An in-situ precast mold for a pervious concrete pile and a method of pile formation
By using in-situ precast molds for permeable concrete piles and employing elastic spiral rods and limiting rope structures, the problems of borehole wall collapse and spiral groove wall deformation were solved, enhancing the pile's bearing capacity and soil layer control capabilities, reducing the pile defect rate, and realizing an efficient method for permeable concrete pile construction.
Patent Information
- Authority / Receiving Office
- CN · China
- Patent Type
- Patents(China)
- Current Assignee / Owner
- SHANDONG LUQIAO GROUP CO LTD
- Filing Date
- 2025-12-05
- Publication Date
- 2026-05-19
AI Technical Summary
Existing permeable concrete piles are prone to borehole wall collapse and spiral groove wall deformation during the pile formation process, resulting in poor bearing capacity and insufficient soil deformation control, as well as a high pile defect rate.
An in-situ prefabrication mold for permeable concrete piles is adopted, including a borehole internal support assembly. It uses an elastic helical rod and a limiting rope structure to form a receiving cavity and a connecting cavity through the limiting rope and connecting rope. Combined with permeable cloth and limiting pipe, it ensures the stability and permeability of the borehole inner wall and increases the contact area between the pile and the soil.
It improves the bearing capacity and soil deformation control of permeable concrete piles, reduces the pile defect rate, reduces mechanical energy consumption and carbon emissions, simplifies the operation process, and improves the efficiency of mechanical operations.
Smart Images
Figure CN121374845B_ABST
Abstract
Description
Technical Field
[0001] This invention relates to special equipment for the production of energy-saving building materials, and particularly to the field of concrete pile forming technology, specifically an in-situ prefabrication mold for permeable concrete piles and a pile forming method. Background Technology
[0002] Permeable concrete piles serve both load-bearing and drainage functions in the strata. They enable rapid drainage through pores, and can be used in mining and road construction to drain the site, reduce groundwater pressure, simplify excavation and dewatering, help drain groundwater from slopes, reduce pore water pressure, and improve slope stability.
[0003] The specific construction principle of permeable concrete piles is as follows: Drill to a set depth using a drilling rig, and while the drill rod is being lifted, permeable concrete is simultaneously injected into the borehole through the inner hole of the drill rod. The permeable concrete then solidifies to form the pile body.
[0004] Permeable concrete piles have a high porosity, providing infiltration channels for groundwater. Therefore, they are often used in engineering projects such as treating soft foundations with high water content, lowering the groundwater level, and preventing soil liquefaction. In the industry, auger drilling rigs are often used for the pile construction of permeable concrete piles. The auger blades cut auger grooves on the inner wall of the borehole. However, during the simultaneous pouring of permeable concrete while lifting the auger, the auger groove wall at the point where the auger blades just exit is unsupported. This causes the auger groove wall to easily deform or collapse under the combined effect of drill rod vibration and soil stress release. The auger profile of the auger groove wall is difficult to maintain, resulting in defects in the auger profile of the permeable concrete pile. Consequently, the bearing capacity of the permeable concrete pile is poor, and the ability to control soil deformation is also poor. Summary of the Invention
[0005] The technical problem to be solved by this invention is to overcome the existing defects and provide an in-situ prefabrication mold and a pile forming method for permeable concrete piles. The in-situ prefabrication mold for permeable concrete piles avoids the collapse of the borehole inner wall, the helical contour of the permeable concrete pile is complete, the contact area between the pile body and the soil is increased, the bearing capacity of the pile body and the ability to control soil deformation are improved, the number of piles used is reduced by improving the quality of individual permeable concrete piles, thereby reducing the energy consumption of operating machinery and reducing carbon emissions. The pile forming method for permeable concrete piles solves problems such as borehole collapse and diameter reduction, and reduces the pile forming defect rate.
[0006] The technical solution adopted by this invention to solve its technical problem includes:
[0007] On the one hand, an in-situ prefabrication mold for permeable concrete piles is provided, including a drilling internal support assembly. The drilling internal support assembly includes an elastic spiral rod, on which a permeable cloth is installed. A limiting tube is inserted inside the elastic spiral rod. The bottom end of the limiting tube has four locking holes arranged along the axis of the limiting tube. Several limiting ropes are provided on the elastic spiral rod, and the middle part of each limiting rope is fixedly connected to a connecting rope.
