A method for constructing an h-pile

Abstract

The application discloses a h-shaped pile construction method and relates to the field of civil engineering or geotechnical engineering, and comprises the following steps: short piles in the front row are constructed normally, a plurality of first cross beam connecting steels are reserved on the top of the piles, and the end of the plurality of first cross beam connecting steels extends out of the short piles in the front row; a rear row pile hole is constructed, a steel protection wall with holes is arranged on the cross beam section, and a plurality of reserved holes are arranged on one side of the steel protection wall with holes; a plurality of second cross beam connecting steels are arranged in the steel protection wall with holes and extend out of the reserved holes; a steel reinforcement cage is arranged at the rear row pile hole, the plurality of second cross beam connecting steels and pile main steels are connected, and pile body concrete is poured; a cross beam foundation pit is excavated, cross beam main steels and cross beam connecting steels are overlapped and bound, and then cross beam concrete is poured; and finally, the foundation pit is backfilled. The single-side steel protection wall with holes is arranged in the rear row pile hole, the embedded steel is connected with the rear row pile main steel, the embedded steel is effectively connected with the cross beam main steel after the embedded steel is exposed by the cross beam foundation pit excavation, and the cross beam concrete is cast in situ, so that the rigid effective connection between the cross beam and the rear row pile is realized.

Description

Technical Field

[0001] This invention relates to the field of civil engineering or geotechnical engineering, and specifically to a method for constructing H-type piles. Background Technology

[0002] H-type piles are planar rigid frame structures. When used for anti-slip purposes, they are generally embedded, meaning the tops of the front and rear piles are located above ground. In this arrangement, the crossbeam is a transversely embedded structure. The construction methods for the front and rear piles of H-type piles can be similar to those for ordinary anti-slip piles, using manual or mechanical drilling, followed by the placement of the reinforcing cage and the casting of concrete. However, the rapid and efficient construction of the crossbeam has always been a challenge. To fully utilize the overall rigidity of the H-type pile, it is essential to ensure that the crossbeam forms a rigid joint with the front and rear piles. Traditional rebar installation methods suffer from unavoidable damage to the main reinforcing bars of the pile (drilling for rebar installation may break the main reinforcing bars), low strength, high technical requirements for construction personnel, and poor quality control. These problems are particularly pronounced when the crossbeam is haunched. Furthermore, rebar installation is time-consuming, which is detrimental to the stability of the crossbeam foundation pit. Therefore, it is necessary to research and propose a safe and efficient construction method for H-type piles. Summary of the Invention

[0003] To address the shortcomings of existing technologies, this invention aims to provide a construction method for H-type piles. This method involves installing a single-sided perforated steel retaining wall inside the pile hole of the rear pile, connecting pre-embedded reinforcing bars with the main reinforcing bars of the rear pile, excavating the foundation pit of the crossbeam to expose the pre-embedded reinforcing bars, effectively connecting them with the main reinforcing bars of the crossbeam, and then casting concrete in place, thereby achieving a rigid and effective connection between the crossbeam and the rear pile.

[0004] This invention is achieved through the following technical solution:

[0005] A method for constructing H-type piles includes the following steps:

[0006] S1: The front row of short piles is constructed normally, and several first crossbeam connecting steel bars are reserved at the top of the piles. The ends of several first crossbeam connecting steel bars extend out of the front row of short piles and extend towards the rear row of long piles.

[0007] S2: After construction, the pile holes are divided into three sections: the lower section of the beam, the crossbeam section, and the cantilever section. The crossbeam section is equipped with a perforated steel retaining wall, and the side of the perforated steel retaining wall facing the direction of the front row of short piles has several reserved holes.

[0008] S3: Several second crossbeam connecting steel bars are installed inside the perforated steel retaining wall and extend out of the reserved hole;

[0009] S4: Place a steel cage at the rear pile hole, connect several second crossbeam connecting steel bars and pile main reinforcement, and pour pile body concrete.

