Novel tubular pile connecting method and tubular pile connecting structure

Abstract

The invention belongs to the technical field of pipe piles, and particularly relates to a novel pipe pile connecting method and a pipe pile connecting structure.The novel pipe pile connecting method comprises the steps that a matched reinforcement cage is arranged in a pile hole of a prefabricated pipe pile, a pipe pile top rear-inserting steel bar is arranged on the upper side of a top end plate of the prefabricated pipe pile, and a tensioning anchor hole structure of the top end plate of the prefabricated pipe pile is fully utilized; according to the novel pipe pile connecting method, the pipe pile top rear-inserted steel bars are mechanically connected in the tensioning anchor holes, the bending moment resisting requirement of the steel bar cage can be shared, and therefore the steel bar use amount of the steel bar cage is reduced. The mode that the steel bar cage and the pipe pile top rear-inserted steel bars are used in a combined mode guarantees the bending moment resisting capacity of the upper structure of the pipe pile; the steel bar consumption is obviously reduced, and the economic benefit is obvious.

Description

Technical Field

[0001] The invention belongs to the technical field of pipe piles, and in particular relates to a novel pipe pile connection and a pipe pile connection structure. Background Art

[0002] Precast pipe piles are widely used in various types of buildings. For example, in the current construction of sheet pile elevated bridges, precast pipe piles are driven into the ground as piers of the elevated bridges. The piers of sheet pile elevated bridges include continuous piles and transition piles. For continuous piers, the top of the pier and the beam of the bridge deck need to be cast as one through concrete. This is also stipulated in the "Prestressed Concrete Pipe Piles" (National Building Standard Design Atlas 10G409), that is, the upper part of the pipe pile is connected to the pedestal or foundation beam. At present, the precast pipe piles are connected to their upper structures by the core-filled steel cage and the core-filled concrete on the upper part of the pile hole of the precast pipe piles. The upper structure is anchored and connected. This connection method has the following problems: Since the inner diameter of the precast pipe pile is small, the stiffness provided to the connection part is small, and when the stiffness requirement is large, the amount of steel bars used is too much, and the economic benefit is poor. Summary of the invention

[0003] The present invention aims to provide a novel pipe pile connection method and a pipe pile connection structure, so as to reduce the amount of steel bars used while ensuring the earthquake resistance through the novel pipe pile connection method, thereby improving the economic benefits.

[0004] To achieve the above objectives, the present invention adopts the following technical solutions: A novel pipe pile connection method is provided, comprising: The novel pipe pile connection method is used to connect the top of a prefabricated pipe pile with an upper structure located above the prefabricated pipe pile, wherein the prefabricated pipe pile has an outer diameter of 590 to 610 mm and a wall thickness of 105 to 115 mm; A matching outer sleeve steel pipe is sleeved on the top of the prefabricated pipe pile, the top of the outer sleeve steel pipe extends upward to the bottom surface of the upper structure, a pile connection section is between the top surface of the prefabricated pipe pile and the bottom surface of the upper structure, and the pile connection section is wrapped in the outer sleeve steel pipe; Arrange a steel cage matching the pile hole of the prefabricated pipe pile, the lower part of the steel cage is located in the pile hole of the prefabricated pipe pile, and the upper part of the steel cage penetrates the pile connection section upward and extends into the upper structure. The reinforcement parameter table of the steel cage is as follows: At least three pipe pile top rear-inserted steel bars are arranged on the upper side of the top end plate of the prefabricated pipe pile, the diameter of the pipe pile top rear-inserted steel bars is 24 mm, the material is HRB600, and the bottom of the pipe pile top rear-inserted steel bars is fixedly connected to the tension anchor hole of the top end plate; The tops of the main reinforcement of the steel cage and the steel bars inserted at the top of the pipe piles pass through the upper structure, and anchor heads are provided on the tops of the main reinforcement and the steel bars inserted at the top of the pipe piles, and the anchor heads are pressed tightly against the top surface of the upper structure, and the main reinforcement and the steel bars inserted at the top of the pipe piles are tensioned between the top end plate and the top surface of the upper structure through the anchor heads; The concrete is poured after the supporting formwork to form the pile connection section and the upper structure, wherein the concrete poured to form the pile connection section is non-shrinkage concrete with a strength not less than C50.

[0005] Preferably, six rear-inserted steel bars are provided at the top of the pipe pile and are evenly distributed on the top end plate along the circumferential direction.

[0006] Preferably, the bottom of the rear-inserted steel bars at the top of the pipe pile are connected to the tensioning anchor holes of the top end plate by threaded connection or / and welding; the main bars of the steel cage and the top of the rear-inserted steel bars at the top of the pipe pile are fixedly connected to the corresponding anchor heads by threaded connection or / and welding.

[0007] Preferably, the height of the pile connection section is less than 400 mm.

