TWM500117U - Pre-stressed concrete pile - Google Patents

Description

Prestressed concrete pile

The present invention relates to a pile type, and more particularly to a prestressed concrete pile having an inner hole in a longitudinal axis and a reinforcing unit interposed in the inner hole.

Prestressed concrete piles can be used for large or important buildings as a substructure to transfer the building's load to the soil bearing layer or to a harder site to increase the safety and stability of the building structure.

In prestressed concrete piles, prestressed concrete pipe piles are the most commonly used pile types in engineering. Taking prestressed concrete pipe piles as an example, prestressed concrete piles need to be placed deep into the soil layer to provide sufficient soil carrying capacity. However, most of the existing prestressed concrete piles are pre-made in the factory and then transported to the construction site. Carry out the construction of buried soil.

Limited to the length limit of factory molds and transport vehicles, existing prestressed concrete piles are generally up to about 18 meters long. In the case of limited length of single prestressed concrete piles, most of the existing piles are connected by multiple prestressed concrete piles. Ways to extend the length of prestressed concrete piles to reach the depth of the soil.

Referring to Figure 1, the existing prestressed concrete pile includes a pile 11 With the pile 12 below. The upper pile 11 has an upper tubular body 111 made of concrete, and two upper end plates 112 respectively sealed at opposite ends of the upper tubular body 111. The lower pile 12 has a lower tubular body 121 made of concrete, and two lower end plates 122 respectively sealed at opposite ends of the lower tubular body 121. The upper end plate 112 and the lower end plate 122 of the upper and lower butt joints are welded by welding to extend the overall length.

As we all know, the structural strength of the welded portion of the upper pile 11 and the lower pile 12 is relatively weak, and the welded portion of the upper pile 11 and the lower pile 12 is exposed to the environment of underground soil or groundwater for a long time, which is prone to corrosion and joint. Strength and durability. During the use period of the prestressed concrete pile for 50 to 100 years, once the upper end plate 112 and the lower end plate 122 which are joined to each other at the joint of the upper pile 11 and the lower pile 12 are rusted, the bearing of the prestressed concrete pile is caused. Damage or loss of force, which in turn leads to damage to buildings. Therefore, how to improve the strength and durability of prestressed concrete piles has become the goal of the relevant industry.

Therefore, the object of the present invention is to provide a prestressed concrete pile capable of improving structural strength and durability. .

Therefore, the prestressed concrete pile of the present invention comprises a lower pile unit and at least one upper pile unit that are joined to each other, and a reinforcing unit that is inserted into the lower pile unit and the upper pile unit.

The lower pile unit includes a lower pile body formed with a longitudinal hollow hollow inner hole. The upper pile unit includes an upper pile body that is engaged with the lower pile body, and the upper pile body is formed with a longitudinally hollow upper pile inner hole communicating with the inner hole of the lower pile. The reinforcing unit is configured to insert the inner hole of the upper pile and the lower pile The inner hole is connected to the upper pile body and the lower pile body.

Another object of the present invention is to provide a prestressed concrete pile capable of improving structural strength and durability.

The prestressed concrete pile of the present invention comprises a pile unit and a pile unit which are joined to each other, and a reinforcement unit which is combined with the pile unit and the pile unit.

The lower pile unit includes a lower pile body formed with a longitudinal lower pile inner hole and a tapered end closed end. The upper pile unit includes an upper pile body that is engaged with the lower pile body, and the upper pile body is formed with a longitudinally hollow upper pile inner hole communicating with the inner hole of the lower pile. The reinforcing unit is configured to insert the inner hole of the upper pile and the inner hole of the lower pile to connect the upper pile body and the lower pile body.

The utility model has the advantages that the reinforcing unit of the upper pile body and the lower pile body is connected by inserting the inner hole of the upper pile and the inner hole of the lower pile to enhance the pair of the pile unit and the pile unit which are mutually engaged Vertical pressure, tensile force and horizontal shear capacity, which in turn improves structural strength and durability.

