Bidirectional stirring construction process for improving overall uniformity of pile body
The design of large-circulation bidirectional mixing equipment and sickle-shaped blades solved the problem of uneven pile strength and achieved overall uniformity and stability of the pile body.
Patent Information
- Application Number
- CN202511278874.8
- Authority / Receiving Office
- CN · China
- Patent Type
- Applications(China)
- Current Assignee / Owner
- Priority Date
- 2025-09-02
- Filing Date
- 2025-09-09
- Publication Date
- 2025-10-17
AI Technical Summary
In existing two-way mixing construction, there is a problem that the spraying medium and the soil layer are mixed unevenly, resulting in uneven pile strength, especially the strength at the center of the pile is higher than the strength at the edge of the pile.
A large-circulation bidirectional mixing device is used. The inner drill rod and the outer drill rod rotate in opposite directions. The inner drill bit and the outer drill bit are connected. A large-circulation structure is set on the outside of the casing. The sickle-shaped blades are used to mix and solidify the slurry in the radial and longitudinal directions to ensure the overall uniformity of the pile body.
The uniformity of the overall strength of the pile body is achieved, ensuring that the upper and lower layers of soil are fully mixed, and improving the overall quality and stability of the pile body.
Smart Images
Figure CN120797658A_ABST
Abstract
Description
Technical Field
[0001] The present invention relates to the technical field of pile foundations, and in particular to a bidirectional mixing construction process for improving the overall uniformity of a pile body. Background Art
[0002] Soft soil refers to fine-grained soil deposited along coasts, lakes, valleys, and riverbanks. It has a naturally high water content, a large porosity, high compressibility, and low shear strength. The construction of an increasing number of highways, railways, and ports will inevitably pass through areas with soft soil foundations. Strengthening the foundation with cement-soil mixing piles is a common improvement measure. Bidirectional mixing piles utilize cement / curing agent as the solidifying material. Using specialized mixing machinery and slurry pumps, the soft soil and curing material are forcibly mixed deep within the foundation. Through a series of physical and chemical reactions between the curing material and the soft soil, the soft soil is hardened into a composite foundation with integrity, water stability, and a high bearing capacity.
[0003] Currently, two major issues with bidirectional mixing construction are uneven mixing of the spraying medium (cement slurry or powdered material) with the soil layer; and significant variations in geological parameters between different strata, resulting in inconsistent pile quality at different depths when using the same solidifying material for reinforcement. Existing bidirectional mixing technology often uses spray nozzles located on the inner drill pipe surface, which can easily lead to grouting and accumulation. This results in uneven pile strength after hardening, with the center of the pile being much stronger than the edge.
[0004] Based on this, the present invention is very necessary to fundamentally improve the existing mixing technology, otherwise it will inevitably limit the applicability of the two-way mixing process. Based on this, the present invention proposes a two-way mixing construction process that improves the overall uniformity of the pile body. Summary of the Invention
[0005] In response to the above-mentioned technical problems existing in the prior art, the present invention proposes a two-way mixing construction process to improve the overall uniformity of the pile body, thereby overcoming the shortcomings of the prior art. When the mixing pile crosses different soil layers, the mixing effect is inconsistent, and the same stratum cannot be migrated longitudinally after being mixed evenly, that is, the solidified soil of the upper and lower layers cannot be fully mixed to form a uniform material. By setting up a large circulation structure, the entire pile can be fully mixed to ensure the uniform strength of the overall pile body. During radial mixing, the two layers of sickle-shaped blades on the inner drill bit form an inward and outward turning effect, which promotes the full mixing of the solidified slurry within the radial range.