[0008] Preferably, a temporary steel hoop located at the bottom of the outer jacket steel pipe is sleeved on the prefabricated pipe pile, and the outer jacket steel pipe is supported on the temporary steel hoop.

[0009] Preferably, a rubber strip is provided on the top of the outer jacket steel pipe, and the rubber strip is used to pad the bottom surface of the upper structure.

[0010] Preferably, the inner wall of the outer sleeve steel pipe is welded to the edge of the top end plate.

[0011] The present invention also provides a novel pipe pile connection structure, which comprises an upper structure located above the prefabricated pipe pile, and a pile connection section located between the top surface of the prefabricated pipe pile and the bottom surface of the upper structure; A matching steel cage is arranged in the pile hole of the prefabricated pipe pile, wherein the lower portion of the steel cage is located in the pile hole of the prefabricated pipe pile, and the upper portion of the steel cage passes through the pile connection section upward and extends into the upper structure; A plurality of pipe pile top rear-inserted steel bars are arranged on the upper side of the top end plate of the prefabricated pipe pile, and the bottoms of the pipe pile top rear-inserted steel bars are fixedly connected to the tension anchor holes of the top end plate; The tops of the main reinforcement of the steel cage and the rear-inserted reinforcement of the pipe piles pass through the upper structure, and anchor heads are provided on the tops of the main reinforcement and the rear-inserted reinforcement of the pipe piles. The anchor heads are pressed tightly against the top surface of the upper structure, and the main reinforcement and the rear-inserted reinforcement of the pipe piles are tensioned between the top end plate and the top surface of the upper structure through the anchor heads.

[0012] Preferably, the outer diameter of the prefabricated pipe pile is 590-610 mm, the wall thickness is 105-115 mm, and the reinforcement parameter table of the steel cage is as follows: The pipe pile top back-inserted steel bars are provided with 6 pieces, which are evenly distributed on the top end plate along the circumferential direction. The diameter of the pipe pile top back-inserted steel bars is 24mm, and the material is HRB600; The height of the pile connection section is less than 400 mm, and the concrete cast to form the pile connection section is non-shrinkage concrete with a strength not less than C50.

[0013] Preferably, a matching outer sleeve steel pipe is sleeved on the top of the prefabricated pipe pile, the top end of the outer sleeve steel pipe extends upward to the bottom surface of the upper structure, the pile connecting section is wrapped in the outer sleeve steel pipe, the inner wall of the outer sleeve steel pipe is welded to the edge of the top end plate, and a rubber strip is provided on the top of the outer sleeve steel pipe, which is padded on the bottom surface of the upper structure.

[0014] Compared with the prior art, the beneficial effects of the present invention are as follows: the novel pipe pile connection method arranges a matching steel cage in the pile hole of the precast pipe pile, and arranges a pipe pile top rear inserted steel bar on the upper side of the top end plate of the precast pipe pile, so as to make full use of the tensioning anchor hole structure of the top end plate of the precast pipe pile, and the bending moment requirements of the steel cage can be shared by mechanically connecting the pipe pile top rear inserted steel bar in the tensioning anchor hole, thereby reducing the amount of steel bars used in the steel cage. In the novel pipe pile connection method, since the pipe pile top rear inserted steel bars are distributed at the outer side of the upper pile connection section of the precast pipe pile, a steel cage is arranged in the center of the pile connection section, and the pipe pile top rear inserted steel bars are arranged on the outer side, the entire pile connection section has good bending moment resistance at different radial positions. Compared with the connection method in which only a core-filled steel cage and a core-filled concrete are arranged on the top of the precast pipe pile, the entity diameter that can withstand the bending moment is expanded, and the bending moment resistance improvement effect is significant. It can be seen that the combined use of the steel cage and the pipe pile top rear inserted steel bars significantly reduces the amount of steel bars while ensuring the bending moment resistance of the pipe pile upper structure, and has significant economic benefits. BRIEF DESCRIPTION OF THE DRAWINGS

[0015] The accompanying drawings are used to provide a further understanding of the present invention and constitute a part of the specification. Together with the embodiments of the present invention, they are used to explain the present invention and do not constitute a limitation of the present invention. In the accompanying drawings: Figure 1 It is a structural schematic diagram of a novel pipe pile connection structure implemented according to an embodiment of the novel pipe pile connection method of the present invention.

[0016] Figure 2 This is a schematic diagram of the inner structure of the upper part of the prefabricated pipe pile of a new pipe pile connection structure implemented according to an embodiment of the new pipe pile connection method of the present invention.

[0017] Figure 3It is a schematic structural diagram of the top end plate of the prefabricated pipe pile in one embodiment of the novel pipe pile connection method of the present invention.

[0018] Figure 4 This is an analysis chart of the bending capacity of the pier top sections of several different new pipe pile connection structures constructed according to the new pipe pile connection method of the present invention under simulated E1 and E2 earthquake actions.