2‧‧‧Upper unit

21‧‧‧Upper pile

210‧‧‧Upper hole

211‧‧‧Upper body

212‧‧‧Upper connector

3‧‧‧Unloading unit

31‧‧‧Lower pile

310‧‧‧Underhole hole

311‧‧‧ Lower body

312‧‧‧Connecting parts

313‧‧‧Connected segments

314‧‧‧ bottom section

315‧‧‧Open end

316‧‧‧closed end

4‧‧‧Reinforcement unit

40‧‧‧Baffle

41‧‧‧Steel cage

411‧‧‧Vertical steel bars

412‧‧‧Spiral stirrups

42‧‧‧Corrugated concrete

43‧‧‧ stuffing soil

D1‧‧‧ diameter

T1‧‧‧ thickness

200‧‧‧ hammer head

201‧‧‧Special tube

A‧‧‧ pick up

Other features and effects of the present invention will be apparent from the following description of the drawings, wherein: FIG. 1 is a cross-sectional view showing a conventional prestressed concrete pile; FIG. 2 is a cross-sectional view showing the new prestressed concrete pile Fig. 3 is another cross-sectional view showing the aspect of the reinforcing unit in the first embodiment; Fig. 4 is a cross-sectional view showing another example of the upper tube and the lower tube FIG. 5 is a cross-sectional view showing a second embodiment of the present invention; FIG. 6 is a cross-sectional view showing a third embodiment of the present invention; FIG. 7 is a cross-sectional view showing the present invention A fourth embodiment of a prestressed concrete pile; Fig. 8 is a cross-sectional view showing a fifth embodiment of the present invention; and Fig. 9 is a cross-sectional view showing a sixth embodiment of the present novel prestressed concrete pile; FIG. 11 is a cross-sectional view showing a radial cross-sectional view of the sixth embodiment; and FIG. 12 is a cross-sectional view showing the prestressed concrete pile of the present invention. A seventh embodiment; and Fig. 13 is a cross-sectional view showing an eighth embodiment of the present novel prestressed concrete pile.

Before the present invention is described in detail, it should be noted that in the following description, similar elements are denoted by the same reference numerals.

Referring to Figures 2 and 3, a first embodiment of the present type of prestressed concrete pile includes a pile unit 2 and a lower pile unit 3 joined to each other, and a piercing unit 3 and the pile unit 2 reinforcement unit 4.

The upper pile unit 2 includes a tubular upper pile body 21 formed with a longitudinal hollow upper pile inner hole 210. The upper pile body 21 has a prestressed concrete and surrounds the upper pile inner hole 210. The tubular body 211 and the two annular upper connecting members 212 respectively connected to the upper end of the upper tubular body 211 and communicating with the upper inner hole 210 are made of a metal material.

The lower pile unit 3 includes a lower pile body 31 that is engaged with the upper pile body 21 and has a longitudinally hollow lower pile inner hole 310 that communicates with the upper pile inner hole 210. The lower pile body 31 has a lower pipe body 311 made of prestressed concrete and surrounding the inner hole 310 of the lower pile, and two are respectively connected to the two ends of the lower pipe body 311 and communicate with the lower pile. The hole 310 is an annular lower connecting piece 312 made of a metal material. It should be particularly noted that in the present embodiment, the upper tube body 211 and the lower tube body 311 are prestressed concrete pipe piles having a circular outer edge of the section. Of course, in practical applications, the upper tube The body 211 and the lower tubular body 311 may also be prestressed concrete hollow square piles having a rectangular outer edge as shown in FIG. 4, and the same effect can still be achieved.

In the present embodiment, the upper tube body 211 and the lower tube body 311 have a length of 15 meters, an outer diameter of 700 mm, and an inner diameter of 480 mm. The upper connector 212 and the lower connector 312 have a thickness of 22 mm and are made of steel.

The lower pile body 31 and the upper pile body 21 are respectively welded to the upper connecting piece 212 located below the upper pipe body 211 by a lower connecting member 312 located above the lower pipe body 311 to communicate with the upper pipe body 211. And the lower pipe body 311, and a joint A of the upper pile body 21 and the lower pile body 31 is formed.

The reinforcing unit 4 includes a gap from the lower connector 312 a partition 40 disposed in the inner hole 310 of the lower pile, a reinforcing cage 41 penetrating the upper pile body 21 and extending into the lower pile body 31 and contacting or approaching the partition 40, and a pouring The upper pile inner hole 210 and the lower pile inner hole 310 are combined with the reinforcing cage 41 and the upper pile body 21 and the core concrete 42 of the lower pile body 31. It should be particularly noted that, for convenience of explanation, the core-filled concrete 42 in FIG. 2 is not drawn with a hatching line, and in the present embodiment, the reinforcing cage 41 close to the partition 40 is used for description. In practical application, The reinforcing cage 41 may also be in direct contact with the partition 40, and the same effect can be achieved.

