A pile bottom slag reduction grouting device and its application method

Abstract

The present invention relates to the technical field of building construction, and specifically to a pile bottom slag reduction grouting device and a method of using the same. The device includes: a double tube straightening ring arranged in a steel cage in a pile hole; and also includes a double tube, the double tube is arranged in the double tube straightening ring, a vibrator is installed on the upper part of the double tube, a baffle is arranged at the lower end of the double tube, the double tube includes a sleeved inner tube and an outer tube, the top end of the inner tube is used to connect to a waste pipe, the top end of the outer tube is used to connect to a high-pressure water pipe, a slag suction pipe is arranged at the lower end of the inner tube, a water spray pipe is arranged at the lower end of the outer tube, the lower end of the water spray pipe is closed, and water injection holes are arranged at the outer periphery, and a blade foot is arranged circumferentially at the lower end of the baffle. The pile bottom slag reduction grouting device of the present invention realizes the thinning of pile bottom sediment and can cooperate with pile bottom grouting.

Description

Technical Field

[0001] The invention relates to the technical field of building construction, and in particular to a pile bottom slag reduction grouting device and a use method thereof. Background Art

[0002] If the sediment at the bottom of underwater cast-in-place piles is too thick, it will affect the bearing capacity of the piles. Therefore, my country's regulations stipulate that the sediment at the bottom of end-bearing piles shall not exceed 50mm, and the sediment at the bottom of friction piles shall not exceed 150mm. However, when the pile hole passes through a thick quicksand layer, the sediment at the bottom of the pile often exceeds the limit. Despite measures such as cleaning the bottom and changing the ratio of the wall protection mud, it is sometimes still difficult to meet the requirements of the regulations.

[0003] Grouting at the bottom of piles is a method with certain effects in reducing sediment or compensating for the adverse effects of sediment. However, for thick sediment, the treatment effect of grouting at the bottom of piles is poor. The main reason is that the sediment at the bottom of piles is in a saturated state, and the injection of slurry will cause the excess pore pressure in the sediment to increase rapidly. However, due to the poor dissipation environment of excess pore pressure in sediment, the excess pore pressure in thick sediment dissipates slowly, and the initial setting time of slurry is much shorter than the completion time of sediment consolidation and compaction, so that the sediment cannot be effectively compressed (squeezed), and the slurry is difficult to be evenly distributed in the sediment, and the adverse effects of sediment still exist. Therefore, in order to give full play to the effect of grouting at the bottom of piles to weaken or even eliminate the influence of sediment, it is very necessary to thin the sediment. If grouting at the bottom of piles is used in conjunction, the influence of sediment can be eliminated (grouting has a better effect on the reinforcement of thin sediment), and the soil at the bottom of piles can be strengthened, which can further improve the bearing capacity of piles.

[0004] The Chinese invention patent application with publication number CN103147707A discloses a complete method for treating pile bottom sediment, which uses a single-hole bottom cleaning method to perform pile bottom sediment cleaning operations, drills a core hole in the center of the pile foundation to ensure that the cleaning radius of the single hole can cover the entire sediment area under the pile foundation, and uses a high-pressure rotary jet machine and an air compressor to thoroughly clean the pile bottom, so that the single-hole bottom cleaning can achieve the effect of multi-hole bottom cleaning; the complete method for treating pile bottom sediment provided by the present invention also uses grouting material instead of cement slurry, cement mortar or fine stone concrete as the material for pile bottom replacement, which has the characteristics of large vertical expansion rate and high strength compared with cement slurry or cement mortar, and has the construction feasibility of being able to be poured in narrow holes compared with fine stone concrete. This method requires drilling at least one hole in the pile after the concrete has solidified, and then replacing the original sediment space with a filling slurry. However, (1) coring in concrete piles is expensive and time-consuming; (2) when the pile bottom is thick with sediment, the strength of the filling slurry used to replace the sediment is usually difficult to reach the high strength of the pile body, and broken piles are easily formed at the joints, which may have a significant impact on the properties of the pile; (3) if there is still a quicksand layer within the sediment thickness range, high-pressure jetting and air compressor bottom cleaning are likely to disturb the quicksand layer, making it difficult to remove the sediment. Summary of the invention

[0005] Aiming at the problem of thick sediment at the bottom of pile, the present invention develops a pile bottom sediment reduction grouting device and a use method thereof, which can achieve the purpose of thinning the sediment at the bottom of pile and reinforcing the remaining sediment at the bottom of pile and the soil at the pile end and pile side by grouting.