[0006] The application discloses a bidirectional mixing construction technology for improving the overall uniformity of a pile body, characterized by adopting a large-circulation bidirectional mixing equipment for construction, wherein a power head drives an inner drill rod and an outer drill rod to rotate in opposite directions, the lower ends of the inner drill rod and the outer drill rod are connected with an inner drill bit and an outer drill bit respectively, a sleeve is coaxially arranged outside the outer drill rod, and two sets of large-circulation structures are symmetrically arranged on the sleeve; the large-circulation structure comprises a transmission wheel arranged between the sleeve and the power head, the transmission wheel drives a chain to rotate in a ring shape, a stirring plate is arranged on the chain, and a rib plate is welded on the sleeve and located between the ring-shaped chains; at least two layers of blades are arranged on the inner drill bit, the two layers of blades are in a sickle-shaped structure, and the bending directions of the two layers of blades are opposite; and the specific construction technology is as follows. Step one: preparation before construction The sizes of the inner drill bit and the outer drill bit are selected according to the designed pile diameter, and the length and width of the rib plate are selected; the interval of the holes opened on the rib plate is selected according to the stratum condition; and the equipment is moved to the designed pile position, and the drill tip is aligned with the center of the pile position. Step two: downhole construction The power head is started to drive the inner drill rod and the outer drill rod to rotate in opposite directions, thereby driving the inner drill bit and the outer drill bit to rotate in opposite directions, and the downhole construction is started; when the inner drill bit and the outer drill bit enter below the ground, the solidifying agent slurry is started to be sprayed; when the lower transmission wheel in the large-circulation structure enters below the ground, the two sets of large-circulation structures are started; at this time, the rotation of the inner drill bit drives the two layers of sickle-shaped structures to rotate, the solidifying agent slurry is reciprocatingly migrated along the radial direction of the pile body, the large-circulation structure drives the mixed solidifying agent slurry to be longitudinally migrated, and the reciprocating stirring is performed on the pile body to a certain height above the designed depth. Step three: uphole construction When the uphole construction is started, the rotation directions of the inner drill rod and the outer drill rod are opposite to those in the downhole construction; the solidifying agent slurry is continuously sprayed in the lifting process; when the lower transmission wheel in the large-circulation structure is lifted above the ground, the rotation is stopped; when the inner drill bit and the outer drill bit are lifted above the ground, the rotation is stopped, and the pumping of the solidifying agent slurry is stopped.
[0007] Preferably, the inner drill rod, the outer drill rod and the sleeve are coaxially arranged, the sleeve is located outside the outer drill rod, the sleeve and the outer drill rod are sealed by a sealing sleeve, a channel between the sleeve and the outer drill rod is used as a high-pressure gas channel, a gas nozzle is arranged on the sleeve, and whether to add gas is determined according to the construction condition.
[0008] Preferably, the length of the rib plate is the clearance height between the two transmission wheels, the outermost side of the rib plate is the same as the outermost side of the outer drill bit, the rib plate is provided with holes along the length direction, and the holes with different intervals are selected according to different project requirements.
[0009] Preferably, the reciprocating stirring height is 1.5-2.0 times the distance from the drill tip to the lower transmission wheel.
[0010] The application has the beneficial technical effects that: When mixing piles span different soil layers, the mixing effect is inconsistent. Even after mixing evenly within the same layer, the solidified soil in the upper and lower layers cannot be fully mixed to form a uniform material. By setting up a large circulation structure, the entire pile is fully mixed, ensuring uniform strength throughout the pile. During radial mixing, the two sickle-shaped blades on the inner drill bit create an inward and outward movement, promoting thorough mixing of the solidified slurry within the radial range. BRIEF DESCRIPTION OF THE DRAWINGS
[0011] Figure 1 This is a cross-sectional schematic diagram of a large-circulation bidirectional mixing device for improving the uniformity of the pile body according to the present invention.
[0012] Figure 2 This is a side schematic diagram of a large-circulation bidirectional mixing device for improving the uniformity of the pile body according to the present invention.
[0013] Figure 3 This is a schematic diagram of the inner drill bit structure of a large-circulation bidirectional mixing device for improving the uniformity of the pile body according to the present invention.
[0014] Figure 4 This is a schematic diagram of the different-side circulation of solidified slurry during the use of a large-circulation bidirectional mixing equipment for improving the uniformity of the pile body according to the present invention.
[0015] Figure 5 This is a schematic diagram of the same-side circulation of solidified slurry during use of a large-circulation bidirectional mixing equipment for improving pile body uniformity according to the present invention.