The baffle 40 divides the lower pile inner hole 310 into a communicating section 313 communicating with the upper pile inner hole 210, and a bottom section 314 separated from the communicating section 313, and the reinforcing cage 41 extends into the connecting section 313. In the present embodiment, the partition 40 is a steel plate having a thickness of 4 mm, and the depth of the connecting portion 313 is 3 meters, and the bottom portion 314 is 12 meters. In other words, the cored concrete 42 will penetrate deep into the inner hole 310 of the lower pile to a depth of 3 meters. In actual use, the partition 40 may also use wood or other materials, and the partition 40 may be disposed in the lower pile hole 310 first, or may be fixed in the lower pile at the construction site by using a hanging mold. The same effect can be achieved in the hole 310.

In the present embodiment, the steel cage 41 has 12 vertical steel bars having a diameter of 22 mm, a relief strength Fy=4,200 kg/cm ² (about 412 N/mm ² ) and all or part of which protrudes from the top of the upper pile body 21. 411, and a plurality of diameters of 10 mm, a relief strength Fy = 2,800 kg / cm ² (about 274 N / mm ² ) and 150 cm apart from the spiral stirrups 412 outside the vertical steel bars 411, due to the viewing angle relationship 3 Only one of the spiral stirrups 412 is shown. The core-filled concrete 42 is a concrete to which a micro-expansion agent is added and has a compressive strength of 210 kg/cm ² (about ²¹ N/mm ² ). The vertical reinforcing bar 411 protrudes from the upper connecting member 212 and can serve as a connection between the upper pile body 21 and the upper base cap (not shown).

In the embodiment, the vertical reinforcing bars 411 all protrude from the upper connecting member 212. In practical applications, only a part of the vertical reinforcing bars 411 protrude from the upper connecting member 212 to achieve the same function.

The upper connecting member 212 and the lower connecting member 312 are engaged with the partition 40 located in the inner hole 310 of the lower pile, so that the steel cage 41 is combined with the cored concrete 42 to form and be placed on the upper pile body 21 and A reinforced concrete reinforcing unit 4 in the lower pile body 31 and having a length of about 18 meters. When the upper connecting body 212 and the lower connecting member 312 of the upper pile body 21 and the joint of the lower pile body 31 are rusted, the prestressing force can still be lifted through the reinforcing steel cage 41 and the cored concrete 42. The bearing capacity of concrete piles for vertical pressure, tensile force and horizontal shear.

In the present embodiment, even if the upper connecting member 212 and the lower connecting member 312 which are welded to each other cannot be subjected to tensile force due to corrosion, the reinforcing unit 4 can still exert the equivalent of the number of reinforcing bars by the reinforcing steel area by the steel bar fall strength. Pulling force is equivalent to 12*(π/4*2.22)*4200=191586kg, about 191tons. Other loads such as vertical pressure and horizontal shear force will also be improved at the same time because the reinforcing unit 4 is simultaneously lifted.

Moreover, since the length of the reinforcing unit 4 is long, the friction and tensile force between the core-filled concrete 42 and the upper pipe body 211 and the lower pipe body 311 can be increased to fully cover the foundation cap above the pre-stressed concrete pile ( The force of the figure (not shown) is transmitted to the upper pile body 21 and the lower pile body 31.

The present embodiment is a core-filled concrete 42 and a steel cage 41 which are used for the pile head treatment (or pile head reinforcement) between the upper pile and the foundation pile which are often used in the construction of the prestressed concrete pipe pile, and are generally used in this case. The depth of the pile inner hole 210 is further extended and deeper beyond the upper pile body 21 and the pile A of the lower pile body 31 to reach the lower pile inner hole 310 of the lower pile body 31, After the reinforcing steel cage 41 and the poured core concrete 42 are hardened, a reinforcing unit 4 penetrating the upper pile 2 and the lower pile 3 is formed.

Referring to FIG. 5, a second embodiment of the present type of prestressed concrete pile is substantially similar to the first embodiment. The difference is that the prestressed concrete pile includes two upper and lower welded pile units 2, the reinforcement The unit 4 is inserted into the pile unit 2 and extends into the pile unit 3.

Since the present embodiment is substantially similar to the first embodiment, it can be achieved in addition to the same effects as the first embodiment. The joining of the plurality of pile units 2 can increase the overall length of the prestressed concrete pile and deep into the depth of the underground soil layer to meet the greater bearing capacity requirements. This embodiment mainly describes an application example of three or more prestressed concrete piles.

