Compacted and expanded composite pile in prestressed pipe pile hole and construction method

Abstract

The invention relates to the technical field of foundation composite piles, in particular to a rammed and expanded composite pile in a prestressed pipe pile hole and a construction method, and the rammed and expanded composite pile in the prestressed pipe pile hole comprises a prefabricated hollow pipe pile, a core filling reinforcement cage, a rammed and expanded head steel cylinder, a plug connector and a pile bottom end rammed and expanded head carrier. According to the construction method, the prefabricated hollow pipe pile is matched with the punning expanded head steel cylinder and the pile bottom sealing device, so that the prefabricated hollow pipe pile and the punning expanded head steel cylinder serve as bearing components and also serve as a sleeve, the construction method that pile sinking is conducted firstly and then ramming and expanding core filling is conducted is formed, the steel sleeve does not need to be lifted, the construction efficiency is improved, and the construction cost is reduced. And the filler is circumferentially dispersed from the bottom of the tamping and expanding head steel cylinder to the outer wall of the tamping and expanding head steel cylinder, so that a formed tamping and expanding head carrier at the bottom end of the pile is formed by the tamping and expanding head steel cylinder and the dry hard concrete filled and wrapped on the inner wall and the outer wall of the tamping and expanding head steel cylinder, and the overall firmness of the tamping and expanding composite pile in the prestressed pipe pile hole is further improved.

Description

Technical Field

[0001] The invention relates to the technical field of foundation composite piles, and specifically proposes a prestressed pipe pile hole ramming and expansion composite pile and a construction method. Background Art

[0002] Composite carrier piles are composed of a concrete pile body and a rammed and expanded carrier at the pile bottom. Traditional construction methods generally use steel casing to vibrate and sink, pull out, ram and expand the filler into the hole through the steel casing, and then lower the steel cage and cast the concrete pile body.

[0003] However, during the process of tamping and expanding the filler, the lateral construction of the tamping has a large impact range, which is easy to produce the soil squeezing effect and have a negative impact on the temporary piles, and the tamping density is difficult to control. The length of the construction pile is limited by the height of the equipment, and it is difficult to lift the steel casing for long pile construction. The ordinary hammering method is not easy to construct under the condition of a hard interlayer. The filler will produce a vibration when it is tamped. When the water level of the construction site is high, it is necessary to seal and stop the water. The process is complex and restricted, the construction period is long, and the quality is difficult to guarantee; and after the steel cage is inserted and placed, when pouring concrete and vibrating the concrete, the steel cage is easy to shake under the vibration force of the concrete during vibration, which affects the quality of the composite carrier pile. Therefore, a composite pile tamped and expanded in the hole of a prestressed pipe pile and a construction method are proposed to solve the above problems. Summary of the invention

[0004] In view of the above problems, the embodiments of the present application provide a prestressed pipe pile hole tamping expansion composite pile and a construction method to solve the technical problems in the related art.

[0005] In order to achieve the above-mentioned purpose, the embodiment of the present application provides the following technical solutions: a prestressed pipe pile in-hole tamping and expansion composite pile, comprising a prefabricated hollow pipe pile, a core-filled steel cage, a tamping and expansion head steel cylinder, a connector and a tamping and expansion head carrier at the bottom end of the pile, the interior of the prefabricated hollow pipe pile is a hollow circular hole, the bottom of the prefabricated hollow pipe pile is equipped with a connecting sleeve through high-strength bolts, the lower end of the connecting sleeve is equipped with a tamping and expansion head steel cylinder through high-strength bolts, the tamping and expansion head steel cylinder is circular and cylindrical, and the tamping and expansion head steel cylinder is concentric with the prefabricated hollow pipe pile and has the same inner diameter.

[0006] The inner wall at the lower end of the tamping and enlarging head steel cylinder and the lower end of the inner ring surface of the connecting sleeve are both provided with an annular groove. During the static pressure pile sinking operation, the bottom of the tamping and enlarging head steel cylinder of the prefabricated hollow pipe pile is closed by a pile bottom closing device.

[0007] After the static pressure pile sinking operation of the prefabricated hollow pipe pile is completed, the pile bottom sealing device is moved upward to the outside of the prefabricated hollow pipe pile, and fillers and dry hard concrete are put into the prefabricated hollow pipe pile one by one and compacted to form a compacted enlarged head carrier at the bottom of the pile.

[0008] The lower end of the core-filled steel cage is equipped with a connector that is plugged into the annular groove opened on the connecting sleeve. When the core-filled steel cage is installed into the interior of the prefabricated hollow pipe pile, the connector at the lower end of the core-filled steel cage is inserted into the annular groove opened on the inner wall of the connecting sleeve to limit and lock the core-filled steel cage.

[0009] The upper end of the core-filled steel cage inside the precast hollow pipe pile is connected to the pile cap steel bar. The core-filled steel cage and the pile cap steel bar are poured by self-compacting concrete of the same grade as the precast hollow pipe pile, and the required prestressed pipe pile hole ramming and expansion composite pile is obtained by vibration compaction and curing.

[0010] In one possible implementation, the pile bottom closing device includes a support ring and a pile bottom steel plate arranged in sequence from top to bottom, the inner ring surface of the support ring and the top of the pile bottom steel plate are jointly equipped with a hollow connecting sleeve, the inner ring surface of the support ring is fixedly connected to the hollow connecting sleeve by a connecting strip, and the side wall of the pile bottom steel plate and the outer ring surface of the support ring near the lower end are provided with guide grooves evenly arranged along the circumference of the hollow connecting sleeve, the guide groove is slidably connected to a sliding assembly that is plugged into the corresponding annular groove, and the hollow connecting sleeve is equipped with a pulling drive group that pulls the sliding assembly to slide along the guide groove.