[0016] Among them, 1-power head, 2-inner drill rod, 3-outer drill rod, 4-casing, 5-drive wheel, 6-chain, 7-rib, 8-inner drill bit, 9-outer drill bit, 11-motor, 12-inner drill rod drive shaft, 13-inner drill rod gear, 14-outer drill rod drive shaft, 15-outer drill rod gear, 16-slurry pipe, 17-large circulation structure drive motor. DETAILED DESCRIPTION Example
[0017] like Figures 1-5 As shown, a bidirectional mixing construction process for improving the overall uniformity of the pile body is constructed using a large-circulation bidirectional mixing equipment. The power head 1 of the equipment drives the inner drill rod 2 and the outer drill rod 3 to rotate in opposite directions. The lower ends of the inner drill rod 2 and the outer drill rod 3 are connected to the inner drill bit 8 and the outer drill bit 9 respectively. A casing 4 is coaxially arranged on the outer side of the outer drill rod 3. Two sets of large-circulation structures are symmetrically arranged on the casing 4; the large-circulation structure includes: a transmission wheel 5 is arranged between the casing 4 and the power head 1, the transmission wheel 5 drives the chain 6 to rotate in an annular manner, and the chain 6 is provided with a stirring plate, and a rib 7 is welded to the casing 4 and is located between the rings of the chain 6; at least two layers of blades are arranged on the inner drill bit 8, both of which are sickle-shaped structures, but the bending directions of the two layers of blades are opposite; the specific construction process is as follows: Step one: preparation before construction According to the design pile diameter, the size of the inner drill bit 8 and the outer drill bit 9 is selected, the length and width of the rib plate 7 are selected; according to the stratum condition, the interval of the opening of the hole on the rib plate 7 is selected; the equipment is moved to the designed pile position, and the drill tip is aligned with the center of the pile position; Step two: drilling construction Start the power head, drive the inner drill rod 2 and the outer drill rod 3 to rotate in opposite directions, and then drive the inner drill bit 8 and the outer drill bit 9 to rotate in opposite directions, and start drilling. When the inner drill bit 8 and the outer drill bit 9 enter below the ground, start spraying the solidifying agent slurry. When the lower transmission wheel 5 in the large circulation structure enters below the ground, start the two sets of large circulation structure. At this time, the rotation of the inner drill bit 8 drives the two-layer sickle-shaped structure to rotate, and the solidifying agent slurry migrates and mixes along the radial direction of the pile body. The large circulation structure drives the mixed solidifying agent slurry to migrate longitudinally. When the designed depth is reached, the inner reciprocating stirring is within a certain height above the pile end; Step three: drilling construction When starting to pull out the drill, the rotation direction of the inner drill rod 2 and the outer drill rod 3 is opposite to that when drilling. The solidifying agent slurry is continuously sprayed during the lifting process. When the lower transmission wheel 5 in the large circulation structure is pulled out above the ground, the rotation is stopped. When the inner drill bit 8 and the outer drill bit 9 are pulled out above the ground, the rotation is stopped, and the pumping of the solidifying agent slurry is also stopped.
[0018] Preferably, the inner drill rod 2, the outer drill rod 3, and the casing 4 are coaxially arranged. The casing 4 is outside the outer drill rod 3. The casing 4 and the outer drill rod 3 are sealed by a sealing sleeve. The passage between the casing 4 and the outer drill rod 3 serves as a high-pressure gas passage. A gas nozzle is arranged on the casing 4. Whether to add gas is determined according to the construction situation.
[0019] Preferably, the length of the rib plate 7 is the clearance height between the two transmission wheels 5. The outermost side of the rib plate 7 is the same as the outermost side of the outer drill bit 9. The rib plate 7 is provided with holes along the length direction. Different intervals of the holes are selected according to different project requirements.
