CN114561935A

CN114561935A - Precast concrete pile

Info

Publication number: CN114561935A
Application number: CN202210199082.1A
Authority: CN
Inventors: 胡浩林; 王雨桐; 黄新龙
Original assignee: Hubei Jiegu Construction Technology Co ltd
Current assignee: Hubei Jiegu Construction Technology Co ltd
Priority date: 2022-03-02
Filing date: 2022-03-02
Publication date: 2022-05-31

Abstract

The invention discloses a precast concrete pile, which comprises a pile body, wherein one end of a main rib of the precast concrete pile is connected with a connecting pipe, the other end of the main rib is connected with a tensioning sleeve, the connecting pipe is arranged in the pile body, one end port of the connecting pipe, which is far away from the main rib, faces the outer side of the end surface of the pile body, a clamping piece is arranged in the connecting pipe, the tensioning sleeve is arranged in the pile body, one end port of the tensioning sleeve, which is far away from the main rib, faces the outer side of the end surface of the pile body, an inserting rod is fixed at the end port of the tensioning sleeve, the inserting rod comprises an inserting rod fixing part and an inserting rod clamping part, the length of the inserting rod clamping part is more than or equal to three times of the diameter of the main rib, and the length of the inner space of the connecting pipe is more than or equal to three times of the diameter of the main rib; the inserted bar joint portion of two adjacent precast concrete piles can insert in the connecting pipe and with the joint of card firmware. The precast concrete pile disclosed by the invention realizes the coaxial and consistent connection of the real pile-forming main reinforcements, so that the shearing resistance, the bending resistance and the pulling resistance of one pile are optimal.

Description

Precast concrete pile

Technical Field

The invention relates to the technical field of precast concrete piles, in particular to a precast concrete pile.

Background

With the continuous improvement of the economic level of China, the precast concrete pile goes through the rapid development stage from the introduction of advanced products, technologies and processes to the independent and independent research and development of new products and new processes from Japan, and becomes one of the countries with the largest global pipe pile yield, the largest variety, the most complete specification and the widest application range in China at present. According to statistics, the output of the precast concrete pile in China is 45362 kilometers in 2020, and the yield is increased by 5.44% on year-on-year basis. Meanwhile, higher requirements are provided for the vertical bearing capacity and the comprehensive properties of bending resistance, shearing resistance and pulling resistance of the pile. In order to obtain a better construction effect, the welding connection process of the pile end plate of the precast concrete pile in the prior art cannot effectively guarantee the welding quality due to human factors in engineering practice, and has low construction efficiency and environmental pollution. Therefore, a precast concrete pile of a novel connection structure is urgently needed to be developed.

Disclosure of Invention

The invention aims at solving the problems and researches and designs a precast concrete pile. The technical means adopted by the invention are as follows:

a precast concrete pile comprises a pile body, wherein one end of a main rib of the precast concrete pile is connected with a connecting pipe, the other end of the main rib is connected with a tensioning sleeve, the connecting pipe is arranged in the pile body, a port of one end, far away from the main rib, of the connecting pipe faces the outer side of the end face of the pile body, a clamping piece is arranged in the connecting pipe, the tensioning sleeve is arranged in the pile body, a port of one end, far away from the main rib, of the tensioning sleeve faces the outer side of the end face of the pile body, a jack rod is fixed at the port of the tensioning sleeve, the jack rod comprises a jack rod fixing part and a jack rod clamping part, the jack rod fixing part is used for being connected with the port of the tensioning sleeve, the jack rod clamping part is used for being clamped with the clamping piece, the length of the jack rod clamping part is more than or equal to three times of the diameter of the main rib, and the length of the inner space of the connecting pipe is more than or equal to three times of the diameter of the main rib; the inserted bar clamping parts of two adjacent precast concrete piles can be inserted into the connecting pipe and clamped with the clamping piece.

Further, the length of the inserted bar clamping part is less than or equal to the length of the inner space of the connecting pipe.

Furthermore, the connecting pipe comprises a connecting pipe main body and a connecting part used for being connected with the main rib, the connecting part is a flange which is inward in the radial direction, and the flange can limit the upset head of the main rib in the connecting pipe main body.

Further, the length of the connecting pipe main body is 60 mm or more.

Further, the length of the connecting pipe main body is 100 mm-300 mm.

Furthermore, one side of the connecting part facing the inner side of the connecting pipe main body is a concave conical surface.

Further, the vertex angle of the conical surface is 120 degrees.

