CN203821376U - Pre-tensioning method centrifugal concrete pile with steel strands - Google Patents

Abstract

The utility model relates to a pre-tensioned centrifugal concrete pile with a steel strand, which comprises a concrete pile body, a reinforcement cage, and the reinforcement cage includes a prestressed main reinforcement, a stirrup and an end plate, and is characterized in that: the prestressed main reinforcement is a steel strand , said at least one end plate is provided with several tapered holes whose diameter gradually expands from the inside to the outside. The inner surface of the clip is provided with locking teeth, and the multiple clips are combined to form a chuck assembly for clamping steel strands. The outer peripheral surface of the chuck assembly forms a cone surface matching the tapered hole, and the center of the chuck assembly forms a Each steel strand passes through the inner tooth hole in the corresponding chuck assembly and is locked by the inner tooth hole. It is a practical and feasible centrifugal concrete pile with steel strands, and the connection and locking methods of steel strands are simple and reasonable, easy to operate and low in cost, so that the application of steel strands to centrifugal concrete piles can be realized and has industrial application actual value.

Description

A pretensioned centrifugal concrete pile with steel strands

technical field

The utility model belongs to the technical field of pile foundation engineering of various building structure systems, in particular to a pretensioned centrifugal concrete pile with steel strands.

Background technique

All kinds of building structures generally involve pile foundation engineering. There are many products used in pile foundation engineering in the existing market, such as bored piles and prestressed centrifugal concrete pipe piles (including pipe piles and square piles). Under the current level of economic development and construction technology conditions, the field of architectural design has entered a new stage of development, and the requirements for pile foundations are also constantly improving. The technical performance of existing products can no longer meet the needs of the rapidly developing construction market. Highlights a number of serious technical flaws.

The development and production of prestressed centrifugal concrete piles began in the 1960s. At the beginning, the prestressed main reinforcement of centrifugal concrete piles mainly used high-strength steel wires. However, due to the small diameter and smooth surface of the high-strength steel wires, there was a defect of insufficient grip with concrete. Various technical indicators cannot meet the needs of construction. In the 1980s, prestressed centrifugal concrete piles began to use prestressed concrete steel rods as the main reinforcement, because it was prefabricated in the factory, with high production efficiency, relatively high strength of the main reinforcement, high concrete strength, convenient construction, and faster cycle. However, it has been widely used in the field of construction and has been used until now, and it occupies a dominant position in the current traditional pile foundation engineering. However, in the process of production and use, there are many problems in the centrifugal concrete pile with steel rod as the main reinforcement, such as the high brittleness of the steel rod and its low tensile strength (the design value of the tensile strength is 1000MPa, and the highest value of the tensile strength is 1420MPa) , which cannot meet the current construction technical requirements; in order to facilitate stretching in production, the technology of steel rod heading head must be used, and the steel rod is heated to form a mushroom-shaped head, so that the heading head can be connected with the end plate of the pile body and stretched. The plate is stuck for prestressed tensioning, but due to the hot heading of the steel bar, the strength and material of the pier head will be damaged; at the same time, due to the inconsistent accuracy of the steel bar pier head, it cannot be aligned with the end during tensioning. The plates are in full contact, resulting in partial damage to the end plates; the steel rods are not well controlled due to cutting precision, resulting in different lengths of the steel rods, uneven stress, or even breaking during the tensioning process; in addition, the steel cage is formed by welding, Steel rods are damaged due to high temperature welding. The above-mentioned various defects lead to obvious deficiencies in technical performances such as bending resistance and shear resistance of existing centrifugal concrete piles whose main reinforcement adopts steel rods for prestressed concrete. In engineering applications, earthquakes, typhoons and other uncertain factors will cause large bending moments and horizontal forces on the upper part of the pile foundation of buildings, and road bridges or railway bridges will also produce large bending moments due to the dynamic load of transport vehicles. moment and horizontal force. When the above-mentioned traditional centrifugal concrete piles are used in the above-mentioned projects, they are often unable to be used because of insufficient bending resistance and shear resistance, especially in high-rise buildings. In addition, in foundation pit enclosure, slope support and other projects, ordinary centrifugal concrete piles cannot be applied on a large scale due to insufficient bending and shearing properties. For safety reasons, many regions in my country have banned the use of centrifugal concrete piles in some pile foundation projects in recent years.

