a one-to-one correspondence mode, each diameter-expanding blade comprises a fan-shaped annular plate and an arc limiting plate, a slide way penetrating through the plate body is formed in the fan-shaped annular plate, the fan-shaped annular plate is installed between the upper end plate and the lower end plate and is sleeved outside the connecting rib plates through the slide way, so that a sliding pair limiting the fan-shaped annular plate to move along the radial direction is formed, the size of the arc limiting plate is larger than the gap between the upper end plate and the lower end plate, and the arc limiting plate can be limited to move outwards continuously when moving outwards to the limiting position; and the outward surfaces of the upper end plate and the lower end plate are respectively provided with a connecting piece for connecting a tubular pile joint.

In the first aspect, the number of the expanding blades and the number of the connecting ribs in the expanding joint are both at least 3.

In the first aspect, the number of the expanding blades and the number of the connecting ribs are both 4.

Preferably, in the first aspect, the connecting members on the upper end plate and the lower end plate are connecting bolts, the threaded sections of the connecting bolts are fixed on the end plates, and the bolt heads of the connecting bolts are spaced from the surface of the end plates; the end plate hole on the end plate adopts the reducing hole, have the first hole district and the second hole district of intercommunication in the reducing hole, wherein the hole size in first hole district can supply the bolt head stretches into, and the bolt head can move to the second hole district from first hole district, but the hole size in second hole district can't make the bolt head directly break away from the second hole district.

Preferably, in the diameter-expanding joint, all diameter-expanding blades are annularly spliced to form a complete ring, and all arc-shaped limiting plates are annularly spliced to form a complete cylinder.

As the preferable mode of the first aspect, the tubular pile joint is prefabricated integrally with the tubular pile.

In a second aspect, the utility model provides a pile extension hole enlargement subassembly for precast tubular pile, which comprises the pile extension device and a hole expander matched with the hole enlargement joint in any scheme of the first aspect;

the reamer comprises a driving mechanism, a plurality of groups of cross arms and a reamer end plate; in each group of the cross arms and the reaming end plate, the reaming end plate is connected with the driving mechanism through the cross arms; all the cross arms connected with the driving mechanism have the same size and posture, so that all the reaming end plates can be synchronously stretched under the driving of the driving mechanism, and a gathering state and an expansion state are respectively formed at two limit positions of a stretching stroke; in the gathering state, the gathered sizes of all the reaming end plates can integrally extend into the enclosed space of the arc limiting plates of all the expanding blades in the contraction state; in an expansion state, the expanded sizes of all the expanding end plates can enable all the expanded blades to prop up the arc limiting plates in the inner rings of the upper end plate and the lower end plate after being expanded.

In the reamer according to the second aspect of the present invention, the driving mechanism is a hydraulic linear driving device including a hydraulic cylinder, a hydraulic piston rod, a first hydraulic pipe, a second hydraulic pipe, a fixed end block, and a sliding end block; the hydraulic cylinder and the hydraulic piston rod are assembled to form a piston driving mechanism, and two hydraulic cylinders separated by a piston head of the hydraulic piston rod in the hydraulic cylinder are respectively communicated with a first hydraulic pipe and a second hydraulic pipe; the bottom of the hydraulic oil cylinder is fixedly connected with a sliding end block, the rear end part of an output rod of the piston rod penetrates through a guide hole in the sliding end block and is fixed on the fixed end block, one end of each of two arm rods of each cross arm is fixed on the fixed end block and the sliding end block respectively, and the other end of each of the two arm rods is connected with a corresponding reaming end plate respectively.

Preferably, a stopper is arranged at a connection position of each cross arm and the reaming end plate, the stopper is fixed on the reaming end plate and is provided with a sliding groove parallel to the reaming end plate, and the other end of one arm rod of each cross arm needs to slide in the sliding groove of the stopper to limit the telescopic stroke of the cross arm.

Preferably, in the second aspect, the piston drive mechanism is arranged along the centre of the whole underreamer, and all the cross arms are arranged uniformly in a direction perpendicular to the centre line of the underreamer.