Further, the clamping piece comprises a clamping piece main body fixed in the connecting pipe through threads and more than two elastic clamping pieces arranged on the clamping piece main body, and the inserting rod clamping portion can penetrate through the space between the more than two elastic clamping pieces and realize clamping through resilience of the elastic clamping pieces.

Further, the end of the elastic clamping piece faces the connecting part, and the distance between the end of the elastic clamping piece and the opening end of the connecting pipe is greater than or equal to 60% of the length of the connecting pipe.

Further, the clamping piece main body is fixed in the middle of the connecting pipe main body.

Further, the inserted bar is still including being used for connecting the inserted bar fixed part with the inserted bar connecting portion of inserted bar joint portion, the external diameter of inserted bar connecting portion is greater than the external diameter of inserted bar fixed part just is less than the internal diameter of connecting pipe.

Compared with the prior art, the precast concrete pile realizes coaxial and consistent connection of the real pile-forming main reinforcements, the strength of the connecting part is stronger than that of the main reinforcements, the integrity of the connected pile-forming is ensured, and the optimal shearing resistance, bending resistance and pulling resistance of one pile are really realized on the premise that the bearing capacity can completely meet the construction requirement; simultaneously, the cooperation sets up the inserted bar, and during the construction, the structure is glued in the connecting pipe of stake connection is poured into, then inserts the inserted bar joint portion of stake connection in the connecting pipe of stake connection, when the structure is glued and is not solidified yet, plays the effect of temporary connection, and the quick construction of being convenient for guarantees the engineering progress. The use method of the precast concrete pile is characterized in that the joints are fixedly connected through the engineering glue, and the engineering glue generally has good corrosion resistance, so that the precast concrete pile has strong corrosion resistance after being formed.

Drawings

Fig. 1 is a schematic perspective view of a precast concrete pile according to a first embodiment of the present disclosure, in which the precast concrete pile is a tubular pile.

Fig. 2 is a structural view before concrete is poured in fig. 1.

Fig. 3 is a top view of fig. 1.

Fig. 4 is a sectional view a-a of fig. 3.

Fig. 5 is a schematic structural view of a plurality of sections of precast concrete piles after being connected, wherein two sections of precast concrete piles are shown.

Fig. 6 is a schematic sectional view showing a structure of the precast concrete pile according to the present disclosure after the precast concrete pile is connected.

Fig. 7 is an enlarged schematic view of the dotted line in fig. 6.

FIG. 8 is an end view of the present invention after the connection tubes, rods, retainer and tension sleeves have been connected.

Fig. 9 is a cross-sectional view taken at D-D of fig. 8.

Fig. 10 is a structural view of a connection pipe disclosed in the present invention.

FIG. 11 is a block diagram of a tensioning sleeve according to the present disclosure.

Fig. 12 is a structural view of the insert rod disclosed in the present invention.

Fig. 13 is a cross-sectional view of the fastener disclosed in the present invention.

Fig. 14 is a left side view of fig. 13.

Fig. 15 is a schematic perspective view of a second embodiment of the precast concrete pile disclosed in the present invention, which is a square pile.

Fig. 16 is a structural view before concrete is poured in fig. 15.

Fig. 17 is a front view of a second embodiment of the precast concrete pile disclosed in the present invention.

Fig. 18 is a sectional view taken at B-B of fig. 17.

Fig. 19 is a top view of a second embodiment of the precast concrete pile disclosed in the present invention.

Fig. 20 is a schematic structural view of a multi-section precast concrete pile after connection, in which two precast concrete square piles are shown.

Fig. 21 is a cross-sectional view taken at C-C in fig. 20.

In the figure: 10. pile body, 11, main rib, 12, pier nose, 2, connecting pipe, 20, connecting pipe main part, 21, connecting part, 22, conical surface, 3, clamping piece, 30, clamping piece main part, 31, elastic clamping piece, 4, tensioning sleeve, 5, inserted bar, 50, inserted bar fixing part, 51, inserted bar clamping part, 52 and inserted bar connecting part.