[0008] The two ends of the limiting rope are respectively connected to two positions circumferentially spaced 150°-180° apart on the elastic spiral rod. The limiting rope passes through two non-adjacent locking holes on the limiting tube. Two locking components are fixed on the limiting rope. The length of the limiting rope between the two locking components is greater than the inner diameter of the limiting tube. The length of the limiting rope is greater than the inner diameter of the elastic spiral rod.
[0009] The borehole internal support assembly is located inside the drill rod, the bottom end of the drill rod is detachably equipped with a pile tip, the outside of the drill rod is equipped with a helical blade, and the top end of the limiting tube is rotatably connected to the drill rod.
[0010] Among them, the limiting ropes include a first limiting rope and a second limiting rope that are adjacent to each other in the axial direction of the limiting tube. The two positions of the first limiting rope are connected to form a first connecting direction, and the two positions of the second limiting rope are connected to form a second connecting direction. The angle between the first connecting direction and the second connecting direction is 85°-90°.
[0011] In this system, the two locking components on a limiting rope are both located inside the limiting tube, and the two position points on the corresponding elastic spiral rod of the limiting rope are both bent inward.
[0012] As a preferred embodiment of the present invention, the limiting rope is a plant fiber rope, animal hair rope, polylactic acid fiber rope, or polyhydroxyalkanoate fiber rope.
[0013] As a preferred embodiment of the present invention, the connecting rope is a plant fiber rope, animal hair rope, polylactic acid fiber rope, or polyhydroxyalkanoate fiber rope.
[0014] As a preferred embodiment of the present invention, each limiting rope is wrapped with a soft branch tube, and the connecting rope is wrapped with an inner tube, with one end of the branch tube communicating with the inner cavity of the inner tube.
[0015] As a preferred embodiment of the present invention, a water outlet control component is installed on the branch pipe at a position away from the inner pipe.
[0016] As a preferred embodiment of the present invention, the branch pipe is fixedly connected to one end of the strip elastic member at a position away from the inner pipe, and the strip elastic member is wrapped inside the limiting rope after bending and deformation.
[0017] As a preferred embodiment of the present invention, the bottom end of the limiting tube is fixed with an outwardly expanding member, and the outwardly expanding member has a sliding hole corresponding to the position of each card hole.
[0018] A limiting component is fixed to the inner wall of the limiting tube near each card hole.
[0019] As a preferred embodiment of the present invention, the permeable fabric is strip-shaped, and the strip-shaped permeable fabric is spirally arranged within the spiral pitch gap of the elastic spiral rod, and the spiral direction of the spirally arranged permeable fabric is the same as the spiral direction of the elastic spiral rod, and the permeable fabric and the elastic spiral rod are fixedly connected.
[0020] As a preferred embodiment of the present invention, the permeable fabric is cylindrical, and the inner or outer wall of the elastic spiral rod is fixedly connected to the permeable fabric.
[0021] On the other hand, a method for forming permeable concrete piles is also provided, which uses any of the aforementioned permeable concrete pile in-situ prefabrication molds, including the following steps:
[0022] The bottom end of the limiting tube is inserted into the elastic screw rod from the top end of the elastic screw rod, and all the locking parts on the limiting rope are located inside the limiting tube. The elastic screw rod is bent inwards at the position corresponding to the limiting rope.
[0023] The flexible helical rod is placed inside the drill rod, and the bottom end of the connecting rope is fixed to the pile tip, which is installed at the bottom end of the drill rod.
[0024] The drill rod is mounted on an external auger pile driver, which drives the drill rod to drill underground.
[0025] After drilling is completed, rotate the drill rod in the opposite direction to separate the drill rod from the pile tip, leaving the pile tip at the bottom of the borehole.
[0026] During the upward movement of the drill rod, permeable concrete is injected into the permeable fabric. The elastic spiral rod below the drill rod regains its shape and presses against the spiral groove formed by the spiral blades on the inner wall of the borehole.