[0019] In the figure, the reference numerals indicate: prefabricated pipe pile 1, support plate 11, top end plate 12, tensioning anchor hole 121, main reinforcement anchor hole 122, reinforcement hole 123, upper structure 2, outer jacket steel pipe 3, rubber strip 31, pile connection section 4, steel cage 5, main reinforcement 51, steel bar inserted at the top of pipe pile 6, anchor head 7. DETAILED DESCRIPTION

[0020] 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.

[0021] In one embodiment, a new pipe pile connection method is provided, combining Figure 1 As shown, the novel pipe pile connection method is used to connect the top of the prefabricated pipe pile 1 with the upper structure 2 located above the prefabricated pipe pile 1. The outer diameter of the prefabricated pipe pile 1 is 600 mm and the wall thickness is 110 mm.

[0022] This method mainly studies the pile top connection structure of prefabricated pipe piles of about 600mm. This type of prefabricated pipe piles is widely used in various buildings including highway bridges, and the research is of great significance. In the subsequent reinforcement parameters, reinforcement is carried out according to this type of prefabricated pipe piles to reduce the amount of steel bars used and ensure that the pile top structure meets the requirements of seismic resistance indicators. It can be foreseen that for prefabricated pipe piles with an outer diameter of 590-610mm and a wall thickness of 105-115mm, the reinforcement data in this method can be applied. The upper structure 2 above the prefabricated pipe pile 1 mentioned here can be a cap or a foundation beam. For example, for a bridge structure, the upper structure is used to support the top beam of the bridge.

[0023] In this method, combined Figure 1 As shown, a matching outer steel pipe 3 is sleeved on the top of the prefabricated pipe pile 1, and the top of the outer steel pipe 3 extends upward to the bottom surface of the upper structure 2. Between the top surface of the prefabricated pipe pile 1 and the bottom surface of the upper structure 2 is a pile connection section 4, which is wrapped in the outer steel pipe 3.

[0024] The lower half of the outer jacket steel pipe 3 is sleeved on the top of the prefabricated pipe pile 1, and the upper half is the height of the pile connection section 4. The wall thickness of the outer jacket steel pipe 3 is about 6 mm. By arranging the outer jacket steel pipe 3, on the one hand, it is convenient to cast the pile connection section 4, and on the other hand, it is to enhance the bending strength of the pile connection section 4.

[0025] In this method, combined Figure 1 As shown, a steel cage 5 matching the pile hole of the prefabricated pipe pile 1 is arranged, the lower part of the steel cage 5 is located in the pile hole of the prefabricated pipe pile 1, and the upper part of the steel cage 5 penetrates the pile connection section 4 upward and extends to the upper structure 2. The reinforcement parameter table of the steel cage 5 is as follows: Table 1-Reinforcement parameters of the steel cage in the new pipe pile connection method .

[0026] Combination Figure 2 As shown, a support plate 11 is provided on the upper part of the pile hole of the prefabricated pipe pile 1. The support plate 11 is a round thin steel plate with a thickness of about 4 to 5 mm. The bottom of the steel cage 5 is supported on the support plate 11. The steel cage 5 is used as a skeleton of the concrete poured in the upper part of the pile hole of the prefabricated pipe pile 1, and as a partial skeleton of the pile connection section 4 and the upper structure 2. The reinforcement parameters of the steel cage 5 first consider the requirements of the upper structure of the prefabricated pipe pile 1 for resisting bending moment, and secondly consider the amount of steel bars, and consider the size requirements of the prefabricated pipe pile 1. Under the condition of meeting the construction requirements, the amount of steel bars is reduced and the requirements for resisting bending moment are guaranteed. Specifically, the steel cage 5 uses 8 main bars 51, the diameter of the main bars 51 is 32 mm, the material of the main bars 51 is ‌HRB600, the stirrups are arranged at intervals of 8 cm along the main bars 51, the stirrups are made of ‌HRB400 steel with a diameter of 12 mm, and the main bars 51 are made of materials with stronger yield strength and tensile strength to meet the requirements of the top structure of the prefabricated pipe pile 1 for resisting bending moment.

[0027] In this method, combined Figure 1 As shown, at least three pipe pile top rear-inserted steel bars 6 are arranged on the upper side of the top end plate 12 of the prefabricated pipe pile 1. The diameter of the pipe pile top rear-inserted steel bars 6 is 24 mm, and the material is HRB600. Figure 3 As shown, the bottom of the rear-inserted steel bar 6 at the top of the pipe pile is fixedly connected to the tensioning anchor hole 121 of the top end plate 12.