[0011] In one possible implementation, the side wall of the tamping and enlarging head steel cylinder is provided with evenly arranged discharge holes, and a sealing sleeve connected to the hollow connecting sleeve through a bracket is provided on the hollow connecting sleeve. The sealing sleeve is inserted into the tamping and enlarging head steel cylinder to seal the discharge holes, and the top of the sealing sleeve is connected to the support ring through a rib rod.

[0012] In one possible implementation, the lifting drive group includes a main steel wire rope installed on the top of a hollow connecting sleeve and sliding up and down. The side wall of the hollow connecting sleeve is provided with through holes evenly arranged along its circumference and corresponding to the sliding components one by one. A branch steel wire rope is fixedly installed on the top of the sliding component. The other end of the branch steel wire rope passes through the corresponding through hole and is connected to the main steel wire rope. A friction-reducing guide wheel assembly is installed in the through hole, and an elastic reset assembly is installed between the inner ring surface of the support ring and the middle part of the pile bottom steel plate and the corresponding sliding component.

[0013] In one possible implementation, the anti-friction guide wheel assembly includes two limit guide wheels symmetrically arranged up and down, the two limit guide wheels are rotatably connected to the upper and lower sides of the through hole through mounting seats, and the branch wire rope is wound around the corresponding limit guide wheels.

[0014] In one possible implementation, the elastic reset assembly includes an L-shaped plate whose horizontal section end is connected to the sliding assembly. After the L-shaped plate passes through the guide groove, the vertical section of the L-shaped plate is connected to the inner ring surface of the corresponding support ring or the inner wall of the lower end of the hollow connecting sleeve through a reset spring.

[0015] In a possible implementation, the plug-in component is a plug-in steel bar obliquely installed at the bottom of a circle of steel bars located on the outer circle of the core-filled steel cage.

[0016] The present invention also provides a construction method for ramming and expanding composite piles in prestressed pipe pile holes, comprising the following steps: S1, construction preparation: preparing and inspecting construction machinery, instruments, equipment, tools and prefabricated hollow pipe piles.

[0017] S2, long spiral hole drilling: according to the design line, a 300mm long φ6mm steel bar is driven into the center of the pile position for positioning; after the pile position is positioned, the long spiral drilling machine is steadily positioned and centered, the verticality of the drill rod is checked and adjusted, and then the long spiral drilling machine is used for drilling operations. After drilling to the designed elevation, the long spiral drilling machine is taken out and removed to obtain the required pile hole.

[0018] S3, cleaning the inner wall of the pile hole: the pile hole is cleaned by an existing cleaning device, and after the cleaning is completed, the diameter of the pile hole and the vertical flatness of the pile hole are tested and accepted.

[0019] S4, pipe pile bottom sealing: When the prefabricated hollow pipe pile drives the compaction and enlargement head steel cylinder to sink to the bottom of the pile hole, the sliding assembly on the pile bottom sealing device is inserted into the corresponding annular groove. At this time, the pile bottom steel plate and the support ring are locked by moving up and down, and the pile bottom steel plate will seal the bottom of the compaction and enlargement head steel cylinder.

[0020] S5, pipe pile static pressure sinking: the piles are hoisted and fed by the existing special crane. When the prefabricated hollow pipe pile and the compaction enlarged head steel cylinder underneath are transported to the vicinity of the existing pile driver, the pile driver drives the prefabricated hollow pipe pile and the compaction enlarged head steel cylinder and presses the prefabricated hollow pipe pile and the compaction enlarged head steel cylinder into the pile hole, and presses the compaction enlarged head steel cylinder at the lower end of the prefabricated hollow pipe pile to the designed elevation.

[0021] S6, the bottom of the pipe pile is opened: when the prefabricated hollow pipe pile and the compaction and expansion head steel cylinder at its bottom sink to the designed elevation, the driving source drives the lifting drive group on the pile bottom closing device to pull the sliding assembly to move and disengage from the corresponding annular groove, and then drives the pile bottom steel plate, the support ring and the lifting drive group to move upward out of the prefabricated hollow pipe pile, thereby opening the bottom of the compaction and expansion head steel cylinder.

[0022] S7, column hammer filling tamping: fill the material from the upper inlet of the precast hollow pipe pile, and then use the column hammer to tamp the filling material in free fall until the compaction state meets the requirements; then lift the column hammer to fill the dry hard concrete, and continue to tamp the dry hard concrete to the bottom of the precast hollow pipe pile through the column hammer until a compacted enlarged head carrier is formed at the bottom of the pile.

[0023] S8, installation of the core-filled steel cage: first lift the column hammer to the outside of the prefabricated hollow pipe pile, then insert the core-filled steel cage into the prefabricated hollow pipe pile until the bottom of the core-filled steel cage contacts the top of the tamping enlarged head carrier at the bottom of the pile. At this time, the connector at the lower end of the core-filled steel cage is inserted into the annular groove provided on the inner wall of the connecting sleeve to limit and lock the core-filled steel cage.

[0024] S9, installation of pile cap reinforcement and formwork: lay a 10cm thick graded crushed stone cushion around the upper end of the precast hollow pipe pile and compact it; then tie the pile cap reinforcement, tie and connect the pile cap reinforcement to the core-filled steel cage inside the precast hollow pipe pile, and ensure that the precast hollow pipe pile extends into the pile cap reinforcement by 5cm. Finally, install the pile cap side formwork around the pile cap reinforcement.