[0010] S5: Excavate the foundation pit for the crossbeam, lower the main reinforcement bars of the crossbeam, and lap and tie the front and rear ends of the main reinforcement bars of the crossbeam to the connecting reinforcement bars of the first crossbeam and the connecting reinforcement bars of the second crossbeam respectively, and then weld them. After that, pour the concrete for the crossbeam.

[0011] S6: Finally, backfill the foundation pit.

[0012] Compared to existing technologies, to fully utilize the overall rigidity of H-type piles, it is essential to ensure that the crossbeam forms a rigid joint with the front and rear piles. Traditional rebar installation methods suffer from unavoidable damage to the main reinforcement bars of the pile (drilling for rebar installation may break the main reinforcement bars), low strength, high technical requirements for construction personnel, and poor quality control. This invention provides an H-type pile construction method that uses a single-sided perforated steel retaining wall installed in the pile hole of the rear pile. The pre-embedded steel bars are connected to the main reinforcement bars of the rear pile. After the pre-embedded steel bars are exposed in the excavation of the crossbeam foundation pit, they are effectively connected to the main reinforcement bars of the crossbeam and then cast-in-place concrete, achieving a rigid and effective connection between the crossbeam and the rear pile. In the specific scheme, a perforated steel retaining wall is set in the crossbeam section at the rear pile hole, which facilitates the extension of several second crossbeam connecting steel bars from the reserved holes. One end of the steel retaining wall is located inside the perforated steel retaining wall and connected to the main pile reinforcement, while the other end extends into the soil. When excavating the crossbeam foundation pit, the first and second crossbeam connecting steel bars at both ends of the crossbeam are manually excavated using small tools. After exposing all the embedded steel bars, the soil on the steel bars is cleaned, dried, and rusted. The perforated steel retaining wall at the end of the crossbeam is cut and the pile concrete is roughened. Then, the front and rear ends of the main reinforcement of the crossbeam can be lapped and tied to the first and second crossbeam connecting steel bars, respectively, and welded. Then, the crossbeam concrete can be poured. At this time, the extended second crossbeam connecting steel bars achieve a rigid and effective connection between the crossbeam and the rear pile, which greatly improves the construction efficiency and avoids damage to the main pile reinforcement.

[0013] A further proposed solution involves pushing the ends of the second crossbeam connecting reinforcing bars out of the perforated steel retaining wall. Step S3 further includes the following steps: A lifting device is installed inside the perforated steel retaining wall. The output end of the lifting device has a tray. Several ends of the second crossbeam connecting reinforcing bars are connected to the tray. By driving the lifting device, several second crossbeam connecting reinforcing bars are pushed into the soil on one side of the perforated steel retaining wall. In this solution, the second crossbeam connecting reinforcing bars are positioned by the tray, and the lifting device can push them out, facilitating the connection between the protruding parts of the second crossbeam connecting reinforcing bars and the main reinforcing bars of the crossbeam. Additionally, most of the second crossbeam connecting reinforcing bars can be pushed out, facilitating the installation of the reinforcing cage. After the reinforcing cage is installed, a certain length of the second crossbeam connecting reinforcing bars is pulled back, thus leaving sufficient connection length between the L-shaped reinforcing bars and the second crossbeam connecting reinforcing bars.

[0014] In a further improvement, the lifting device is a jack.

[0015] A further proposed solution involves installing a positioning tray when setting up the jack inside the perforated steel retaining wall. The tray has several rebar holes for placing the connecting rebar of the second crossbeam. The rebar holes and the reserved holes are aligned horizontally and vertically, and then the connecting rebar of the second crossbeam is placed. The jack base is placed on the mountain-side of the perforated steel retaining wall, and the reaction force provided by the mountain-side of the perforated steel retaining wall is used to push the connecting rebar of the second crossbeam horizontally into the overburden soil.

[0016] In a further step, to achieve a rigid connection between the second crossbeam connecting reinforcement and the main pile reinforcement, step S4 further includes the following steps: after lowering the reinforcement cage at the rear pile hole, several L-shaped reinforcements are placed inside the perforated steel retaining wall, one side of the L-shaped reinforcement is connected to the main pile reinforcement, and the other side of the L-shaped reinforcement is connected to the end of the second crossbeam connecting reinforcement.