[0027] Compared with the prior art, the beneficial effects of the present invention are:
[0028] 1. The in-situ prefabrication mold for the permeable concrete pile of the present invention has the following characteristics: On the one hand, the limiting rope forms a receiving cavity inside the spiral permeable concrete pile, and the connecting rope forms a connecting cavity inside the spiral permeable concrete pile. Water in the receiving cavity can flow into other receiving cavities through the connecting cavity, thereby improving the temporary water storage performance inside the spiral permeable concrete pile. Water in the connecting cavity can also be extracted to achieve a rapid reduction in the soil moisture content. On the other hand, the branch pipe continuously sprays water and increases the water pressure inside the receiving cavity, thereby achieving reverse flushing of particles on the spiral permeable concrete pile and particles on the permeable cloth, ensuring the permeability of the spiral permeable concrete pile.
[0029] 2. The in-situ prefabrication mold of the permeable concrete pile in the example of the present invention, the spiral blades and the permeable cloth make the permeable concrete in the borehole solidify into a spiral permeable concrete pile, which increases the contact area between the pile body and the soil and improves the vertical compressive bearing capacity of the pile body.
[0030] 3. In the example of the present invention, the in-situ prefabrication mold for the permeable concrete pile has a limiting rope that is biodegradable. The limiting rope creates a cavity inside the spiral permeable concrete pile, allowing water outside the spiral permeable concrete pile to enter the cavity, which facilitates a rapid reduction in the water content of the soil.
[0031] 4. In the example of the permeable concrete pile prefabrication mold of the present invention, a limiting component is fixed on the inner wall of the limiting tube near each card hole, and the carding component is provided with a carding groove that matches the limiting component to reduce the deformation of the limiting tube.
[0032] 5. In the example of the permeable concrete pile prefabrication mold of the present invention, after the outer expansion component causes the limiting rope to disengage from the clamping hole of the limiting tube, the distance between the two clamping components on the limiting rope gradually increases, thereby causing the elastic spiral rod to gradually return to its inward bending position, allowing the protective mud outside the permeable cloth to gradually flow out, and avoiding impact damage to the permeable cloth.
[0033] 6. The pile formation method of permeable concrete piles exemplified by the present invention is simple to operate. When the drill rod is removed, the elastic spiral rod abuts against the spiral groove formed by the spiral blade on the inner wall of the borehole, and the permeable cloth is attached to the inner wall of the borehole, which solves problems such as hole collapse and diameter reduction and reduces the defect rate of pile formation. Attached Figure Description
[0034] Figure 1 This is a schematic diagram of the main structure of the present invention;
[0035] Figure 2 for Figure 1 A partial cross-sectional view of one embodiment;
[0036] Figure 3 for Figure 1 Another embodiment of the schematic diagram of a partial cross-section;
[0037] Figure 4 This is a schematic diagram of the limiting tube and elastic spiral rod structure of the present invention;
[0038] Figure 5 This is a top view of the borehole internal support assembly of the present invention;
[0039] Figure 6 This is a bottom view of the borehole internal support assembly of the present invention;
[0040] Figure 7 for Figure 6 Enlarged schematic diagram of the structure at point A;
[0041] Figure 8 This is a schematic diagram of the elastic helical rod bending inward under tension according to the present invention;
[0042] Figure 9 for Figure 8 Enlarged schematic diagram of the structure at point B;
[0043] Figure 10 This is a partial cross-sectional view of the connecting rope and the limiting rope of the present invention.
[0044] In the diagram: 1. Limiting pipe, 2. Spiral blade, 3. Drill rod, 4. Pile tip, 5. Permeable cloth, 6. Elastic spiral rod, 7. Clamping hole, 8. Clamping component, 9. Connecting rope, 10. Limiting rope, 11. Limiting component, 12. Outward expansion component, 13. Water outlet control component, 14. Strip elastic component, 15. Branch pipe, 16. Inner pipe. Detailed Implementation
[0045] The technical solutions of the present invention will be clearly and completely described below with reference to the accompanying drawings of the embodiments of the present invention. Obviously, the described embodiments are only some embodiments of the present invention, and not all embodiments. All other embodiments obtained by those skilled in the art based on the embodiments of the present invention without creative effort are within the scope of protection of the present invention.