[0025] S10, concrete pouring: Use self-compacting concrete of the same grade as the precast hollow pipe piles to cast the core-filling steel cage in the precast hollow pipe piles and the pile cap steel bars.

[0026] The above one or more technical schemes in the embodiments of the present invention have at least one of the following beneficial effects: 1. A prestressed pipe pile hole rammed and expanded composite pile and construction method designed by the present invention, through the prefabricated hollow pipe pile, the rammed and expanded head steel cylinder and the pile bottom closing device, so that the prefabricated hollow pipe pile and the rammed and expanded head steel cylinder are used as both load-bearing components and casings, forming a construction method of first sinking the pile and then ramming and expanding the core, without the need to lift the steel casing, thereby improving the construction efficiency, and the hammer weight remains unchanged during the construction of the internal ramming carrier, the lateral impact range is reduced when ramming the filler, and the influence on the loosening of the temporary pile is reduced, and at the same time, the filler is dispersed circumferentially from the bottom of the rammed and expanded head steel cylinder to the outer wall of the rammed and expanded head steel cylinder, so that the rammed and expanded head carrier at the bottom end of the pile is formed by the rammed and expanded head steel cylinder and the dry hard concrete filled and wrapped with the inner and outer walls, further improving the overall firmness of the prestressed pipe pile hole rammed and expanded composite pile.

[0027] 2. In the process of pile sinking, the present invention closes the bottom of the tamping and enlarging head steel cylinder through the pile bottom closing device, thereby improving the application scope of the tamping and enlarging composite piles in the prestressed pipe pile hole, and the support ring in the pile bottom closing device is connected with the hollow connecting sleeve and the sliding component is plugged into the annular groove on the connecting sleeve, so that the bottom of the connecting sleeve is supported, and then the upper and lower sides of the tamping and enlarging head steel cylinder are supported, thereby improving the supporting force and anti-extrusion ability of the tamping and enlarging head steel cylinder and the pile bottom steel plate.

[0028] 3. The present invention has a connector installed at the lower end of the core-filled steel cage, which is plugged into the annular groove provided on the connecting sleeve. When the core-filled steel cage is installed into the interior of the prefabricated hollow pipe pile, the connector at the lower end of the core-filled steel cage is inserted into the annular groove provided on the inner wall of the connecting sleeve, so as to limit and lock the core-filled steel cage, thereby further improving the connection strength between the core-filled steel cage and the prefabricated hollow pipe pile, and preventing the core-filled steel cage from moving up and down under the action of vibration force during the process of vibrating the concrete after pouring the concrete, thereby affecting the quality of the rammed and expanded composite pile in the prestressed pipe pile hole. BRIEF DESCRIPTION OF THE DRAWINGS

[0029] In order to more clearly illustrate the embodiments of the present invention or the technical solutions in the prior art, the drawings required for use in the embodiments or the description of the prior art will be briefly introduced below. Obviously, the drawings described below are only embodiments of the present invention. For ordinary technicians in this field, other drawings can be obtained based on the provided drawings without paying creative work.

[0030] Figure 1 It is a step diagram of the construction method of the ramming and expanding composite pile in the hole of the prestressed pipe pile of the present invention.

[0031] Figure 2 It is a schematic structural diagram of a pile hole formed after drilling according to the present invention.

[0032] Figure 3 It is a structural schematic diagram of the construction status of construction steps 4 and 5 of the present invention.

[0033] Figure 4 It is a structural schematic diagram of the present invention when the prefabricated hollow pipe pile and the compaction enlarged head steel tube are inserted into the pile hole, the pile bottom sealing device is moved out of the prefabricated hollow pipe pile, and dry hard concrete is filled into the prefabricated hollow pipe pile.

[0034] Figure 5 It is a schematic diagram of the construction status structure of construction step 7 of the present invention.

[0035] Figure 6 It is a schematic diagram of the construction status structure of construction step 8 of the present invention.

[0036] Figure 7 It is a schematic diagram of the construction status structure of construction step 9 of the present invention.

[0037] Figure 8 It is a schematic diagram of the structure of the composite pile rammed and expanded in the hole of the prestressed pipe pile formed in construction step 10 of the present invention.

[0038] Fig. 9 The present invention Figure 6 Enlarged view of point A in .

[0039] Fig.10It is a partial structural schematic diagram of the prefabricated hollow pipe pile, the compacted enlarged head steel tube and the pile bottom sealing device of the present invention.

[0040] Fig.11 The present invention Fig.10 Enlarged view of point B in .

[0041] Fig.12 The present invention Fig.10 Enlarged view of point C in the figure.

[0042] Figure numerals: 1. Prefabricated hollow pipe pile; 2. Core-filled steel cage; 3. Connecting sleeve; 4. Ramming and enlarged head steel cylinder; 40. Discharge hole; 41. Bracket; 42. Sealing sleeve; 5. Annular groove; 6. Pile bottom closing device; 60. Support ring; 61. Pile bottom steel plate; 62. Connecting strip; 63. Guide slide groove; 64. Sliding assembly; 65. Lifting drive group; 650. Main steel wire rope; 651. Through hole; 652. Branch steel wire rope; 660. L-shaped plate; 661. Reset spring; 670. Limiting guide wheel; 671. Mounting seat; 68. Hollow connecting sleeve; 7. Plug-in; 8. Column hammer; 9. Ramming and enlarged head carrier at the bottom of the pile; 10. Template; 11. Pile hole. DETAILED DESCRIPTION

[0043] The following will be combined with the drawings in the embodiments of the present invention to clearly and completely describe the technical solutions in the embodiments of the present invention. Obviously, the described embodiments are only part of the embodiments of the present invention, not all of the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field without creative work are within the scope of protection of the present invention.

