Cast-in-situ bored pile grouting method and grouting device applying same

Abstract

The invention relates to the technical field of grouting of cast-in-situ bored piles, in particular to a grouting method of a cast-in-situ bored pile and a grouting device applying the method, and the grouting method of the cast-in-situ bored pile comprises the following steps: S1, forming a hole of the cast-in-situ bored pile to form a to-be-constructed hole; s2, reinforcement cages are manufactured, multiple sets of grouting conveying assemblies are installed on the reinforcement cages, and the number of the reinforcement cages and the number of the grouting conveying assemblies are both multiple; s3, the reinforcement cages are hoisted and placed into the to-be-constructed hole, the adjacent reinforcement cages are connected through welding, and meanwhile the mud jacking conveying assemblies on the adjacent reinforcement cages are connected through connecting pieces; s4, the grouting conveying assembly located on the uppermost portion is connected with a grouting assembly; s5, grouting is conducted through the grouting assemblies, the grouting conveying assemblies convey the grout, and meanwhile the multiple grouting conveying assemblies independently output the grout in the sequence from bottom to top; s5, when slurry output meets the set requirement, the grouting assembly is closed, and the grouting assembly is dismantled; s6, the cast-in-situ bored pile is formed, and construction is completed.

Description

Technical Field

[0001] This invention relates to the field of grouting technology for bored piles, and more particularly to a grouting method for bored piles and a grouting device using this method. Background Technology

[0002] With the rapid development of high-rise buildings and bridges in my country, the requirements for the bearing capacity of building foundations are becoming increasingly stringent. The foundation type generally uses bored cast-in-place piles, requiring a relatively intact rock stratum as the bearing layer, and demanding large pile lengths and diameters. Through years of practice and research, Chinese researchers have solved the problem of insufficient pile end bearing capacity in foundations where the bearing layer is not rock by using the post-grouting method, achieving significant economic benefits.

[0003] Post-grouting refers to the process where a grouting steel pipe is hoisted to the bottom of the pile. After the pile body reaches the design strength, cement grout is injected into the pores of the crushed stone layer at the pile tip through the grouting steel pipe. This causes the previously poor soil at the pile tip to cement into a high-strength bearing layer. Under the pressure of the grouting pump, the cement grout diffuses from the pores at the pile tip outwards. Within a single pile, the outward diffusion of the cement grout is equivalent to increasing the diameter of the pile tip, and the downward diffusion is equivalent to increasing the pile length. In a group of piles, all the grout becomes connected, making the crushed stone layer a unified whole, thus ensuring that the bearing layer meets the structural load-bearing capacity requirements.

[0004] However, there are also some problems in the construction process of bored piles with post-grouting. For example, after the grouting pipe is sunk to the bottom of the pile, it is easy for the grouting pipe to become blocked. Secondly, only the bottom of the pile foundation is reinforced, and the overall strength and stability of the pile body still need to be strengthened. Summary of the Invention

[0005] The technical problem to be solved by the present invention is: In order to solve the technical problems in the prior art, the present invention provides a grouting method for bored piles and a grouting device for applying the method.

[0006] The technical solution adopted by this invention to solve its technical problem is: a grouting method for bored cast-in-place piles, comprising the following steps: S1, drilling a bored cast-in-place pile to form a hole to be constructed; S2, fabricating a reinforcing cage and installing a grouting conveying assembly on the reinforcing cage, wherein multiple sets of the reinforcing cage and the grouting conveying assembly are provided; S3, hoisting the reinforcing cage into the hole to be constructed, connecting adjacent reinforcing cages by welding, and connecting the grouting conveying assemblies on adjacent reinforcing cages by connectors; S4, connecting the uppermost grouting conveying assembly to the grouting assembly; S5, grouting is performed through the grouting assembly, the grouting conveying assembly conveys the grout, and multiple grouting conveying assemblies individually output grout in a bottom-up sequence; S6, when the grout output reaches the set requirements, the grouting assembly is turned off and removed; S7, the bored cast-in-place pile is formed, and the construction is completed.