[0046] Example 1: Please refer to Figures 1-9 This embodiment discloses an in-situ prefabrication mold for permeable concrete piles, including a drilling internal support assembly. The drilling internal support assembly includes an elastic spiral rod 6, on which a permeable cloth 5 is installed. A circular limiting tube 1 is inserted inside the elastic spiral rod 6. The bottom end of the limiting tube 1 has four locking holes 7 at equal angles around the axis of the limiting tube 1, which are arranged along the axis of the limiting tube 1. Several limiting ropes 10 are provided on the elastic spiral rod 6, and the middle part of each limiting rope 10 is fixedly connected to a connecting rope 9.
[0047] The two ends of the limiting rope 10 are connected to two positions circumferentially spaced 150°-180° apart on the elastic spiral rod 6. The limiting rope 10 passes through two non-adjacent locking holes 7 on the limiting tube 1. Two locking elements 8 are fixed on the limiting rope 10. The length of the limiting rope 10 between the two locking elements 8 is greater than the inner diameter of the limiting tube 1. The length of the limiting rope 10 is greater than or equal to the inner diameter of the elastic spiral rod 6.
[0048] The drilling internal support assembly is located inside the drill rod 3. The bottom end of the drill rod 3 is detachably equipped with a pile tip 4. A helical blade 2 is installed on the outside of the drill rod 3. The top end of the limiting tube 1 is connected to the drill rod 3 through a bearing or a rotating pin. The outer diameter of the elastic helical rod 6 is less than or equal to the outer diameter of the helical blade 2. The inner diameter of the elastic helical rod 6 is greater than the outer diameter of the drill rod 3. The pitch of the helical blade 2 is equal to the pitch of the elastic helical rod 6. The helical direction of the helical blade 2 is the same as the helical direction of the elastic helical rod 6.
[0049] Among them, the plurality of limiting ropes 10 include a first limiting rope and a second limiting rope that are arbitrarily adjacent in the axial direction of the limiting tube 1. The two position points connected by the first limiting rope form a first connecting direction, and the two position points connected by the second limiting rope form a second connecting direction. The angle between the first connecting direction and the second connecting direction is 85°-90°.
[0050] Among them, the two locking elements 8 on the limiting rope 10 are both located inside the limiting tube 1, and the two position points on the corresponding elastic spiral rod 6 of the limiting rope 10 are bent inward.
[0051] The working process and principle of this embodiment are as follows:
[0052] The worker inserts the bottom end of the limiting tube 1 into the elastic spiral rod 6 from the top end of the elastic spiral rod 6, and all the locking parts 8 on the limiting ropes 10 are located inside the limiting tube 1. The elastic spiral rod 6 bends inward at the positions corresponding to the limiting ropes 10, and the projected area of the elastic spiral rod 6 in the plane perpendicular to the axial direction of the elastic spiral rod 6 becomes smaller. Then the worker places the elastic spiral rod 6 into the drill rod 3, and the bottom end of the connecting rope 9 is fixed to the pile tip 4. The pile tip 4 is detachably installed at the bottom end of the drill rod 3.
[0053] Workers install drill rod 3 on an external auger pile driver. The external auger pile driver drives drill rod 3 to drill underground. After drilling is completed, drill rod 3 is rotated in the opposite direction to separate drill rod 3 from pile tip 4, with pile tip 4 remaining at the bottom of the borehole.
[0054] During the upward movement of drill rod 3, workers inject permeable concrete into permeable cloth 5, and the liquid level of permeable concrete in permeable cloth 5 is 10.0cm to 10.0cm higher than the bottom of drill rod 3.
[0055] The pile tip 4 pulls the limiting rope 10 relative to the limiting tube 1 via the connecting rope 9. When the locking element 8 disengages from the limiting tube 1, the elastic spiral rod 6 returns to its original shape corresponding to the locking element 8. The part of the elastic spiral rod 6 that has returned to its original shape abuts against the spiral groove formed by the spiral blade 2 on the inner wall of the borehole. The elastic spiral rod 6 and the permeable cloth 5 prevent the inner wall of the borehole from collapsing. The elastic spiral rod 6 and the permeable cloth 5 cause the permeable concrete in the borehole to solidify into a spiral permeable concrete pile, which increases the contact area between the pile body and the soil, improves the vertical compressive bearing capacity of the pile body, and reduces the number of piles used by improving the quality of a single permeable concrete pile, thereby shortening the construction period, reducing the density of on-site machinery and the probability of cross-operations, improving the operating efficiency of machinery, and avoiding idle work or inefficient operation caused by mutual interference of machinery.