[0020] Preferably, the height of the reciprocating stirring is 1.5-2.0 times the distance from the drill tip to the lower transmission wheel 5. Embodiment
[0021] As Figures 1-5As shown, a large circulation bidirectional stirring device for improving pile uniformity, comprising a power head 1, an inner drill rod 2, an outer drill rod 3, a sleeve 3, a transmission wheel 5, a chain 6, a rib plate 7, an inner drill bit 8, and an outer drill bit 9; the power head 1 drives the inner drill rod 2 and the outer drill rod 3 to rotate in opposite directions, the lower ends of the inner drill rod 2 and the outer drill rod 3 are connected with the inner drill bit 8 and the outer drill bit 9 respectively, the outer side of the outer drill rod 3 is coaxially provided with the sleeve 3, and two sets of large circulation structures are symmetrically arranged on the sleeve 3; the large circulation structure comprises: the transmission wheel 5 is arranged between the sleeve 3 and the power head 1, the transmission wheel 5 drives the chain 6 to rotate in a ring shape, the chain 6 is provided with a stirring plate, the rib plate 7 is welded on the sleeve 3 and located between the chain 6 in a ring shape; the blades of the inner drill bit 8 are arranged in a sickle-shaped structure. When the mixing pile crosses different soil layers, the stirring effect is inconsistent, and the same stratum cannot be vertically migrated after uniform stirring, that is, the solidified soil of the upper and lower layers cannot be fully mixed to form a uniform material, by arranging the large circulation structure, the whole pile is fully mixed and uniform, and the overall strength of the pile body is ensured. When radial stirring, through the two layers of sickle-shaped blades on the inner drill bit 8, the effect of turning inward and lifting outward is formed, which promotes the mixing of the solidified slurry in the radial range.
[0022] Preferably, the power head 1 structure comprises a motor 11, an inner drill rod drive shaft 12, an inner drill rod gear 13, an outer drill rod drive shaft 14, an outer drill rod gear 15, a slurry pipe 16, and a large circulation structure drive motor 17; the motor 11 drives the inner drill rod drive shaft 12 and the outer drill rod drive shaft 14 to rotate, the inner drill rod drive shaft 12 is engaged with the inner drill rod gear 13 for transmission, the outer drill rod drive shaft 14 is engaged with the outer drill rod gear 15 for transmission, the slurry pipe 16 is connected with a faucet structure outside and connected with the inner drill rod 2 inside, and the slurry is transmitted to the inner drill bit 8 and sprayed out.
[0023] Preferably, the transmission wheel 5 is fixed by a transmission shaft, one end of the transmission shaft is connected with the large circulation structure drive motor 17, and the other end is connected with the sleeve 3 through a bearing.
[0024] Preferably, the inner drill rod 2, the outer drill rod 3, and the sleeve 3 are coaxially arranged, the sleeve 3 is located on the outer side of the outer drill rod 3, the sleeve 3 and the outer drill rod 3 are sealed by a sealing sleeve, the channel between the sleeve 3 and the outer drill rod 3 is used as a high-pressure gas channel, and a gas nozzle is arranged on the sleeve 3 to determine whether to add gas according to the construction condition. By increasing the gas, the solidified slurry is further mixed by gas lifting.
[0025] Preferably, the length of the rib plate 7 is the clearance height between the two transmission wheels 5, the outermost side of the rib plate 7 is the same as the outermost side of the outer drill bit 9, and the two rib plates 7 divide the pile body into two parts, and through the longitudinal movement of the chain 6, the solidified slurry is longitudinally migrated. When the two chains 6 rotate in the same direction, the two spaces separated by the rib plate 7, the solidified slurry in one space is migrated upward as a whole, and the solidified slurry in the other space is migrated downward as a whole, so that a large circulation of the whole pile is formed. The rib plate 7 is provided with holes along the length direction, and different intervals of holes are selected according to different project requirements. The holes provided on the rib plate 7 are used to change the depth of circulation, for example, the whole pile crosses less strata, mainly two strata, so that the holes can be arranged with a larger interval. When the two chains 6 rotate in opposite directions, the two spaces separated by the rib plate 7, the solidified slurry in the two spaces is migrated upward and downward by half, so that a large circulation of the half pile is formed.
[0026] Preferably, at least two layers of blades are arranged on the inner drill bit 8, and the two layers of blades are both in the shape of a sickle, but the bending directions of the two layers of blades are opposite. The different bending directions of the two layers of blades make the inner turning and the outer lifting not performed by the same layer, so that the mixing effect is better after the radial migration and stirring.
