A self-cleaning slag and pouring coupling device for cast-in-place piles and a construction method

Abstract

The present invention discloses a coupling device for self-cleaning slag and pouring of cast-in-place piles, which includes a diversion steel reinforcement cage and a grouting assembly; the grouting assembly is arranged in the diversion steel reinforcement cage and is parallel or coincident with the axis of the diversion steel reinforcement cage. The diversion steel reinforcement cage includes a steel reinforcement cage and spiral diversion blades welded to the outer periphery of the steel reinforcement cage; the spiral diversion blades extend spirally along the height direction of the steel reinforcement cage. The grouting assembly includes a grouting conduit, a threaded casing and a connecting piece; the threaded casing is rotatably connected to the outer periphery of the bottom of the grouting conduit through the connecting piece to rotate around the axis of the grouting conduit; the threads formed on the outer surface of the threaded casing match the spiral extension direction of the spiral diversion blades. The present invention also discloses a combined construction method for self-cleaning slag and pouring of cast-in-place piles, which uses the above device to remove the sediment at the bottom of the pile while pouring concrete. The device and the construction method improve the slag cleaning efficiency and the pile forming quality of the cast-in-place piles.

Description

Technical Field

[0001] The present invention relates to the technical field of construction pile foundation engineering construction, and particularly relates to a self-cleaning slag and pouring coupling device for cast-in-place piles and a construction method thereof. Background Art

[0002] In the field of cast-in-place pile construction, the treatment of sediment at the bottom of the pile is a key technical problem affecting the bearing performance of the pile foundation. In traditional processes, physical cleaning methods such as high-pressure jet hole cleaning and mechanical grab slag removal are usually adopted. Such processes require a separate slag cleaning process before pouring, resulting in an interruption in the construction process. Moreover, limited by the depth and diameter of the pile hole, there are problems such as a large slag cleaning blind area and poor equipment adaptability. Some technologies pre-lay a crushed stone cushion layer at the bottom of the pile, but this method not only has a large construction difficulty and increases material costs, but also easily aggravates the risk of uneven settlement of the foundation due to uneven compaction of the cushion layer. In addition, traditional processes often achieve slag peeling and floating through the self-force of concrete during the concrete pouring stage. However, especially in the construction of large-diameter piles, due to insufficient concrete impact force and turbulent flow state, it is difficult to form an effective lifting force on the sediment, resulting in the inability to completely break the adhesion force between the sediment and the bottom of the pile, and the slag cleaning effect is not good. Although current technological developments have tried to introduce the principles of fluid mechanics to optimize the catheter structure, the slag flushing ability is still limited.

[0003] There is an urgent need for an innovative solution that combines dynamic energy conversion and process integration to simultaneously complete slag peeling, lifting and discharging during the concrete pouring process, and fundamentally improve the slag cleaning efficiency and pile forming quality. Summary of the Invention

[0004] The main technical problem to be solved by the present invention is to provide a slag cleaning and pouring device for cast-in-place piles and a construction method thereof, so as to improve the efficiency of slag cleaning operations and the pile forming quality of cast-in-place piles.

[0005] To solve the above technical problems, the present invention provides a self-cleaning slag and pouring coupling device for cast-in-place piles, including a diversion steel reinforcement cage and a grouting assembly; the grouting assembly is arranged in the diversion steel reinforcement cage and is parallel or coincident with the axis of the diversion steel reinforcement cage;

[0006] The diversion steel reinforcement cage includes a steel reinforcement cage and spiral diversion blades welded to the outer periphery of the steel reinforcement cage; the spiral diversion blades extend spirally along the height direction of the steel reinforcement cage and are used to provide an upward lifting force to the flowing concrete slurry and guide the formation of a vortex;

[0007] The grouting assembly includes a grouting catheter, a threaded casing and a connecting piece; the threaded casing is rotatably connected to the outer periphery of the bottom of the grouting catheter through the connecting piece so as to rotate around the axis of the grouting catheter under the drive of the vortex; the thread formed on the outer surface of the threaded casing matches the spiral extension direction of the spiral diversion blades.

[0008] In a preferred embodiment, the grouting conduit is configured as a threaded structure near the slurry outlet.

[0009] In a preferred embodiment, the spiral guide vanes are arranged along the entire height on the outer periphery of the steel reinforcement cage.

[0010] In a preferred embodiment, the spiral guide vanes form a spiral surface with a concave center.

[0011] In a preferred embodiment, the connecting member includes a rotating support and a plurality of connecting rods; the rotating support is rotationally connected to the grouting conduit along the axial direction; one ends of the plurality of connecting rods are detachably connected to the rotating support, and the other ends are connected to the top of the threaded casing.

[0012] In a preferred embodiment, a plurality of card slots are arranged at intervals along the circumferential direction of the rotating support, and the card slots include a counterbore provided at the top of the rotating support and a notch communicating with the counterbore;

[0013] The connecting rod enters or exits the card slot through the notch; the connecting rod is provided with a protrusion at the top end, and the protrusion is placed in the counterbore and is in limit fit with the notch.