Detailed Description

Example 1

As shown in fig. 1 to 4, a first embodiment of a precast concrete pile disclosed by the present invention is a precast concrete pile, which is a pipe pile and includes a pile body 10, a main reinforcement 11 of the precast concrete pile has one end connected to a connecting pipe 2 and the other end connected to a tensioning sleeve 4, the connecting pipe 2 is disposed in the pile body 10, and an end of the connecting pipe 2, which is far away from the main reinforcement 11, faces an outer side of an end surface of the pile body 10, a clamping member 3 is disposed in the connecting pipe 2, the tensioning sleeve 4 is disposed in the pile body 10, and an end of the tensioning sleeve 4, which is far away from the main reinforcement 11, faces an outer side of the end surface of the pile body 10, as shown in fig. 11, the tensioning sleeve 4 is of a sleeve structure, one end is a radially inward flange for connecting to the main reinforcement, and the other end is provided with an internal thread, an insertion rod 5 is fixed to an end of the tensioning sleeve 4, as shown in fig. 12, the insertion rod 5 includes an insertion rod fixing portion 50 for connecting to the end of the sleeve 4 and an insertion rod clamping member 51 for clamping the clamping member 3, in this embodiment, the inserted bar fixing portion 50 is provided with an external thread for connecting with the tensioning sleeve 4, preferably, the inserted bar 5 further includes an inserted bar connecting portion 52 for connecting the inserted bar fixing portion 50 with an inserted bar clamping portion 51, an outer diameter of the inserted bar connecting portion 52 is larger than an outer diameter of the inserted bar fixing portion 50 but smaller than an inner diameter of the connecting pipe, so that the inserted bar is quickly connected with the tensioning sleeve in place and the inserted bar can be completely inserted into the connecting pipe, a length of the inserted bar clamping portion 51 is larger than or equal to three times of a diameter of the main rib 11, an end of the inserted bar clamping portion is provided with an inserted bar clamping head 53, and a length of an inner space of the connecting pipe 2 is larger than or equal to three times of the diameter of the main rib 11; as shown in fig. 5, 6 and 7, the rod clamping portions 51 of the insertion rods of two adjacent precast concrete piles can be inserted into the connecting pipe 2 and clamp the rod clamps 53 to the clamping members 3, and further, the length of the rod clamping portions 51 is less than or equal to the length of the inner space of the connecting pipe 2.

Further, as shown in fig. 8, 9 and 10, the connecting pipe 2 includes a connecting pipe main body 20 and a connecting portion 21 for connecting with the main bar 11, the connecting pipe main body 20 is provided with internal threads, the connecting portion 21 is a radially inward flange, and the flange can limit the upset head 12 of the main bar in the connecting pipe main body 20. The connecting pipe main body 20 and the connecting part 21 are of an integral structure, and can be processed through processing modes such as stamping, machining and the like, and the parts do not need to be assembled when in use, so that the production and construction efficiency is improved. The length of the connecting pipe main body is more than or equal to three times of the diameter of the main reinforcement of the concrete pile, the length of the connecting pipe main body is preferably more than seven times of the diameter of the main reinforcement, and the inserting length is guaranteed. The connecting pipe comprises a connecting pipe body and is characterized in that a clamping piece used for clamping an inserted rod is arranged inside the connecting pipe body, and the inserted rod clamped by the clamping piece is an inserted rod arranged on different pile bodies together with the connecting pipe.

Further, the length of the connecting pipe main body 20 is greater than or equal to 60 mm, and preferably, the length of the connecting pipe main body 20 is 100 mm to 300 mm, so that the insertion length is ensured, and the connection strength of the main rib is ensured.

Further, one side of the connecting portion 21 facing the inner side of the connecting pipe main body 20 is a concave conical surface 22, preferably, the vertex angle of the conical surface 22 is 120 degrees, so that the connecting pipe and the main rib are ensured to be coaxial, and further, the anti-cracking performance, the bending resistance and the tensile resistance of the pile connection are improved.

Further, as shown in fig. 13 and 14, the fastening member 3 includes a fastening member main body 30 fixed in the connecting pipe by a screw thread and two or more elastic clamping pieces 31 disposed on the fastening member main body 30, and the plunger clamping portion 51 can pass through between the two or more elastic clamping pieces 31 and realize clamping by resilience of the elastic clamping pieces 31. Specifically, the main reinforcement adopts the rod iron structure, and the rod iron heading can radially strut a plurality of elasticity cards 31 and pass, and later the elasticity card kick-backs, blocks the rod iron heading, realizes the joint. The end of the elastic clamping piece 31 faces the connecting part 21, the distance a between the end of the elastic clamping piece 31 and the opening end of the connecting pipe is larger than or equal to 60% of the length of the connecting pipe, the temporary connecting effect is guaranteed, and meanwhile the consistency of main rib connection is guaranteed.

