Pile hole grouting device for sand layer and gravel layer sites and construction method of pile hole grouting device
By using a bottom-up continuous grouting method, seamless connection is achieved when drilling in sand and gravel layers using auger drill rods and chemical grout, solving the problems of hole collapse and environmental pollution, and improving construction quality and efficiency.
Patent Information
- Authority / Receiving Office
- CN · China
- Patent Type
- Applications(China)
- Current Assignee / Owner
- SHAANXI LONGHAI XINCHUANG FOUNDATION ENG CO LTD
- Filing Date
- 2026-03-19
- Publication Date
- 2026-05-12
AI Technical Summary
When drilling in sandy and gravelly areas, conventional mud wall protection is ineffective, with a high probability of borehole collapse, resulting in low construction quality and efficiency, as well as mud spillage causing environmental pollution and high costs.
The bottom-up, continuous grouting method is adopted. The movable cover plate at the bottom of the auger drill rod opens automatically. Combined with the grout delivery channel and grout storage tank, the drilling and grouting are seamlessly connected. The hole wall is reinforced with chemical liquid grout made of high molecular polymer material to prevent mud overflow.
It effectively suppresses borehole collapse, reduces construction costs, improves construction efficiency, ensures construction quality, avoids environmental pollution, and achieves effective reinforcement of loose strata.
Smart Images
Figure CN122013791A_ABST
Abstract
Description
Technical Field
[0001] This invention relates to the field of civil engineering technology, and in particular to a pile hole grouting device and its construction method for sand and gravel layers. Background Technology
[0002] Concrete-poured piles are a common type of pile, possessing strong stability and strength. However, when drilling in areas with sand or gravel layers, failure to protect the borehole wall can lead to collapse, making subsequent construction impossible. Therefore, protecting the borehole wall is essential. Currently, the conventional method for protecting the borehole wall is to use drilling mud, typically prepared from bentonite or a mixture of bentonite and crushed clay. For drilling in sand and gravel layers, a large mud pit is usually set up on-site. During drilling, the mud from the mud pit is continuously poured into the borehole from top to bottom. Inside the borehole, during the process, a mud pump at the center of the borehole extracts the viscous mud to the ground, where it is then reinjected into a mud pit for sedimentation. The settled and diluted mud is then recycled back into the pile hole to complete the wall grouting. However, the existing technology has poor wall protection effect and a high probability of borehole collapse. Furthermore, when grouting is performed from the ground surface downwards, the drilling rods are driven down sequentially, which can easily cause the circulating mud to overflow from the borehole opening, resulting in serious environmental pollution. This necessitates subsequent solidification of the overflowing mud sediment, which not only increases costs but also significantly reduces the overall construction quality and efficiency. Summary of the Invention
[0004] This invention provides a pile hole grouting device and its construction method for sand and gravel layer sites, which can effectively solve the problem of hole collapse, achieve zero pollution to the site environment, reduce costs and improve construction efficiency and quality.
[0005] This invention provides a grouting device for pile holes in sand and gravel layers, including a drilling rig power head and a spiral drill rod connected to the rotating end of the drilling rig power head. The length of the spiral drill rod matches the depth of the foundation hole. A grout delivery channel is provided in the middle of the spiral drill rod. A drill bit is fixed to the bottom end of the spiral drill rod by a flange. The grout outlet is located below the drill bit, and a rotatable conical movable cover plate is hinged to one side of the grout outlet. As the spiral drill rod is raised, the movable cover plate below the drill bit automatically rotates and opens under its own weight. The grouting device also includes a pipe body, a connecting sleeve, a grout storage tank, and a grout delivery pipe, which allows the slurry in the grout delivery channel to flow out. The pipe body is hollow and has a grout inlet at the top. The connecting sleeve is inserted into the top of the spiral rod of the auger and the two are rotatably connected. The lower end of the pipe body is inserted into the connecting sleeve. As the auger rotates, the pipe body remains stationary. The grout storage tank is filled with chemical slurry for reinforcing the inner wall of the foundation hole. One end of the grout delivery pipe extends into the grout storage tank, and the other end is connected to the grout inlet. The slurry is delivered from the grout storage tank to the grout inlet.