[0007] The grouting method for bored piles of the present invention, by installing the grouting delivery assembly on the reinforcing cage, allows the grouting delivery assembly and the reinforcing cage to be hoisted together and placed at the bottom of the pile, reducing additional hoisting processes. At the same time, the reinforcing cage can support the grouting delivery assembly, and the grouting delivery assembly can also strengthen the reinforcing cage. Secondly, when the pile body is long, the reinforcing cage is generally made of multiple welded sections, and the grouting delivery assembly is spliced ​​together by connectors to adapt to the case of long pile bodies. Finally, each grouting delivery assembly can also output grout independently, and the output sequence is from bottom to top, which can increase the strength and stability of the pile body while ensuring the stability of the bearing layer. Moreover, the reinforcement of the upper part of the pile body can interact with the reinforcement of the bottom of the pile body to improve the overall stability of the pile body.

[0008] A grouting device, employing the aforementioned grouting method for bored piles, includes a grouting assembly and a grouting conveying assembly. Multiple grouting conveying assemblies are arranged vertically, each connected to a reinforcing cage. The uppermost grouting conveying assembly is connected to the grouting assembly, and adjacent grouting conveying assemblies are connected via connectors. Each grouting assembly includes a grouting pipe, a grouting pump, and a grouting valve. One end of the grouting pipe is connected to the uppermost grouting conveying assembly, and the other end is connected to a grout conveying device. The grouting pump and grouting valve are both mounted on the grouting pipe.

[0009] Furthermore, the grouting conveying assembly includes a flow pipe and a grouting ring. The flow pipe is connected to the grouting ring, and both the flow pipe and the grouting ring are fixedly connected inside the reinforcing cage. The side wall of the grouting ring is provided with a grouting hole, and the grouting hole is provided with an anti-backflow component.

[0010] Furthermore, the grouting holes are arranged in multiple sets along the circumference of the grouting ring, and each set of grouting holes has two holes along its own axial direction. The anti-backflow component includes two sealing members and an elastic member connected between the two sealing members. The two sealing members cover the two grouting holes in the same set, and the elastic member is located inside the grouting ring. The elastic member applies a pulling force to the two sealing members.

[0011] Furthermore, the grouting hole is axially arranged along the height direction.

[0012] With the above technical solution, the grouting hole is set axially along the height direction, which facilitates the grout to flow out vertically, thereby making it easier to increase the length of the pile.

[0013] Furthermore, the grouting hole is axially arranged in the horizontal direction.

[0014] With the above technical solution, the grouting hole is set axially in the horizontal direction, which facilitates the grout to flow out horizontally, and thus makes it easier to increase the diameter of the pile.

[0015] Furthermore, the tension of the elastic element in the multiple sets of grouting conveying assemblies increases gradually from bottom to top.

[0016] The above technical solution involves selecting elastic components with different tensions to control the order of grout output from different grouting delivery components. This ensures that the grouting delivery component at the bottom starts outputting grout first, guaranteeing the reliability of the bearing layer at the bottom of the pile. Simultaneously, when the pressure output by the grouting pump can overcome the pressure of all elastic components, all grouting delivery components output grout together, achieving overall reinforcement of the pile.

[0017] Furthermore, the sealing component includes a cone and a cover that are connected to each other. The large end of the cone is connected to the cover. The cone is inserted into the grouting hole, and the side of the cover facing the cone contacts the outer wall of the grouting ring.

[0018] Through the above technical solution, the cooperation of the cover, cone, and elastic element can seal the grouting hole when the grouting ring is not outputting grout, preventing the outer grout from entering the grouting ring and clogging the pipe. The cone can control the change in the cross-sectional size of the grouting hole when it outputs grout. Since the large end of the cone is connected to the cover, the cross-sectional area of ​​the grouting hole that can supply grout flow gradually decreases when the grout flows out of the grouting ring. Therefore, the pressure of the grout output from the grouting hole can be increased through the Venturi effect, thereby improving the grouting effect.