[0017] In a further embodiment, the other side of the L-shaped steel bar and the end of the connecting steel bar of the second crossbeam are welded together. When welding on both sides, the lap length should not be less than 5d, and when welding on one side, the lap length should not be less than 10d; where d is the diameter of the connecting steel bar of the second crossbeam.

[0018] In a further step, to ensure sufficient connection length with the L-shaped reinforcing bars, step S4 also includes the following steps: after placing several L-shaped reinforcing bars inside the perforated steel retaining wall, several of the second crossbeam connecting reinforcing bars need to be pulled back and removed according to the connection length between the L-shaped reinforcing bars and the second crossbeam connecting reinforcing bars.

[0019] In a further embodiment, step S5, the excavation of the crossbeam foundation pit also includes the following steps:

[0020] Excavate the crossbeam foundation pit in an inverted trapezoidal or rectangular shape. Horizontal steel pipes are erected at the bottom of the crossbeam to support the front and rear piles. At the first and second crossbeam connecting steel bars at both ends of the crossbeam, small tools are used to manually excavate to expose all the pre-embedded steel bars. After the steel bars are cleaned of soil, air-dried and derusted, the perforated steel retaining wall at the end of the crossbeam is cut and the concrete of the pile body is roughened.

[0021] A further proposed solution is to install a row of temporary steel columns on both sides of the beam foundation pit when the overburden layer has poor stability. These columns extend into the soil for temporary support. After the temporary support is installed, the beam foundation pit is excavated in a rectangular shape. The support width does not exceed the width of the pile.

[0022] In a further embodiment, step S5, before pouring the concrete for the crossbeam, includes the following steps:

[0023] The first and second beam connecting steel bars were manually excavated using small tools, and then cleaned and rusted. The first and second beam connecting steel bars within the haunch height range were then bent at the angle required by the design. After installing the bottom formwork with the haunch, the beam concrete was poured.

[0024] Compared with the prior art, the present invention has the following advantages and beneficial effects:

[0025] 1. This invention provides a construction method for H-type piles, which involves setting a single-sided perforated steel retaining wall inside the pile hole of the rear pile, connecting the pre-embedded steel bars with the main reinforcement of the rear pile, and effectively connecting the pre-embedded steel bars with the main reinforcement of the cross beam after the excavation of the cross beam foundation pit, and then casting concrete in place to achieve a rigid and effective connection between the cross beam and the rear pile.

[0026] 2. This invention provides a construction method for H-shaped piles, solving the problems of long construction cycles and unstable joint connections in conventional rebar anchoring methods, and ensuring controllable construction quality. Through the connection of pre-embedded rebars and L-shaped rebars, the main reinforcement of the crossbeam and the main reinforcement of the pile body are fully overlapped and anchored, ensuring a rigid connection between the crossbeam and the piles before and after. Attached Figure Description

[0027] To more clearly illustrate the technical solutions of the exemplary embodiments of the present invention, the accompanying drawings used in the embodiments will be briefly described below. It should be understood that the following drawings only show some embodiments of the present invention and should not be considered as a limitation of the scope. For those skilled in the art, other related drawings can be obtained based on these drawings without creative effort. In the drawings:

[0028] Figure 1 This is a schematic diagram of the structure of the reserved reinforcing steel bars according to one embodiment of the present invention;

[0029] Figure 2 A cross-sectional view of an h-type pile according to an embodiment of the present invention;

[0030] Figure 3 An isometric view of a perforated steel retaining wall according to an embodiment of the present invention;

[0031] Figure 4 This is a schematic diagram of the structure for jacking up the second crossbeam connecting steel bars according to an embodiment of the present invention;

[0032] Figure 5 This is a schematic diagram of an L-shaped steel bar connection according to an embodiment of the present invention;

[0033] Figure 6 This is a schematic diagram of the construction of a beam with a haunch, according to an embodiment of the present invention.