[0044] In order to enable those skilled in the art to better understand the scheme of the present invention, the present invention is further described in detail below in conjunction with the accompanying drawings and specific embodiments.

[0045] See also Figure 3 , Figure 4 and Fig. 9 A prestressed pipe pile in-hole tamping and expansion composite pile comprises a prefabricated hollow pipe pile 1, a core-filled steel cage 2, a tamping and expansion head steel cylinder 4, a connector 7 and a tamping and expansion head carrier 9 at the bottom end of the pile. The interior of the prefabricated hollow pipe pile 1 is a hollow circular hole. The bottom of the prefabricated hollow pipe pile 1 is installed with a connecting sleeve 3 through a high-strength bolt (not shown in the figure), and the lower end of the connecting sleeve 3 is installed with a tamping and expansion head steel cylinder 4 through a high-strength bolt (not shown in the figure). The tamping and expansion head steel cylinder 4 is circular and cylindrical, and is concentric with the prefabricated hollow pipe pile 1 and has the same inner diameter.

[0046] See also Figure 3 and Fig.10The inner wall at the lower end of the tamping and enlarging head steel cylinder 4 and the lower end of the inner ring surface of the connecting sleeve 3 are both provided with an annular groove 5. During the static pressure pile sinking operation of the prefabricated hollow pipe pile 1, the bottom of the tamping and enlarging head steel cylinder 4 is closed by a pile bottom closing device 6 to prevent soil and other impurities from entering the prefabricated hollow pipe pile 1 and the tamping and enlarging head steel cylinder 4 to form pile core soil when the prefabricated hollow pipe pile 1 drives the tamping and enlarging head steel cylinder 4 to sink the pile.

[0047] See also Figure 3 , Figure 4 and Figure 5 After the static pressure pile sinking operation of the prefabricated hollow pipe pile 1 is completed, the pile bottom closing device 6 is moved upward to the outside of the prefabricated hollow pipe pile 1, and fillers and dry hard concrete are put into the prefabricated hollow pipe pile 1 one by one and compacted to form a compacted enlarged head carrier 9 at the bottom of the pile, thereby improving the overall firmness of the prefabricated hollow pipe pile 1.

[0048] See also Figure 6 and Fig. 9 The lower end of the core-filled steel cage 2 is equipped with a connector 7 that is plugged into the annular groove 5 opened on the connecting sleeve 3. When the core-filled steel cage 2 is installed into the prefabricated hollow pipe pile 1, the connector 7 at the lower end of the core-filled steel cage 2 is inserted into the annular groove 5 opened on the inner wall of the connecting sleeve 3 to limit and lock the core-filled steel cage 2.

[0049] See also Figure 7 and Figure 8 The upper end of the core-filled steel cage 2 inside the prefabricated hollow pipe pile 1 is connected to the pile cap steel bar. The core-filled steel cage 2 and the pile cap steel bar are poured by self-compacting concrete of the same grade as the prefabricated hollow pipe pile 1, and the required prestressed pipe pile hole ramming and expansion composite pile is obtained by vibration compaction and curing.

[0050] The use of prefabricated hollow pipe piles 1 in combination with the compaction enlarged head steel tube 4 as the force transmission rod of the carrier pile ensures the construction quality of the pile body. At the same time, the dry hard concrete is filled into the prefabricated hollow pipe piles 1 to avoid lateral diffusion of the dry hard concrete during tamping. Under the premise of unchanged hammer weight, the lateral influence range is reduced when tamping the filler, and the influence on the loosening of the temporary pile is reduced. The quality of the carrier is controlled by penetration degree and has the characteristics of immediate pressing. The quality of each link in the whole construction process is controllable.

[0051] See also Fig. 9The connector 7 is a splicing steel bar obliquely installed at the bottom of a circle of steel bars in the outer circle of the core-filling steel cage 2. During the downward movement of the core-filling steel cage 2, the splicing steel bar collides with the top of the tamping and enlargement head carrier 9 at the bottom of the pile. At this time, the splicing steel bar at the lower end of the core-filling steel cage 2 is gradually bent and tilted and inserted into the annular groove 5 provided on the inner wall of the connecting sleeve 3. When the bottom of the core-filling steel cage 2 collides with the top of the tamping and enlargement head carrier 9, the splicing steel bar is in a horizontal state and is plugged into the annular groove 5 provided on the inner wall of the connecting sleeve 3, thereby limiting and locking the core-filling steel cage 2, further improving the connection strength between the core-filling steel cage 2 and the prefabricated hollow pipe pile 1, and avoiding the up and down movement of the core-filling steel cage 2 under the action of vibration force during the vibration of concrete, which affects the quality of the tamped and expanded composite pile in the prestressed pipe pile hole.

[0052] See also Figure 3 and Fig.10 The pile bottom closing device 6 includes a support ring 60 and a pile bottom steel plate 61 arranged in sequence from top to bottom. The inner ring surface of the support ring 60 and the top of the pile bottom steel plate 61 are jointly installed with a hollow connecting sleeve 68. The inner ring surface of the support ring 60 is fixedly connected to the hollow connecting sleeve 68 through a connecting strip 62. The side wall of the pile bottom steel plate 61 and the outer ring surface of the support ring 60 near the lower end are both provided with guide grooves 63 evenly arranged along the circumference of the hollow connecting sleeve 68. A sliding component 64 that is plugged into the corresponding annular groove 5 is slidably connected to the guide groove 63. A pulling drive group 65 that pulls the sliding component 64 to slide along the guide groove 63 is installed on the hollow connecting sleeve 68.