[0019] Furthermore, the outer side of the cover is covered with a rubber layer, which is in contact with the outer wall of the grouting ring.

[0020] The above technical solution reduces the possibility of grout entering the grouting ring from the outside by having the rubber layer contact the outer wall of the grouting ring.

[0021] Furthermore, the connector includes a first connector, a connecting pipe, and a second connector. One end of the connecting pipe is connected to the first connector, and the other end is connected to the second connector. The first connector is connected to the conveying pipe of the grouting conveying assembly located above, and the second connector is connected to the conveying pipe of the grouting conveying assembly located below.

[0022] The beneficial effects of this invention are: 1. By installing the grouting delivery assembly onto the reinforcing cage, the grouting delivery assembly and the reinforcing cage can be hoisted together and placed at the bottom of the pile, reducing additional hoisting processes. At the same time, the reinforcing cage can support the grouting delivery assembly, and the grouting delivery assembly can also strengthen the reinforcing cage. Secondly, when the pile is long, the reinforcing cage is generally made of multiple welded sections, while the grouting delivery assembly can be spliced ​​together through connectors to adapt to the case of long piles. Finally, each grouting delivery assembly can also output grout independently, and the output sequence is from bottom to top, which can increase the strength and stability of the pile while ensuring the stability of the bearing layer. Moreover, the reinforcement of the upper part of the pile can interact with the reinforcement of the bottom of the pile to improve the overall stability of the pile. 2. By selecting elastic components with different tensions, the order of grout output from different grouting delivery components is controlled, so that the grouting delivery component at the bottom starts to output grout first, ensuring the reliability of the bearing layer at the bottom of the pile. At the same time, when the pressure output by the grouting pump can overcome the pressure of all elastic components, all grouting delivery components output grout together, realizing the overall strengthening of the pile body. 3. The cooperation of the cover, cone, and elastic element can seal the grouting hole when the grouting ring is not outputting grout, preventing the outer grout from entering the grouting ring and clogging the pipe. The cone can control the change in the cross-sectional size of the grouting hole when it outputs grout. Since the large end of the cone is connected to the cover, the cross-sectional area of ​​the grouting hole that can supply grout flow gradually decreases when the grout flows out of the grouting ring. Therefore, the pressure of the grout output from the grouting hole can be increased through the Venturi effect, thereby improving the grouting effect. Attached Figure Description

[0023] The present invention will be further described below with reference to the accompanying drawings and embodiments.

[0024] Figure 1 This is a schematic diagram illustrating the overall structure of the grouting device and the reinforcing cage in this invention.

[0025] Figure 2 yes Figure 1 A magnified view of part A in the middle.

[0026] Figure 3 This is a schematic diagram illustrating the structure of the anti-backflow component in this invention.

[0027] In the diagram: 1. Reinforcing cage; 2. Grouting assembly; 21. Grouting pipe; 22. Grouting pump; 3. Grouting conveying assembly; 31. Flow pipe; 32. Grouting ring; 33. Anti-backflow assembly; 331. Sealing component; 3311. Cone; 3312. Cover; 332. Elastic component; 4. Connecting component; 41. First connector; 42. Connecting pipe; 43. Second connector. Detailed Implementation

[0028] The present invention will now be described in further detail with reference to the accompanying drawings. These drawings are simplified schematic diagrams, illustrating only the basic structure of the invention, and therefore only show the components relevant to the invention.