[0006] Preferably, the end of the slurry delivery pipe placed inside the slurry storage tank is connected to a slurry delivery pump, which is used to pressurize and deliver the slurry from the storage tank into the slurry delivery pipe.
[0007] Preferably, the chemical slurry comprises a polymeric material, polyacrylamide, and water.
[0008] Preferably, the drilling rig power head includes a support for support, and a support platform is provided on one side of the drilling rig power head. The support platform includes a base, a tower, and a winch device. The base is supported by the ground, and the tower is fixedly connected to the base. A longitudinally extending slide rail is provided on one side of the tower, and the lower part of the tower is movable. The support of the drilling rig power head is slidably connected to the slide rail on the side wall of the tower through a sliding member. The winch device is used for hoisting and raising the longitudinal displacement of the slide rail of the drilling rig power head to adjust the height.
[0009] Preferably, the depth of the chemical grouting pile hole is 6m to 50m, and the diameter of the chemical grouting pile hole is 400mm to 800mm.
[0010] Preferably, the drilling rig power head also includes a motor, a reducer, a drive gear, and a driven gear. The upper end of the auger drill rod is inserted into the support of the drilling rig power head and the two are rotatably connected. The driven gear is fixedly sleeved on the upper part of the auger rod body. The motor housing and the reducer housing are both fixedly connected to the support. The motor output shaft is fixedly connected to the reducer input shaft. The drive gear is sleeved and fixedly connected to the reducer output shaft. The drive gear and the driven gear mesh.
[0011] Preferably, the grout delivery pipe is a flexible pipe structure with an allowable length for extension.
[0012] This invention also provides a construction method for a pile hole grouting device for sand and gravel layers, comprising the following steps: Drilling rig power head positioning and drilling: The pile hole grouting device is located at the preset pile position. Start the drilling rig power head to drive the spiral drill rod to rotate, so that the spiral drill rod drills vertically into the soil layer until the designed hole depth is reached. During the drilling process, the spiral blades continuously transport the soil in the hole to the hole opening, realizing dry operation of soil extraction and hole formation. Grouting preparation: After the drilling depth reaches the design requirements, stop drilling and keep the auger rod at the bottom of the hole; Opening the grout outlet and grouting: Start the winch equipment and slowly lift the auger drill rod. The movable cover plate of the drill bit rotates downward around the hinge point under its own weight and opens. Start the grout pump and transport the pre-mixed chemical slurry in the slurry storage tank to the grout inlet of the pipe body through the grout delivery pipe. The slurry flows out through the connecting sleeve, the grout delivery channel of the auger drill rod, and the drill bit in sequence and is injected into the bottom of the hole. Grouting while drilling: During the continuous lifting of the auger drill rod, the grouting pump is kept running continuously, so that the chemical grout is continuously injected into the pile hole from the bottom of the hole upwards until the auger drill rod is completely pulled out of the hole and the chemical grout fills the entire pile hole.
[0013] Compared with existing technologies, the beneficial effects of this invention are as follows: This invention uses an integrated drilling and grouting technique, employing bottom-up, continuous grouting to reinforce the borehole wall. This effectively reinforces loose strata while minimizing disturbance to the borehole wall, significantly improving construction quality. Because grouting is performed at the bottom of the pile hole using a spiral drill rod, repeated grouting operations using a grout pump are eliminated, greatly improving construction efficiency. During grouting, the lifting of the spiral drill rod is synchronized with the grouting rate, preventing mud overflow and environmental pollution. Since this invention does not involve mud overflow, subsequent mud solidification steps are also unnecessary, significantly reducing costs. Furthermore, compared to traditional structures, this invention produces transportable and reusable soil, not mud, that is drilled from the pile hole opening during the drilling process.