[0027] In the description of the embodiments of the present application, it should be understood that the terms "upper", "lower", and the like indicate the orientation or positional relationship shown in the drawings, and are only used to facilitate the description of the present application and simplify the description, and do not indicate or imply that the device or element referred to must have a particular orientation, be constructed and operated in a particular orientation, and therefore cannot be understood as a limitation on the present application. In the description of the present application, it should be noted that unless otherwise specified and limited, the terms "arranged", "connected" should be understood broadly, for example, it can be fixedly connected, or detachably connected, or integrally connected, it can be directly connected, or indirectly connected through an intermediate medium, or the internal communication of two elements. For those skilled in the art, the specific meaning of the above terms in the present application can be understood through specific circumstances.
[0028] Of course, the above description is not a limitation on the present application, and the present application is not limited to the above examples. Changes, modifications, additions or substitutions made by those skilled in the art within the essential scope of the present application also belong to the protection scope of the present application.
Claims
1. A bidirectional mixing construction process for improving the overall uniformity of a pile body, characterized in that: A large-circulation bidirectional mixing device is used for construction. The power head of the device drives the inner drill pipe and the outer drill pipe to rotate in opposite directions. The lower ends of the inner drill pipe and the outer drill pipe are connected to the inner drill bit and the outer drill bit respectively. A casing is coaxially arranged on the outer side of the outer drill pipe, and two sets of large-circulation structures are symmetrically arranged on the casing. The large-circulation structure includes: a transmission wheel is arranged between the casing and the power head, and the transmission wheel drives the chain to rotate in an annular manner. The chain is provided with a stirring plate. The ribs are welded to the casing and located between the chain rings. At least two layers of blades are arranged on the inner drill bit. Both layers of blades have a sickle-shaped structure, but the bending directions of the two layers of blades are opposite. The specific construction process is as follows: Step 1: Preparation before construction Select the sizes of the inner and outer drill bits according to the designed pile diameter, and the length and width of the ribs. Choose the spacing of the holes on the ribs according to the ground conditions. Move the equipment to the designed pile position, and align the drill tip with the center of the pile. Step 2: Drilling Start the power head, drive the inner drill rod and the outer drill rod to rotate in opposite directions, and then drive the inner drill bit and the outer drill bit to rotate in opposite directions, and start drilling. When the inner drill bit and the outer drill bit enter below the ground, start spraying the curing agent slurry. When the transmission wheel in the lower part of the large circulation structure enters below the ground, start the two sets of large circulation structures. At this time, the rotation of the inner drill bit drives the rotation of the two sickle-shaped structures, and the curing slurry migrates and mixes radially along the pile body. The large circulation structure drives the mixed curing agent slurry to circulate longitudinally. When the designed depth is reached, it is stirred reciprocally at a certain height above the pile end. Step 3: Drilling construction When the drill starts to be lifted, the rotation direction of the inner drill rod and the outer drill rod is opposite to that when the drill is lowered. The curing agent slurry is continuously sprayed during the lifting process. When the transmission wheel in the lower part of the large circulation structure is lifted above the ground, the rotation is stopped. When the inner drill bit and the outer drill bit are lifted above the ground, the rotation is stopped and the pumping of the curing agent slurry is stopped.
2. A two-way mixing construction process for improving the overall uniformity of the pile body according to claim 1, characterized in that: The inner drill rod, outer drill rod and casing are all coaxially arranged. The casing is on the outside of the outer drill rod. The casing and the outer drill rod are sealed by a sealing sleeve. The channel between the casing and the outer drill rod serves as a high-pressure gas channel, and a gas nozzle is set on the casing. Whether to add gas is determined according to the construction situation.
3. A two-way mixing construction process for improving the overall uniformity of the pile body according to claim 1, characterized in that: The length of the rib plate is the clearance height between the two transmission wheels. The outermost side of the rib plate is the same as the outermost side of the outer drill bit. The rib plate is provided with holes along the length direction. Holes of different spacings can be selected according to different project requirements.
4. A two-way mixing construction process for improving the overall uniformity of the pile body according to claim 1, characterized in that: The height of the reciprocating stirring is 1.5-2.0 times the distance from the drill tip to the lower transmission wheel.