[0056] Preferably, the permeable fabric is geotextile, permeable striped fabric or plant fiber fabric, and the pile tip 4 is made of concrete or metal.
[0057] Preferably, the locking element 8 is a knot or a plastic block fixed to the limiting rope 10.
[0058] Preferably, the elastic helical rod 6 is made of elastic steel or elastic plastic.
[0059] Furthermore, regarding the connection methods of drill rod 3 and pile tip 4, the first method involves a groove at the bottom of drill rod 3 and a protrusion on pile tip 4 that matches the groove. The groove and protrusion are initially positioned by interlocking. Then, a ring-shaped steel hoop is used to enclose the connection between drill rod 3 and pile tip 4, locking them together as one unit. After the drill rod 3 drives the pile tip 4 to rotate and drill to the set depth, the drill rod 3 is rotated in the opposite direction to disengage the groove and protrusion. The drill rod 3 is then removed from the borehole, and the pile tip 4 is embedded in the soil layer and remains. This method is suitable for soft foundations, can prevent borehole collapse, and ensure the bearing capacity of the pile tip. The second method involves connecting the bottom of drill rod 3 and pile tip 4 using an electromagnetic switch commonly used in existing technologies.
[0060] Furthermore, the ratio of the cross-sectional area of the limiting rope 10 perpendicular to the length direction to the cross-sectional area of the drill rod 3 perpendicular to the axial direction is 1.0:50.0-10000.0, and the ratio of the cross-sectional area of the limiting rope 10 perpendicular to the length direction to the cross-sectional area of the connecting rope 9 perpendicular to the length direction is 1.0:1.0-500.0.
[0061] Furthermore, the connecting rope 9 can be replaced with a fixing rod, one end of which is fixedly connected to the pile tip 4.
[0062] Example 2: Figures 4-10As shown, this embodiment discloses an in-situ prefabrication mold for permeable concrete piles. Its structure is roughly the same as that of Embodiment 1. The difference is that the limiting rope 10 in this embodiment is made of a biodegradable material, such as plant fiber rope, animal hair rope, polylactic acid fiber rope, or polyhydroxyalkanoate fiber rope.
[0063] Preferably, the permeable fabric 5 is a polyester geotextile or a polypropylene geotextile.
[0064] The working process and principle of this embodiment are as follows:
[0065] After the permeable concrete inside the borehole solidifies into spiral permeable concrete for a period of time, the limiting rope 10 is biodegraded. The limiting rope 10 creates a cavity inside the spiral permeable concrete pile, allowing water from outside the spiral permeable concrete pile to enter the cavity, which facilitates a rapid reduction in the water content of the soil.
[0066] Example 3: Figures 4-7 , Figure 10 As shown, this embodiment discloses an in-situ prefabrication mold for permeable concrete piles. Its structure is roughly the same as that of Embodiment 2. The difference is that the connecting rope 9 in this embodiment is made of a biodegradable material. The connecting rope 9 is a plant fiber rope, animal hair rope, polylactic acid fiber rope or polyhydroxyalkanoate fiber rope.
[0067] The working process and principle of this embodiment are as follows:
[0068] After the permeable concrete in the borehole solidifies into a spiral permeable concrete pile for a period of time, both the connecting rope 9 and the limiting rope 10 are biodegraded. The limiting rope 10 creates a cavity inside the spiral permeable concrete pile, and the connecting rope 9 creates a connecting cavity inside the spiral permeable concrete pile. Water in the cavities can flow into other cavities through the connecting cavities, improving the temporary water storage performance of the spiral permeable concrete pile. Workers can pump out the water in the connecting cavities to achieve a rapid reduction in the soil moisture content.
[0069] Preferably, both the connecting rope 9 and the limiting rope 10 are adhered to microorganisms with degradation effects. The limiting rope 10 and the elastic spiral rod 6 are connected by a carbon fiber rope, and the limiting rope 10 is located inside the spiral permeable concrete pile.