Bored cast-in-place pile is another kind of pile widely used in the field of construction pile foundation engineering. Its production is completed by on-site casting. The production process is to drill a pile hole on the construction site first, and then put the steel cage into the pile hole. , and then pour concrete into the hole, and it can be used after natural curing for a long time after forming to reach a certain strength. This kind of pile body has strong vitality because of its high bearing capacity and ability to adapt to complex geology, but this kind of cast-in-situ pile needs to deal with the mud pumped out during construction, and the environmental pollution is quite serious. It is seldom used; in addition, during the pile-forming process of cast-in-situ piles, it is easy to collapse the hole wall and break the interlayer of piles. If it encounters karst caves or cavities, it will cause a lot of waste of concrete; On-site pouring is completed and requires long-term natural maintenance, and factory production cannot be realized, so the efficiency is low and the construction period is long.

Due to the high tensile strength of the steel strand (the design value of the tensile strength is 1320MPa, and the highest tensile strength can reach 1960MPa), in recent years, Chinese enterprises and scientific research institutions have also conducted a lot of research on the application of steel strands to centrifugal concrete piles. , but so far no technical solutions with practical value have emerged. Such as a Chinese utility model patent "A Pipe Pile Reinforcement Cage Equipped with Steel Strand" with the patent No. ZL201220538453.6 (announcement No. CN202865836U) discloses such a reinforcement cage in which the steel strand is matched with the prestressed steel rod Due to the difference in tensile strength between the steel rod and the steel strand, when the overall prestress is applied at the same time, the tension can only be controlled by the low tensile strength of the steel rod, and the high tensile strength performance of the steel strand cannot be exerted. Therefore, in this patent, the steel strand is equivalent to the role played by the steel rod, and the high tensile strength performance that the steel strand should have is not realized. For example, the tensile strength of the steel strand is used as the control standard, and at the same time the overall When stretched, the steel rod will break and fail. In addition, this patent does not disclose how to specifically connect, fix, and stretch steel strands in pretensioned centrifugal concrete piles, so this patented technology basically does not have realistic practical value and operability in pile foundation engineering.

Another example is that an application number is CN200510050212.1 (announcement number is CN1687534A) Chinese invention patent application " pretensioned steel strand prestressed concrete pipe pile " discloses such a kind of concrete pipe pile with steel strand, its prestressed main reinforcement adopts steel There are stretching holes on the end plate, and the steel strands pass through the stretching holes to make anchors. The patent application also does not disclose how to realize the connection and anchorage of the steel strand and the end plate in the pretensioned centrifugal concrete pile and its specific production method. For ordinary technicians in the field of concrete pile manufacturing, because of the large span of the industry, It is generally impossible to know how to apply steel strands to the production of pretensioned centrifugal concrete piles; in addition, according to the technical solution described and the attached drawings of the patent application, there are protruding anchors on the end face of the formed pile , making it impossible to connect piles, the protruding anchors are easily broken during piling construction, thereby destroying the prestress of the pile body and reducing its technical performance such as bending resistance and shear resistance. Therefore, it cannot be produced according to the technical solution disclosed by it, and even if it is produced, it cannot be applied to pile foundation engineering at all. This patent only theoretically proposes a general technical conception of applying steel strands to pretensioned centrifugal concrete piles , but cannot be applied in actual production and construction.