[0006] The technical solution of the present invention is:

[0007] A pile bottom slag reduction grouting device comprises: a double-tube straightening ring arranged in a steel cage in a pile hole; and further comprising:

[0008] A double tube, wherein the double tube is arranged in a double tube straightening ring, a vibrator is installed on the upper part of the double tube, a baffle is arranged at the lower end of the double tube, the double tube comprises a sleeved inner tube and an outer tube, the top end of the inner tube is used to connect to a waste discharge pipe, the top end of the outer tube is used to connect to a high-pressure water pipe, a slag suction pipe is arranged at the lower end of the inner tube, a water spray pipe is arranged at the lower end of the outer tube, the lower end of the water spray pipe is closed, and water injection holes are arranged at the outer periphery, and a blade foot is arranged circumferentially at the lower end of the baffle.

[0009] In a further optimized solution, the baffle plate is a conical panel with a hole in the middle, and the cone apex angle of the baffle plate is 150-170°.

[0010] In a further optimization scheme, the baffle plate is provided with 4 to 12 through holes arranged cross-symmetrically relative to the center of the baffle plate, and a movable cover is provided on the through hole. When the movable cover is opened, the opening points to the top of the panel cone. A concentric water spray pipe and a slag suction pipe are preset in the hole at the center of the top of the baffle cone. The baffle plate is fixedly connected to the water spray pipe and the slag suction pipe. The slag suction pipe and the water spray pipe are detachably connected to the inner pipe and the outer pipe of the double pipe respectively. When sinking, the movable cover on the through hole of the baffle plate is opened, and after sinking to the bottom of the pile hole, the movable cover of the through hole on the baffle plate is closed. Because there is water in the pile hole, the diameter of the baffle plate is only slightly smaller than the pile hole. When in use, the water below the baffle plate enters the top of the baffle plate through the through hole, so that the baffle plate is convenient to sink and the disturbance to the sand layer of the hole wall is greatly reduced.

[0011] In a further optimization scheme, the through hole is a circular hole.

[0012] In a further optimization scheme, the axes of the water ejection holes are all inclined outward from the water spray pipe, with an angle of 5° to 20° with the horizontal plane.

[0013] In a further optimization scheme, the double tube straightening ring includes an outer ring and an inner ring, and reinforcing ribs are radially arranged between the outer ring and the inner ring, wherein the outer ring is integrated with the frame bars of the steel cage.

[0014] The method for using the above-mentioned pile bottom slag reduction grouting device comprises the following steps:

[0015] (1) Drilling pile holes: Drill pile holes to the designed bottom elevation and measure the thickness of the sediment at the bottom of the pile.

[0016] (2) Lifting and placing the slag-reducing grouting device and steel cage at the bottom of the pile: Lift the slag-reducing grouting device and steel cage at the bottom of the pile and sink them into the pile hole.

[0017] (3) Place the concrete pouring conduit and funnel, connect the inner tube to the waste pipe of the mud pump, and connect the outer tube to the high-pressure water pipe;

[0018] (4) Concrete pouring. Then, high-pressure water is delivered to the outer pipe, and the sediment is diluted and liquefied to form a suspension, which is sucked into the sediment suction pipe and discharged into the waste discharge pipe along the inner pipe; the baffle and the steel cage sink synchronously, and the blade foot of the baffle cuts off the sediment until the blade foot cuts into the original soil layer at the bottom of the pile hole, and then the mud pump is turned off, the high-pressure water is stopped, and the double pipe is vibrated until it stops sinking;