[0070] Example 4: Figure 10 As shown, this embodiment discloses an in-situ prefabrication mold for permeable concrete piles. Its structure is roughly the same as that of Embodiment 3. The difference is that in this embodiment, each limiting rope 10 is wrapped with a soft branch pipe 15, and the connecting rope 9 is wrapped with an inner tube 16. One end of the branch pipe 15 is connected to the inner cavity of the inner tube 16.
[0071] The working process and principle of this embodiment are as follows:
[0072] The staff connects one end of the inner pipe 16 to an external water pump. The external water pump draws water from an external water source into the inner pipe 16. The water in the inner pipe 16 is sprayed out through the branch pipe 15, flushing the blockage in the accommodating cavity into the connecting cavity, thereby preventing the accommodating cavity from becoming blocked.
[0073] Furthermore, the branch pipe 15 continuously sprays water, raising the water pressure in the accommodating cavity to 1.0MPa-10.0MPa, thereby achieving reverse flushing of particles on the spiral permeable concrete pile and particles on the permeable cloth 5, ensuring the permeability of the spiral permeable concrete pile.
[0074] Preferably, the ratio of the cross-sectional area of the inner tube 16 to the cross-sectional area of the branch tube 15 is 5.0-30.0:1.0.
[0075] Example 5: Figure 10 As shown, this embodiment discloses an in-situ prefabrication mold for permeable concrete piles. Its structure is roughly the same as that of embodiment four. The difference is that in this embodiment, a water outlet control component 13 is installed at a position of the branch pipe 15 away from the inner pipe 16. The water outlet control component 13 is a nozzle or a flat nozzle. The water outlet control component 13 controls the flow rate of water sprayed from the inner pipe 16 so that the water pressure in each inner pipe 16 is similar.
[0076] Example 6: Figure 10 As shown, this embodiment discloses an in-situ prefabrication mold for permeable concrete piles. Its structure is roughly the same as that of Embodiment 4. The difference is that in this embodiment, the branch pipe 15 is fixedly connected to one end of the strip elastic member 14 at the position away from the inner pipe 16. After the strip elastic member 14 is bent and deformed, it is wrapped in the limiting rope 10. The strip elastic member 14 is an elastic metal rod or an elastic plastic rod.
[0077] The working process and principle of this embodiment are as follows:
[0078] After the limiting rope 10 degrades naturally, the strip elastic element 14 presses against the inner wall of the accommodating cavity to prevent the branch pipe 15 from moving within the accommodating cavity.
[0079] Example 7: Figures 4-7 As shown, this embodiment discloses an in-situ prefabrication mold for permeable concrete piles. Its structure is roughly the same as that of Embodiment 1. The difference is that the bottom end of the limiting tube 1 in this embodiment is fixed with an outwardly expanding part 12. The outwardly expanding part 12 has a sliding hole corresponding to the position of each card hole 7.
[0080] Furthermore, a limiting element 11 is fixed on the inner wall of the limiting tube 1 near each card hole 7. The limiting element 11 is a card strip arranged along the axial direction of the limiting tube 1. The carding element 8 is provided with a card groove that matches the card strip to reduce the deformation of the limiting tube 1.
[0081] The working process and principle of this embodiment are as follows:
[0082] After the expansion member 12 causes the limiting rope 10 to disengage from the locking hole 7 of the limiting tube 1, the distance between the two locking members 8 on the limiting rope 10 gradually increases, thereby causing the elastic spiral rod 6 to gradually return to its inward bending position, allowing the protective mud outside the permeable cloth 5 to gradually flow out, avoiding impact damage to the permeable cloth 5, and preventing movable particles in the soil from entering the pores of the permeable concrete pile, thus ensuring the permeability of the permeable concrete pile.
[0083] The permeable cloth 5 prevents the permeable concrete from coming into contact with the soil during the solidification process, and prevents soil clods from entering the permeable concrete pile, so that the permeable concrete is evenly distributed throughout the permeable concrete pile.
[0084] Example 8: As Figure 3 As shown, this embodiment discloses an in-situ prefabrication mold for permeable concrete piles. Its structure is roughly the same as that of Embodiment 1. The difference is that the permeable cloth 5 in this embodiment is strip-shaped. The strip-shaped permeable cloth 5 is spirally arranged in the spiral pitch gap of the elastic spiral rod 6, and the spiral direction of the spirally arranged permeable cloth 5 is the same as the spiral direction of the elastic spiral rod 6. The permeable cloth 5 and the elastic spiral rod 6 are fixedly connected.