[0014] Specifically, by setting the auger drill rod to a hollow structure and opening a grouting channel, and by setting a hinged drill bit at the bottom of the drill rod and a structure that automatically opens by the weight of the drill bit's movable cover plate, a seamless connection between drilling and grouting is achieved. After drilling is completed, grouting can be carried out directly without excessive drilling. At the same time, by setting a connecting sleeve at the top of the auger drill rod that rotates with the pipe body, the pipe body remains stationary during the rotation of the drill rod, ensuring a stable connection and continuous grout supply in the grouting pipeline, and avoiding pipeline entanglement or leakage caused by the rotation of the drill rod. The chemical slurry pre-mixed in the grout storage tank of this invention is directly injected into the bottom of the hole through the grouting pipe, pipe body, connecting sleeve, grouting channel, and drill bit, and continuously fills the pile hole from bottom to top as the drill rod is slowly lifted, achieving immediate support and reinforcement of the hole wall and effectively suppressing the occurrence of hole collapse. Attached Figure Description
[0016] Figure 1 A schematic diagram of a pile hole grouting device for sand and gravel layer sites provided in an embodiment of the present invention; Figure 2 A schematic diagram of a portion of the drill bit structure of a pile hole grouting device for sand and gravel layers provided in an embodiment of the present invention; Figure 3 This is a front cross-sectional view of a portion of the drilling rig power head of a pile hole grouting device for sand and gravel layers, provided as an embodiment of the present invention.
[0017] Explanation of reference numerals in the attached figures: 1. Drilling rig power head; 11. Motor; 12. Reducer; 13. Drive gear; 14. Driven gear; 15. Support; 2. Spiral drill rod; 21. Grouting channel; 22. Spiral rod body; 31. Grouting inlet; 4. Connecting sleeve; 5. Grouting tank; 6. Grouting pipe; 7. Grouting pump; 8. Support platform; 81. Base; 82. Tower; 83. Slide rail; 84. Winch equipment. Detailed Implementation
[0018] The following detailed description of a specific embodiment of the present invention is provided in conjunction with the accompanying drawings. However, it should be understood that the scope of protection of the present invention is not limited to the specific embodiment.
[0019] 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," "axial," "radial," and "circumferential" indicate the orientation or positional relationship based on the orientation or positional relationship shown in the accompanying drawings. They are only for the convenience of describing the technical solution of this 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. Therefore, they should not be construed as limitations on this invention.
[0020] refer to Figure 1 , Figure 2 and Figure 3This invention provides a grouting device for pile holes in sand and gravel layers, including a drilling head 1 and a spiral drill rod 2 connected to the rotating end of the drilling head 1. The length of the spiral drill rod 2 matches the depth of the foundation hole. A grouting channel 21 is provided in the middle of the spiral drill rod 2. A drill bit 23 is fixedly connected to the bottom end of the spiral drill rod 2 via a flange. The grout outlet is located below the drill bit 23, and a rotatable conical movable cover plate 24 is hinged to one side of the grout outlet. As the spiral drill rod 2 is raised, the movable cover plate 24 below the drill bit 23 automatically rotates and opens under its own weight to facilitate grout delivery. The slurry flows out of channel 21. The grouting device also includes: pipe body 3, connecting sleeve 4, slurry storage tank 5 and slurry delivery pipe 6. The pipe body 3 is hollow and has a slurry inlet 31 at the top. The connecting sleeve 4 is inserted into the top of the spiral rod 22 of the spiral drill rod 2 and the two are rotatably connected. The lower end of the pipe body 3 is inserted into the connecting sleeve 4. As the spiral drill rod 2 rotates, the pipe body 3 remains stationary. The slurry storage tank 5 is filled with chemical slurry for reinforcing the inner wall of the foundation hole. One end of the slurry delivery pipe 6 extends into the slurry storage tank 5 and the other end is connected to the slurry inlet 31. The slurry is delivered to the slurry inlet 31 through the slurry storage tank 5.