[0028] The steel bars 6 inserted at the top of the pile and the steel cage 5 installed in front together serve as the skeleton of the pile connection section 4 and the upper structure 2. In this way, the reduction in the bending moment resistance caused by the reduction in the number of main bars in the steel cage 5 is offset, but the bending moment resistance of the top connection structure of the prefabricated pile 1 is generally guaranteed, and the amount of steel bars used is reduced. Figure 3As shown, 18 reinforcement holes 123 are provided on the top end plate 12 of the prefabricated pipe pile 1, each reinforcement hole 123 includes a smaller main reinforcement anchor hole 122 and a larger tension anchor hole 121, the tension anchor hole 121 has an internal thread, the main reinforcement anchor hole 122 and the tension anchor hole 121 are pre-designed structures on the top end plate 12 of the prefabricated pipe pile 1, and the number of main reinforcement anchor holes and tension anchor holes on the top end plates of different prefabricated pipe piles may be different, but the top rear-inserted steel bars 6 of the pipe piles can all be connected through the tension anchor holes. The number of the top rear-inserted steel bars 6 of the pipe piles set on the upper side of the top end plate 12 of the prefabricated pipe pile 1 is set according to the bending resistance requirements. The more the number of the top rear-inserted steel bars 6 of the pipe piles is, the stronger the bending moment resistance capacity of the top connection structure of the prefabricated pipe pile 1 is, but it will lead to an increase in the cost of steel bars.

[0029] In this method, combined Figure 1 As shown, the top of the main reinforcement 51 of the steel cage 5 and the rear-inserted reinforcement 6 of the pipe pile passes through the upper structure 2, and an anchor head 7 is provided on the top of the main reinforcement 51 and the rear-inserted reinforcement 6 of the pipe pile. The anchor head 7 is pressed tightly against the top surface of the upper structure 2, and the main reinforcement 51 and the rear-inserted reinforcement 6 of the pipe pile are tensioned between the top end plate 12 and the top surface of the upper structure 2 through the anchor head 7.

[0030] Here, by providing the anchor head 7, the main reinforcement 51 of the reinforcement cage 5 and the rear-inserted reinforcement 6 at the top of the pipe pile are firmly connected to the upper structure 2, thereby improving the axial pull-out resistance.

[0031] In this method, combined Figure 1 As shown, concrete is poured after the support formwork to form the pile connection section 4 and the upper structure 2, wherein the concrete poured to form the pile connection section 4 is non-shrinkage concrete with a strength not less than C50.

[0032] The pile section 4 and the upper structure 2 are cast after the steel bars are arranged, so that the top of the prefabricated pipe pile 1 is connected to the upper structure 2 through a connecting structure of steel bars and concrete materials. The upper structure 2 is a part of the main structure of a building such as a bridge, and there is also a steel bar structure of the main part of the bridge inside it.

[0033] Based on the above embodiments, it can be known that in the novel pipe pile connection method, since the rear-inserted steel bars at the top of the pipe pile are distributed on the outer side of the upper pile connection section of the prefabricated pipe pile, a steel cage is arranged in the center of the pile connection section, and the rear-inserted steel bars at the top of the pipe pile are arranged on the outer side. The entire pile connection section has good moment resistance at different radial positions. Compared with the connection method in which only a core-filled steel cage and core-filled concrete are arranged on the top of the prefabricated pipe pile, the entity diameter that can withstand the moment is expanded, and the moment resistance improvement effect is significant.

[0034] The novel pipe pile connection method arranges a matching steel cage 5 in the pile hole of the prefabricated pipe pile 1, and sets a pipe pile top back-inserted steel bar 6 on the upper side of the top end plate 12 of the prefabricated pipe pile 1. By anchoring the main reinforcement 51 of the steel cage 5 and the top of the pipe pile top back-inserted steel bar 6 through the anchor head 7, the bending moment resistance of the top structure of the prefabricated pipe pile 1 can be guaranteed. In addition, since the pipe pile top back-inserted steel bar 6 is set on the upper side of the top end plate 12 of the prefabricated pipe pile 1, the amount of steel bars used in the steel cage 5 can be reduced. For bridge construction, since a large number of bridge piers need to be arranged, each bridge pier corresponds to a pile, so the amount of steel bars used in the bridge piers is greatly reduced in total, and the cost saving effect is significant. It should be noted that in the novel pipe pile connection method, the concrete material used in the pile connection section 4 is also related to the bending moment resistance. In this method, the pile connection section 4 is cast with non-shrinkage concrete with a strength not less than C50. After analysis, the concrete of this strength combined with the steel mesh in this embodiment can ensure the bending resistance.

[0035] Furthermore, in another embodiment, in the novel pipe pile connection method, six pipe pile top rear-inserted steel bars 6 are provided, which are evenly distributed circumferentially on the top end plate 12. After analysis, it is found that the provision of six pipe pile top rear-inserted steel bars 6 can better control the amount of steel bars while ensuring the moment resistance capacity of the upper connection structure of the prefabricated pipe pile.