[0019] Specifically: The first continuous pouring of concrete must at least reach the top elevation of the quicksand layer to prevent quicksand from continuing to flow into the hole and causing defective piles or even broken piles. As the concrete continues to be poured, the vibrator and mud pump are turned on to deliver high-pressure water to the outer tube of the double tube. The high-pressure water enters the water jet along the outer tube of the double tube and is sprayed into the sediment from the water jet hole on the water jet. Since the sediment is sparse and saturated, the sediment is diluted and liquefied to form a suspension under the vibration of the water jet and the vibrator. The sediment suspension is sucked into the sediment suction pipe under the suction force of the mud pump and enters the waste pipe along the inner tube of the double tube and is discharged into the waste slurry pool. As the sediment suspension is discharged, the baffle sinks, and the steel cage sinks synchronously at this time, and the blade feet of the outer periphery of the baffle cut the sediment under. This process is repeated until the blade feet cut into the original soil layer at the bottom of the pile hole, the mud pump is turned off, the high-pressure water is stopped, and the vibration is maintained until the double tube no longer sinks. At this time, the thickness of the sediment at the bottom of the hole will be reduced to less than 50mm.

[0020] (5) After the slag reduction work is completed, slurry is injected to solidify the slag to increase the end bearing capacity of the pile. Alternatively, high-pressure grouting is implemented to strengthen the slag, pile end and pile side soil, greatly increasing the pile end resistance.

[0021] In a further optimization plan, during the slag reduction process, if the double tube is found to be deflected and the steel cage is deflected to the side, the steel cage will be pushed to the other side and only the vibrator on the opposite side of the deviation will be turned on to generate eccentric vibration. The double tube will gradually return to the center position of the pile hole and the baffle will also be adjusted.

[0022] The beneficial effects of the present invention are:

[0023] In the pile bottom residue reduction grouting device of the present invention, the baffle plate can separate the sediment in the pile hole from the concrete in a flowing state above it, and high-pressure water enters the water jet hole of the water spray pipe through the outer tube of the double tube to stir the sediment. Under the suction of the mud pump, the sediment suspension is discharged from the sediment suction pipe through the inner tube of the double tube and the waste discharge pipe to the designated position on the surface. As the sediment decreases, the baffle plate moves down with the cutting edge under the vibration of the vibrator and the deadweight of the overlying concrete in a flowing state. In this cycle, the sediment is continuously thinned, and finally a pile is formed and the sediment at the bottom of the pile is ensured to meet the specification requirements. Subsequently, the sediment can be grout-reinforced with the help of a double tube or replaced with a grouting pipe, and even the soil at the pile end can be strengthened to greatly improve the bearing capacity of the pile. The pile bottom residue reduction grouting device of the present invention achieves the thinning of the sediment at the bottom of the pile and can cooperate with the pile bottom grouting. BRIEF DESCRIPTION OF THE DRAWINGS

[0024] Figure 1 The present invention is a schematic structural diagram of a pile bottom slag reduction grouting device.

[0025] Figure 2 The present invention is a schematic structural diagram of a baffle plate, a slag suction pipe and a water spray pipe of a pile bottom slag reduction grouting device.

[0026] Figure 3 for Figure 2 Enlarged view of point A in the middle.

[0027] Figure 4 The present invention provides a top view of a baffle plate, a slag suction pipe and a water spray pipe of a pile bottom slag reduction grouting device.

[0028] Figure 5 The present invention is a schematic structural diagram of a double-tube straightening ring of a pile bottom slag reduction grouting device.

[0029] Figure 6 The present invention is a schematic structural diagram of a double tube and a vibrator of a pile bottom slag reduction grouting device.

[0030] Figure 7 It is a structural schematic diagram of a pile bottom slag reduction grouting device after being hoisted into a pile hole according to the present invention.

[0031] Figure 8 This is a schematic diagram of one embodiment of a pile bottom slag reduction grouting device of the present invention: slag reduction and grouting reinforcement of the slag and the soil near it.

[0032] Fig. 9 This is a schematic diagram of the second embodiment of the pile bottom slag reduction grouting device of the present invention: slag reduction and grouting solidification of the sediment.

