A grouting and extrusion prestressed pipe pile and its construction method

Abstract

The present invention discloses a grouting and extrusion prestressed pipe pile, which relates to the field of construction and includes a prestressed pipe pile, a pile head, and a grouting device. The prestressed pipe pile is connected to the pile head, and the outer diameter of the pile head matches the prestressed pipe pile. The pile head includes a pile tip, a steel pipe, an upper sealing plate, a lower sealing plate, and a limiting device. The pile tip is arranged on one side of the upper sealing plate; one end of the steel pipe is closed and connected to the other side of the upper sealing plate; the lower sealing plate includes a grouting port, and the lower sealing plate is closed and arranged on the other end of the steel pipe. A grouting overflow is provided on the side wall of the steel pipe. The limiting device is arranged on the outer peripheral wall of the steel pipe. The grouting device is connected to the outer side of the pile head through the limiting device and the outer peripheral wall. The grouting device covers the grouting overflow. The technical effects of the present invention are simple construction, low comprehensive cost, and low impact on the environment.

Description

Technical Field

[0001] The present invention relates to the field of building construction, in particular to a grouting and extrusion prestressed pipe pile and a construction method thereof. Background Art

[0002] Prestressed pipe piles are widely used in engineering construction due to their reliable quality, efficient construction, and low cost. However, due to their relatively weak engagement with the surrounding soil, the pile body strength is relatively high, especially for pull-out piles, resulting in a waste of resources. Based on the precast pile sinking process, there are two main existing methods for grouting and enlarged base precast pile construction:

[0003] (1) Drilling and implantation, grouting and bottom expansion: that is, first drill a hole, then hoist and implant the prefabricated pile body (steel prestressed pipe pile or prestressed prestressed pipe pile) equipped with a grouting and bottom expansion device, then inject cement mortar to replace the mud in the hole, and finally grouting and bottom expansion.

[0004] (2) Mixing and implanting, grouting and bottom expansion: first construct cement-soil mixing piles at the designed pile position, then implant the prefabricated pile body equipped with grouting and bottom expansion device into the cement-soil mixing pile, and finally perform grouting and bottom expansion.

[0005] The above construction method has defects that need to be improved: First, there are many construction links and low construction efficiency. Whether it is drilling and planting, or mixing and planting, it adds a construction link in addition to the precast pile sinking, which reduces construction efficiency. Second, it consumes a lot of materials and has high construction costs. After the precast pile is placed in the drilled hole, cement mortar needs to be injected to fill the gap between the precast pile and the hole wall. The construction of cement-soil mixing piles consumes a large amount of cement and incurs construction costs. Third, it discharges a lot of waste and has a great impact on the environment. Drilling a hole produces a large amount of mud. The planting of precast piles in cement-soil mixing piles will also discharge a large amount of cement soil, which has a great impact on the environment. Therefore, it is necessary for engineering technicians to develop a new grouting-molded expanded-bottom precast pile and its construction method to improve the bite force between the prestressed pipe pile and the surrounding soil, and make the construction process simpler, more efficient, material-saving, labor-saving and environmentally friendly. Summary of the Invention

[0006] In view of the above-mentioned defects of the prior art, the technical problem to be solved by the present invention is to save grouting materials while improving the bite force between the prestressed pipe piles and the surrounding soil.

[0007] To achieve the above object, the present invention provides a grouting and expansion prestressed pipe pile, comprising a prestressed pipe pile, a pile head and a grouting device, wherein the prestressed pipe pile is connected to the pile head, and the outer diameter of the pile head matches that of the prestressed pipe pile, wherein:

[0008] The pile head includes a pile tip, a steel pipe, an upper sealing plate, a lower sealing plate, and a limiting device. The pile tip is arranged on one side of the upper sealing plate; one end of the steel pipe is closed and connected to the other side of the upper sealing plate, the lower sealing plate includes a grouting port, and the lower sealing plate is closed and arranged on the other end of the steel pipe. A grouting overflow is provided on the side wall of the steel pipe. The limiting device is arranged on the outer peripheral wall of the steel pipe. The slurry binding device is connected to the outer side of the pile head through the limiting device and the outer peripheral wall, and the slurry binding device covers the grouting overflow.

[0009] Furthermore, at least two first stiffening plates are provided between the upper sealing plate and the lower sealing plate, one end of the first stiffening plate is connected to the upper sealing plate, and the other end of the first stiffening plate is connected to the lower sealing plate, dividing the steel pipe into multiple semi-enclosed areas.