[0053] After the pile hole 11 is bored and cleaned (see Figure 2 ), before the prefabricated hollow pipe pile 1 drives the compaction and enlargement head steel cylinder 4 to sink to the bottom of the pile hole 11, the sliding assembly 64 on the pile bottom closing device 6 is inserted into the corresponding annular groove 5, at which time the pile bottom steel plate 61 and the support ring 60 are locked by upward and downward displacement, and the pile bottom steel plate 61 closes the bottom of the compaction and enlargement head steel cylinder 4 to prevent the soil and other impurities in the pile hole 11 from entering the prefabricated hollow pipe pile 1 and the compaction and enlargement head steel cylinder 4 to form pile core soil when the prefabricated hollow pipe pile 1 drives the compaction and enlargement head steel cylinder 4 to sink to the bottom of the pile hole 11, and the support ring 60 is connected with the hollow connecting sleeve 68 and the sliding assembly 64 is plugged into the annular groove 5 on the connecting sleeve 3, so that the bottom of the connecting sleeve 3 is supported, and then the upper and lower sides of the compaction and enlargement head steel cylinder 4 are supported, thereby improving the supporting force and anti-extrusion ability of the compaction and enlargement head steel cylinder 4 and the pile bottom steel plate 61.

[0054] When the prefabricated hollow pipe pile 1 and the compaction enlarged head steel cylinder 4 at its bottom sink to the designed elevation, the driving source drives the lifting drive group 65 on the pile bottom closing device 6 to pull the sliding assembly 64 to move and disengage from the corresponding annular groove 5, and then drives the pile bottom steel plate 61, the support ring 60 and the lifting drive group 65 to move upward out of the prefabricated hollow pipe pile 1, thereby opening the bottom of the compaction enlarged head steel cylinder 4 to fill the prefabricated hollow pipe pile 1 with dry hard concrete and compact it.

[0055] See also Figure 7 and Fig.10 The side wall of the tamping and enlarging head steel cylinder 4 is provided with evenly arranged discharge holes 40, and a sealing sleeve 42 connected to the hollow connecting sleeve 68 is sleeved thereon through a bracket 41. The sealing sleeve 42 is inserted into the tamping and enlarging head steel cylinder 4 to seal the discharge holes 40, and the top of the sealing sleeve 42 is connected to the support ring 60 through a rib rod.

[0056] The pile bottom closing device 6 closes the bottom of the compaction and enlargement head steel cylinder 4, and the sealing sleeve 42 seals the discharge hole 40 to prevent the silt outside the side wall of the pile hole 11 from entering the compaction and enlargement head steel cylinder 4 from the discharge hole 40 when the prefabricated hollow pipe pile 1 drives the compaction and enlargement head steel cylinder 4 to sink to the bottom of the pile hole 11; when the bottom of the compaction and enlargement head steel cylinder 4 is opened, the pile bottom steel plate 61, the support ring 60 and the lifting drive group 65 move upward out of the prefabricated hollow pipe pile 1, and the sealing sleeve 42 moves upward out of the prefabricated hollow pipe pile 1 along with the hollow connecting sleeve 68 and the support ring 60, thereby opening the discharge hole 40.

[0057] Afterwards, dry hard concrete is filled into the prefabricated hollow pipe pile 1. When the column hammer 8 is used to continuously tamp the dry hard concrete, part of the dry hard concrete moves to the outside of the compaction enlarged head steel cylinder 4 through the discharge hole 40 and squeezes the soil outside the compaction enlarged head steel cylinder 4, and the remaining dry hard concrete diffuses toward the bottom of the compaction enlarged head steel cylinder 4 and in the circumferential direction. The column hammer 8 tamps the dry hard concrete to the bottom of the prefabricated hollow pipe pile 1 to form a compaction enlarged head carrier 9 at the bottom end of the pile. At this time, the compaction enlarged head carrier 9 at the bottom end of the pile is formed by the compaction enlarged head steel cylinder 4 and the dry hard concrete filled and wrapped with the inner and outer walls of the pile, further improving the overall firmness of the prefabricated hollow pipe pile 1.

[0058] See also Figure 3 and Fig.10The lifting drive group 65 includes a main steel wire rope 650 installed on the top of the hollow connecting sleeve 68 for sliding up and down. The side wall of the hollow connecting sleeve 68 is provided with through holes 651 evenly arranged along its circumference and corresponding to the sliding components 64 one by one. A branch steel wire rope 652 is fixedly installed on the top of the sliding component 64. The other end of the branch steel wire rope 652 passes through the corresponding through hole 651 and is connected to the main steel wire rope 650. A friction-reducing guide wheel assembly is installed in the through hole 651. Elastic reset assemblies are installed between the inner ring surface of the support ring 60 and the middle part of the pile bottom steel plate 61 and the corresponding sliding component 64.

[0059] When the prefabricated hollow pipe pile 1 and the compaction and enlargement head steel cylinder 4 at its bottom sink to the designed elevation, the main steel wire rope 650 is pulled by a driving source (such as a winder), and the main steel wire rope 650 drives the sliding assembly 64 connected to it to move out of the corresponding annular groove 5 through the branch steel wire rope 652, and the sliding assembly 64 is disengaged from the corresponding annular groove 5, and then the main steel wire rope 650 continues to move upward and drives the pile bottom steel plate 61, the support ring 60 and the hollow connecting sleeve 68 to move upward and out of the prefabricated hollow pipe pile 1, thereby opening the bottom of the compaction and enlargement head steel cylinder 4.