[0033] In the accompanying drawings, 1 is a steel cage, 2 is a double tube straightening ring, 21 is an outer ring, 22 is an inner ring, 23 is a reinforcing rib, 3 is a double tube, 31 is an inner tube, 32 is an outer tube, 4 is a vibrator, 5 is a baffle, 51 is a movable cover, 52 is a through hole, 53 is a blade foot, 6 is a slag suction pipe, 7 is a water spray pipe, 71 is a water injection hole, 72 is a partition, 8 is a pile hole, 9 is a conduit, 10 is a funnel, 11 is a waste discharge pipe, 12 is a high-pressure water pipe, 13 is sediment, 14 is soil, and 15 is concrete. DETAILED DESCRIPTION

[0034] The present invention is described in more detail below through specific implementation modes to facilitate understanding of the technical solution of the present invention, but is not intended to limit the protection scope of the present invention.

[0035] Example 1 Pile bottom slag reduction grouting device

[0036] The pile bottom slag reduction grouting device of this embodiment includes:

[0037] A double tube straightening ring 2 is arranged in the steel cage 1 in the pile hole 8; the double tube straightening ring 2 includes an outer ring 21 and an inner ring 22, and a reinforcing rib 23 is radially arranged between the outer ring 21 and the inner ring 22, wherein the outer ring 21 is integrated with the frame bars of the steel cage 1. The diameter of the inner ring 22 is suitable to accommodate the double tube 3 (bottom of the steel cage) or the concrete pouring conduit 9 (top of the steel cage). The inner ring 22 and the reinforcing rib 23 are round steel bars with the same diameter as the frame bars. The inner ring 22 can be replaced with a small diameter round steel bar due to its small diameter. Generally, two are arranged at the bottom of the steel cage 1 with a spacing of 2m, and one to two are arranged at the top of the steel cage 1 with a spacing of 2m. The steel cage straightening ring is arranged at the hole mouth and fixed to the ground surface to straighten the steel cage 1. It has a similar structure to the double-tube straightening ring 2, but has a different size. The inner ring of the steel cage straightening ring should be able to accommodate the outer envelope size of the cross-section of the steel cage 1. The outer ring diameter of the steel cage straightening ring is 200 to 600 mm larger than the pile hole diameter. There are vertical steel nails on it to fix it in the surface soil. For easy installation and disassembly, the steel cage straightening ring can be designed to be composed of two half-petals.

[0038] The pile bottom slag reduction grouting device also includes a double tube 3, which includes a sleeved inner tube 31 and an outer tube 32. The outer tube 32 of the double tube 3 has a diameter of 50 to 60 mm, the inner tube 31 has an outer diameter of 30 to 40 mm, and the wall thickness of the outer tube 32 and the inner tube 31 is 2 to 4 mm. The outer tube 32 is a steel tube, and the inner tube 31 can be a PVC tube or a thin-walled aluminum alloy tube. When making the double tube 3, the double tube 3 can be formed by sleeved two independent tubes, or it can be composed of concentric tube sections connected into a whole.

[0039] The top of the inner tube 31 is used to connect to the waste pipe 11, and the upper part of the outer tube 32 is connected to the high-pressure water pipe 12. Specifically, a water inlet pipe is provided on one side of the top of the outer tube 32 for connecting to the high-pressure water pipe 12. A slag suction pipe 6 is provided at the lower end of the inner tube 31, and a water spray pipe 7 is provided at the lower end of the outer tube 32. The lower end of the water spray pipe 7 is closed and a water jet hole 71 is provided on the outer periphery. The axis of the water jet hole 71 is inclined to the outside of the water spray pipe 7 and the angle with the horizontal plane is 5° to 20°. The outer periphery of the outer tube 32 of the double tube 3 can be coated with lubricating oil to reduce the resistance of pulling the tube.