[0021] In the above embodiments, the present invention, through integrated drilling and grouting, bottom-up, and continuous grouting to reinforce the borehole wall, effectively reinforces loose strata while minimizing disturbance to the borehole wall, significantly improving construction quality. Since grouting is performed at the bottom of the pile hole via the auger drill rod 2, repeated grouting operations using a grout pump are eliminated, greatly improving construction efficiency. During grouting, the lifting of the auger drill rod 2 is synchronized with the grouting rate, preventing mud overflow and environmental pollution. Because there is no mud overflow, subsequent mud solidification steps are also unnecessary, significantly reducing costs. Furthermore, compared to traditional structures, the material drilled from the pile hole is transportable and reusable soil, not mud. Specifically, this is achieved by setting the auger drill rod 2 as a hollow structure and opening... The grouting channel 21, along with the hinged drill bit 23 at the bottom of the drill rod and the movable cover plate 24 of the drill bit 23 which automatically opens under its own weight, achieves seamless connection between drilling and grouting. After drilling is completed, grouting can be carried out directly without excessive drilling. At the same time, by setting a connecting sleeve 4 at the top of the spiral drill rod 2 that is rotatably connected to the pipe body 3, the pipe body 3 remains stationary during the rotation of the drill rod, ensuring stable connection and continuous grout supply of the grouting pipe 6, and avoiding pipe entanglement or leakage caused by the rotation of the drill rod. The chemical slurry pre-mixed in the grout storage tank 5 of this invention is directly injected into the bottom of the hole through the grouting pipe 6, pipe body 3, connecting sleeve 4, grouting channel 21, drill bit 23 and movable cover plate 24, and continuously fills the pile hole from bottom to top as the drill rod is slowly lifted, achieving immediate support and reinforcement of the hole wall. Compared with mud wall protection, it effectively inhibits the occurrence of hole collapse.
[0022] Further, refer to Figure 1 The end of the slurry delivery pipe 6 placed inside the slurry storage tank 5 is connected to a slurry delivery pump 7, which is used to pressurize and deliver the slurry in the slurry storage tank 5 into the slurry delivery pipe 6.
[0023] In the above embodiments, the present invention uses a grout pump 7 to pressurize and transport the chemical slurry, ensuring smooth flow of the slurry in the grouting pipe 6 and the grouting channel 21 of the drill pipe. This avoids insufficient slurry supply or flow interruption caused by pipeline resistance or excessively high slurry viscosity, ensuring the continuity and uniformity of the grouting process. At the same time, the pressurizing effect of the grout pump 7 allows the slurry to be injected into the bottom of the hole at a sufficient flow rate and pressure, which is beneficial to the penetration and diffusion of the slurry in the pores of the hole wall, further enhancing the wall protection effect and improving the reliability of grouting reinforcement.
[0024] Furthermore, the chemical slurry comprises the polymer material polyacrylamide and water.
[0025] In the above embodiments, the present invention optimizes the composition design of the chemical slurry by using a compound of polymer and wall-protecting agents to give the slurry good fluidity, permeability and curing performance. After being injected into the borehole wall, the chemical slurry can quickly penetrate into the pores of the loose soil and effectively improve the integrity and anti-collapse ability of the borehole wall soil through cementation and curing. Preferably, 20 kg to 60 kg of polymer material in one cubic meter of water is dissolved and thoroughly stirred to form the chemical slurry. The ratio is determined according to the particle size of sand and gravel.
[0026] Further, refer to Figure 1 and Figure 3 The drilling rig power head 1 includes a support 15 for support. A support platform 8 is provided on one side of the drilling rig power head 1. The support platform 8 includes a base 81, a tower 82 and a winch device 84. The base 81 is supported by the ground, and the tower 82 is fixedly connected to the base 81. A longitudinally extending slide rail 83 is provided on one side of the tower 82. The support 15 of the drilling rig power head 1 is slidably connected to the slide rail 83 on the side wall of the tower 82 through a sliding member. The winch device 84 is used to hoist and lift the drilling rig power head 1 to adjust its height by longitudinally displacing it along the slide rail 83.