[0034] Figure 7 This is a schematic diagram of an inverted trapezoidal excavation and a rectangular excavation according to an embodiment of the present invention.

[0035] The attached diagram shows the markings and corresponding component names:

[0036] 1-Short piles in the front row, 2-First crossbeam connecting reinforcement, 3-Long piles in the rear row, 4-Steel retaining wall with holes, 5-Second crossbeam connecting reinforcement, 6-Lifting device, 7-Platform, 8-L-shaped reinforcement, 9-Pile main reinforcement, 10-Bottom formwork, 11-Crossbeam main reinforcement, 12-Reserved hole, 13-Temporary steel column. Detailed Implementation

[0037] To make the objectives, technical solutions, and advantages of the present invention clearer, the present invention will be further described in detail below with reference to the embodiments and accompanying drawings. The illustrative embodiments and descriptions of the present invention are only used to explain the present invention and are not intended to limit the present invention.

[0038] Example:

[0039] This embodiment provides a method for constructing H-type piles, such as... Figures 1-7 As shown, the specific steps include the following:

[0040] The overall construction sequence is as follows: front pile (with slotted grooves for pre-reserved crossbeam connecting steel bars) - rear pile - crossbeam.

[0041] (1) Construction of the first row of short piles 1: The pile body is constructed according to the normal procedure, and several first crossbeam connecting steel bars 2 are reserved at the top of the pile, such as Figure 1 As shown.

[0042] (2) Construction of the rear row of long piles 3: The pile holes of the rear piles are divided into three sections for retaining walls: the lower section of the beam, the crossbeam section, and the cantilever section. The crossbeam section adopts a single-sided perforated steel retaining wall, that is, a perforated steel retaining wall 4 is set in the crossbeam section, with several reserved holes on one side. The cantilever section selects a suitable retaining wall method according to the excavation method (manual or mechanical). After the hole is formed, the pre-embedded steel bars of the second crossbeam are pushed in (the pre-embedded steel bars of the second crossbeam are straight bars, and the steel bars protrude about 45cm from the perforated steel retaining wall). Then the pile reinforcement cage is lowered. Since the pre-embedded steel bars of the second crossbeam need to leave a connection length with the L-shaped steel bars, the pre-embedded steel bars of the second crossbeam need to be pulled out by no less than 10d (d is the diameter of the second pre-embedded steel bars). Finally, the L-shaped steel bars are connected to the main reinforcement 9 of the pile and the pre-embedded steel bars, and the pile body concrete is poured.

[0043] (3) Processing of steel retaining wall with holes: The steel retaining wall is processed in the factory. The side of the retaining wall beam is provided with pre-embedded bar positioning holes (drilling). The hole diameter should be the diameter of the pre-embedded bar + 2mm.

[0044] (4) Construction of embedded reinforcement: Position the jack tray 7, align the reinforcement holes of tray 7 with the reinforcement holes of the steel retaining wall horizontally and vertically, place the embedded reinforcement of the second crossbeam, and place the jack (4) bases on the mountain side (back side) of the perforated steel retaining wall 4. Rely on the reaction force provided by the back side steel retaining wall to push the embedded reinforcement horizontally into the overburden soil (the reinforcement protrudes about 5cm).

[0045] (5) Lowering the pile body reinforcement cage: The reinforcement cage is lifted into the pile hole by a crane. During the lowering process, it is necessary to avoid hooking the second pre-embedded crossbeam reinforcement.

[0046] (6) Connection between the embedded steel bars and the main reinforcement bars 9 of the pile: The steelworker carries the "L"-shaped steel bars down to the position of the embedded steel bars, connects one end of the "L"-shaped steel bars to the embedded steel bars, and connects the other end to the main reinforcement bars on the back side of the pile reinforcement cage. The "L"-shaped steel bars and the embedded steel bars can be welded together, and the lap length meets the requirements of the specifications (double-sided welding should not be less than 5d, and single-sided welding should not be less than 10d). The section of the embedded steel bars that has been pulled out should be cleaned and dried before welding to ensure that the welding is firm.

[0047] (7) The concrete of the pile body after the cast-in-place method.