Compared with the prior art, the utility model, following beneficial effect has:

the utility model provides a pile extension device for precast tubular pile can utilize this pile extension device to connect two sections precast tubular piles to ask to satisfy actual pile body length demand in a flexible way through the concatenation. In addition, the pile splicing device adopts an expanding joint which can form an expanding structure after pile sinking is finished, the expanding joint is provided with a diameter-variable mechanism which can stretch out and draw back along the radial direction of the cross section of the pile body, and the diameter-variable mechanism has a contraction state of completely contracting in the pile body and an expanding state of extending out of the pile body, so that the resistance between the pile body and the soil body around the pile is not additionally increased in the pile sinking process.

In addition, in order to cooperate this pile extension device that has the hole enlargement joint, the utility model also provides a reamer, after all tubular piles were squeezed into the soil layer, put down all reamer that the reaming end plate is in the state of gathering together to the hole enlargement joint position, can drive all reaming end plates and outwards extend to the expanded state in step, form the hole enlargement structure that improves pile foundation bearing capacity. And the reamer can be recycled after being used, so that the use cost is low.

Drawings

FIG. 1 is a schematic view showing an assembled state of a pipe pile, an expanding joint and a pile splicing device;

fig. 2 is a three-dimensional schematic view of the expanded joint in a contracted state.

Fig. 3 is a schematic plan view of the expanded diameter joint in a contracted state.

Fig. 4 is a schematic cross-sectional view of the expanded joint in a contracted state.

Fig. 5 is a three-dimensional schematic view of an expanding blade.

Fig. 6 is a schematic plan view of the expanded joint in an expanded state.

Fig. 7 is a three-dimensional schematic view of the expanded joint in an expanded state.

Fig. 8 is a plan view schematically showing a pipe pile joint.

Fig. 9 is a schematic view of the underreamer in a retracted state.

Fig. 10 is a schematic view of the underreamer in a deployed state.

Fig. 11 is a schematic view showing the underreamer retracted inside the tubular pile.

Fig. 12 is a schematic view showing a state where the reamer is deployed in the tubular pile.

The reference numbers in the figures are: the pipe pile comprises a pipe pile 1, an expanding joint 2, an upper end plate 201, a lower end plate 202, a connecting rib plate 203, an expanding blade 204, a connecting bolt 205, a pipe pile joint 3, an end plate 301, an end plate hole 302, an underreamer 4, a hydraulic oil cylinder 401, a hydraulic piston rod 402, a first hydraulic pipe 403, a second hydraulic pipe 404, a cross arm 405, a limiter 406, a pin shaft 407, a fixed end block 408, a sliding end block 409 and an expanding end plate 410.

Detailed Description

In order to make the above objects, features and advantages of the present invention more comprehensible, embodiments of the present invention are described in detail below with reference to the accompanying drawings. In the following description, numerous specific details are set forth in order to provide a thorough understanding of the present invention. The present invention may, however, be embodied in many different forms and should not be construed as limited to the embodiments set forth herein, as those skilled in the art will be able to make similar modifications without departing from the spirit and scope of the present invention. The utility model discloses technical characteristics in each embodiment all can carry out corresponding combination under the prerequisite that does not conflict with each other.

In the description of the present invention, it will be understood that when an element is referred to as being "connected" to another element, it can be directly connected to the other element or be indirectly connected to the other element, i.e., intervening elements may be present. In contrast, when an element is referred to as being "directly connected to" another element, there are no intervening elements present.

In the description of the present invention, it is to be understood that the terms "first", "second", and the like are used for descriptive purposes only and are not to be construed as indicating or implying relative importance or to imply that the number of indicated technical features is significant. Thus, a feature defined as "first" or "second" may explicitly or implicitly include at least one such feature.

In a preferred embodiment of the present invention, a pile splicing device for prefabricated tubular piles is provided, which is used to connect two sections of tubular piles 1, wherein the tubular piles 1 to be connected are prefabricated tubular pile sections. As shown in fig. 1, the pile splicing device comprises an expanding joint 2 and a pipe pile joint 3, wherein an upper pipe pile 1 and a lower pipe pile 1 are connected through the expanding joint 2 and the pipe pile joint 3. The specific structure and the connection and cooperation relationship between the components are described in detail below.