[0027] In the above embodiments, the present invention, by setting up a support platform 8 composed of a base 81, a tower 82, a slide rail 83, and a winch device 84, achieves stable support and precise lifting control of the drilling rig power head 1 during drilling and grouting processes. The winch device 84 drives the drilling rig power head 1 to move longitudinally along the slide rail 83, ensuring uniform feed of the spiral drill rod 2 during drilling and smooth lifting during grouting, avoiding hole wall disturbance or drilling deviation caused by drill rod vibration or tilting. The reinforcing ribs set between the tower 82 and the base 81 further enhance the stability of the structure, meeting the mechanical requirements of deep hole and large-diameter drilling construction. Specifically, the spiral rod body 22 of the spiral drill rod 2 is rotatably inserted into the support platform through multiple bearings. Inside the base 15, the connecting sleeve 4 is welded and fixed to the support 15. The connecting sleeve 4 and the spiral rod body 22 rotate relative to each other in a sealed manner. The winch device 84 includes a winch motor, a steel wire rope for pulling, a drum for winding the steel wire rope, and a pulley block. By rotating the winch motor, the steel wire rope is tightened. Under the guidance of the pulley block, the steel wire rope drives the support 15 of the drilling rig power head 1 to slide longitudinally along the slide rail 83 by means of a sliding member, so as to adjust the overall height of the drilling rig power head 1 and the spiral drill rod 2. Considering that the connection point between the tower 82 and the base 81 needs to withstand high stress, in this embodiment, an inclined reinforcing rib is fixed between the flange of the tower 82 and the base 81 to enhance stability.
[0028] Furthermore, the depth of the chemical grouting pile hole is 6m to 50m, and the diameter of the chemical grouting pile hole is 400mm to 800mm.
[0029] In the above embodiments, the numerical range set by the present invention covers the construction needs of most rammed and expanded cast-in-place piles in the field of civil engineering, and has good versatility and adaptability. This range can not only meet the accuracy requirements of shallow foundation construction, but also adapt to the needs of deep foundation engineering with large depth and large diameter operations, providing flexible technical options for different engineering scenarios.
[0030] Further, refer to Figure 1 and Figure 3 The drilling rig power head 1 also includes a motor 11, a reducer 12, a drive gear 13, and a driven gear 14. The upper end of the spiral drill rod 2 is inserted into the support 15 of the drilling rig power head 1 and the two are rotatably connected. The driven gear 14 is fixedly sleeved on the upper part of the spiral rod body 22 of the spiral drill rod 2. The housing of the motor 11 and the housing of the reducer 12 are both fixedly connected to the support 15. The output shaft of the motor 11 is fixedly connected to the input shaft of the reducer 12. The drive gear 13 is sleeved and fixedly connected to the output shaft of the reducer 12. The drive gear 13 meshes with the driven gear 14.
[0031] In the above embodiments, the present invention drives the spiral drill rod 2 to rotate through a gear transmission system composed of a motor 11, a reducer 12, a drive gear 13, and a driven gear 14, thereby achieving smooth power output transmission and precise speed control. The gear transmission structure is compact, has high transmission efficiency, and strong load-bearing capacity, and can adapt to the high torque drilling requirements under complex geological conditions. At the same time, the integrated installation design of the motor 11, reducer 12, and support 15 reduces the equipment footprint and improves the flexibility of on-site layout.
[0032] Further, refer to Figure 1 The grout delivery pipe 6 is a soft pipe structure with an allowable length for extension.
[0033] In the above embodiments, by setting the grout delivery pipe 6 as a flexible pipe structure and reserving a length margin, the longitudinal displacement requirements of the drill rod during drilling and grouting are effectively met, avoiding the problems of pulling, breaking or leakage caused by rigid pipe connection. Moreover, the flexible pipe structure is also convenient for quick on-site deployment and storage, improving construction efficiency and reducing the difficulty of equipment installation.