[0048] (8) Construction of the crossbeam. The crossbeam foundation pit is excavated in an inverted trapezoidal or rectangular shape. Horizontal steel pipe supports are erected at the bottom of the crossbeam to support the front and rear piles. The first crossbeam connecting steel bar 2 and the second crossbeam connecting steel bar 5 at both ends of the crossbeam are excavated manually with small tools to expose all the pre-embedded steel bars. The steel bars are then cleaned of soil, air-dried and derusted. The perforated steel retaining wall 4 at the end face of the crossbeam is cut and the pile body concrete is roughened. The crossbeam steel bars are tied. After the main reinforcement 11 of the crossbeam is welded, the crossbeam concrete is poured. After curing until the concrete strength meets the requirements, the foundation pit is backfilled. When the stability of the overburden is poor, the crossbeam foundation pit can be temporarily supported by hammer-driven steel pipe piles or steel sheet piles, and then rectangular excavation can be used. The support width should not exceed the width of the pile body.

[0049] Crossbeam support steel pipes: The steel pipe diameter is not less than 150mm, the wall thickness is not less than 5mm, and the number of pipes is not less than 5 per m (h pile transverse direction). Wedge-shaped steel pads are installed at both ends of the steel pipes, and flanges are used for splicing. The total length is consistent with the net distance between the front and rear piles.

[0050] (9) Construction of the beam haunch: Excavate and expose the embedded steel bars using manual tools and clean and remove rust. Then bend the embedded steel bars within the haunch height range at the angle required by the design. After installing the bottom formwork with the haunch, pour the beam concrete. The rest is the same as the previous step.

[0051] (10) Construction of circular cross-section pile beam: The hole-forming steel retaining wall 4 opening method and other construction are the same as before, the difference is that the jack needs to use a circular arc reaction base.

[0052] The above scheme employs a single-sided perforated steel retaining wall 4 within the pile hole of the rear pile, with pre-embedded reinforcing bars connected to the main reinforcing bars 9 of the rear pile. After the pre-embedded reinforcing bars are exposed during the excavation of the crossbeam foundation pit, they are effectively connected to the main reinforcing bars 11 of the crossbeam and then cast-in-place concrete, achieving a rigid and effective connection between the crossbeam and the rear pile. This solves the problems of long construction cycle and unstable joint connections associated with conventional rebar anchoring methods, ensuring controllable construction quality. Through the connection between the pre-embedded bars and L-shaped reinforcing bars, the main reinforcing bars 11 of the crossbeam and the main reinforcing bars of the pile body are fully overlapped and anchored, ensuring a rigid connection between the crossbeam and the front and rear piles.

[0053] The specific embodiments described above further illustrate the purpose, technical solution, and beneficial effects of the present invention. It should be understood that the above description is only a specific embodiment of the present invention and is not intended to limit the scope of protection of the present invention. Any modifications, equivalent substitutions, improvements, etc., made within the spirit and principles of the present invention should be included within the scope of protection of the present invention.

Claims

1. A method for constructing H-type piles, characterized in that, Includes the following steps: S1: The front row of short piles (1) is constructed normally, and several first crossbeam connecting steel bars (2) are reserved at the top of the pile. The ends of several first crossbeam connecting steel bars (2) extend out of the front row of short piles (1) and extend towards the rear row of long piles (3). S2: After construction, the pile holes are divided into three sections: the lower section of the beam, the crossbeam section, and the cantilever section. The crossbeam section is equipped with a perforated steel retaining wall (4). The perforated steel retaining wall (4) has several reserved holes (12) on the side facing the front row of short piles (1). S3: Several second crossbeam connecting steel bars (5) are installed inside the perforated steel retaining wall (4) and extend out of the reserved hole (12); S4: Place a steel cage at the rear pile hole, connect several second crossbeam connecting steel bars and pile main reinforcement (9), and pour pile body concrete. S5: Excavate the foundation pit of the crossbeam, lower the main reinforcement (11) of the crossbeam, and lap and tie the front and rear ends of the main reinforcement (11) of the crossbeam to the first crossbeam connecting reinforcement (2) and the second crossbeam connecting reinforcement (5) respectively, and weld them, and then pour the crossbeam concrete. S6: Finally, backfill the foundation pit.