[0040] The double pipe 3 is arranged in the double pipe straightening ring 2, and a vibrator 4 is installed on the upper part of the double pipe 3. The vibrator 4 is used for cutting down the blade foot, liquefying the sediment 13, adjusting the baffle plate 5 and compacting the concrete 15. The vibrator 4 is composed of 2 to 3 micro vibrators evenly distributed along the circumference and fixed on the double pipe 3 by a clamp. When all the micro vibrators are working, they will promote the cutting down of the blade foot 53, the liquefaction of the sediment 13, the downward movement and compaction of the concrete 15 in the hole; when some of the micro vibrators are working, they are used for adjusting the double pipe 3 and the baffle plate 5, and correcting the deviation of the blade foot 53. The deviation correction is based on the degree of deflection of the double pipe 3 and the steel cage 1.

[0041] The lower end of the double tube 3 is provided with a baffle plate 5, and the lower end of the baffle plate 5 is circumferentially provided with a blade foot 53. The baffle plate 5 is a conical panel with a hole in the middle, the cone top angle of the baffle plate 5 is 150-170 degrees, and the cone bottom size is slightly smaller than the pile hole diameter, so that it is easy to put into the pile hole 8. The material of the baffle plate 5 is a reinforced concrete thin plate or a steel plate.

[0042] When the material of the baffle plate 5 is a steel plate, the thickness of the baffle plate 5 is 4 to 10 mm. When the material of the baffle plate 5 is a reinforced concrete plate, the thickness of the baffle plate 5 is 50 to 100 mm. The blade foot 53 is made of steel, has a downward extension length of 50 to 100 mm, and a thickness of 4 to 10 mm.

[0043] The baffle plate 5 is provided with 4 to 12 through holes 52 arranged symmetrically with respect to the center of the baffle plate. In this embodiment, there are 4 through holes 52, which are circular holes with a diameter of 30 to 60 mm. A movable cover 51 is provided on the through hole 52, and the movable cover 51 is hinged to the baffle plate 5. When the movable cover 51 is opened, the opening points to the top of the cone of the baffle plate 5. A concentric water spray pipe 7 and a slag suction pipe 6 are pre-installed in the hole at the center of the cone top of the baffle plate 5. The baffle plate 5 is fixedly connected to the water spray pipe 7 and the slag suction pipe 6. The slag suction pipe 6 and the water spray pipe 7 are detachably connected to the inner tube 31 and the outer tube 42 of the double tube 3, respectively. Specifically, the water spray pipe 7 and the slag suction pipe 6 are steel pipes. A partition plate 72 is provided at the lower end of the water spray pipe 7 to close the lower end of the water spray pipe 7. The water spray pipe 7 and the slag suction pipe 6 are connected by the partition plate 72 to form a concentric double tube shape. The upper ends of the water spray pipes are provided with inner threads or bayonets, which are connected with the double tube 3 by thread or bayonet. The inner diameter of the water spray pipe 7 is consistent with the inner diameter of the outer tube 32 of the double tube 3, and the inner diameter of the slag suction pipe 6 is consistent with the inner tube 31 of the double tube 3. Two circles of water jet holes 71 are arranged at the lower section of the water jet pipe 7. The upper circle of water jet holes 71 is located near the lower boundary of the baffle plate 5, and the lower circle of water jet holes 71 is slightly higher than the bottom end of the water jet pipe 7. The axes of the water jet holes 71 are all inclined outward from the pipe, and the angle with the horizontal plane is 5° to 20°. The inclination angle of the upper circle of water jet holes 71 is greater than that of the lower circle of water jet holes 71. 3 to 6 water jet holes 71 are evenly arranged along the circumference of the pipe, and the hole diameter is 5mm.

[0044] When sinking, the movable cover 51 on the baffle plate 5 opens under the water dynamic pressure below the baffle plate 5. After sinking to the bottom of the pile hole 8, the movable cover 51 on the baffle plate 5 closes the through hole 52 under the action of its own weight, cutting off the connection between the sediment 13 and the concrete 15 in the flowing state above. Because there is water in the pile hole 8, the diameter of the baffle plate 5 is only slightly smaller than the pile hole 8. When in use, the water below the baffle plate 5 enters the top of the baffle plate 5 through the through hole 52, so that the baffle plate 5 can sink smoothly and greatly reduce the disturbance of the pore wall of the sand layer. In addition, a concentric water spray pipe 7 and a slag suction pipe 6 are pre-installed in the hole at the center of the cone top of the baffle plate 5. The baffle plate 5 is fixedly connected to the water spray pipe 7 and the slag suction pipe 6. The slag suction pipe 6 and the water spray pipe 7 are detachably connected to the inner tube 31 and the outer tube 32 of the double tube 3, respectively. Therefore, when in use, it must be slowly sunk into the pile hole 8 to avoid the disturbance of water flow formed during sinking and causing new sediment to appear.