The utility model discloses an among the precast pile body structure, the pile body is formed by the vertical concatenation in proper order of the prefabricated tubular pile 1 edge of multisection in the mill. The length of the whole pile body can be adjusted by combining different numbers of tubular piles 1. For the convenience of description, the utility model discloses in with the terminal surface that needs carry out the concatenation with another section tubular pile 1 among one section tubular pile 1 call the concatenation terminal surface.

Above-mentioned tubular pile 1 can be prefabricated into the pipeline section that satisfies intensity according to certain parameter in the mill, and its processing mode is similar with common precast tubular pile, no longer gives unnecessary details. In addition, in order to be suitable for different construction scenes, the tubular piles 1 can be designed to have different diameters and different length types, and pile bodies with different design parameters can be directly connected in a combined mode through the tubular piles 1 with different parameters.

In order to ensure that two sections of tubular piles 1 can be conveniently and reliably connected, tubular pile connectors 3 are respectively fixed on the splicing end faces of any two sections of adjacent tubular piles 1, and the tubular pile connectors 3 on the two splicing end faces are clamped and fixed through expanding connectors 2, so that the two sections of adjacent tubular piles 1 are reliably connected. Simultaneously, in order to form corresponding hole enlargement structure, the utility model discloses set up in hole enlargement joint 2 and can follow the radial flexible variable diameter mechanism of pile body cross section, variable diameter mechanism has the contraction state of contracting in the pile body completely and stretches out the hole enlargement state of pile body.

As shown in fig. 2 and 3, the expanding joint 2 includes an upper end plate 201, a lower end plate 202, a connecting rib 203, and an expanding blade 204. The upper end plate 201 and the lower end plate 202 are arranged in parallel with a certain space kept therebetween for mounting the connecting rib plate 203. In the present embodiment, the upper end plate 201 and the lower end plate 202 are both circular rings. As shown in fig. 4, the connecting ribs 203 in this embodiment have 4 pieces in total, and are arranged in a circular ring shape at equal angles. Each connecting rib 203 is connected with the upper end plate 201 at the top and connected with the lower end plate 202 at the bottom, so that a connecting structure capable of bearing loads in the direction of the vertical end plate is formed between the upper end plate 201 and the lower end plate 202 through 4 connecting ribs 203. In the present embodiment, the diameter-variable mechanism that can expand and contract in the radial direction of the shaft cross section in the diameter-expanding joint 2 is realized by the diameter-expanding blades 204.

The expanding blades 204 are assembled with the connecting ribs 203 in a one-to-one correspondence. As shown in fig. 5, each expanding blade 204 includes a fan-shaped ring plate and an arc-shaped limiting plate, the fan-shaped ring plate is provided with a slideway penetrating the plate body, the width of the slideway is slightly larger than the thickness of the connecting rib plate 203, and the outer end of the slideway keeps a certain distance from the outer arc-shaped edge of the fan-shaped ring plate. The fan-shaped annular plate is arranged between the upper end plate 201 and the lower end plate 202, and the fan-shaped annular plate is sleeved outside the connecting rib plate 203 through a slide way, so that a sliding pair for limiting the fan-shaped annular plate to move along the radial direction is formed. Therefore, when the variable diameter mechanism is in the contracted state, the expanding blades 204 are completely contracted between the upper end plate 201 and the lower end plate 202, and their tips do not protrude beyond the outer annular surfaces of the upper end plate 201 and the lower end plate 202, as shown in fig. 3. When the diameter-variable mechanism needs to be changed into a diameter-expanded state, the diameter-expanded blades 204 can be pushed radially by an external force to move outwards under the limiting action of the connecting rib plates 203, so that the outer edges of the blades extend out of the outer ring surfaces of the upper end plate 201 and the lower end plate 202. In the actual process, since the outside of the pile body is generally the soil around the pile, in order to facilitate the expanding blades 204 to be in an expanding state, the outer annular surface of the expanding blades 204 can be chamfered into a sharp angle. In addition, the purpose of providing the arc-shaped limiting plate at the inner arc-shaped edge of the fan annular plate is to control the limit position of outward movement of the diameter-expanding blades 204 in order to make the surface diameter-expanding blades 204 excessively spread away from the upper end plate 201 and the lower end plate 202. The arc-shaped limiting plates are arranged perpendicular to the fan-shaped annular plates, and a complete cylindrical surface is preferably formed when all the arc-shaped limiting plates are in a contraction state under the assembly state of the expanding joint 2. The size of the limiting plate should be larger than the gap between the upper end plate 201 and the lower end plate 202, and the arc limiting plate can be attached to the inner arc side of the upper end plate 201 and the lower end plate 202 when moving outwards to the limit position, so as to limit the arc limiting plate to move outwards continuously. As shown in fig. 6 and 7, the four expanding blades 204 in the variable diameter mechanism are in the expanded diameter state, at this time, the equivalent diameter is obviously expanded relative to the outer diameter of the pile body, and the four expanding blades 204 are horizontally inserted into the soil layer, so that a reliable expanded diameter structure is formed, and the bearing capacity and the uplift resistance of the pile body can be greatly increased.