Referring to FIG. 6, a third embodiment of the present type of prestressed concrete pile is substantially similar to the first embodiment, and the difference is that the partition 40 is coupled to the lower connecting member 312 away from the pile unit 2. Below, the frictional force and the tensile force between the cored concrete 42 and the upper tubular body 211 and the lower tubular body 311 are increased by increasing the depth of the reinforcing unit 4 extending into the lower tubular body 311. The main difference between this embodiment and the first embodiment is that the reinforcing unit 4 is penetrated to the full depth of the lower pile 3, and the bonding force of the reinforcing unit 4 and the lower pile 3 can be further strengthened.

Referring to FIG. 7, the fourth embodiment of the present invention is substantially similar to the first embodiment. The difference is that the partition 40 is coupled to the lower tubular body 311 away from the upper tubular body 211. One end of the reinforcing unit 4 is inserted into the lower tube body 311 to increase the friction and tensile force between the core-filled concrete 42 and the upper tube body 211 and the lower tube body 311.

Referring to FIG. 8, a fifth embodiment of the present type of prestressed concrete pile is substantially similar to the first embodiment, and the difference is that the reinforcing unit 4 includes a stuffing soil packed in the inner hole 310 of the lower pile. 43. A reinforcing cage 41 for inserting the upper inner hole 210 and the lower inner hole 310, and a pouring into the upper inner hole 210 and the lower inner hole 310 and adjacent to the packing soil 43 to be combined The reinforcing cage 41 and the upper pile body 21 and the core-filled concrete 42 of the lower pile body 31. For convenience of explanation, the cored concrete 42 is not drawn with a hatching.

Since the present embodiment is substantially similar to the first embodiment, in addition to the same effect as the first embodiment, the replacement of the partition 40 by the stuffing soil 43 is not only relatively inexpensive, but also easy to apply. Improve convenience.

Referring to Figure 9, a sixth embodiment of the present type of prestressed concrete pile is substantially similar to the first embodiment, and the difference is that the lower pile body 31 has a prestressed concrete and is circumferentially defined. The lower tubular body 311 of the lower pile inner hole 310 and an annular lower connecting member 312 connected to the open end 315 and made of a metal material and communicating with the lower pile inner hole 310. The lower tubular body 311 has an open end 315 that communicates with the inner bore 310 of the lower pile, and A closed end 316 opposite to the open end 315 and having a tapered shape, the annular lower connecting member 312 is connected to the open end 315 and made of a metal material.

Since the present embodiment is substantially similar to the first embodiment, the tapered end portion 316 can be applied to the hammering or pressing of the prestressed concrete pile, except that the same effect as the first embodiment can be achieved. The construction method is adopted, and the soil layer is placed in a convenient and labor-saving manner.

Referring to Figure 10, the sixth embodiment of the present invention comprises the following steps from left to right: first, the upper and lower joined pile units 2 and the lower pile unit 3 are suspended to the construction position, in this embodiment In the example, the upper pile body 21 and the lower pile body 31 have a length of 15 meters, an outer diameter of 700 mm, and an inner diameter of 460 mm; and then, the upper pile body 21 which is joined up and down by the hammer head 200 of the pile driver And the lower pile body 31 is driven into the soil layer to the design depth; next, the steel cage 41 is placed into the upper pipe body 211 and the lower pipe body 311; then, a Tremie Pipe 201 is extended. The upper pile body 21 and the lower pile body 31 are inserted into the pile body 21; finally, the cored concrete 42 is poured into the upper pile body 21 and the lower pile body 31 by the special tube 201, and the core-filled concrete 42 is hardened. After that, the prestressed concrete pile is completed.

Referring to Figures 10 and 11, the inner diameter of the upper tubular body 211 and the lower tubular body 311 is 480 mm, and the thickness T1 of the protective layer on both sides of the core-filled concrete 42 is about 50 mm, and the spiral stirrup 412 has a diameter of 10 After the male and vertical steel bars 411 have a diameter of 22 mm, the diameter D1 of the circle surrounded by the vertical steel bars 411 is about 316 mm (ie, 480-2*50-2*10-2*22=316). The special tube 201 suitable for concrete grouting with deep penetration depth is generally the diameter 6 吋, 8吋, or 10吋, the diameter D1 of the circle surrounded by the vertical reinforcing bars 411 is about 316 mm, which is enough for the general dense pipe 201 to be inserted into the space surrounded by the vertical reinforcing bars 411. Sufficiently the general tight tube 201 is inserted into the construction.