[0034] Specifically, the grout delivery pipe 6 is fitted onto the grout inlet 31 of the pipe body 3. The grout delivery pipe 6 is bound with cable ties for sealing and fixing at the position corresponding to the position of the pipe body 3. This invention uses cable ties to bind and seal the connection between the grout delivery pipe 6 and the grout inlet 31 of the pipe body 3, ensuring the reliability of the pipeline connection, preventing grout leakage during high-pressure grouting, and ensuring the cleanliness of the construction environment and the safety of the operators. This connection method has a simple structure, is easy to disassemble and assemble, and is convenient for quick on-site maintenance and replacement. Since cable ties are a conventional technical means, this invention is not shown in the figure.
[0035] This invention also provides a construction method for a pile hole grouting device for sand and gravel layers, comprising the following steps: Drilling power head 1 positioning and drilling: The pile hole grouting device is located at the preset pile position. Rotate the movable cover plate 24 under the drill bit 23 so that the movable cover plate 24 seals the lower opening of the spiral rod body 22 and the grout outlet of the drill bit 23. Start the drilling power head 1 to drive the spiral drill rod 2 to rotate, so that the spiral drill rod 2 drills vertically into the soil layer until the designed hole depth is reached. During the drilling process, the movable cover plate 24 and the drill bit 23 are always in a sealed and tight state during the pressure process. The spiral blades continuously transport the soil in the hole to the hole opening to realize dry operation of soil extraction and hole formation. Grouting preparation: After the drilling depth reaches the design requirements, stop drilling and keep the auger rod 2 at the bottom of the hole; Opening the grout outlet and grouting: Start the winch 84 and slowly lift the spiral drill rod 2. Due to the hinge, the movable cover plate 24 of the drill bit 23 rotates downward around the hinge point under its own weight and opens. Start the grout pump 7 and transport the pre-mixed chemical slurry in the slurry storage tank 5 to the grout inlet 31 of the pipe body 3 through the grout pipe 6. The slurry flows out through the connecting sleeve 4, the grout channel 21 of the spiral drill rod 2, and the drill bit 23 in sequence and is injected into the bottom of the hole. Grouting while lifting the drill rod: During the continuous lifting of the auger rod 2, the grouting pump 7 is kept running continuously, so that the chemical grout is continuously injected into the pile hole from the bottom of the hole upwards until the auger rod 2 is completely lifted out of the hole and the chemical grout fills the entire pile hole.
[0036] In the above embodiments, after grouting is completed, the pile hole grouting device is removed, and the rammed and expanded pile construction equipment is placed at the grouted pile hole for subsequent rammed and expanded cast-in-place pile construction. Through the integrated drilling and grouting process, which proceeds from bottom to top and is continuous, seamless connection between drilling and grouting is achieved, avoiding the risk of hole collapse caused by prolonged exposure of the hole wall after drilling in traditional processes. During the grouting process, the grout continuously fills from the bottom of the hole upwards, effectively expelling water and air from the hole and ensuring full contact and penetration between the grout and the hole wall, forming a uniform and dense protective layer. This method has a clear operation process and well-defined control parameters, making it easy to implement on-site and control quality. It provides an efficient and reliable solution for rammed and expanded cast-in-place pile construction in loose strata.
[0037] Specifically, the lifting speed of the auger drill rod 2 is matched with the grouting flow rate of the grouting pump 7 to ensure that the chemical grout is continuously filled in the pile hole without interruption. The chemical grout is prepared according to the formation collapse situation and is made of high molecular polymer and wall protection agent. It is used to reinforce the hole wall of easily collapsed formations such as sand layer, gravel layer or backfill soil layer.