[0029] In the description of this invention, it should be understood that the terms "center," "longitudinal," "lateral," "length," "width," "thickness," "upper," "lower," "front," "rear," "left," "right," "vertical," "horizontal," "top," "bottom," "inner," "outer," "clockwise," "counterclockwise," "axial," "radial," and "circumferential," etc., indicating orientation or positional relationships based on the orientation or positional relationships shown in the accompanying drawings, are only for the convenience of describing the invention and simplifying the description, and do not indicate or imply that the device or element referred to must have a specific orientation, or be constructed and operated in a specific orientation, and therefore should not be construed as a limitation of the invention. Furthermore, features defined with "first" or "second" may explicitly or implicitly include one or more of that feature. In the description of this invention, unless otherwise stated, "a plurality of" means two or more. In the description of this invention, it should be noted that, unless otherwise explicitly specified and limited, the terms "installed," "connected," and "linked" should be interpreted broadly, for example, as a fixed connection, a detachable connection, or an integral connection; as a mechanical connection or an electrical connection; as a direct connection or an indirect connection through an intermediate medium; or as a connection within two components. Those skilled in the art can understand the specific meaning of the above terms in this invention according to the specific circumstances. Example 1

[0030] In a first aspect, the present invention discloses a grouting method for bored cast-in-place piles.

[0031] Reference Figures 1 to 3 A grouting method for bored piles, referring to Figure 1 It includes the following steps: S1. Drilling and grouting piles to form holes for construction.

[0032] S2. The steel cage 1 is fabricated, and the grouting conveying assembly 3 is installed on the steel cage 1. Both the steel cage 1 and the grouting conveying assembly 3 are equipped with multiple sets.

[0033] S3. The steel cage 1 is hoisted and placed into the hole to be constructed. The adjacent steel cages 1 are connected by welding. At the same time, the grouting conveying components 3 on the adjacent steel cages 1 are connected by connectors 4.

[0034] S4. Connect the grouting conveying assembly 3 at the top to the grouting assembly 2.

[0035] S5. Grouting is performed by grouting assembly 2, and grouting conveying assembly 3 conveys the grout. At the same time, multiple grouting conveying assemblies 3 individually output grout in a bottom-up sequence.

[0036] S5. When the grout output reaches the set requirements, shut down the grouting assembly 2 and remove the grouting assembly 2.

[0037] S6. The bored piles are formed, and the construction is completed.

[0038] During construction, by installing the grouting conveying component 3 onto the reinforcing cage 1, the grouting conveying component 3 and the reinforcing cage 1 can be hoisted together and placed at the bottom of the pile, reducing additional hoisting processes. At the same time, the reinforcing cage 1 can support the grouting conveying component 3, and the grouting conveying component 3 can also strengthen the reinforcing cage 1. Secondly, when the pile body is long, the reinforcing cage 1 is generally made of multiple sections welded together. The grouting conveying component 3 is spliced ​​together by the connector 4, thus adapting to the case of long pile bodies. Finally, each grouting conveying component 3 can also output grout independently, and the output sequence is from bottom to top, which can increase the strength and stability of the pile body while ensuring the stability of the bearing layer. Moreover, the reinforcement of the upper part of the pile body can interact with the reinforcement of the bottom of the pile body to improve the overall stability of the pile body.

[0039] Secondly, this application discloses a grouting device.

[0040] A grouting device, employing the above-mentioned grouting method for bored piles, with reference to... Figures 1 to 3 It includes a grouting assembly 2 and a grouting conveying assembly 3. Multiple grouting conveying assemblies 3 are provided in the vertical direction. Each grouting conveying assembly 3 is connected to a steel cage 1. The uppermost grouting conveying assembly 3 is connected to the grouting assembly 2. Adjacent grouting conveying assemblies 3 are connected by connectors 4.

[0041] Specifically, the grouting assembly 2 includes a grouting pipe 21, a grouting pump 22, and a grouting valve. One end of the grouting pipe 21 is connected to the uppermost grouting conveying assembly 3, and the other end is connected to the grout conveying device. Both the grouting pump 22 and the grouting valve are installed on the grouting pipe 21, and high-pressure conveying is achieved through the grouting pump 22. The grout conveying device can be a concrete truck or a concrete mixing silo, etc. A pressure gauge is also installed on the grouting pipe 21 to monitor the pipeline pressure.