[0060] See also Fig.10 and Fig.12 The friction-reducing guide wheel assembly includes two limit guide wheels 670 symmetrically arranged in an upper and lower manner. The two limit guide wheels 670 are rotatably connected to the upper and lower sides of the through hole 651 through mounting seats 671 respectively. The branch steel wire rope 652 is wound around the corresponding limit guide wheels 670. The limit guide wheels 670 are used to reduce the friction between the through hole 651 and the branch steel wire rope 652 and the wear of the branch steel wire rope 652, thereby extending the service life of the branch steel wire rope 652.

[0061] See also Fig.10 and Fig.11 The elastic reset component includes an L-shaped plate 660 whose horizontal section end is connected to the sliding component 64. After the L-shaped plate 660 passes through the guide groove 63, the vertical section of the L-shaped plate 660 is connected to the inner ring surface of the corresponding support ring 60 or the inner wall of the lower end of the hollow connecting sleeve 68 through a reset spring 661.

[0062] In the initial state, the sliding assembly 64 is inserted into the corresponding annular groove 5 under the elastic force of the return spring 661; when the sliding assembly 64 needs to be disengaged from the annular groove 5, the branch wire rope 652 pulls the sliding assembly 64 to move, and the sliding assembly 64 pulls the return spring 661 to extend through the L-shaped plate 660 until the sliding assembly 64 is disengaged from the annular groove 5.

[0063] See also Figure 1-Figure 10The present invention also provides a construction method for a prestressed pipe pile hole tamping and expansion composite pile, comprising the following steps: S1, construction preparation: preparing and inspecting construction machinery, instruments, equipment, tools and prefabricated hollow pipe piles 1.

[0064] S2, long spiral hole drilling: according to the design line, a 300mm long φ6mm steel bar is driven into the center of the pile position for positioning; after the pile position is positioned, the long spiral drilling machine is stably positioned and centered, the verticality of the drill rod is checked and adjusted, and then the long spiral drilling machine is used for drilling. After drilling to the designed elevation, the long spiral drilling machine is taken out and removed to obtain the required pile hole 11.

[0065] S3, cleaning the inner wall of the pile hole: the pile hole 11 is cleaned by an existing cleaning device, and after the cleaning is completed, the diameter of the pile hole 11 and the vertical flatness of the pile hole 11 are detected and accepted.

[0066] S4, pile bottom sealing: when the prefabricated hollow pile 1 drives the compaction and enlargement head steel cylinder 4 to sink to the bottom of the pile hole 11, the sliding assembly 64 on the pile bottom closing device 6 is inserted into the corresponding annular groove 5. At this time, the pile bottom steel plate 61 and the support ring 60 are locked by the up and down displacement, and the pile bottom steel plate 61 seals the bottom of the compaction and enlargement head steel cylinder 4.

[0067] S5, static pressure pile sinking: the piles are hoisted and fed by a special crane equipped at present. When the prefabricated hollow pipe pile 1 and the compaction and enlarged head steel cylinder 4 thereunder are transported to the vicinity of the existing pile driver, the pile driver drives the prefabricated hollow pipe pile 1 and the compaction and enlarged head steel cylinder 4 and presses the prefabricated hollow pipe pile 1 and the compaction and enlarged head steel cylinder 4 into the pile hole 11, and presses the compaction and enlarged head steel cylinder 4 at the lower end of the prefabricated hollow pipe pile 1 to the designed elevation.

[0068] S6, the bottom of the pile is opened: when the prefabricated hollow pile 1 and the compacted enlarged head steel tube 4 at its bottom sink to the designed elevation, the driving source drives the lifting drive group 65 on the pile bottom closing device 6 to pull the sliding assembly 64 to move and disengage from the corresponding annular groove 5, and then drives the pile bottom steel plate 61, the support ring 60 and the lifting drive group 65 to move upward out of the prefabricated hollow pile 1, thereby opening the bottom of the compacted enlarged head steel tube 4.

[0069] S7, column hammer filling tamping: filling is carried out from the upper end inlet of the precast hollow pipe pile 1, and then the column hammer 8 performs free fall to tamp the filling material until the dense state meets the requirements; then the column hammer 8 is lifted to fill the dry hard concrete, and the column hammer 8 continues to tamp the dry hard concrete to the bottom of the precast hollow pipe pile 1 until the pile bottom end tamping enlarged head carrier 9 is formed.

[0070] S8, installation of the core-filled steel cage: first lift the column hammer 8 to the outside of the prefabricated hollow pipe pile 1, and then insert the core-filled steel cage 2 into the prefabricated hollow pipe pile 1 until the bottom of the core-filled steel cage 2 contacts the top of the tamping enlarged head carrier 9 at the bottom of the pile. At this time, the connector 7 at the lower end of the core-filled steel cage 2 is inserted into the annular groove 5 provided on the inner wall of the connecting sleeve 3 to limit and lock the core-filled steel cage 2.

[0071] S9, installation of pile cap reinforcement and formwork: lay a 10 cm thick graded crushed stone cushion around the upper end of the precast hollow pipe pile 1 and compact it; then tie the pile cap reinforcement, tie and connect the pile cap reinforcement to the core-filled reinforcement cage 2 inside the precast hollow pipe pile 1, and ensure that the precast hollow pipe pile 1 extends into the pile cap reinforcement by 5 cm, and finally install the pile cap side formwork 10 around the pile cap reinforcement.