Additionally, the utility model discloses in, the effect of upper end plate 201 is the tubular pile joint 3 of connecting the 1 bottom of a tubular pile that is located the top, and the effect of lower end plate 202 is then the tubular pile joint 3 of connecting the 1 top of a tubular pile that is located the below. In order to facilitate the connection between the end plate and the tubular pile joint 3, the outward surfaces of the upper end plate 201 and the lower end plate 202 may be respectively provided with a connecting member for connecting the tubular pile joint 3. But the concrete form of the connecting piece can be reasonably designed according to the concrete form of the pipe pile joint 3

It should be understood that, although the number of the expanding blades 204 and the number of the connecting ribs 203 are 4 in the above embodiments, the number may be adjusted according to the actual implementation in other embodiments, and is at least 3, or may be more than 4. Preferably, in the expanding joint 2, all the expanding blades 204 are annularly spliced to form a complete circular ring, and all the arc-shaped limiting plates are annularly spliced to form a complete cylinder.

As another preferred form of the embodiment of the present invention, as shown in fig. 8, the pipe pile joint 3 includes an end plate 301 and an end plate hole 302. The pipe pile joint 3 is fixed on the splicing end face of the pipe pile 1 through an end plate 301, and the fixation can be directly prefabricated during factory processing. In addition, the end plate 301 is provided with end plate holes 302 uniformly arranged along the circumference of the end plate to be connected and matched with the connecting pieces on the upper end plate 201 and the lower end plate 202. In order to ensure that the end plate holes 302 can be installed in a matching manner, the number and the positions of the end plate holes 302 are the same as the number of connecting pieces on the expanding joint 2, so that the connecting pieces on the upper end plate 201 and the lower end plate 202 can be exactly matched and fixed in the end plate holes 302.

As another preferred form of the embodiment of the present invention, the connecting members on the upper end plate 201 and the lower end plate 202 are connecting bolts 205, and the threaded sections of the connecting bolts 205 are fixed on the upper end plate 201 or the lower end plate 202, but the bolt heads need to keep a distance from the surface of the end plate. The connecting bolts 205 may be welded or screwed to the upper end plate 201 and the lower end plate 202. The end plate hole 302 on the end plate 301 is a variable diameter hole, the variable diameter hole is provided with a first hole area and a second hole area which are communicated with each other, wherein the size of the hole of the first hole area can be used for the bolt head of the connecting bolt 205 to extend into the first hole area, and when the connecting bolt 205 and the upper end plate 201 or the lower end plate 202 move relatively, the bolt head can move from the first hole area to the second hole area. However, in order to ensure the connection fixing function, the size of the hole of the second hole area needs to ensure that the bolt head cannot be directly separated from the second hole area. It should be noted that, since the size of the bolt head is larger than the size of the hole of the second hole area, but the bolt head needs to be able to move from the first hole area to the second hole area, the second hole area is actually a hole with an inner cavity, and the size of the hole is smaller than the size of the bolt head, but the inner cavity below the hole can still accommodate the bolt head.