It can be seen from the above that the prestressed centrifugal concrete piles and bored piles with steel rods as the main reinforcement widely used in the market can no longer meet the needs of the current pile foundation engineering, and the pretensioning method using steel strands as the main reinforcement can no longer meet the needs of the current pile foundation engineering. Centrifugal concrete piles are only a technical idea at present. Since the steel strands are twisted by multiple steel wires, they are not easy to be welded or entangled. Therefore, how to connect and fix steel strands in pretensioned centrifugal concrete piles and how to stretch steel strands is the key to realize the manufacture of pretensioned centrifugal concrete piles with steel strands. There is no appearance of centrifugal concrete piles with steel strands as the main reinforcement with architectural practical value.

Utility model content

The technical problem to be solved by the utility model is to provide a pretensioned centrifugal concrete pile with steel strands for the above-mentioned deficiencies in the prior art, which overcomes the problem of connection and fixation of the steel strands in the pretensioned centrifugal concrete piles , which makes it possible to use steel strands for the main reinforcement inside the centrifugal concrete pile and has practical application value, and greatly improves the technical performance of the centrifugal concrete pile such as bending resistance, shear resistance and tensile resistance.

The technical scheme adopted by the utility model to solve the above-mentioned technical problems is: a pretensioned centrifugal concrete pile with steel strands, including a hollow concrete pile body, a steel cage located in the concrete pile body, and the steel cage includes axially arranged The prestressed main reinforcement, the stirrup placed outside the main reinforcement and the end plate at the end of the pile body are characterized in that: the prestressed main reinforcement is a steel strand, and at least one end plate and the steel strand adopt a first clamp Chip structure connection, that is, there are several tapered holes on the end plate that gradually expand from the inside to the outside. The tapered holes are set in one-to-one correspondence with the steel strands. The inner surface of each clip is provided with locking teeth. The multiple clips are combined to form a chuck assembly for clamping the steel strand. The outer peripheral surface of the chuck assembly forms a cone surface matching the cone hole. The center of the chuck assembly forms an inner tooth hole, and each steel strand passes through the inner tooth hole in the corresponding chuck assembly and is locked by the inner tooth hole, and the outer end surface of the chuck assembly is flush with the outer end surface of the end plate or slightly lower.

A pretensioned centrifugal concrete pile with steel strands, comprising a hollow concrete pile body and a reinforcement cage located in the concrete pile body, the reinforcement cage including axially arranged prestressed main reinforcement, and stirrups wound around the main reinforcement And the end plate located at the end of the pile body is characterized in that: the prestressed main reinforcement is a steel strand, and at least one end plate is connected with the steel strand by a second clamping structure, that is, there are several holes on the end plate. Each counterbore is placed with a transition piece that matches the shape of the counterbore. The front end of the transition piece has a ring-shaped shoulder that sinks into the large hole of the counterbore. The transition piece has a diameter from the inside to the outside. Gradually enlarged transitional tapered holes, the transitional tapered holes are set in one-to-one correspondence with the steel strands, and multiple clips are placed in each transitional tapered hole, and the inner surface of each clip is provided with locking teeth. The pieces are spliced together to form a chuck assembly for clamping steel strands. The outer peripheral surface of the chuck assembly forms a cone surface matching the transition tapered hole, and the center of the chuck assembly forms an inner tooth hole. The steel strands The wires pass through the inner gear holes in the corresponding chuck components and are locked by the inner gear holes, and the outer end surfaces of the chuck components are flush with or slightly lower than the outer end surfaces of the end plates. It differs from the previous pretensioned centrifugal concrete pile in that a transition part is set in the end plate, and a tapered hole is set on the transition part, because the processing of the sink hole is more convenient than the tapered hole, and the It is easier to process the tapered hole on the transition part than on the end cover. At the same time, we can also make the transition part made of materials with better performance than the end plate, so that the relative distance between the steel strand and the end plate The fixation is more secure.

The outer periphery of the chuck assembly composed of multiple clips is provided with an annular groove, and a hoop for fastening the multiple clips is placed in the annular groove. The hoop can be a steel traveler or a rubber ring, and the arrangement of the hoop can make the chuck assembly composed of multiple clips more reliable.