[0085] The elastic helical rod 6 rests against the helical groove formed by the helical blade 2 on the inner wall of the borehole, and the permeable cloth 5 is attached to the inner wall of the borehole.
[0086] Furthermore, the external auger drives the drill rod 3 into the pre-drilled hole, and the inner wall of the hole is smaller than the outer diameter of the drill rod 3. The pile tip 4 is provided with a slot or opening for the flow of wall-protecting mud. The in-situ prefabricated mold of this permeable concrete pile enlarges the original hole and provides internal support for the inner wall of the hole after passing through the hole.
[0087] Example 9: Figure 2 , Figure 5 , Figure 6 As shown, this embodiment discloses an in-situ prefabrication mold for permeable concrete piles. Its structure is roughly the same as that of Embodiment 1. The difference is that the permeable cloth 5 in this embodiment is cylindrical, and the inner or outer wall of the elastic spiral rod 6 is fixedly connected to the permeable cloth 5.
[0088] The elastic helical rod 6 rests against the helical groove formed by the helical blade 2 on the inner wall of the borehole, and the permeable cloth 5 is attached to the inner wall of the borehole.
[0089] Example 10: As Figures 1-10 As shown, this embodiment discloses a method for forming permeable concrete piles, applied to the in-situ prefabrication mold of permeable concrete piles in any one of Embodiments 1 to 9, including the following steps:
[0090] The bottom end of the limiting tube 1 is inserted into the elastic spiral rod 6 from the top end of the elastic spiral rod 6, and the locking parts 8 on all the limiting ropes 10 are located inside the limiting tube 1. The elastic spiral rod 6 is bent inward at the position corresponding to the limiting rope 10.
[0091] The elastic helical rod 6 is placed inside the drill rod 3, and the bottom end of the connecting rope 9 is fixed to the pile tip 4, which is installed at the bottom end of the drill rod 3.
[0092] Drill rod 3 is installed on an external auger pile driver, which drives drill rod 3 to drill underground.
[0093] After drilling is completed, rotate drill rod 3 in the opposite direction to separate drill rod 3 from pile tip 4, leaving pile tip 4 at the bottom of the borehole.
[0094] During the upward movement of drill rod 3, permeable concrete is injected into permeable cloth 5. The elastic spiral rod 6 below drill rod 3 recovers its shape and abuts against the spiral groove formed by spiral blade 2 on the inner wall of the borehole.
[0095] The working process and principle of this embodiment are as follows:
[0096] The method for forming permeable concrete piles is simple to operate. When the drill rod 3 is removed, the elastic spiral rod 6 abuts against the spiral groove formed by the spiral blade 2 on the inner wall of the borehole, and the permeable cloth 5 is attached to the inner wall of the borehole to avoid problems such as hole collapse and diameter reduction, thereby reducing the defect rate of pile formation.
[0097] Although embodiments of the invention have been shown and described, it will be understood by those skilled in the art that various changes, modifications, substitutions and alterations can be made to these embodiments without departing from the principles and spirit of the invention.
Claims
1. An in-situ prefabrication mold for permeable concrete piles, characterized in that: The device includes a borehole internal support assembly, which includes an elastic spiral rod (6), on which a permeable cloth (5) is installed. A limiting tube (1) is inserted inside the elastic spiral rod (6). Four locking holes (7) are provided at the bottom end of the limiting tube (1) along the axial direction of the limiting tube (1). Several limiting ropes (10) are provided on the elastic spiral rod (6). The middle part of each limiting rope (10) is fixedly connected to a connecting rope (9). The two ends of the limiting rope (10) are respectively connected to two positions on the elastic spiral rod (6) with a circumferential interval of 150°-180°. The limiting rope (10) passes through two non-adjacent locking holes (7) on the limiting tube (1). Two locking elements (8) are fixed on the limiting rope (10). The length of the limiting rope (10) between the two locking elements (8) is greater than the inner diameter of the limiting tube (1). The length of the limiting rope (10) is greater than the inner diameter of the elastic spiral rod (6). The drilling internal support assembly is located inside the drill rod (3), the bottom end of the drill rod (3) is detachably equipped with a pile tip (4), the outside of the drill rod (3) is equipped with a spiral blade (2), and the top end of the limiting tube (1) is rotatably connected to the drill rod (3). Among them, several limiting ropes (10) include a first limiting rope and a second limiting rope that are adjacent to each other in the axial direction of the limiting tube (1). The two position points connected by the first limiting rope form a first connecting direction, and the two position points connected by the second limiting rope form a second connecting direction. The angle between the first connecting direction and the second connecting direction is 85°-90°. Among them, the two locking parts (8) on a limiting rope (10) are both located inside the limiting tube (1), and the two position points on the corresponding elastic spiral rod (6) of the limiting rope (10) are bent inward; The bottom end of the connecting rope (9) is fixed on the pile tip (4), and the pile tip (4) pulls the limiting rope (10) relative to the limiting tube (1) through the connecting rope (9).