Further, the fastening member main body 30 is fixed to the middle of the connecting pipe main body 20, that is, the fastening member main body 30 is spaced apart from both ends of the connecting pipe main body 20. The inner wall of the connecting pipe is provided with threads from the opening end to the middle part, the clamping piece is screwed in from the opening end of the connecting pipe, and the threads can be used for being connected with a tensioning device during tensioning and can also enhance the connection strength between the main ribs.

As shown in fig. 6 and 7, which are schematic diagrams of two sections of precast concrete pipe piles in a connection state, a connection pipe 2 is disposed in a pile body 10 of a precast concrete pile and connected with a main reinforcement 11 in the same pile body through a connection portion 21, a port of one end far away from the main reinforcement 11 faces the outside of an end face of the pile body, the port of the connection pipe 2 forms a sleeve portion for pile connection, when connecting the piles, structural adhesive is poured into the connection pipe, then an insertion rod clamping portion 51 of another pile is inserted into the connection pipe 2 for pile connection, the insertion rod clamping portion 51 of the another pile is clamped through a clamping member 3, and then pile sinking construction is performed. When the structural adhesive is not solidified, the clamping piece is arranged to play a role in temporary connection, so that rapid construction is facilitated, and the progress of engineering is guaranteed. In the construction method, the splicing parts do not need to be assembled on site, and the construction efficiency is high.

When the connecting pipe of this application embodiment is used for connecting precast concrete pile, realized that real stake-forming owner muscle is coaxial, unanimous connection (as shown in fig. 7), after the stake, the main muscle of all single section stakes is connected as an organic wholely through the connected mode of this patent), and the intensity of connecting portion is stronger than the intensity of main muscle itself (as shown in table 1, table 2 and table 3, this patent precast concrete pile connection structure test result shows that, connecting portion is in the experiment of anti-crack shear force test, bending resistance, tensile, and the intensity of junction is stronger than the intensity of main muscle itself. The connecting pipe is arranged in the pile body, a port of one end, far away from the main rib, of the connecting pipe faces the outer side of the end face of the pile body, the connecting pipe plays a role of the main rib in the pile body, and the strength of the connecting pipe is far greater than that of the main rib; meanwhile, if the main reinforcement is a prestressed main reinforcement, the connecting pipe replaces a tensioning nut. Because the connection of the invention is gapless connection of two single piles, the bearing capacity mainly depends on the structural strength of the piles, so the bearing capacity of the invention is not repeated herein and can completely meet the construction requirement, and finally the optimal shear resistance, bending resistance and pulling resistance of one pile are really realized; because the joints are fixedly connected through the engineering adhesive, the engineering adhesive generally has good corrosion resistance, so that the precast concrete pile has strong corrosion resistance after being formed.

During construction of the connecting pipe, the connecting pipe body connected with the pile is filled with structural glue, and then the inserting rod clamping portion connected with the pile is inserted into the connecting pipe for connecting the pile to be fixedly connected. The magnitude of the connection force between the single piles at this time is evaluated by calculation through the bond strength. The bond strength is generally determined by r ═ p/3.14 dL. p is the pull-out force, d is the diameter of the steel bar, and L is the embedding length of the steel bar. Bond strength: generally expressed in terms of bond strength of concrete. The physical quantity of the concrete against the sliding ability of the steel bar is expressed by dividing its sliding force by the bond area (mpa), and in general, the bond strength refers to the shear stress along the contact surface between the steel bar and the concrete, i.e., the bonding stress. In fact, the stress and deformation state of concrete around the reinforcing steel bar are complex, and the bond strength changes with the bond length of the reinforcing steel bar, so the bond strength changes with the type of the reinforcing steel bar, the appearance shape, the embedding position in the concrete and the direction, and is also related to the strength of the concrete, namely the higher the compressive strength of the concrete. The strength of the engineering glue is usually several times of that of concrete, so that the engineering glue with the strength of the pile body concrete being more than 2 times of that of the engineering glue is selected, and the main reinforcement extends into the connecting pipe and has effective bonding (connecting) length more than or equal to seven times of the diameter of the main reinforcement, so that the requirement of the strength of the connecting part can be completely met. For verification, experiments are specially carried out before the application of the patent, and the verification results are shown in tables 1, 2 and 3.

TABLE 1 record of the anti-cracking and shearing force test of the pipe pile

Table 1 is this patent the tubular pile experiment record of precast concrete pile, anti-split in the experimentation, when the loading capacity reached hundredth percent, the junction did not appear the crack, and the pile body did not appear the crack. When the load force reaches 110%, no crack appears at the joint when the load is finished, and a crack with the width of 0.1 mm appears on the pile body for the first time. The strength of the connecting structure is far higher than that of the pile body.