Each chuck assembly is composed of three clips. Tests have proved that each chuck assembly is composed of three clips, and its various indicators are better, and the positioning of the steel strand and the tapered hole is the most reliable.

The above-mentioned end plate is also provided with a plurality of threaded connection holes for connecting with the anchor plate or the tension plate.

The above two end plates and the steel strands are all connected by the first clip-type structure or the second clip-type structure, so that both ends of the steel strands can be firmly connected to the end plates through the clip-type structure; of course It can also be that only one end plate is connected with the steel strand by a clip structure, the other end of the concrete pile can have no end plate, and the steel strand at the other end can be connected and fixed in other ways to realize production during production.

Compared with the prior art, the pretensioned centrifugal concrete pile has the advantages of: steel strands are used for all the main reinforcement, so that the tensile strength of the main reinforcement is consistent, and the overall performance of the pile body is greatly improved; the steel strand passes through the chuck composed of clips The assembly is fixed with the tapered hole in the end plate, and the overall tensioning method is combined with the pre-tensioning of a single steel strand. When pre-tensioning, the outer end surface of the chuck assembly can be supported by a through-hole jack. And let the steel strand pass through the inner tooth hole, and stretch the steel strand externally through the traction part of the core jack. After the core jack is removed, the steel strand relaxes and retracts, and the retraction of the steel strand drives the chuck The component retracts toward the small diameter of the tapered hole to firmly fix the collet component and the conical hole, and further tightens the inner tooth hole in the collet component to lock the steel strand, and then pulls the screw rod for overall tensioning. Pull, pull to the specified value to lock the nut, carry out centrifugal forming, remove the anchor plate and tension plate after forming, release the steel strand, and finally cut and polish the steel strand exposed from the end plate, and the manufacture is completed The centrifugal concrete pile has no anchorage part protruding from the end plate, and is a practical centrifugal concrete pile with steel strands, and the connection and locking methods of the steel strands in the centrifugal concrete pile are simple and reasonable, easy to operate and The low cost makes it possible to apply the steel strand to the centrifugal concrete pile and has practical value for industrial application; the centrifugal concrete pile of the present invention adopts the steel strand with extremely high performance, which makes its bending resistance, shear resistance and tensile performance Greatly improve.

Description of drawings

Fig. 1 is the structural representation of the utility model first embodiment;

Figure 2 is an enlarged view of A in Figure 1;

Fig. 3 is a sectional view along the line BB of Fig. 1;

Fig. 4 is a side view of the first embodiment of the utility model;

Fig. 5 is a three-dimensional schematic diagram of the chuck assembly in two embodiments of the present invention;

Fig. 6 is a three-dimensional exploded view of the chuck assembly in two embodiments of the present invention;

Fig. 7 is the structural representation of the second embodiment of the utility model;

Figure 8 is an enlarged view of C in Figure 7;

Fig. 9 is a sectional view along the line DD of Fig. 7;

Fig. 10 is a side view of the second embodiment of the present utility model.

Detailed ways

The utility model is described in further detail below in conjunction with the accompanying drawings.

As shown in Figures 1-6, it is the first embodiment of the present utility model.

A pretensioned centrifugal concrete pile with steel strands, comprising a hollow concrete pile body 1 and a reinforcement cage inside the concrete pile body 1, the concrete pile body 1 can be a circular pile, a square pile, or a polygonal pile And various pretensioned prestressed centrifugal concrete special-shaped piles. The reinforcement cage includes axially arranged prestressed main reinforcements, stirrups 4 wound outside the main reinforcements and end plates 2 at both ends, the prestressed main reinforcements are steel strands 3 , and the Fixing can be done by manual binding, automatic binding machine binding or other mechanical methods. The concrete pile body 1 can also be axially arranged with non-prestressed steel bars, anchor bars and pile hoops, which is a conventional design for centrifugal concrete piles.