[0036] Furthermore, in another embodiment, the bottom of the post-insertion steel bar 6 at the top of the pipe pile in the novel pipe pile connection method is connected to the tension anchor hole of the top end plate 12 by threaded connection, and the main bar 51 of the steel cage 5 and the top of the post-insertion steel bar 6 at the top of the pipe pile are fixedly connected to the corresponding anchor head 7 by threaded connection. In other embodiments, the bottom of the post-insertion steel bar at the top of the pipe pile can also be connected to the tension anchor hole of the top end plate by welding, or by threaded connection and welding. The main bar of the steel cage and the top of the post-insertion steel bar at the top of the pipe pile can be fixedly connected to the corresponding anchor head by welding, or by threaded connection and welding.

[0037] Furthermore, in another embodiment, in the novel pipe pile connection method, the height of the pile connection section 4 is less than 400 mm, and the height of the pile connection section 4 cannot be too high so as not to affect the moment resistance capacity.

[0038] Furthermore, in another embodiment, in the novel pipe pile connection method, a temporary steel hoop 32 located at the bottom of the outer steel pipe 3 is sleeved on the prefabricated pipe pile 1, and the outer steel pipe 3 is supported on the temporary steel hoop 32. The outer steel pipe 3 is supported by the temporary steel hoop 32 to prevent the outer steel pipe 3 from falling from the top of the prefabricated pipe pile 1.

[0039] Furthermore, in another embodiment, in the novel pipe pile connection method, a rubber strip 31 is provided at the top of the outer sleeve steel pipe 3, and the lower part of the rubber strip 31 has a groove which is sleeved on the top of the outer sleeve steel pipe 3. The rubber strip 31 is padded on the bottom surface of the upper structure 2, thereby preventing the top of the outer sleeve steel pipe 3 from making hard contact with the bottom surface of the upper structure 2 and affecting the moment resistance capacity of the top cross section of the pile connection section 4.

[0040] Furthermore, in another embodiment, in the new pipe pile connection method, the inner wall of the outer sleeve steel pipe 3 is welded to the edge of the top end plate 12, and a circle of fillet welds is welded between the inner wall of the outer sleeve steel pipe 3 and the edge of the top end plate 12 to fix the outer sleeve steel pipe 3.

[0041] In one embodiment, a new pipe pile connection structure is provided, such as Figure 1 As shown, the novel pipe pile connection structure includes an upper structure 2 located above the prefabricated pipe pile 1, and a pile connection section 4 located between the top surface of the prefabricated pipe pile 1 and the bottom surface of the upper structure 2. Both the upper structure 2 and the pile connection section 4 are concrete reinforced structures, wherein a matching steel cage 5 is arranged in the pile hole of the prefabricated pipe pile 1, the lower part of the steel cage 5 is located in the pile hole of the prefabricated pipe pile 1, and the upper part of the steel cage 5 penetrates the pile connection section 4 upward and extends into the upper structure 2. In this embodiment, the size and reinforcement method of the steel cage 5 are suitable for prefabricated pipe piles with an outer diameter of 590-610 mm and a wall thickness of 105-115 mm. The reinforcement parameter table of the steel cage 5 is as follows: Table 2-Reinforcement parameters of the steel cage in the new pipe pile connection structure .

[0042] Six pipe pile top rear-inserted steel bars 6 are arranged on the upper side of the top end plate 12 of the prefabricated pipe pile, and the bottom of the pipe pile top rear-inserted steel bars 6 is fixedly connected to the tension anchor hole 121 of the top end plate 12. Figure 3 As shown, 18 reinforcement holes 123 are provided on the top end plate 12 of the prefabricated pipe pile 1, each reinforcement hole 123 includes a smaller main reinforcement anchor hole 122 and a larger tension anchor hole 121, the tension anchor hole 121 has an internal thread, the main reinforcement anchor hole 122 and the tension anchor hole 121 are pre-designed structures on the top end plate 12 of the prefabricated pipe pile 1, and the number of main reinforcement anchor holes and tension anchor holes on the top end plates of different prefabricated pipe piles may be different, but the top rear inserted steel bars 6 of the pipe piles can all be connected through the tension anchor holes. The number of the top rear inserted steel bars 6 of the pipe piles arranged on the upper side of the top end plate 12 of the prefabricated pipe pile 1 is set according to the bending resistance requirements. The more the number of the top rear inserted steel bars 6 of the pipe piles is, the stronger the bending moment resistance capacity of the top connection structure of the prefabricated pipe pile 1 is, but it will lead to an increase in the cost of steel bars. In this embodiment, 6 top rear inserted steel bars 6 of the pipe piles are arranged to better control the amount of steel bars while ensuring the bending moment resistance capacity of the upper connection structure of the prefabricated pipe pile.