The inner tube hole 210 and the lower pile inner hole 310 are deeply penetrated by the special tube 201 to inject the core-filled concrete 42 to avoid material separation. Therefore, after the core-filled concrete 42 is dry and hard, the upper pile is The body 21 and the lower pile body 31 form a strong frictional force.

It should be particularly noted here that FIG. 10 is illustrated by a hammer type (or press-in type) construction method, and is not limited thereto in practical applications.

Referring to FIG. 12, the seventh embodiment of the present type of prestressed concrete pile is substantially similar to the sixth embodiment. The difference is that the reinforcing unit 4 includes a partition disposed in the inner hole 310 of the lower pile. 40.

The perfusion quality of the cored concrete 42 can be improved by using the partition 40 as a support template for the cored concrete 42.

Referring to Figure 13, the eighth embodiment of the present invention is substantially similar to the seventh embodiment, except that the reinforcing unit 4 includes a stuffing soil 43 that is packed in the inner bore 310 of the lower pile. a reinforcing cage 41 for inserting the upper inner hole 210 and the lower inner hole 310, and a pouring into the upper inner hole 210 and the lower inner hole 310 and contacting the filling soil 43 to The reinforcing cage 41 and the upper pile body 21 and the core-filled concrete 42 of the lower pile body 31 are combined.

Since the present embodiment is substantially similar to the seventh embodiment, in addition to achieving the same functions as the seventh embodiment, The replacement of the partition 40 by the stuffing soil 43 is not only relatively inexpensive, but also facilitates the convenience of application.

The prestressed concrete pile of the present invention utilizes the reinforcing unit 4 that is inserted into the upper pile body 21 and the lower pile body 31 to connect the upper pile body 21 and the lower pile body 31 to lift the mutually coupled lower pile unit 3 and The ability of the pile unit 2 to withstand vertical pressure, tensile force and horizontal shear force, thereby improving the structural strength and durability, can indeed achieve the purpose of the present invention.

However, the above is only a preferred embodiment of the present invention, and is not intended to limit the scope of the present invention, that is, the simple equivalent changes and modifications made in accordance with the scope of the present patent application and the contents of the patent specification, All remain within the scope of this new patent.

2‧‧‧Upper unit

21‧‧‧Upper pile

210‧‧‧Upper hole

211‧‧‧Upper body

212‧‧‧Upper connector

3‧‧‧Unloading unit

31‧‧‧Lower pile

310‧‧‧Underhole hole

311‧‧‧ Lower body

312‧‧‧ Lower connector

313‧‧‧Connected segments

314‧‧‧ bottom section

4‧‧‧Reinforcement unit

40‧‧‧Baffle

41‧‧‧Steel cage

411‧‧‧Vertical steel bars

412‧‧‧Spiral stirrups

42‧‧‧Corrugated concrete

A‧‧‧ pick up

Claims (12)