[0010] Furthermore, the opening of the semi-enclosed area is opposite to the grouting overflow.

[0011] Furthermore, the pulp bundling device is a waterproof canvas bag.

[0012] Furthermore, one end of the waterproof canvas bag is connected to the limiting device, and the other end of the waterproof canvas bag is bonded to the prestressed pipe pile by a sealant.

[0013] Furthermore, the prestressed pipe pile and the pile head are separate, and the prestressed pipe pile and the pile head are connected by welding.

[0014] Furthermore, the grouting port has threads.

[0015] Furthermore, it also includes: a second stiffening plate, and the grouting port penetrates the lower sealing plate through the second stiffening plate.

[0016] The present invention also provides a construction method using the aforementioned grouting and expansion prestressed pipe piles, comprising:

[0017] Connect the grouting pipe to the grouting port;

[0018] The grouting and expansion prestressed pipe pile and the grouting pipe are sunk into the soil layer by using a direct pile sinking process until the piles are sunk to the designed elevation;

[0019] Cement slurry is injected into the grouting and expansion prestressed pipe pile through the grouting pipe, and the cement slurry expands the grout binding device to form a pile bottom expansion section.

[0020] Furthermore, the cement slurry uses P42.5 cement with a water-cement ratio of between 0.55 and 0.60.

[0021] The technical effects of the present invention are:

[0022] (1) The grouting pipe and grouting device are directly sunk into the soil layer along with the prestressed pipe piles. There is no need for drilling, cement mortar replacement of mud, or cement-soil mixing pile construction. Grouting and expansion are carried out in an interspersed manner, which does not occupy the absolute construction period. Therefore, it is as efficient as traditional prestressed pipe pile construction.

[0023] (2) Low overall cost: It saves the filling cement mortar required for the drilling and implantation process, saves the cement required for the cement-soil mixing pile implantation process, saves materials, and reduces the construction links;

[0024] (3) Small impact on the environment: It avoids the mud discharge problem in the drilling implantation process or the cement soil discharge problem in the "mixing implantation" process.

[0025] The concept, specific structure and technical effects of the present invention will be further described below in conjunction with the accompanying drawings to fully understand the purpose, characteristics and effects of the present invention. BRIEF DESCRIPTION OF THE DRAWINGS

[0026] Other features, objects and advantages of the present invention will become more apparent upon reading the detailed description of non-limiting embodiments made with reference to the following drawings:

[0027] Figure 1 A top view of an embodiment of the present invention;

[0028] Figure 2 This is a cross-sectional view of the AA structure of an embodiment of the present invention;

[0029] Figure 3 This is a cross-sectional view of the pile tip structure BB according to an embodiment of the present invention;

[0030] Figure 4 This is a cross-sectional view of an embodiment of the present invention combined with a prestressed pipe pile.

[0031] Explanation of the accompanying symbols: 1-pile head; 2-grouting pipe; 3-pipe pile; 4-welding surface; 5-grouting device; 101-upper sealing plate; 102-lower sealing plate; 103-pile tip; 104-first stiffening plate; 105-limiting device; 106-grouting overflow; 107-second stiffening plate; 108-steel pipe; 10-grouting port. DETAILED DESCRIPTION

[0032] The following describes several preferred embodiments of the present invention with reference to the accompanying drawings to make its technical content clearer and easier to understand. The present invention can be embodied in many different forms of embodiments, and the scope of protection of the present invention is not limited to the embodiments mentioned herein.

[0033] In the drawings, components with identical structures are denoted by the same reference numerals, and components with similar structures or functions are denoted by similar reference numerals. The size and thickness of each component shown in the drawings are arbitrary and are not limited by the present invention. For clarity, the thickness of components in some places in the drawings is appropriately exaggerated.

[0034] Figure 1 The figure shows a pile tip of a grouting and expansion prestressed pipe pile of the present invention, the pile tip 103, which is arranged on the outside of the upper cover plate 101 of the pile head 1. The pile tip 103 can use a conventional pile tip such as a cross-shaped steel pile tip, an open-shaped steel pile tip, or a conical steel pile tip, so that the prestressed pipe pile is driven into the soil by pressure.

[0035] Figures 2 to 4 The specific internal structure of the grouting and expansion prestressed pipe pile is shown, which includes a pile head 1, a prestressed pipe pile 3 and a grout binding device 5. The prestressed pipe pile 3 is connected to the pile head 1, and the outer diameter of the pile head 1 matches the prestressed pipe pile 3.