[0043] The pipe pile top back-inserted steel bars 6 are evenly distributed on the top end plate 12 along the circumferential direction. The diameter of the pipe pile top back-inserted steel bars 6 is 24 mm and the material is HRB600. The main bars 51 of the steel cage 5 and the top of the pipe pile top back-inserted steel bars 6 pass through the upper structure 2 and anchor heads 7 are provided on the top of the main bars 51 and the top of the pipe pile top back-inserted steel bars 6. The anchor heads 7 are pressed tightly against the top surface of the upper structure 2. The main bars 51 and the pipe pile top back-inserted steel bars 6 are tensioned between the top end plate 12 and the top surface of the upper structure 2 through the anchor heads 7. By providing the anchor heads 7, the main bars 51 of the steel cage 5 and the pipe pile top back-inserted steel bars 6 are firmly connected to the upper structure 2, which can improve the axial pull-out resistance.

[0044] In this embodiment, the height of the pile connection section 4 is less than 400 mm, and the concrete cast to form the pile connection section is non-shrinkage concrete with a strength not lower than C50. The height of the pile connection section 4 cannot be too high so as not to affect the bending moment resistance. The concrete used in the pile connection section 4 is non-shrinkage concrete with a strength not lower than C50. After analysis, concrete of this strength combined with the steel mesh in this embodiment can ensure the bending resistance.

[0045] In this embodiment, a matching outer jacket steel pipe 3 is sleeved on the top of the prefabricated pipe pile 1, and the top of the outer jacket steel pipe 3 extends upward to the bottom surface of the upper structure 2. The pile connection section 4 is wrapped in the outer jacket steel pipe 3. The lower half of the outer jacket steel pipe 3 is sleeved on the top of the prefabricated pipe pile 1, and the upper half is the height of the pile connection section 4. The wall thickness of the outer jacket steel pipe 3 is about 6mm. By arranging the outer jacket steel pipe 3, on the one hand, it is convenient to cast the pile connection section 4, and on the other hand, it is to enhance the bending strength of the pile connection section 4. A rubber strip 31 is provided on the top of the outer jacket steel pipe 3, and the lower part of the rubber strip 31 has a groove sleeved on the top of the outer jacket steel pipe 3. The rubber strip 31 is cushioned on the bottom surface of the upper structure 2, so as to avoid the top of the outer jacket steel pipe 3 from hard contact with the bottom surface of the upper structure 2, which affects the bending moment resistance of the top cross section of the pile connection section 4. The inner wall of the outer sleeve steel pipe 3 is welded to the edge of the top end plate 12 . Specifically, a circle of fillet weld is welded between the inner wall of the outer sleeve steel pipe 3 and the edge of the top end plate 12 , so as to fix the outer sleeve steel pipe 3 .

[0046] By understanding the structure of the end plate of the pipe pile, the novel pipe pile connection structure makes full use of the tensioning anchor hole 121 at the top end plate 12 of the prefabricated pipe pile 1, and mechanically connects the pipe pile top rear inserted steel bar 6 with the tensioning anchor hole 121, so that the pull-out resistance of the pipe pile top rear inserted steel bar 6 meets the requirements of the specification. Combined with the use of the steel cage 5, the connection stiffness of the prefabricated pipe pile 1 and its upper structure 2 can be effectively increased, and the bending moment resistance capacity of the novel pipe pile connection structure is ensured, while saving the amount of steel bars, with obvious economic benefits.

[0047] In order to evaluate the application effect of the new pipe pile connection method, the seismic resistance of several different types of new pipe pile connection structures constructed by this method was analyzed as follows: (1) Analysis object This new pipe pile connection method is applied to the sheet pile structure. In accordance with the requirements of "Code for Seismic Design of Highway Bridges" (JTG / T2231-01-2020) (hereinafter referred to as "seismic code"), the seismic analysis of the pile-sheet structure (the connection between the pile and the sheet, the pier height is 5.2m, which is the most unfavorable structural arrangement for seismic resistance of the entire line) is carried out through finite element software, in order to optimize the reinforcement design of the pile-sheet connection of the pile-sheet structure.

[0048] The pile-sheet structure adopts E1 elasticity and E2 elasticity as the seismic fortification targets. Therefore, when the new pipe pile connection method is applied to the sheet pile structure, it is necessary to ensure that the cross-section of the new pipe pile connection structure constructed by the new pipe pile connection method can still maintain an elastic state under the action of E2 earthquake, so as to reduce the work of post-earthquake maintenance and reinforcement.