[0038] The movable cover plate 24 is opened as follows: when the drill bit 23 is at the bottom of the hole and the spiral drill rod 2 is lifted, the movable cover plate 24 of the drill bit 23 is automatically disengaged from the drill bit 23, and the movable cover plate 24 swings downward around the hinge point under the action of gravity, so that the grouting channel 21 and the grout outlet are in an open state.
[0039] The present invention also provides a method for subsequent rammed and expanded cast-in-place pile construction, specifically: The special rammed pile driver is positioned at the pile hole, and the pile pipe is driven into the soil layer around the grouted pile hole, so that the bottom end of the pile pipe enters the soil layer to a certain height. The cylindrical hammer is used to compact the soil at the bottom of the pile tube, thus sealing the bottom of the pile tube. After sealing, the pile pipe is sunk into the grouted pile hole. Dry-hard concrete is poured into the pile pipe, and a cylindrical heavy hammer is used to ram the dry-hard concrete at the bottom of the pile pipe, so that the sealing soil and part of the dry-hard concrete are rammed out of the bottom of the pile pipe, forming an enlarged head of dry-hard concrete. The reinforcing cage is placed into the pile pipe, and concrete is poured into the pile pipe. Concrete is poured in while the pile pipe is being pulled out, until the pile pipe is completely pulled out of the ground, thus completing the pile foundation construction.
[0040] This invention provides an implementation example: Geological overview of a certain project (from top to bottom) ① Fine sand layer 8m, ② Medium sand layer 3m, ③ Sandstone.
[0041] The design scheme involves drilling holes at the pile locations first, followed by the construction of rammed and enlarged concrete cast-in-place piles. The piles are 11m long, with sandstone as the bearing layer, a pile diameter of Ф500mm, a single pile bearing capacity of 4000KN, and a total of 1250 piles.
[0042] Implementation plan: First, drill holes at the pile locations according to the design requirements. The hole diameter is Ф500mm and the drilling depth is 11m. The drilling is carried out using the technology of this invention. The long spiral drill rod 2 has a diameter of Ф500mm and a length greater than 11m. Stop drilling at a depth of 11m, turn on the winch 84, and simultaneously turn on the grout pump 7. While lifting the spiral drill rod 2, inject chemical grout into the pile hole until the hole opening is reached. Then, sink the pile pipe of the rammed and enlarged pile into the pile hole and complete the entire pile foundation construction according to the rammed and enlarged cast-in-place pile construction process.
[0043] The above-disclosed embodiments are merely a few specific examples of the present invention. However, the embodiments of the present invention are not limited thereto, and any variations that can be conceived by those skilled in the art should fall within the protection scope of the present invention.
Claims
1. A grouting device for pile holes in sandy or gravelly soil layers, characterized in that, The device includes a drilling rig power head (1) and a spiral drill rod (2) connected to the rotating end of the drilling rig power head (1). The spiral drill rod (2) has a length matching the depth of the foundation hole, a grouting channel (21) in the middle of the spiral drill rod (2), a drill bit (23) fixedly connected to the bottom end of the spiral drill rod (2) via a flange, a grout outlet below the drill bit (23), and a rotatable conical movable cover plate (24) hinged to one side of the grout outlet. As the spiral drill rod (2) is raised, the movable cover plate (24) below the drill bit (23) automatically rotates and opens by its own weight to allow the grout in the grouting channel (21) to flow out. The grouting device also includes: The tube body (3) is hollow and has a slurry inlet (31) at the top. The connecting sleeve (4) is inserted into the top of the spiral rod body (22) of the spiral drill rod (2) and the two are rotatably connected. The lower end of the tube body (3) is inserted into the connecting sleeve (4). As the spiral drill rod (2) rotates, the tube body (3) remains stationary. The slurry storage tank (5) is filled with chemical slurry for reinforcing the inner wall of the foundation hole; The slurry delivery pipe (6) extends into the slurry storage tank (5) at one end and is connected to the slurry inlet (31) at the other end. The slurry is delivered from the slurry storage tank (5) to the slurry inlet (31).