[0036] The pile head 1 includes a pile tip 103, a steel pipe 108, an upper sealing plate 101, a lower sealing plate 102 and a limiting device 105. The pile tip 103 is arranged on one side of the upper sealing plate 101; one end of the steel pipe 108 is closed and connected to the other side of the upper sealing plate 101, the lower sealing plate 102 includes a grouting port 10, and the lower sealing plate 102 is closed and arranged on the other end of the steel pipe 108. A grouting overflow 106 is provided on the side wall of the steel pipe 108, and the limiting device 105 is arranged on the outer wall of the steel pipe 108. The grouting device 5 is connected to the outer wall of the steel pipe 108 through the limiting device 105 to the outside of the pile head 1, and the grouting device 5 covers the grouting overflow 106.

[0037] The cement slurry enters the steel pipe 108 from the grouting port 10, flows after being poured into the steel pipe 108, and overflows from the grouting overflow port 106. After overflowing, the cement slurry pushes the grout binding device 5, and expands the grout binding device 5. The expanded grout binding device 5 squeezes and expands the surrounding soil, which can increase and reinforce the density of the soil around the prestressed pipe pile, improve the pull-out resistance and pressure resistance of the prestressed pipe pile, and greatly improve the pile-soil bite effect.

[0038] Furthermore, if Figure 3 As shown, a plurality of first stiffening plates 104 are provided between the upper sealing plate 101 and the lower sealing plate 102. One end of the first stiffening plate 104 is connected to the upper sealing plate 101, and the other end of the first stiffening plate 104 is connected to the lower sealing plate 102, dividing the steel pipe 108 into a plurality of semi-enclosed areas.

[0039] The first stiffening plates 104 primarily serve to channel the cement slurry. When the cement slurry enters the steel pipe 108 through the grouting port 10, it initially diffuses outward from the port 10 and is then channeled through the first stiffening plates, locally squeezing out the slurry. By adjusting the angle between the first stiffening plates 104 to adjust the opening of the semi-enclosed area, the slurry extrusion force can be adjusted, resulting in a greater ultimate expansion force for the grouting device of the prestressed pile (see figure) to accommodate varying soil types.

[0040] Furthermore, the opening of the semi-enclosed area can be opposite to the grouting overflow 106, so that the extrusion force of the cement slurry is directly transmitted from the grouting overflow 106 to the slurry bundling device 5. The diameter of the grouting overflow 106 is preferably about 6 to 10 mm.

[0041] Furthermore, a second stiffening plate 107 is included, through which the grouting port 10 penetrates the lower sealing plate 102. The second stiffening plate further enhances the strength of the steel pipe 108, thereby preventing the pile head 1 from being damaged by both the upper pressure and the soil pressure during the process of sinking the prestressed pipe pile into the soil.

[0042] Furthermore, the grout binding device 5 uses a waterproof canvas bag, which is tied to the pile head 1 through a limiting device 105 and covers the grouting overflow 106.

[0043] Furthermore, in order to prevent the waterproof canvas bag from falling off due to the friction of the soil during the pile sinking process, the other end of the waterproof canvas bag can be further bonded to the prestressed pipe pile 3 using sealant. During the grouting stage after the pile sinking process, the waterproof canvas bag is squeezed and expanded by the cement slurry, and the bonding surface between the waterproof canvas bag and the prestressed pipe pile 3 will fall off. As a result, the waterproof canvas bag can receive more injected cement slurry. At this time, the waterproof canvas bag plays the role of guiding the cement slurry to prevent excessive infiltration of the cement slurry into the surrounding soil.

[0044] Optionally, due to the site limitations of the construction site, the prestressed pipe pile 3 and the pile head 1 are separated, so that the prestressed pipe pile 3 and the pile head 1 can be manufactured separately in a factory and transported to the construction site, and then directly welded together at the construction site. Figure 4 The welding surface 4 of the prestressed pipe pile 3 and the pile head 1 is shown.

[0045] Furthermore, in order to fix the grouting pipe and the grouting port 10 and prevent the grouting pipe from deviating from the grouting port 10 during the pile sinking process, threads can be machined on the grouting port 10 and the grouting pipe and the grouting port 10 are threadedly connected.

[0046] The present invention also discloses a construction method using the aforementioned grouting and expansion prestressed pipe piles, comprising:

[0047] Connect the grouting pipe to the grouting port 10:

[0048] The aforementioned grouting and expansion prestressed pipe piles and grouting pipes are sunk into the soil using direct pile sinking technology until the piles reach the designed elevation.

[0049] Cement slurry is injected into the grouting and expansion prestressed pipe pile through the grouting pipe, and the cement slurry expands the grout binding device to form a pile bottom expansion section.