TABLE 2 record of the bending resistance test of the pipe pile

Table 2 is this patent the tubular pile bending test record of precast concrete stake, in the bending resistance experimentation, load capacity reaches when hundredth percent, and the junction does not appear the crack when holding the load, and the pile body does not appear the crack. When the load force reaches 115%, no crack appears at the joint when the load holding is finished, and cracks appear for the first time. The strength of the connecting structure is far higher than that of the pile body.

Table 3 is this patent the tubular pile tensile load inspection report of precast concrete pile, among the tensile load inspection process, in 3 experiments that surpass standard 125KN, the reinforcing bar broke when being 165.5KN respectively, reinforcing bar pier head fracture when two 150.3KN, reinforcing bar fracture when three 162.8 KN.

TABLE 3 tensile load test report

Current connected mode can't reach the result of use of this patent all, and traditional supplementary muscle plug-in connection mode exists to assist muscle 4 and directly pegs graft in precast concrete pile owner muscle in the concrete preformed hole 5, glues the two through the structure during the construction, assists muscle 4 and concrete connection, and its pile body connects comprehensive mechanical properties: the shearing resistance, the bending resistance and the pulling resistance are far lower than those of the patent, the pile foundation is only suitable for a pile foundation with a vertical bearing capacity requirement, and the main reinforcements are not connected on the same axis; in addition, the construction time is limited by the setting time of the glue. The traditional end plate welding connection meets the requirements of pile-forming shear resistance and bending resistance, but the uplift pile needs to be specially customized; when the electric welding is used for welding connection, the full welding is required to be carried out for three times, and the welding heat can cause secondary damage to concrete and a steel bar pier head. In addition, the construction cost and the welding cost of the anchoring end plates at the two ends of the pile are far higher than the implementation cost of the method, and the precast concrete pile with the end plates at the two ends of the traditional pile also runs against the great trend of 'energy conservation, emission reduction and double carbon policy'; according to the calculation mode of the average pile length of 11 meters in the industry, the output of the precast concrete pile in China is 45362 ten thousand extension meters (data source, China association for concrete and cement products), calculated in 2020, about 8247 ten thousand end plates are needed, namely about 160 ten thousand tons of steel are consumed, about 100 hundred million expenses are needed in conversion, and after the steel is replaced, about 288 ten thousand tons of carbon emission (calculated according to the standard that about 1.8 tons of carbon is emitted per ton of crude steel) can be reduced every year.

Example 2

Fig. 15 to 21 show a second embodiment of a precast concrete pile disclosed in the present invention, which is different from embodiment 1 in that the precast concrete pile in embodiment 1 is a tubular pile, the precast concrete pile in this embodiment is a square pile, and includes a pile body 10, one end of a main reinforcement 11 of the precast concrete pile is connected to a connecting pipe 2, the other end is connected to a tensioning sleeve 4, the connecting pipe 2 is disposed in the pile body 10, and an end port of the connecting pipe 2, which is far away from the main reinforcement 11, faces the outside of an end face of the pile body 10, a fastener 3 is disposed in the connecting pipe 2, the tensioning sleeve 4 is disposed in the pile body 10, and an end port of the tensioning sleeve 4, which is far away from the main reinforcement 11, faces the outside of the end face of the pile body 10, the tensioning sleeve 4 is of a sleeve structure, one end is a radially inward flange for connecting with the main reinforcement, the other end is provided with an internal thread, a port of the tensioning sleeve 4 is fixed with a plunger 5, the inserted bar 5 comprises an inserted bar fixing part 50 used for being connected with a port of the tensioning sleeve 4 and an inserted bar clamping part 51 used for being clamped with the clamping piece 3, in this implementation, external threads are arranged on the inserted bar fixing part 50 and used for being connected with the tensioning sleeve 4, preferably, the inserted bar 5 further comprises an inserted bar connecting part 52 used for connecting the inserted bar fixing part 50 with the inserted bar clamping part 51, the outer diameter of the inserted bar connecting part 52 is larger than the outer diameter of the inserted bar fixing part 50 but smaller than the inner diameter of the connecting pipe, so that the inserted bar can be quickly connected with the tensioning sleeve in place and can be completely inserted into the connecting pipe, the length of the inserted bar clamping part 51 is larger than or equal to three times of the diameter of the main rib 11, an inserted bar clamping head 53 is arranged at the end part of the inserted bar clamping part, and the length of the inner space of the connecting pipe 2 is larger than or equal to three times of the diameter of the main rib 11; the inserted bar clamping parts 51 of the inserted bars of two adjacent precast concrete piles can be inserted into the connecting pipe 2 and enable the inserted bar clamping heads 53 to be clamped with the clamping parts 3, and further, the length of the inserted bar clamping parts 51 is smaller than or equal to that of the inner space of the connecting pipe 2.