[0045] Embodiment 2 Implementation method 1 of the pile bottom slag reduction grouting device: slag reduction and grouting reinforcement of the slag and the surrounding soil

[0046] (1) Drilling pile holes.

[0047] Drill the pile holes to the designed bottom elevation using appropriate conventional methods, such as Figure 8 (a) Measure the thickness of the sediment at the bottom of the pile.

[0048] (2) Install the double-tube straightening ring in the steel cage, pass the double-tube through the double-tube straightening ring in the steel cage, and then connect it with the slag suction pipe and water spray pipe in the baffle plate by thread or bayonet.

[0049] Check the penetration of the double pipe with the water spray pipe and the slag suction pipe. Apply lubricant or mold release agent to the outer circumference of the double pipe.

[0050] (3) Lifting and placing the slag-reducing grouting device and steel cage at the bottom of the pile: Lift the slag-reducing grouting device and steel cage at the bottom of the pile and sink them into the pile hole.

[0051] After the steel cage and the pile bottom slag reduction grouting device are hoisted and placed, a steel cage straightening ring can be installed on the ground at the hole mouth as needed.

[0052] After the pile bottom slag reduction grouting device is in place, place the concrete pouring conduit and funnel, connect the inner pipe to the waste pipe of the mud pump, and connect the outer pipe to the high-pressure water pipe;

[0053] (4) Concrete pouring: The first continuous concrete pouring should be done to make the concrete height at least reach the top elevation of the quicksand layer to prevent quicksand from continuing to flow into the hole and causing defective piles or even broken piles. As the concrete pouring continues, the vibrator and mud pump are started to deliver high-pressure water to the outer tube of the double tube. The high-pressure water enters the water jet pipe along the outer tube of the double tube and is sprayed into the sediment from the water jet hole on the water jet pipe. Since the sediment is sparse and saturated, the sediment is diluted and liquefied to form a suspension under the vibration of the water jet and the vibrator. The sediment suspension is sucked into the sediment suction pipe under the suction force of the mud pump, and enters the waste discharge pipe along the inner tube of the double tube and is discharged into the waste slurry pool. As the sediment suspension is discharged, the baffle sinks, and the blade feet on the outer periphery of the baffle cut into the sediment. This process is repeated until the blade feet finally cut into the original soil layer at the bottom of the pile hole. The mud pump is turned off, the high-pressure water is stopped, and the vibration is maintained until the double tube does not sink or reaches the bottom elevation of the pile hole. At this time, the thickness of the sediment at the bottom of the hole will be reduced to less than 50mm. Figure 8 (b)(c)(d).

[0054] During the slag reduction process, if the double tube is found to be deflected (the steel cage is deflected to the side), the steel cage will be pushed to the other side, and at the same time, only the micro-vibrator on the opposite side of the deflection will be turned on to generate deflected vibration. The double tube will gradually return to the center position of the pile hole, and the baffle will be adjusted.

[0055] (5) Weakening or even eliminating the adhesion between concrete and the double tube: Before and after the initial setting of the concrete in the pile hole, the double tube is rotated several times with a small amplitude. At this time, the double tube cannot be separated from the slag suction pipe and water spray pipe on the baffle plate, thereby weakening or even eliminating the adhesion between the concrete and the outer wall of the double tube.

[0056] (6) Remove the double tube and insert the PVC grouting tube.