2. The pile hole grouting device for sand and gravel layers as described in claim 1, characterized in that, The end of the slurry delivery pipe (6) placed inside the slurry storage tank (5) is connected to a slurry delivery pump (7), which is used to pressurize and deliver the slurry in the slurry storage tank (5) into the slurry delivery pipe (6).
3. The pile hole grouting device for sand and gravel layers as described in claim 1, characterized in that, The chemical slurry comprises polyacrylamide, a polymeric material, and water.
4. A pile hole grouting device for sand and gravel layers as described in claim 2, characterized in that, The drilling rig power head (1) includes a support (15) for support, and a support platform (8) is provided on one side of the drilling rig power head (1). The support platform (8) includes: The base (81) is supported by the ground; The tower (82) is fixedly connected to the base (81). A slide rail (83) extending longitudinally is provided on one side of the tower (82). The support (15) of the drilling rig power head (1) is slidably connected to the slide rail (83) on the side wall of the tower (82) through a sliding member. The bottom of the tower (82) can be displaced. A winch (84) is used to hoist and raise the drill power head (1) longitudinally along the slide rail (83) to adjust its height.
5. A pile hole grouting device for sand and gravel layers as described in claim 1, characterized in that, The depth of the chemical grouting pile hole is 6m to 50m, and the diameter of the chemical grouting pile hole is 400mm to 800mm.
6. A pile hole grouting device for sand and gravel layers as described in claim 4, characterized in that, The drilling rig power head (1) also includes a motor (11), a reducer (12), a drive gear (13), and a driven gear (14). The upper end of the spiral drill rod (2) is inserted into the support (15) of the drilling rig power head (1) and the two are rotatably connected. The driven gear (14) is fixedly sleeved on the upper part of the spiral rod body (22) of the spiral drill rod (2). The housing of the motor (11) and the housing of the reducer (12) are both fixedly connected to the support (15). The output shaft of the motor (11) is fixedly connected to the input shaft of the reducer (12). The drive gear (13) is sleeved and fixedly connected to the output shaft of the reducer (12). The drive gear (13) meshes with the driven gear (14).
7. A pile hole grouting device for sand and gravel layers as described in claim 1, characterized in that, The grout delivery pipe (6) is a soft pipe structure with an extended length allowance.
8. A pile hole grouting device for sand and gravel layers as described in claim 1, characterized in that, An inclined reinforcing rib is fixed between the tower (82) and the base (81) via a flange to enhance stability.
9. A construction method for a pile hole grouting device for sand and gravel layers as described in claim 6, characterized in that, Includes the following steps: Drilling power head (1) positioning and drilling: The pile hole grouting device is located at the preset pile position. Start the drilling power head (1) to drive the spiral drill rod (2) to rotate, so that the spiral drill rod (2) drills vertically into the soil layer until the designed hole depth is reached. During the drilling process, the spiral blades continuously transport the soil in the hole to the hole opening to realize dry operation of soil extraction and hole formation. Grouting preparation: After the drilling depth reaches the design requirements, stop drilling and keep the auger rod (2) at the bottom of the hole; Open the grout outlet and grouting: Start the winch (84), slowly lift the spiral drill rod (2), and the movable cover plate (24) of the drill bit (23) rotates downward around the hinge point under its own weight to open. Start the grout pump (7) to transport the pre-mixed chemical liquid slurry in the slurry storage tank (5) to the grout inlet (31) of the pipe body (3) through the grout pipe (6). The liquid slurry flows out through the connecting sleeve (4), the grouting channel (21) of the spiral drill rod (2), and the drill bit (23) in sequence and is injected into the bottom of the hole. Grouting while lifting the drill rod: During the continuous lifting of the auger rod (2), the grouting pump (7) is kept working continuously so that the chemical grout is continuously injected into the pile hole from the bottom of the hole upwards until the auger rod (2) is completely lifted out of the hole and the chemical grout fills the entire pile hole.