The two end plates 2 and the steel strands 3 are connected by the first clamp structure, that is, several end plates 2 are provided with several tapered holes 21 whose diameter gradually expands from the inside to the outside, and the tapered holes 21 are connected to the steel strands. The wires 3 are arranged in one-to-one correspondence, and a plurality of clips 5 are placed in each tapered hole 21. The inner surface of each clip 5 is provided with a locking tooth 51, and the multi-piece clips 5 are assembled to form a steel strand 3, each chuck assembly 6 in this embodiment is composed of three clips 5. The outer periphery of the collet assembly 6 composed of multiple clips 5 is provided with an annular groove 63, and a hoop 64 for fastening the multiple clips 5 is placed in the annular groove 63, and the hoop 64 can be a steel traveler or a rubber ring .

The outer peripheral surface of the chuck assembly 6 forms a conical surface 61 matching the tapered hole 21, and the center of the chuck assembly 6 forms an inner tooth hole 62, and each steel strand 3 passes through the inner teeth in the corresponding chuck assembly. The hole 62 is locked by the inner gear hole 62 , and the outer end surface of the chuck assembly 6 is flush with or slightly lower than the outer end surface of the end plate 2 .

The locking process of the steel strand 3 by the inner gear hole 62 is as follows: after the steel strand 3 is stretched and relaxed, the retraction of the steel strand 3 drives the chuck assembly 6 back toward the small diameter of the tapered hole 21. shrink the collet assembly 6 and the tapered hole 21 firmly, and make the inner tooth hole 62 in the collet assembly further tighten and block the steel strand 3.

The end plate 2 is also provided with a plurality of threaded connection holes 22 for connecting with the anchor plate.

The main bars are all made of steel strands 3, and the steel strands 3 are fixed through the chuck assembly 6 composed of clips 5 and the tapered hole 21 in the end plate 2. When the overall tension is adopted, the support plate is supported by a hydraulic jack, and then Pull the tensioning plate through the screw rod, and when it reaches the specified value, lock the nut, which is the conventional tensioning method for centrifugal piles; when the combination of overall tensioning and single steel strand pretensioning is adopted, the When the first steel strand is pre-tensioned, the outer end surface of the clamp assembly 6 can be supported by the core-through jack, and the steel strand 3 can pass through the inner tooth hole 62, and the steel strand 3 can be supported by the traction part of the core-through jack on the outside. After tensioning, the steel strand 3 relaxes and retracts after the core-through jack is removed, and the retraction of the steel strand 3 drives the collet assembly 6 to retract toward the small diameter direction of the tapered hole 21 to align the collet assembly 6 with the tapered The hole 21 is firmly fixed, and the inner tooth hole 62 in the chuck assembly 6 is further clamped and the steel strand 3 is stuck, and then the overall tension is carried out, followed by centrifugal forming. After the forming is completed, the anchor plate is removed, tensioned Pull the plate, stretch the steel strand 3, and finally cut the steel strand 3 exposed from the end plate 2 and polish it. The completed centrifugal concrete pile has no anchorage part protruding from the end plate, which is a practical and feasible method. Centrifugal concrete piles with steel strands, and the connection and locking methods of the steel strands in the centrifugal concrete piles are simple and reasonable, easy to operate and low in cost, so that the application of steel strands to centrifugal concrete piles can be realized and has practical industrial application Value; the centrifugal concrete pile of the present invention has greatly improved its bending resistance, shear resistance and tensile performance due to the use of high-performance steel strands.

As shown in Figures 5-10, it is the second embodiment of the present utility model.

The difference between this embodiment and the first embodiment is that the two end plates 2 are connected with the steel strand 3 by a second clamping structure, that is, several counterbores 23 are opened on each end plate 2, each A transition part 7 whose shape matches the counterbore 23 is placed in the hole 23. The front end of the transition part 7 has an annular shoulder 71 sunken in the large hole of the counterbore 23. The transition part 7 has a diameter gradually increasing from the inside to the outside. Enlarged transitional tapered hole 72, the transitional tapered hole 72 and the steel strand 3 are provided in one-to-one correspondence, and a plurality of clips 5 are placed in each transitional tapered hole 72, and the inner surface of each clip 5 is provided with locking teeth 51, the multiple clips 5 are assembled to form a chuck assembly 6, the outer peripheral surface of the chuck assembly 6 forms a conical surface 61 matching the transition tapered hole 72, and the center of the chuck assembly 6 forms an inner tooth hole 62, Each steel strand 3 passes through the inner tooth hole 62 in the corresponding chuck assembly and is locked by the inner tooth hole 62 , and the outer end surface of the chuck assembly 6 is flush with or slightly lower than the outer end surface of the end plate 2 .