[0057] Within 2 hours after the initial setting of the concrete in the pile hole, remove the double pipe and insert the PVC grouting pipe into the sediment (there are 3-5 small holes on the PVC grouting pipe section below the baffle). If the inner pipe of the double pipe is independently set, only the outer pipe can be removed and the inner pipe can be retained for use as the grouting pipe. Inject cement slurry or cement mortar into the gap on the outer wall of the grouting pipe. Figure 8 (e).

[0058] (7) Grouting to solidify the pile bottom: When the concrete in the pile hole reaches a certain strength or 28 days after the concrete in the hole is poured, 2-3MPa cement slurry is injected into the sediment through the grouting pipe for multiple times. The high-pressure cement slurry rushes in and stirs the sediment and mixes with the sediment. At the same time, the high-pressure cement slurry will also form splitting channels in the sediment and the surrounding soil, and at the pile-soil interface, forming a network of veined slurry liquid. When the slurry flow input is basically 0 or the grouting pressure is maintained for 1 hour, the grouting pipe is closed and the grouting is completed. After 3-7 days, the network of veined slurry liquid solidifies, the slurry reinforcement area is formed, and the exposed grouting pipe is cut off to form a pile. Figure 8 (f)(g).

[0059] Embodiment 3 Implementation method 2 of the pile bottom slag reduction grouting device: slag reduction and grouting solidification of slag

[0060] like Figure 5 As shown, the specific implementation steps are as follows:

[0061] (1) Same as (1) in implementation method 1, such as Fig. 9 (a).

[0062] (2) Same as (2) in Implementation Method 1.

[0063] (3) Same as (3) in implementation method 1, such as Fig. 9 (b).

[0064] (4) Same as (4) in implementation method 1, such as Fig. 9 (b)(c)(d).

[0065] (5) Grouting to solidify sediment: Connect the outer tube of the double tube to the cement slurry, and spray the cement slurry from the water injection hole at a pressure of 2-3 MPa, stir the remaining sediment and mix it with it, turn on and off the mud pump intermittently, suck the water in the sediment and the diluted cement slurry into the sediment suction pipe, and discharge it into the ground waste slurry pool along the inner tube of the double tube. When the discharged waste slurry is undiluted cement slurry, turn off the mud pump first, and then stop grouting. Fig. 9 (e).

[0066] (6) Remove the double tube to form a pile: Remove the double tube before the concrete in the pile hole sets, and pull up the double tube while vibrating. As the double tube vibrates, the concrete in the pile hole flows into the gap left by pulling out the double tube, and the slurry in the slag discharge pipe floats up with the pipe and is finally discharged from the pile hole into the waste slurry pool. The pile is formed when the cement slurry solidifies and the concrete solidifies. Fig. 9 (f).

[0067] The embodiments described above are only preferred embodiments of the present invention and are not intended to limit the scope of implementation of the present invention. Therefore, any equivalent changes or modifications made according to the structures, features and principles described in the patent scope of the present invention should be included in the scope of the patent application of the present invention.

Claims

1. A pile bottom slag reduction grouting device, characterized in that: include: A double-tube straightening ring (2) disposed in a steel cage (1) in a pile hole (8) also includes A double tube (3), the double tube (3) being arranged in a double tube straightening ring (2), the double tube straightening ring (2) comprising an outer ring (21) and an inner ring (22), a reinforcing rib (23) being radially arranged between the outer ring (21) and the inner ring (22), the outer ring (21) being integrated with the erection ribs of the steel cage (1), a vibrator (4) being installed on the upper part of the double tube (3), a baffle plate (5) being arranged at the lower end of the double tube (3), the baffle plate (5) being provided with through holes (52) arranged symmetrically with respect to the center of the baffle plate (5), a movable cover (51) being arranged above the through holes, and when the movable cover (51) is opened, the opening is directed toward the cone top of the baffle plate (5), The double tube (3) comprises a sleeved inner tube (31) and an outer tube (32); a slag suction tube (6) is arranged at the lower end of the inner tube (31), and a water spraying tube (7) is arranged at the lower end of the outer tube (32); the top end of the inner tube (31) is used to connect to a waste discharge tube (11), and the upper part of the outer tube (32) is connected to a high-pressure water pipe (12); a concentric water spraying tube (7) and a slag suction tube (6) are pre-installed in the hole at the center of the cone top of the baffle plate (5); the slag suction tube (6) is detachably connected to the inner tube (31) of the double tube (3), and the water spraying tube (7) is detachably connected to the outer tube (32); the lower end of the water spraying tube (7) is closed and a water jetting hole (71) is arranged on the outer periphery; and a blade foot (53) is circumferentially arranged at the lower end of the baffle plate (5).