Referring to fig. 8, the reducing hole in this embodiment is an 8-shaped hole having a large hole end and a small hole end, which correspond to the first hole area and the second hole area, respectively. The bolt head of the connecting bolt 205 extends from the large hole end and then moves to the small hole end for clamping and fixing. In order to realize the inner cavity at the small hole end, the end plate 301 may be fixed on the splicing end face of the tubular pile 1 at intervals, and the interval height may accommodate the bolt head of the connecting bolt 205. In order to ensure sufficient tensile strength at the eyelet end, the hole peripheral edge of the eyelet end may be provided with a reinforcing structure. In addition, in order to achieve the function of engaging by the rotational anchoring method, the arrangement form of the end plate holes 302 on the end plate 301 needs to be consistent, that is, the first hole regions of all the end plate holes 302 need to be always located in the same direction as the second hole regions when viewed in the clockwise direction.

The pile splicing device can realize reliable connection between the two tubular piles 1, and the diameter-variable mechanism can realize diameter expansion after pile sinking is finished. In the construction process, after the tubular piles 1 are sequentially spliced through the tubular pile joints 3 and the expanding joints 2, the tubular piles are sunk into a foundation by adopting the existing processes such as a static pressure method or a hammering method, and then the expanding joints 2 are expanded, so that the existing tubular pile connecting process does not need to be changed, the universality is good, and the construction is convenient.

In another embodiment of the present invention, since the contracting state and the expanding state of the diameter-variable mechanism in the diameter-expanding joint 2 need to be pushed by external force, the present invention further provides the reamer 4 matched with the diameter-expanding joint 2, both of which jointly form a pile extension diameter-expanding assembly for the precast tubular pile, and the reamer 4 can exert the pushing force along the radial direction of the cross section of the pile body on the diameter-variable mechanism in the pile extension diameter-expanding assembly, so as to convert the diameter-variable mechanism from the contracting state to the expanding state.

As shown in fig. 9, the underreamer 4 includes a drive mechanism and sets of cross arms 405 and underreamer end plates 410. Wherein, in each set of cross arms 405 and reamer end plate 410, reamer end plate 410 is connected to the drive mechanism by one of cross arms 405. Under the driving of the driving mechanism, all the reaming end plates 410 are synchronously stretched and contracted to form a gathering state and an expanding state. In the gathered state, the gathered sizes of all the reaming end plates 410 can integrally extend into the enclosed space of the arc limiting plates of all the expanding blades 204 in the contraction state; in the expanded state, the expanded size of all the expanding end plates 410 enables all the expanded diameter blades 204 to prop up the expanded arc limiting plates in the inner rings of the upper end plate 201 and the lower end plate 202, so that all the expanded diameter blades 204 reach the expanded diameter state.

It should be noted that the specific form of the driving mechanism and the fitting relationship with the cross arm 405 may be adjusted according to the actual application, and in this embodiment, the driving mechanism employs a hydraulic linear driving device. The hydraulic linear drive comprises a hydraulic ram 401, a hydraulic piston rod 402, a first hydraulic line 403 and a second hydraulic line 404. The piston head of the hydraulic piston rod 402 is assembled in the hydraulic oil cylinder 401 and can freely slide, the piston head divides the hydraulic oil cylinder 401 into an upper area and a lower area, the upper hydraulic cylinder is connected with the first hydraulic pipe 403, and the lower hydraulic cylinder is connected with the second hydraulic pipe 404; and the output rod connected with the piston head extends out of the hydraulic oil cylinder 401, and can be pushed to output power outwards through different hydraulic oil input and output states of the first hydraulic pipe 403 and the second hydraulic pipe 404. The cross arm 405 is a scissor-like structure consisting of two links with a pin 407 in between. In this embodiment there are 4 cross arms 405 and 4 reaming end plates 410, with the inner sides of the 4 cross arms 405 fitting together on the same set of fixed end blocks 408 and sliding end blocks 409 and the outer sides fitting separately on the 4 reaming end plates 410. The hydraulic oil cylinder 401 is located at the center of the whole underreamer 4, the bottom of the hydraulic oil cylinder 401 is fixedly connected with a sliding end block 409, the output rod of the piston rod 402 passes through a guide hole in the sliding end block 409 and then is fixedly connected with a fixed end block 408, and the output rod of the piston rod 402 can freely slide in the guide hole. Thus, the relative distance between the fixed end block 408 and the sliding end block 409 can be changed by the piston rod 402, and the hydraulic power is converted into a radial pushing force outside the cross arm 405. As shown in fig. 10, as the relative distance between fixed end block 408 and sliding end block 409 decreases, cross arm 405 pushes reamer end plate 410 outward to an expanded state. As shown in fig. 11 and 12, the collapsed state and the expanded state of all of the reamer end plates 410 correspond to the collapsed state and the expanded state of all of the expanded diameter blades 204, respectively.