[0049] E1 elasticity means that the pipe pile connection structure can still be in an elastic state under the action of E1 earthquake, and E2 elasticity means that the pipe pile connection structure can still be in an elastic state under the action of E2 earthquake. If the structure can maintain an elastic state under the action of earthquake and does not enter the deformation stage, it will not be damaged or collapsed. ‌E2 earthquake action is an earthquake action with a longer recurrence period, and its destructive power is greater than that of E1 earthquake action. Therefore, this article mainly analyzes whether the cross-section of the new pipe pile connection structure constructed by the new pipe pile connection method can still maintain an elastic state under the action of E2 earthquake. Here, the seismic resistance of the pipe pile connection structure with the following four reinforcement modes is analyzed and verified: Table 3 - Reinforcement parameters of four different new pipe pile connection structures constructed by the new pipe pile connection method The four different reinforcement patterns in the table above are of types A, B, C, and D. The difference between the pipe pile connection structures of these four different reinforcement patterns is the number of steel bars inserted behind the top of the pipe pile, which are 3, 4, 5, and 6. The seismic analysis of the pipe pile connection structures of these four different reinforcement patterns is carried out by finite element analysis software. Figure 4 As shown in the figure, when simulating earthquake action, through calculation and analysis under E1 and E2 earthquake actions, under the four cross-section reinforcement modes in the table above, the key cross-section at the connection can maintain elasticity in both the longitudinal and transverse directions under E1 earthquake, meeting the defense requirements. The cross-section yield moment of the key cross-section at the connection under E2 earthquake action in both the longitudinal and transverse directions can reach a certain proportion of the elastic calculation moment, among which the minimum proportion of reinforcement A is 80%, the minimum proportion of reinforcement B is 82%, the minimum proportion of reinforcement C is 85%, and the minimum proportion of reinforcement D is 90%.

[0050] In the above simulated seismic analysis of the pipe-pile connection structure corresponding to the four different reinforcement patterns A, B, C, and D, the bending moment analysis is performed on the pier top section, which is the junction of the top surface of the pile section 4 and the bottom surface of the upper structure 2. This is mainly because the pier top section is the most unfavorable position for seismic resistance in the overall structure.

[0051] In the above analysis, the elastic calculated bending moment is the theoretical bending moment for resisting earthquake action at different earthquake action levels. The elastic calculated bending moment has a design margin. The section yield bending moment is the actual moment resistance capacity of the pipe-pile connection structure with different reinforcement modes when subjected to simulated earthquake action. Considering that the calculated bending moment at the pier top can be reduced to 85%, it is recommended to adopt the D type reinforcement mode, that is, all pile-slab connections (except the junction pier) use 8 32mm diameter HRB600 main bars and 8cm spacing 12mm diameter HRB400 stirrups + 6 25mm diameter HRB600 steel bars connected at the top of the pipe pile. This can ensure that the section of the pile-slab connection remains elastic under E2 earthquake.

[0052] In order to evaluate the application benefits of this new pipe pile connection method, the following analysis is made on the steel bar usage of the pipe pile connection structure corresponding to the previous D reinforcement type and the steel bar usage of another pipe pile connection structure with a reinforcement structure that meets the seismic requirements: In another comparative example of a pipe pile connection structure with a reinforcement structure that meets seismic requirements, the reinforcement parameter table is as follows: Table 4-Reinforcement parameters of pipe pile connection structures with reinforcement structures that meet seismic requirements In this comparative example, a steel cage is set on the upper part of the pile hole of the prefabricated pipe pile, and no steel bars are set on the upper side of the top end plate of the prefabricated pipe pile. Therefore, this reinforcement mode has higher bending moment requirements for the steel cage. In this comparative example, the designed steel cage uses 16 HRB600 main bars with a diameter of 32mm + HRB400 stirrups with a diameter of 12mm and a spacing of 10cm, and the steel consumption is 332.49kg. In the pipe pile connection structure corresponding to the above D reinforcement type, 8 HRB600 main bars with a diameter of 32mm and a spacing of 8cm are used. The steel cage with 12mm diameter HRB400 stirrups + the top of the pipe pile is connected with 6 25mm diameter HRB600 steel bars. The steel consumption is 221.81kg. Compared with the control example, the D reinforcement type saves 110.68kg of steel bars, reducing the steel consumption by 67% of the original design. Obviously, compared with the control example, the D reinforcement type after the previous optimization and adjustment significantly reduces the cost of using steel bars while meeting the seismic requirements. For the above pile-slab structure project, a total of 880t of steel bars are saved, effectively saving 7.18 million yuan.

[0053] It should be noted that, in this article, terms such as "comprises", "includes" or any other variations thereof are intended to cover non-exclusive inclusion, so that a process, method, article or apparatus that includes a series of elements includes not only those elements, but also other elements not explicitly listed, or also includes elements inherent to such process, method, article or apparatus.

[0054] Although embodiments of the present invention have been shown and described, it will be appreciated by those skilled in the art that various changes, modifications, substitutions and variations may be made to the embodiments without departing from the principles and spirit of the present invention, and that the scope of the present invention is defined by the appended claims and their equivalents.