The locking process of the steel strand 3 by the inner gear hole 62 is as follows: after the steel strand 3 is tensioned and relaxed, the retraction of the steel strand 3 drives the chuck assembly 6 toward the small diameter direction of the transition tapered hole 72 Retraction securely fixes the collet assembly 6 and the transition tapered hole 72, and further tightens the inner tooth hole 62 in the collet assembly and blocks the steel strand 3, and the retraction of the steel strand 3 also drives The transition part 7 is moved backward so that the annular shoulder 71 on the transition part 7 is closely combined with the bottom surface of the large hole part of the counterbore 23 .

The main reinforcement is all made of steel strands 3, and the steel strands 3 are fixed through the chuck assembly 6 composed of clips 5 and the transition tapered hole 72 in the end plate 2. When the overall tension is adopted, the support plate is supported by a hydraulic jack. Then pull the tensioning plate through the screw rod, and when it reaches the specified value, lock the nut, which is the conventional tensioning method of centrifugal piles; when the combination of overall tensioning and single steel strand pretensioning is adopted, the When a single steel strand is pre-tensioned, a core-through jack can be used to support the outer end face of the chuck assembly 6, and the steel strand 3 can pass through the inner tooth hole 62, and the steel strand can be tightened externally by the traction part of the core-through jack. 3 is stretched, and the steel strand 3 is loosened and retracted after the core-through jack is removed, and the retraction of the steel strand 3 drives the collet assembly 6 to retract toward the small diameter direction of the transition tapered hole 72 to connect the collet assembly 6 with the The transition tapered hole 72 is firmly fixed, and the inner tooth hole 62 in the chuck assembly is further clamped and stuck to the steel strand 3, and the retraction of the steel strand 3 also drives the transition part 7 to move backward so that the transition part 7 The ring-shaped shoulder 71 on the top is closely combined with the bottom surface of the large hole of the counterbore 23, and then the overall tension is carried out, and centrifugal molding is carried out. After the forming is completed, the anchor plate and the tension plate are removed, and the steel strand 3 is tensioned. Finally, the steel strand 3 exposed from the end plate 2 is cut and polished, and the manufactured centrifugal concrete pile has no anchorage part protruding from the end plate, so it is a practical centrifugal concrete pile with steel strands, and this The connection and locking methods of the steel strands in the centrifugal concrete pile are simple and reasonable, the operation is convenient and the cost is low, so that the application of the steel strand to the centrifugal concrete pile can be realized and has practical value for industrial application; the centrifugal concrete pile of the present invention adopts the The high-performance steel strand greatly improves its bending, shearing and tensile properties.

The centrifugal concrete pile with steel strand mentioned in the utility model can be used as the pole body of the utility pole, can also be used as the ground support pole in the telecommunication base station and the wind power generation system, and can also be used as the support body of other ground engineering. extremely wide.