In order to avoid excessive radial displacement of the output, the reamer end plate 410 is provided with a stopper 406, one end of the cross arm 405 needs to slide in a slide groove of the stopper 406, and both ends of the slide groove constitute two limit positions at which the cross arm 405 rotates. The specific size parameters of the limiter 406 need to be reasonably and optimally designed according to the matching condition with 4 expanding blades 204 in the expanding joint 2, so as to meet the function requirement.

In order to facilitate the extension of the underreamer 4 from the pile top into all the expanding blades 204 in the contracted state inside the pile body, the first hydraulic pipe 403 and the second hydraulic pipe 404 may be rigid pipes located on the central axis of the underreamer 4, the piston driving mechanism is arranged along the center of the entire underreamer 4, and all the cross arms 405 are uniformly arranged in the direction perpendicular to the central axis of the underreamer 4. Thereby, the centering state of the reamer 4 in the pipe pile 1 can be adjusted by controlling the two hydraulic pipes.

The above-mentioned embodiments are merely a preferred embodiment of the present invention, but it is not intended to limit the present invention. Various changes and modifications can be made by one of ordinary skill in the pertinent art without departing from the spirit and scope of the present invention. Therefore, all the technical schemes obtained by adopting the mode of equivalent replacement or equivalent transformation fall within the protection scope of the utility model.

Claims (10)

1. A pile extension device for a prefabricated pipe pile is used for connecting two sections of pipe piles (1), and is characterized by comprising an expanding joint (2) and a pipe pile joint (3); the two sections of tubular piles (1) are prefabricated tubular pile sections, and the tubular pile joints (3) are respectively fixed on the respective connecting end surfaces;

the expanding joint (2) comprises an upper end plate (201), a lower end plate (202), a connecting rib plate (203), expanding blades (204) and connecting bolts (205); the upper end plate (201) and the lower end plate (202) are arranged in parallel at intervals, and a connecting structure capable of bearing loads in the direction vertical to the end plates is formed between the upper end plate and the lower end plate by clamping and fixing a plurality of connecting rib plates (203); the diameter-expanding blades (204) and the connecting rib plates (203) are assembled in a one-to-one correspondence mode, each diameter-expanding blade (204) comprises a fan-shaped annular plate and an arc limiting plate, a slide way penetrating through the plate bodies is formed in the fan-shaped annular plate, the fan-shaped annular plate is installed between the upper end plate (201) and the lower end plate (202), the fan-shaped annular plate is sleeved outside the connecting rib plates (203) through the slide way to form a sliding pair for limiting the radial movement of the fan-shaped annular plate, the size of the arc limiting plate is larger than the gap between the upper end plate (201) and the lower end plate (202), and the arc limiting plates can be limited to move outwards continuously when moving outwards to the limiting position; and the outward plate surfaces of the upper end plate (201) and the lower end plate (202) are respectively provided with a connecting piece for connecting the tubular pile joint (3).

2. Pile extension device for precast tubular piles according to claim 1, wherein the number of the expanding blades (204) and the connecting ribs (203) in the expanding joint (2) is at least 3.