[0050] This construction method eliminates the need for concrete pouring or slurry replacement steps in conventional pile driving, resulting in a simple construction method. Furthermore, cement slurry is injected directly into the steel pipe 108 of the grouting and expansion prestressed pipe pile through the grouting pipe, minimizing the release of cement slurry into the soil. This reduces material consumption and costs while also minimizing environmental impact. The direct pile driving process employed in this construction method includes either static pressure or hammering, requiring simple construction equipment and offering wide adaptability.

[0051] Furthermore, the cement slurry uses P42.5 cement with a water-cement ratio of between 0.55 and 0.60. P42.5 refers to the strength grade of ordinary Portland cement, i.e., the 28-day compressive strength standard of ordinary Portland cement is not less than 42.5 MPa.

[0052] When preparing cement slurry, attention should be paid to stirring to ensure that the slurry does not segregate. The mixing system used should have two slurry barrels (mixing barrel and slurry barrel). The cement mortar liquid must be stirred in the mixing barrel, filtered through a filter screen, and then enter a special slurry barrel. At the same time, the slurry in the slurry barrel should also be equipped with a stirring system. The slurry in the slurry barrel should not be placed for more than 3 hours. The grouting pressure and grouting rate should be strictly controlled during grouting. The termination control standard of grouting adopts the dual control standard of grouting volume and grouting pressure. The grouting flow rate should not exceed 50L / min and should not be lower than the design requirements. The grouting pressure is controlled at 1.0~1.8Mpa.

[0053] The preferred embodiments of the present invention have been described in detail above. It should be understood that numerous modifications and variations based on the concepts of the present invention are possible without inventive effort by those skilled in the art. Therefore, any technical solution that can be derived by one skilled in the art through logical analysis, reasoning, or limited experimentation based on the concepts of the present invention and the prior art should be within the scope of protection defined by the claims.

Claims

1. A grouting and expansion prestressed pipe pile, characterized in that: It includes a prestressed pipe pile, a pile head and a slurry binding device, wherein the prestressed pipe pile is connected to the pile head, and the outer diameter of the pile head matches the prestressed pipe pile, wherein: The pile head includes a pile tip, a steel pipe, an upper sealing plate, a lower sealing plate, and a limiting device, wherein the pile tip is arranged on one side of the upper sealing plate; one end of the steel pipe is sealed and connected to the other side of the upper sealing plate; the lower sealing plate includes a grouting port, and the lower sealing plate is sealed and arranged on the other end of the steel pipe; a grouting overflow is provided on the side wall of the steel pipe; the limiting device is arranged on the outer peripheral wall of the steel pipe; the grouting device is connected to the outer side of the pile head through the limiting device and the grouting device covers the grouting overflow; At least two first stiffening plates are provided between the upper sealing plate and the lower sealing plate, one end of the first stiffening plate is connected to the upper sealing plate, and the other end of the first stiffening plate is connected to the lower sealing plate, dividing the steel pipe into a plurality of semi-enclosed areas; The pulp bundling device is a waterproof canvas bag.

2. The grouting and expansion prestressed pipe pile according to claim 1, characterized in that: The opening of the semi-enclosed area is opposite to the grouting overflow.

3. The grouting and expansion prestressed pipe pile according to claim 1, characterized in that: One end of the waterproof canvas bag is connected to the limiting device, and the other end of the waterproof canvas bag is bonded to the prestressed pipe pile by means of a sealant.

4. The grouting and expansion prestressed pipe pile according to claim 1, characterized in that: The prestressed pipe pile and the pile head are separate and connected by welding.

5. The grouting and expansion prestressed pipe pile according to claim 1, characterized in that: The grouting port has threads.

6. The grouting and expansion prestressed pipe pile according to claim 1, characterized in that: Also includes: The second stiffening plate, the grouting port penetrates the lower sealing plate through the second stiffening plate.

7. A construction method using any one of the grouting and expansion prestressed pipe piles according to claims 1 to 6, characterized in that: include: Connect the grouting pipe to the grouting port; The grouting and expansion prestressed pipe pile and the grouting pipe are sunk into the soil by using a direct pile sinking process until the piles are sunk to the designed elevation; Cement slurry is injected into the grouting and expansion prestressed pipe pile through the grouting pipe, and the cement slurry expands the grout binding device to form a pile bottom expansion section.

8. The construction method according to claim 7, wherein: The cement slurry uses P42.5 cement with a water-cement ratio of 0.55 to 0.60.

Images