2. The method for constructing H-type piles according to claim 1, characterized in that, Step S3 further includes the following steps: a lifting device (6) is installed inside the perforated steel retaining wall (4), the output end of the lifting device (6) is equipped with a tray (7), one end of several second crossbeam connecting steel bars (5) is connected to the tray (7), and by driving the lifting device (6), several second crossbeam connecting steel bars (5) are pushed into the soil on one side of the perforated steel retaining wall (4).

3. The method for constructing an h-shaped pile according to claim 2, characterized in that, The lifting device (6) is a jack.

4. The method for constructing an h-shaped pile according to claim 3, characterized in that, When setting up the jack inside the perforated steel retaining wall (4), a positioning tray (7) is required. The tray (7) has several steel bar holes for placing the second crossbeam connecting steel bar (5). The steel bar holes and several reserved holes are aligned horizontally and vertically. Then, the second crossbeam connecting steel bar (5) is placed. The jack base is placed on the mountain side of the perforated steel retaining wall (4). The reaction force provided by the mountain side of the perforated steel retaining wall (4) is used to push the second crossbeam connecting steel bar (5) horizontally into the overburden soil.

5. The method for constructing an h-shaped pile according to claim 2, characterized in that, Step S4 further includes the following steps: after lowering the steel cage at the rear pile hole, several L-shaped steel bars (8) are placed in the perforated steel retaining wall (4), one side of the L-shaped steel bar (8) is connected to the main pile reinforcement (9), and the other side of the L-shaped steel bar (8) is connected to the end of the second crossbeam connecting reinforcement (5).

6. The method for constructing an h-shaped pile according to claim 5, characterized in that, The other side of the L-shaped steel bar (8) and the end of the second crossbeam connecting steel bar (5) are welded together. When welding on both sides, the lap length should not be less than 5d, and when welding on one side, the lap length should not be less than 10d; d is the diameter of the second crossbeam connecting steel bar (5).

7. The method for constructing an h-shaped pile according to claim 5, characterized in that, Step S4 further includes the following steps: after placing several L-shaped steel bars (8) into the perforated steel retaining wall (4), several second crossbeam connecting steel bars (5) need to be pulled back and pulled out according to the connection length between the L-shaped steel bars (8) and the second crossbeam connecting steel bars (5).

8. The method for constructing an h-shaped pile according to claim 1, characterized in that, In step S5, the excavation of the crossbeam foundation pit also includes the following steps: Excavate the crossbeam foundation pit in an inverted trapezoidal or rectangular shape. Horizontal steel pipes are erected at the bottom of the crossbeam to support the front and rear piles. The first crossbeam connecting steel bar (2) and the second crossbeam connecting steel bar (5) at both ends of the crossbeam are manually excavated using small tools. After exposing all the pre-embedded steel bars, the steel bars and soil are cleaned, dried and rusted, the perforated steel retaining wall (4) on the end face of the crossbeam is cut, and the pile body concrete is roughened.

9. The method for constructing an h-shaped pile according to claim 8, characterized in that, When the stability of the overburden is poor, a row of temporary steel columns (13) are set on both sides of the crossbeam foundation pit to extend into the soil for temporary support. After the temporary support is completed, the crossbeam foundation pit is excavated in a rectangular shape; the support width does not exceed the width of the pile body.

10. The method for constructing an h-shaped pile according to claim 1, characterized in that, Before pouring the concrete for the crossbeam in step S5, the following steps are also included: Manually excavate and expose the first crossbeam connecting steel bar (2) and the second crossbeam connecting steel bar (5) using small tools, and clean and remove rust. Then, bend the first crossbeam connecting steel bar (2) and the second crossbeam connecting steel bar (5) within the haunch height range at the angle required by the design. After installing the bottom formwork (10) with haunches, pour the crossbeam concrete.

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