A prestressed concrete pile comprising: a lower pile unit, comprising a lower pile body formed with a longitudinal hollow lower pile inner hole; at least one upper pile unit comprising an upper pile body engaged with the lower pile body, and the upper pile body The upper pile body is formed with a longitudinal hollow upper pile inner hole communicating with the inner hole of the lower pile; and a reinforcing unit for inserting the inner hole of the hollow upper pile of the upper pile body and the inner hole of the hollow lower pile of the lower pile body To connect the upper pile body with the lower pile body. The prestressed concrete pile according to claim 1, wherein the lower pile body has a lower pipe body made of concrete and surrounding the inner hole of the lower pile, and one end connected to one end of the lower pipe body An annular lower connecting member made of a metal material and connected to the lower tubular body, the upper pile body having an upper tubular body made of concrete and surrounding the inner hole of the upper pile, and being attached thereto One end of the tubular body and correspondingly engaged with the lower connecting member to communicate the annular upper connecting member and the annular upper connecting member of the upper inner bore of the upper pile. The prestressed concrete pile according to claim 2, wherein the reinforcing unit comprises a partition blocking the end of the lower tubular opposite to the lower connecting member. The prestressed concrete pile according to claim 2, wherein the reinforcing unit comprises a partition spaced apart from the lower connecting member in the inner hole of the lower pile, and the partition divides the inner hole of the lower pile into a The pile a connecting section through which the inner holes communicate, and a bottom section separated from the connecting section. The prestressed concrete pile according to claim 2, wherein the lower pile body further has an annular bottom plate disposed on the lower end of the lower connecting body opposite to the lower connecting member and communicating with the inner hole of the lower pile, the reinforcing The unit includes a partition that is placed against the bottom plate of the ring. The prestressed concrete pile according to any one of claims 3 to 5, wherein the reinforcing unit further comprises a reinforcing cage penetrating the inner hole of the upper pile and the inner hole of the lower pile, and a pouring on the upper The inner hole of the pile and the inner hole of the lower pile are in contact with the partition plate to join the steel cage and the core-filled concrete of the upper pile body and the lower pile body, and the steel cage has a majority part or all of the upper pile The vertical steel bars of the body, and the spiral stirrups which are mostly wound around the vertical steel bars, and the core-filled concrete is selected from concrete without added expansion agent or concrete with expansion agent added. The prestressed concrete pile according to claim 2, wherein the reinforcing unit comprises a stuffing soil filled in the inner hole of the lower pile, a reinforcing cage penetrating the inner hole of the upper pile and the inner hole of the lower pile, and Filling the inner hole of the upper pile with the inner hole of the lower pile and contacting the stuffing soil to join the steel cage with the core body of the upper pile body and the lower pile body, the steel cage has a majority portion or The vertical reinforcing bars of the upper pile body are all protruded, and the spiral stirrups which are mostly wound around the vertical reinforcing bars, and the core-filled concrete is selected from concrete which is not added with a swelling agent or concrete which is added with a swelling agent. A prestressed concrete pile comprising: a lower pile unit, comprising a lower pile body formed with a longitudinal lower pile inner hole, the lower pile body having a prestressed concrete and surrounding the inner hole of the lower pile a lower tubular body having an open end communicating with the inner bore of the lower pile and a closed end having a tapered shape opposite to the open end; at least one upper pile unit including a pair with the lower pile body a joint upper pile body, the upper pile body is formed with a longitudinally hollow upper pile inner hole communicating with the inner hole of the lower pile; and a reinforcing unit is disposed to penetrate the upper pile inner hole and the lower pile inner hole to connect the upper pile body The pile body and the lower pile body. The prestressed concrete pile according to claim 8, wherein the lower pile body further has an annular lower connecting member connected to the open end and made of a metal material and communicating with the inner hole of the lower pile, the upper pile Having an upper tubular body made of concrete and surrounding the inner bore of the upper pile, and one end connected to one end of the upper tubular body and correspondingly engaged with the lower connecting member to communicate the inner bore of the lower pile with the upper An annular upper connecting piece of the inner hole of the pile. The prestressed concrete pile according to claim 9, wherein the reinforcing unit comprises a reinforcing cage penetrating the inner hole of the upper pile and the inner hole of the lower pile, and a pouring into the inner hole of the upper pile and the lower pile a hole in the hole and contacting the closed end to join the steel cage and the upper pile body and the lower pile body, the steel cage has a majority of or all of the vertical steel bars protruding from the upper pile body, and most of the intervals Wound around the vertical A spiral stirrup outside the steel bar, and the core-filled concrete is selected from concrete without added expansion agent or concrete with expansion agent added. The prestressed concrete pile according to claim 9, wherein the reinforcing unit comprises a partition spaced apart from the lower connecting member in the inner hole of the lower pile, and the inner hole of the upper pile and the lower pile a reinforcing cage of the hole, and a core filled with the inner hole of the upper pile and the inner hole of the lower pile and contacting the partition to join the reinforcing cage and the upper pile body and the lower pile body, the reinforcing steel The cage has a plurality of or all of the vertical reinforcing bars protruding from the upper pile body, and a plurality of spiral stirrups which are intertwined around the vertical reinforcing bars, and the core-filled concrete is selected from concrete without adding a swelling agent or adding a swelling agent. Concrete. The prestressed concrete pile according to claim 9, wherein the reinforcing unit comprises a stuffing soil packed in the inner hole of the lower pile, a reinforcing cage penetrating the inner hole of the upper pile and the inner hole of the lower pile, and Filling the inner hole of the upper pile with the inner hole of the lower pile and contacting the stuffing soil to join the steel cage with the core body of the upper pile body and the lower pile body, the steel cage has a majority portion or The vertical reinforcing bars of the upper pile body are all protruded, and the spiral stirrups which are mostly wound around the vertical reinforcing bars, and the core-filled concrete is selected from concrete which is not added with a swelling agent or concrete which is added with a swelling agent.