Claims (10)

1. a pre-tensioning system centrifugal concrete pile with steel strand, the concrete pile body (1) that comprises hollow, be positioned at the reinforcing cage of concrete pile body (1), reinforcing cage comprises the main muscle of axial arranged prestressing force, stirrup (4) outside described main muscle and be positioned at the end plate (2) of concrete pile body (1) end around the home, it is characterized in that: the main muscle of described prestressing force is steel strand (3), at least one end plate (2) adopts the first clip type structure to be connected with steel strand (3), on this piece end plate (2), have the bellmouth (21) that several apertures from the inside to the outside expand gradually, bellmouth (21) and steel strand (3) corresponding setting one by one, in each bellmouth (21), be placed with multi-disc intermediate plate (5), the inner surface of each intermediate plate (5) is provided with latch (51), this multi-disc intermediate plate (5) amalgamation forms the chuck component (6) in order to clip steel strand (3), the outer peripheral face of this chuck component (6) forms the cone face (61) matching with described bellmouth (21), in chuck component (6), be formed centrally internal tooth hole (62), described each steel strand (3) are all locked through the interior perforation (62) in corresponding chuck component and by interior perforation (62), the outer face of chuck component (6) flushes with the outer face of described end plate (2) or is lower slightly.

2. the pre-tensioning system centrifugal concrete pile with steel strand according to claim 1, it is characterized in that: the periphery of the described chuck component (6) being comprised of multi-disc intermediate plate (5) is provided with cannelure (63), in this cannelure (63), is placed with multi-disc intermediate plate (5) is bound round to firm cranse (64).

3. the pre-tensioning system centrifugal concrete pile with steel strand according to claim 1, is characterized in that: described each chuck component (6) is comprised of three described intermediate plates (5).

4. the pre-tensioning system centrifugal concrete pile with steel strand according to claim 1, is characterized in that: on described end plate (2), also have a plurality of threaded connection holes (22) in order to be connected with anchor plate or stretch board.

5. the pre-tensioning system centrifugal concrete pile with steel strand according to claim 1, is characterized in that: described two end plates (2) all adopts described the first clip type structure to be connected with steel strand (3).

6. a pre-tensioning system centrifugal concrete pile with steel strand, the concrete pile body (1) that comprises hollow, be positioned at the reinforcing cage of concrete pile body (1), reinforcing cage comprises the main muscle of axial arranged prestressing force, stirrup (4) outside described main muscle and be positioned at the end plate (2) of concrete pile body (1) end around the home, it is characterized in that: the main muscle of described prestressing force is steel strand (3), at least one end plate (2) adopts the second clip type structure to be connected with steel strand (3), on this piece end plate (2), have several counterbores (23), in each counterbore (23), be placed with the transition member (7) that profile and counterbore (23) match, the front end of transition member (7) has the ring-type shoulder block portion (71) in the macropore portion that is sunken to described counterbore (23), in transition member (7), there is the transition bellmouth (72) that aperture expands gradually from the inside to the outside, transition bellmouth (72) and steel strand (3) corresponding setting one by one, in each transition bellmouth (72), be placed with multi-disc intermediate plate (5), the inner surface of each intermediate plate (5) is provided with latch (51), this multi-disc intermediate plate (5) amalgamation forms the chuck component (6) in order to clip steel strand (3), the outer peripheral face of this chuck component (6) forms the cone face (61) matching with described transition bellmouth (72), in chuck component (6), be formed centrally internal tooth hole (62), described each steel strand (3) are all locked through the interior perforation (62) in corresponding chuck component and by interior perforation (62), the outer face of chuck component (6) flushes with the outer face of described end plate (2) or is lower slightly.

7. the pre-tensioning system centrifugal concrete pile with steel strand according to claim 6, it is characterized in that: the periphery of the described chuck component (6) being comprised of multi-disc intermediate plate (5) is provided with cannelure (63), in this cannelure (63), is placed with multi-disc intermediate plate (5) is bound round to firm cranse (64).

8. the pre-tensioning system centrifugal concrete pile with steel strand according to claim 6, is characterized in that: described each chuck component (6) is comprised of three described intermediate plates (5).

9. the pre-tensioning system centrifugal concrete pile with steel strand according to claim 6, is characterized in that: on described end plate (2), also have a plurality of threaded connection holes (22) in order to be connected with anchor plate or stretch board.

10. the pre-tensioning system centrifugal concrete pile with steel strand according to claim 6, is characterized in that: described two end plates (2) all adopts described the second clip type structure to be connected with steel strand (3).