Claims

1. A new pipe pile connection method, characterized in that: include: The novel pipe pile connection method is used to connect the top of a prefabricated pipe pile with an upper structure located above the prefabricated pipe pile, wherein the prefabricated pipe pile has an outer diameter of 590 to 610 mm and a wall thickness of 105 to 115 mm; A matching outer sleeve steel pipe is sleeved on the top of the prefabricated pipe pile, the top of the outer sleeve steel pipe extends upward to the bottom surface of the upper structure, a pile connection section is between the top surface of the prefabricated pipe pile and the bottom surface of the upper structure, and the pile connection section is wrapped in the outer sleeve steel pipe; Arrange a steel cage matching the pile hole of the prefabricated pipe pile, the lower part of the steel cage is located in the pile hole of the prefabricated pipe pile, and the upper part of the steel cage penetrates the pile connection section upward and extends into the upper structure. The reinforcement parameter table of the steel cage is as follows: At least three pipe pile top rear-inserted steel bars are arranged on the upper side of the top end plate of the prefabricated pipe pile, the diameter of the pipe pile top rear-inserted steel bars is 24 mm, the material is HRB600, and the bottom of the pipe pile top rear-inserted steel bars is fixedly connected to the tension anchor hole of the top end plate; The tops of the main reinforcement of the steel cage and the steel bars inserted at the top of the pipe piles pass through the upper structure, and anchor heads are provided on the tops of the main reinforcement and the steel bars inserted at the top of the pipe piles, and the anchor heads are pressed tightly against the top surface of the upper structure, and the main reinforcement and the steel bars inserted at the top of the pipe piles are tensioned between the top end plate and the top surface of the upper structure through the anchor heads; The concrete is poured after the supporting formwork to form the pile connection section and the upper structure, wherein the concrete poured to form the pile connection section is non-shrinkage concrete with a strength not less than C50.

2. The novel pipe pile connection method according to claim 1 is characterized in that: The top of the pipe pile is provided with 6 rear inserted steel bars, which are evenly distributed on the top end plate along the circumferential direction.

3. The novel pipe pile connection method according to claim 1 is characterized in that: The bottom of the rear-inserted steel bars at the top of the pipe pile is connected to the tensioning anchor hole of the top end plate by threaded connection or / and welding; the main bars of the steel cage and the top of the rear-inserted steel bars at the top of the pipe pile are fixedly connected to the corresponding anchor heads by threaded connection or / and welding.

4. The novel pipe pile connection method according to claim 1 is characterized in that: The height of the pile connection section is less than 400 mm.

5. The novel pipe pile connection method according to claim 1 is characterized in that: A temporary steel hoop located at the bottom of the outer jacket steel pipe is sleeved on the prefabricated pipe pile, and the outer jacket steel pipe is supported on the temporary steel hoop.

6. The novel pipe pile connection method according to claim 3 is characterized in that: A rubber strip is arranged on the top of the outer jacket steel pipe, and the rubber strip is used to pad the bottom surface of the upper structure.

7. The novel pipe pile connection method according to claim 1 is characterized in that: The inner wall of the outer sleeve steel pipe is welded to the edge of the top end plate.

8. A new type of pipe pile connection structure, characterized in that: The novel pipe pile connection structure comprises an upper structure located above the prefabricated pipe pile, and a pile connection section located between the top surface of the prefabricated pipe pile and the bottom surface of the upper structure; A matching steel cage is arranged in the pile hole of the prefabricated pipe pile, wherein the lower portion of the steel cage is located in the pile hole of the prefabricated pipe pile, and the upper portion of the steel cage passes through the pile connection section upward and extends into the upper structure; A plurality of pipe pile top rear-inserted steel bars are arranged on the upper side of the top end plate of the prefabricated pipe pile, and the bottoms of the pipe pile top rear-inserted steel bars are fixedly connected to the tension anchor holes of the top end plate; The tops of the main reinforcement of the steel cage and the rear-inserted reinforcement of the pipe piles pass through the upper structure, and anchor heads are provided on the tops of the main reinforcement and the rear-inserted reinforcement of the pipe piles. The anchor heads are pressed tightly against the top surface of the upper structure, and the main reinforcement and the rear-inserted reinforcement of the pipe piles are tensioned between the top end plate and the top surface of the upper structure through the anchor heads.

9. The novel pipe pile connection structure according to claim 8 is characterized in that: The outer diameter of the prefabricated pipe pile is 590-610 mm, the wall thickness is 105-115 mm, and the reinforcement parameter table of the steel cage is as follows: The pipe pile top back-inserted steel bars are provided with 6 pieces, which are evenly distributed on the top end plate along the circumferential direction. The diameter of the pipe pile top back-inserted steel bars is 24mm, and the material is HRB600; The height of the pile connection section is less than 400 mm, and the concrete cast to form the pile connection section is non-shrinkage concrete with a strength not less than C50.

10. The novel pipe pile connection structure according to claim 9 is characterized in that: An outer sleeve steel pipe matching the prefabricated pipe pile is sleeved on the top of the outer sleeve steel pipe, the top end of the outer sleeve steel pipe extends upward to the bottom surface of the upper structure, the pile connecting section is wrapped in the outer sleeve steel pipe, the inner wall of the outer sleeve steel pipe is welded to the edge of the top end plate, and a rubber strip is provided on the top of the outer sleeve steel pipe, which is padded on the bottom surface of the upper structure.

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