[0072] S10, concrete pouring: using self-compacting concrete of the same grade as the precast hollow pipe pile 1 to pour the core-filling steel cage 2 in the precast hollow pipe pile 1 and the pile cap steel bars.

[0073] In the description of the present invention, it is necessary to understand that the terms "length", "width", "up", "down", "vertical", "horizontal", "top", "bottom", "inside", "outside", "axial", "circumferential" and the like indicate orientations or positional relationships based on the orientations or positional relationships shown in the accompanying drawings, and are only for the convenience of describing the present invention and simplifying the description, rather than indicating or implying that the device or element referred to must have a specific orientation, be constructed and operated in a specific orientation, and therefore cannot be understood as a limitation on the present invention.

[0074] In the description of the present invention, it is also necessary to explain that, unless otherwise clearly specified and limited, the terms "set", "connect", "install", and "connect" should be understood in a broad sense, for example, it can be a fixed connection, a detachable connection, or an integral connection; it can be a mechanical connection or an electrical connection; it can be a direct connection, or it can be indirectly connected through an intermediate medium, or it can be the internal communication of two elements. For ordinary technicians in this field, the specific meanings of the above terms in the present invention can be understood according to specific circumstances.

[0075] The embodiments of this specific implementation method are all preferred embodiments of the present invention, and are not intended to limit the protection scope of the present invention. Therefore, all equivalent changes made according to the structure, shape, and principle of the present invention should be included in the protection scope of the present invention.

Claims

1. A prestressed pipe pile hole ramming expansion composite pile, characterized in that: The invention comprises a prefabricated hollow pipe pile (1), a core-filled steel cage (2), a compacting and enlarging head steel cylinder (4), a connector (7) and a compacting and enlarging head carrier (9) at the bottom of the pile. The interior of the prefabricated hollow pipe pile (1) is a hollow circular hole. A connecting sleeve (3) is installed at the bottom of the prefabricated hollow pipe pile (1) via high-strength bolts. A compacting and enlarging head steel cylinder (4) is installed at the lower end of the connecting sleeve (3) via high-strength bolts. The compacting and enlarging head steel cylinder (4) is in a circular cylindrical shape. The compacting and enlarging head steel cylinder (4) is concentric with the prefabricated hollow pipe pile (1) and has the same inner diameter as the prefabricated hollow pipe pile (1). An annular groove (5) is provided on the inner wall at the lower end of the tamping and enlarging head steel cylinder (4) and the lower end of the inner annular surface of the connecting sleeve (3). The bottom of the tamping and enlarging head steel cylinder (4) of the prefabricated hollow pipe pile (1) is sealed by a pile bottom sealing device (6) during the static pressure pile sinking operation. After the static pressure pile sinking operation of the prefabricated hollow pipe pile (1) is completed, the pile bottom sealing device (6) is moved upward to the outside of the prefabricated hollow pipe pile (1), and fillers and dry hard concrete are placed one by one in the prefabricated hollow pipe pile (1) and compacted to form a compacted enlarged head carrier (9) at the bottom end of the pile; The lower end of the core-filled steel cage (2) is provided with a connector (7) that is plugged into and matched with the annular groove (5) provided on the connecting sleeve (3); when the core-filled steel cage (2) is installed into the interior of the prefabricated hollow pipe pile (1), the connector (7) at the lower end of the core-filled steel cage (2) is inserted into the annular groove (5) provided on the inner wall of the connecting sleeve (3) to limit and lock the core-filled steel cage (2); The upper end of the core-filling steel cage (2) inside the prefabricated hollow pipe pile (1) is connected to a pile cap steel bar, and the core-filling steel cage (2) and the pile cap steel bar are poured by pouring self-compacting concrete of the same grade as the prefabricated hollow pipe pile (1), and vibrating and compacting and curing to obtain the desired prestressed pipe pile hole rammed and expanded composite pile.

2. The prestressed pipe pile in-hole tamping and expansion composite pile according to claim 1, characterized in that: The pile bottom closing device (6) comprises a support ring (60) and a pile bottom steel plate (61) arranged in sequence from top to bottom, the inner ring surface of the support ring (60) and the top of the pile bottom steel plate (61) are jointly provided with a hollow connecting sleeve (68), the inner ring surface of the support ring (60) is fixedly connected to the hollow connecting sleeve (68) via a connecting strip (62), the side wall of the pile bottom steel plate (61) and the outer ring surface of the support ring (60) near the lower end are both provided with guide grooves (63) uniformly arranged along the circumference of the hollow connecting sleeve (68), the guide groove (63) is slidably connected with a sliding assembly (64) plug-fitted with a corresponding annular groove (5), and the hollow connecting sleeve (68) is provided with a pulling drive group (65) for pulling the sliding assembly (64) to slide along the guide groove (63).

3. The prestressed pipe pile in-hole tamping and expansion composite pile according to claim 2, characterized in that: The side wall of the tamping and enlarging head steel cylinder (4) is provided with evenly arranged discharge holes (40), and a sealing sleeve (42) connected to the hollow connecting sleeve (68) is sleeved on the hollow connecting sleeve (68) via a bracket (41). The sealing sleeve (42) is inserted into the tamping and enlarging head steel cylinder (4) to seal the discharge holes (40), and the top of the sealing sleeve (42) is connected to the support ring (60) via a rib rod.