[0042] Specifically, the grouting conveying assembly 3 includes a flow pipe 31 and a grouting ring 32. The flow pipe 31 is connected to the grouting ring 32, and both the flow pipe 31 and the grouting ring 32 are fixedly connected inside the reinforcing cage 1. The side wall of the grouting ring 32 is provided with grouting holes, and anti-backflow assembly 33 is provided on the grouting holes. The uppermost flow pipe 31 is connected to the grouting pipe 21.

[0043] More specifically, there are multiple sets of grouting holes arranged circumferentially along the grouting ring 32, and each set of grouting holes has two along its own axial direction. The anti-backflow component 33 includes two sealing members 331 and an elastic member connected between the two sealing members 331. The two sealing members 331 cover the two grouting holes in the same set, and the elastic member is located inside the grouting ring 32. The elastic member applies a pulling force to the two sealing members 331.

[0044] In this embodiment, the grouting hole is set along the height direction to facilitate the grout to flow out in the vertical direction, thereby facilitating the increase of the pile length.

[0045] It should be noted that the tension of the elastic elements in the multiple grouting conveying assemblies 3 increases progressively from bottom to top. Specifically, the elastic element in the lowest grouting conveying assembly 3 has the lowest tension, while the elastic element in the highest grouting conveying assembly 3 has the highest tension. By selecting elastic elements 332 with different tensions, the order of grout output from the different grouting conveying assemblies 3 is controlled, ensuring that the lowest grouting conveying assembly 3 starts outputting grout first, guaranteeing the reliability of the bearing layer at the pile bottom. Simultaneously, when the pressure output by the grouting pump 22 can overcome the pressure of all elastic elements 332, all grouting conveying assemblies 3 output grout together, achieving overall reinforcement of the pile. The elastic element 332 can be an elastic rope or a tension spring.

[0046] The sealing component 331 includes a cone 3311 and a cover 3312 connected to each other. The large end of the cone 3311 is connected to the cover 3312. The cone 3311 is inserted into the grouting hole. The outer side of the cover 3312 is covered with a rubber layer. The rubber layer is in contact with the outer wall of the grouting ring 32 so as to reduce the possibility of grout entering the grouting ring 32 when the grouting hole is not outputting grout.

[0047] The cooperation of the cover 3312, the cone 3311, and the elastic element 332 can seal the grouting hole when the grouting ring 32 is not outputting grout, preventing the outer grout from entering the grouting ring 32 and clogging the pipe. The cone 3311 can control the change in the cross-sectional size of the grouting hole when it outputs grout. Since the large end of the cone 3311 is connected to the cover 3312, the cross-sectional area of ​​the grouting hole that can supply grout flow gradually decreases when the grout flows out of the grouting ring 32. Therefore, the pressure of the grout output from the grouting hole can be increased through the Venturi effect, thereby improving the grouting effect.

[0048] Multiple sets of flow pipe 31 and connector 4 are provided along the circumference of grouting ring 32. Connector 4 includes a first connector 41, a connecting pipe 42 and a second connector 43. One end of the connecting pipe 42 is connected to the first connector 41 and the other end is connected to the second connector 43. The first connector 41 is connected to the conveying pipe of the upper grouting conveying assembly 3 and the second connector 43 is connected to the conveying pipe of the lower grouting conveying assembly 3. Example 2

[0049] The difference from Embodiment 1 is that the grouting holes are arranged axially in the horizontal direction, which facilitates the grout to flow out in the horizontal direction, thereby making it easier to increase the diameter of the pile. Example 3

[0050] The difference from Embodiment 1 is that the grouting holes on the lowest grouting ring 32 are arranged axially along the height direction, while the grouting holes on the remaining grouting rings 32 are arranged horizontally, thereby increasing both the length and diameter of the pile body. Example 4

[0051] The difference from Embodiment 1 is that the grouting ring 32 has two types of grouting holes. One type of grouting hole is axially arranged in the horizontal direction, and the other type of grouting hole is axially arranged in the vertical direction, which makes it easy to increase the length and diameter of the pile at the same time.

[0052] Based on the above-described preferred embodiments of the present invention, and through the foregoing description, those skilled in the art can make various changes and modifications without departing from the inventive concept. The technical scope of this invention is not limited to the contents of the specification, but must be determined according to the scope of the claims.