2. A pile bottom slag reduction grouting device according to claim 1, characterized in that: The baffle plate (5) is a conical panel with a hole in the middle, and the cone apex angle of the baffle plate (5) is 150-170°.

3. A pile bottom slag reduction grouting device according to claim 1, characterized in that: The through hole (52) is a circular hole.

4. A pile bottom slag reduction grouting device according to claim 1, characterized in that: The axes of the water ejection holes (71) are all inclined outwardly from the water ejection pipe (7) and have an angle of 5° to 20° with the horizontal plane.

5. The method for using the pile bottom slag reduction grouting device according to claim 1, characterized in that: The following steps are involved: Step 1: Drilling the pile hole (8): Drill the pile hole (8) to the designed bottom elevation and measure the thickness of the sediment at the bottom of the pile; Step 2: Lifting the pile bottom slag reduction grouting device and the steel cage (1): lifting the pile bottom slag reduction grouting device and the steel cage (1) and sinking them into the pile hole (8); Step 3: Place the concrete pouring conduit (9) and the funnel (10), connect the inner tube (31) to the waste pipe (11) of the mud pump, and connect the outer tube to the high-pressure water pipe (12); Step 4: pouring concrete (15), then conveying high-pressure water into the outer pipe (32), diluting the sediment (13) to form a suspension and being sucked into the sediment suction pipe (6), and then entering the waste discharge pipe (11) along the inner pipe (31) for discharge; the baffle plate (5) and the steel cage (1) sink synchronously, and the blade foot (53) of the baffle plate (5) cuts down the sediment (13) until the blade foot cuts into the original soil layer at the bottom of the pile hole (8), shuts down the mud pump, stops conveying high-pressure water, and vibrates until the double pipe (3) no longer sinks; Step 5: After the slag reduction work is completed, grouting is injected to solidify the slag; or grouting is performed to strengthen the slag (13), the pile end and the soil at the pile side (14).

6. The method for using the pile bottom slag reduction grouting device according to claim 5, characterized in that: Step 4 is as follows: The first continuous pouring of concrete (15) must at least reach the top elevation of the quicksand layer; as the concrete (15) continues to be poured, the vibrator (4) and the mud pump are started to deliver high-pressure water to the outer tube (32) of the double tube (3), the high-pressure water enters the water spray pipe (7) along the outer tube (32) of the double tube (3), and is sprayed from the water injection hole (71) on the water spray pipe (7) into the sediment (13), the sediment (13) is diluted and liquefied to form a suspension, and the sediment (13) suspension is sucked into the sediment (13) under the suction of the mud pump. The slag suction pipe (6) is discharged along the inner pipe (31) of the double pipe (3) into the waste discharge pipe (11); as the suspension of the slag (13) is discharged, the baffle plate (5) sinks, and at this time the steel cage (1) sinks synchronously, and the outer peripheral blade feet (53) of the baffle plate (5) cut down the slag; this process is repeated until the blade feet (53) cut into the original soil layer at the bottom of the pile hole (8), the mud pump is shut down, the high-pressure water is stopped, and the vibration is maintained until the double pipe no longer sinks; at this time, the thickness of the slag (13) at the bottom of the hole will be reduced to less than 50 mm.

7. The method for using the pile bottom slag reduction grouting device according to claim 5, characterized in that: During the slag reduction process, if the double tube (3) deflects and the steel cage (1) deflects to the side, the steel cage (1) is pushed to the other side and only the vibrator (4) on the opposite side is turned on to generate eccentric vibration. The double tube (3) returns to the center of the pile hole (8) and the baffle plate (5) is also adjusted.

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