2. The in-situ prefabrication mold for permeable concrete piles according to claim 1, characterized in that: The limiting rope (10) is a plant fiber rope, animal hair rope, polylactic acid fiber rope or polyhydroxyalkanoate fiber rope.
3. The in-situ prefabrication mold for permeable concrete piles according to claim 2, characterized in that: The connecting rope (9) is a plant fiber rope, animal hair rope, polylactic acid fiber rope or polyhydroxyalkanoate fiber rope.
4. The in-situ prefabrication mold for permeable concrete piles according to claim 3, characterized in that: Each limiting rope (10) is wrapped with a soft branch tube (15), and the connecting rope (9) is wrapped with an inner tube (16). One end of the branch tube (15) is connected to the inner cavity of the inner tube (16).
5. The in-situ prefabrication mold for permeable concrete piles according to claim 4, characterized in that: The branch pipe (15) is equipped with a water outlet control component (13) at a position away from the inner pipe (16).
6. The in-situ prefabrication mold for permeable concrete piles according to claim 4, characterized in that: The branch pipe (15) is fixedly connected to one end of the strip elastic element (14) away from the inner pipe (16), and the strip elastic element (14) is wrapped in the limiting rope (10) after bending and deformation.
7. The in-situ prefabrication mold for permeable concrete piles according to claim 1, characterized in that: The bottom end of the limiting tube (1) is fixed with an outwardly expanding part (12), and the outwardly expanding part (12) is provided with a sliding hole corresponding to the position of each card hole (7); A limiting element (11) is fixed on the inner wall of the limiting tube (1) near each card hole (7).
8. The in-situ prefabrication mold for permeable concrete piles according to claim 1, characterized in that: The permeable cloth (5) is strip-shaped, and the strip-shaped permeable cloth (5) is spirally arranged in the spiral pitch gap of the elastic spiral rod (6). The spiral direction of the spirally arranged permeable cloth (5) is the same as the spiral direction of the elastic spiral rod (6). The permeable cloth (5) and the elastic spiral rod (6) are fixedly connected.
9. The in-situ prefabrication mold for permeable concrete piles according to claim 1, characterized in that: The permeable cloth (5) is cylindrical, and the inner or outer wall of the elastic spiral rod (6) is fixedly connected to the permeable cloth (5).
10. A method for forming permeable concrete piles, applied to the in-situ prefabrication mold of the permeable concrete piles according to any one of claims 1-9, characterized in that, Includes the following steps: The bottom end of the limiting tube (1) is inserted into the elastic screw rod (6) from the top end of the elastic screw rod (6), and all the locking parts (8) on the limiting ropes (10) are located inside the limiting tube (1). The elastic screw rod (6) is bent inward at the position corresponding to the limiting rope (10). The elastic helical rod (6) is placed inside the drill rod (3), and the bottom end of the connecting rope (9) is fixed on the pile tip (4), which is installed at the bottom end of the drill rod (3). The drill rod (3) is installed on an external auger pile driver, which drives the drill rod (3) to drill underground. After drilling is completed, rotate the drill rod (3) in the opposite direction and separate the drill rod (3) from the pile tip (4), leaving the pile tip (4) at the bottom of the borehole; During the upward movement of the drill rod (3), permeable concrete is injected into the permeable cloth (5). The elastic spiral rod (6) below the drill rod (3) recovers its shape and abuts against the spiral groove formed by the spiral blade (2) on the inner wall of the borehole.