3. Pile extension device for precast tubular piles according to claim 1, wherein the number of the expanding blades (204) and the connecting ribs (203) in the expanding joint (2) is 4.

4. A pile extension device for precast tubular piles according to claim 1, wherein the connecting members of the upper end plate (201) and the lower end plate (202) are connecting bolts (205), and the threaded sections of the connecting bolts (205) are fixed on the end plates, and the bolt heads of the connecting bolts are spaced from the surface of the end plates; the variable-diameter hole is adopted in an end plate hole (302) in the end plate (301), a first hole area and a second hole area which are communicated are arranged in the variable-diameter hole, the size of an opening in the first hole area can be used for the bolt head to stretch into, the bolt head can move to the second hole area from the first hole area, and the size of an opening in the second hole area cannot enable the bolt head to be directly separated from the second hole area.

5. The pile extension device for the precast tubular pile according to claim 1, wherein in the diameter-expanding joint (2), all diameter-expanding blades (204) are annularly spliced to form a complete circular ring, and all arc-shaped limiting plates are annularly spliced to form a complete cylinder.

6. Pile extension device for precast tubular piles according to claim 1, wherein the tubular pile joint (3) is precast integrally with the tubular pile (1).

7. A pile extension and diameter expansion assembly for precast tubular piles is characterized by comprising a pile extension device as claimed in any one of claims 1 to 6 and a reamer (4) matched with the diameter expansion joint (2);

the reamer (4) comprises a drive mechanism and sets of cross arms (405) and a reamer end plate (410); wherein in each set of cross arms (405) and reamer end plates (410), the reamer end plates (410) are connected to the drive mechanism by the cross arms (405); all the cross arms (405) connected with the driving mechanism have the same size and posture, so that all the reaming end plates (410) can be synchronously stretched under the driving of the driving mechanism, and a gathering state and an expanding state are respectively formed at two limit positions of a stretching stroke; in the gathering state, the gathered sizes of all the reaming end plates (410) can integrally extend into the enclosed space of the arc-shaped limiting plates of all the expanding blades (204) in the contraction state; in an expanded state, the expanded size of all the expanding end plates (410) can enable all expanding blades (204) to prop up the expanded arc limiting plates in the inner rings of the upper end plate (201) and the lower end plate (202).

8. The pile extension hole enlargement assembly for the precast tubular pile according to claim 7, wherein in the reamer (4), the driving mechanism adopts a hydraulic linear driving device comprising a hydraulic cylinder (401), a hydraulic piston rod (402), a first hydraulic pipe (403), a second hydraulic pipe (404), a fixed end block (408) and a sliding end block (409); the hydraulic cylinder (401) and the hydraulic piston rod (402) are assembled to form a piston driving mechanism, and two hydraulic cylinders separated by a piston head of the hydraulic piston rod (402) in the hydraulic cylinder (401) are respectively communicated with a first hydraulic pipe (403) and a second hydraulic pipe (404); the bottom of the hydraulic oil cylinder (401) is fixedly connected with a sliding end block (409), the rear end part of an output rod of the piston rod (402) penetrates through a guide hole in the sliding end block (409) and is fixed on the fixed end block (408), one end of each of two arm rods of each cross arm (405) is respectively fixed on the fixed end block (408) and the sliding end block (409), and the other end of each of the two arm rods is respectively connected with a corresponding reaming end plate (410).

9. The pile extension and diameter expansion assembly for the precast tubular pile according to claim 8, wherein a stopper (406) is arranged at a connection position of each cross arm (405) and the reaming end plate (410), the stopper (406) is fixed on the reaming end plate (410) and is provided with a sliding groove parallel to the reaming end plate (410), and the other end of one arm rod of the cross arm (405) needs to slide in the sliding groove of the stopper (406) to limit the telescopic stroke of the cross arm (405).

10. A pile extension hole enlargement assembly for precast tubular piles according to claim 8, wherein the piston driving mechanism is arranged along the center of the entire underreamer (4), and all the cross arms (405) are arranged uniformly in the direction perpendicular to the centerline of the underreamer (4).

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