Example 3

When the use method of the precast concrete pile described in embodiment 1 and embodiment 2 is used, structural adhesive is poured into a connecting pipe connected with the pile, then the inserting rod clamping part is inserted into the connecting pipe, and then pile sinking construction is carried out. When the inserted pile is the bottommost pile, the bottom main reinforcement of the inserted pile does not extend out of the end face, a tensioning sleeve connected with the main reinforcement can be arranged at the end face, a pile tip (including but not limited to a concrete pile tip and a steel pile tip) can be arranged at the bottom end, and an end plate can be arranged at the bottom end. One bottom pile may be sequentially connected with one or more precast concrete piles according to embodiments of the present invention. In the construction method, the splicing parts do not need to be assembled on site, and the construction efficiency is high.

The above-mentioned embodiments are merely illustrative of the preferred embodiments of the present invention, and do not limit the scope of the present invention, and various modifications and improvements of the technical solution of the present invention by those skilled in the art should fall within the protection scope defined by the claims of the present invention without departing from the spirit of the present invention.

Claims

1. A precast concrete pile, includes pile body (10), its characterized in that: the precast concrete pile main reinforcement (11) one end links to each other with connecting pipe (2), and the other end is connected with stretch-draw sleeve (4), connecting pipe (2) set up in pile body (10) just one end port that main reinforcement (11) was kept away from in connecting pipe (2) is towards the terminal surface outside of pile body (10), is equipped with card firmware (3) in this connecting pipe (2), stretch-draw sleeve (4) set up in pile body (10) and stretch-draw sleeve (4) keep away from the terminal surface outside of one end port of main reinforcement (11) towards the pile body, and the port of this stretch-draw sleeve (4) is fixed with inserted bar (5), inserted bar (5) are including inserted bar fixed part (50) that are used for being connected with the port of stretch-draw sleeve (4) and inserted bar joint portion (51) that are used for with card firmware (3) joint, the length of inserted bar joint portion (51) is greater than or equal to three times of main reinforcement diameter, the length of the inner space of the connecting pipe (2) is more than or equal to three times of the diameter of the main rib; the inserted bar clamping parts (51) of two adjacent precast concrete piles can be inserted into the connecting pipe (2) and clamped with the clamping pieces (3).

2. The precast concrete pile of claim 1, wherein: the length of the inserted link clamping part (51) is less than or equal to the length of the inner space of the connecting pipe (2).

3. The precast concrete pile of claim 2, wherein: the connecting pipe (2) comprises a connecting pipe main body (20) and a connecting part (21) connected with the main rib (11), the connecting part (21) is a flange which is inward in the radial direction, and the flange can limit the upset head (12) of the main rib (11) in the connecting pipe main body.

4. The precast concrete pile of claim 3, wherein: the length of the connecting pipe main body (20) is more than 60 mm.

5. The precast concrete pile of claim 4, wherein: the length of the connecting pipe main body (20) is 100 mm-300 mm.

6. The precast concrete pile of claim 5, wherein: one side of the connecting part (21) facing the inner side of the connecting pipe main body is a concave conical surface (22).

7. The precast concrete pile according to any one of claims 3 to 6, wherein: the clamping piece (3) comprises a clamping piece main body (30) fixed in the connecting pipe (2) through threads and more than two elastic clamping pieces (31) arranged on the clamping piece main body (30), and the inserted rod clamping portion (51) can penetrate through the elastic clamping pieces (31) and realize clamping through resilience of the elastic clamping pieces (31).

8. The precast concrete pile of claim 7, wherein: the end of the elastic clamping piece (31) faces the connecting part (21), and the distance between the end of the elastic clamping piece (31) and the opening end of the connecting pipe (2) is greater than or equal to 60% of the length of the connecting pipe.

9. The precast concrete pile of claim 8, wherein: the clamping piece main body (30) is fixed in the middle of the connecting pipe main body (20).

10. The precast concrete pile of claim 9, wherein: the inserted bar is still including being used for connecting the inserted bar fixed part with the inserted bar connecting portion of inserted bar joint portion, the external diameter of inserted bar connecting portion is greater than the external diameter of inserted bar fixed part just is less than the internal diameter of connecting pipe.