4. The prestressed pipe pile in-hole tamping and expansion composite pile according to claim 3, characterized in that: The lifting drive group (65) includes a main steel wire rope (650) installed on the top of a hollow connecting sleeve (68) and sliding up and down. The side wall of the hollow connecting sleeve (68) is provided with through holes (651) evenly arranged along its circumference and corresponding to the sliding components (64) one by one. A branch steel wire rope (652) is fixedly installed on the top of the sliding component (64). The other end of the branch steel wire rope (652) passes through the corresponding through hole (651) and is connected to the main steel wire rope (650). A friction-reducing guide wheel assembly is installed in the through hole (651). Elastic reset assemblies are installed between the inner ring surface of the support ring (60) and the middle part of the pile bottom steel plate (61) and the corresponding sliding component (64).

5. The prestressed pipe pile in-hole tamping and expansion composite pile according to claim 4, characterized in that: The friction-reducing guide wheel assembly comprises two position-limiting guide wheels (670) which are symmetrically arranged in an upper and lower manner. The two position-limiting guide wheels (670) are rotatably connected to the upper and lower sides of the through hole (651) respectively through mounting seats (671).

6. The prestressed pipe pile in-hole ramming and expansion composite pile according to claim 5, characterized in that: The elastic reset assembly comprises an L-shaped plate (660) whose horizontal section end is connected to the sliding assembly (64); after the L-shaped plate (660) passes through the guide slide groove (63), the vertical section of the L-shaped plate (660) is connected to the inner ring surface of the corresponding support ring (60) or the inner wall of the lower end of the hollow connecting sleeve (68) via a reset spring (661).

7. The prestressed pipe pile in-hole ramming and expansion composite pile according to claim 1, characterized in that: The plug-in connector (7) is a plug-in steel bar obliquely installed at the bottom of a circle of steel bars located on the outer circle of the core-filled steel bar cage (2).

8. The construction method of a prestressed pipe pile hole tamping and expansion composite pile according to claim 6 comprises the following steps: S1, construction preparation: prepare and inspect construction machinery, instruments, equipment, tools and prefabricated hollow pipe piles (1); S2, long spiral hole drilling: according to the design route, the long spiral drilling machine performs drilling operation, and after drilling to the design elevation, the long spiral drilling machine is removed and removed to obtain the required pile hole (11); S3, cleaning the inner wall of the pile hole: cleaning the pile hole (11), and after the cleaning is completed, testing and accepting the diameter of the pile hole (11) and the vertical flatness of the pile hole (11); S4, pipe pile bottom sealing: when the prefabricated hollow pipe pile (1) drives the tamping and enlarged head steel cylinder (4) to sink to the bottom of the pile hole (11), the sliding assembly (64) on the pile bottom sealing device (6) is inserted into the corresponding annular groove (5), and at this time, the pile bottom steel plate (61) and the support ring (60) are locked by moving up and down, and the pile bottom steel plate (61) seals the bottom of the tamping and enlarged head steel cylinder (4); S5, static pressure pile sinking: the prefabricated hollow pipe pile (1) and the tamping enlarged head steel cylinder (4) are pressed into the pile hole (11) by a pile driver, and the tamping enlarged head steel cylinder (4) at the lower end of the prefabricated hollow pipe pile (1) is pressed to the designed elevation; S6, opening the bottom of the pipe pile: when the prefabricated hollow pipe pile (1) and the compaction enlarged head steel cylinder (4) at the bottom thereof sink to the designed elevation, the driving source drives the lifting drive group (65) on the pile bottom closing device (6) to pull the sliding assembly (64) to move and disengage from the corresponding annular groove (5), and then drives the pile bottom steel plate (61), the support ring (60) and the lifting drive group (65) to move upward out of the prefabricated hollow pipe pile (1), thereby opening the bottom of the compaction enlarged head steel cylinder (4); S7, column hammer filling tamping: filling is carried out from the upper end inlet of the prefabricated hollow pipe pile (1), and then the column hammer (8) performs free fall to tamping the filling material until the compaction state meets the requirements; then the column hammer (8) is lifted to fill the dry hard concrete, and the column hammer (8) continues to tamping the dry hard concrete to the bottom of the prefabricated hollow pipe pile (1) until a compaction enlarged head carrier (9) is formed at the bottom of the pile; S8, installation of the core-filled steel cage: first, lift the column hammer (8) to the outside of the prefabricated hollow pipe pile (1), and then insert the core-filled steel cage (2) into the prefabricated hollow pipe pile (1) until the bottom of the core-filled steel cage (2) contacts the top of the tamping enlarged head carrier (9) at the bottom of the pile. At this time, the connector (7) at the lower end of the core-filled steel cage (2) is inserted into the annular groove (5) provided on the inner wall of the connecting sleeve (3) to limit and lock the core-filled steel cage (2); S9, installation of pile cap reinforcement and formwork: a layer of graded crushed stone cushion is laid around the upper end of the prefabricated hollow pipe pile (1) and compacted; then the pile cap reinforcement is tied and connected to the core-filled reinforcement cage (2) inside the prefabricated hollow pipe pile (1), and the prefabricated hollow pipe pile (1) is ensured to extend 5 cm into the pile cap reinforcement; finally, the pile cap side formwork (10) is installed around the pile cap reinforcement; S10, concrete pouring: using self-compacting concrete of the same grade as the prefabricated hollow pipe pile (1) to pour the core-filling steel cage (2) in the prefabricated hollow pipe pile (1) and the pile cap steel bars.

Images