Claims

1. A grouting method for bored cast-in-place piles and a grouting device using the method, characterized in that, Includes the following steps: S1. Drilling and grouting piles to form holes to be constructed; S2. The steel cage (1) is fabricated and the grouting conveying assembly (3) is installed on the steel cage (1). Both the steel cage (1) and the grouting conveying assembly (3) are provided with multiple sets. S3. The steel cage (1) is hoisted into the hole to be constructed. The adjacent steel cages (1) are connected by welding. At the same time, the grouting conveying components (3) on the adjacent steel cages (1) are connected by connectors (4). S4. Connect the grouting conveying assembly (3) located at the top to the grouting assembly (2); S5. Grouting is performed by the grouting assembly (2), the grouting conveying assembly (3) conveys the grout, and multiple grouting conveying assemblies (3) individually output the grout in a bottom-up order; S5. When the grout output reaches the set requirements, shut down the grouting assembly (2) and remove the grouting assembly (2); S6. The bored piles are formed, and the construction is completed.

2. A grouting device, employing the grouting method for bored piles as described in claim 1, characterized in that, It includes a grouting assembly (2) and a grouting conveying assembly (3). Multiple grouting conveying assemblies (3) are provided in the vertical direction. Each grouting conveying assembly (3) is connected to a steel cage (1). The uppermost grouting conveying assembly (3) is connected to the grouting assembly (2). Adjacent grouting conveying assemblies (3) are connected by connectors (4). The grouting assembly (2) includes a grouting pipe (21), a grouting pump (22), and a grouting valve. One end of the grouting pipe (21) is connected to the uppermost grouting conveying assembly (3), and the other end is connected to the slurry conveying device. The grouting pump (22) and the grouting valve are both installed on the grouting pipe (21).

3. The grouting device according to claim 2, characterized in that, The grouting conveying assembly (3) includes a flow pipe (31) and a grouting ring (32). The flow pipe (31) is connected to the grouting ring (32). Both the flow pipe (31) and the grouting ring (32) are fixedly connected inside the reinforcing cage (1). The side wall of the grouting ring (32) is provided with a grouting hole, and the grouting hole is provided with an anti-backflow assembly (33).

4. The grouting device according to claim 3, characterized in that, The grouting holes are arranged in multiple groups along the circumference of the grouting ring (32), and each group of grouting holes has two along its own axial direction. The anti-backflow component (33) includes two sealing members (331) and an elastic member connected between the two sealing members (331). The two sealing members (331) cover the two grouting holes in the same group respectively. The elastic member is located inside the grouting ring (32) and applies a pulling force to the two sealing members (331).

5. The grouting device as described in claim 4, characterized in that, The grouting holes are arranged axially along the height direction.

6. The grouting device as described in claim 4, characterized in that, The grouting holes are arranged axially in the horizontal direction.

7. The grouting device as described in claim 4, characterized in that, The tension of the elastic element in the multiple sets of grouting conveying assemblies (3) increases gradually from bottom to top.

8. The grouting device as described in claim 4, characterized in that, The sealing component (331) includes a cone (3311) and a cover (3312) connected to each other. The large end of the cone (3311) is connected to the cover (3312). The cone (3311) is inserted into the grouting hole. The side of the cover (3312) facing the cone (3311) contacts the outer wall of the grouting ring (32).

9. The grouting device as described in claim 8, characterized in that, The outer side of the cover (3312) is covered with a rubber layer, which is in contact with the outer wall of the grouting ring (32).

10. The grouting device as described in claim 3, characterized in that, The connector (4) includes a first connector (41), a connecting pipe (42), and a second connector (43). One end of the connecting pipe (42) is connected to the first connector (41), and the other end is connected to the second connector (43). The first connector (41) is connected to the conveying pipe of the grouting conveying assembly (3) located above, and the second connector (43) is connected to the conveying pipe of the grouting conveying assembly (3) located below.

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