[0014] In a preferred embodiment, a circular through cavity is formed through the rotating support in the thickness direction in the middle; a set of bearings are fixedly connected in the circular through cavity; the inner ring of the bearing is fixed on the surface of the grouting conduit.

[0015] In a preferred embodiment, the pitch of the spiral guide vanes is 0.2 to 0.3 times the diameter of the pile hole.

[0016] In a preferred embodiment, the spiral guide vanes are made of steel sheets with a thickness of 5 to 15 millimeters.

[0017] The present invention also provides a combined construction method for self-cleaning slag and pouring of cast-in-place piles. Using the device described above, when pouring concrete, the spiral guide vanes are used to guide the concrete slurry to form a vortex and an upward lifting force, so as to flush out the sediment slurry at the bottom of the pile hole, and combine the buoyancy of the concrete slurry on the sediment slurry to lift the sediment slurry to the orifice of the pile hole; the vortex drives the threaded casing to rotate to enhance the vortex lifting force.

[0018] Compared with the prior art, the technical solution of the present invention has the following beneficial effects:

[0019] Combined with the basic principles of fluid mechanics, through optimizing the structural configuration and connection coordination of the self-cleaning slag and perfusion coupling device, the present invention realizes the effective self-removal of the sediment at the bottom of the pile during the perfusion process of the cast-in-place pile. On the one hand, the multi-directional and three-dimensional lifting force provided by the device can more effectively break the viscous effect between the sediment slurry and the bottom of the pile, thereby enhancing the slag cleaning effect and improving the construction quality of the pile foundation. On the other hand, thanks to the device, the construction personnel can organically combine the slag cleaning operation into the perfusion process, avoiding the process fragmentation of hole cleaning and grouting in the traditional process, which is of great significance for simplifying the construction process, reducing construction investment and improving construction efficiency. In addition, the detachable threaded casing provides convenience for the disassembly, turnover and maintenance of the equipment. Therefore, the device and the construction method synchronously solve the technical problems of incomplete slag cleaning and cumbersome processes in the traditional process by constructing an innovative pile bottom self-cleaning slag system, and have high engineering reference significance and broad engineering application prospects. BRIEF DESCRIPTION OF THE DRAWINGS

[0020] Figure 1 is a three-dimensional schematic diagram of the self-cleaning slag and perfusion coupling device in the embodiment of the present invention;

[0021] Figure 2 is a three-dimensional schematic diagram of the diversion steel cage in the embodiment of the present invention;

[0022] Figure 3 is a three-dimensional schematic diagram of the grouting assembly in the embodiment of the present invention;

[0023] Figure 4 is a three-dimensional schematic diagram of the threaded casing and the connecting piece in the embodiment of the present invention;

[0024] Figure 5 is a three-dimensional schematic diagram of the connecting piece in the embodiment of the present invention;

[0025] Figure 6 is a schematic diagram of the threaded section at the slurry outlet of the grouting conduit in the embodiment of the present invention;

[0026] Figure 7 is a schematic diagram of the combined construction of self-cleaning slag and perfusion of the cast-in-place pile in the embodiment of the present invention.

[0027] The marks in the figure are: 1 - steel cage, 2 - spiral diversion blade, 3 - grouting conduit, 31 - threaded section, 4 - threaded casing, 5 - connecting piece, 51 - rotating support, 511 - circular through cavity, 512 - bearing, 513 - clamping groove, 5131 - counterbore, 5132 - notch, 52 - connecting rod, 521 - protrusion, 6 - concrete slurry, 7 - sediment slurry, 8 - pile hole. DETAILED DESCRIPTION OF THE EMBODIMENTS

[0028] The technical solutions in the embodiments of the present invention will be clearly and completely described below in conjunction with the accompanying drawings in the embodiments of the present invention. Obviously, the described embodiments are only a part of the embodiments of the present invention, rather than all the embodiments. All other embodiments obtained by those of ordinary skill in the art based on the embodiments of the present invention without creative efforts shall fall within the protection scope of the present invention.

[0029] In the description of the present invention, it should be noted that the orientation or positional relationship indicated by the terms "upper", "lower", "inner", "outer", "top / bottom end", etc. is based on the orientation or positional relationship shown in the drawings, and is only for the convenience of describing the present invention and simplifying the description, rather than indicating or implying that the device or element referred to must have a specific orientation, be constructed and operated in a specific orientation, and thus should not be construed as a limitation of the present invention. In addition, the terms "first" and "second" are only used for descriptive purposes and cannot be construed as indicating or implying relative importance.

[0030] In the description of the present invention, it should be noted that unless otherwise clearly specified and limited, the terms "installed", "provided with", "sheathed / connected", "connected", etc. should be understood in a broad sense. For example, "connected" can be a wall-mounted connection, a detachable connection, or an integral connection, can be a mechanical connection, an electrical connection, can be directly connected, or indirectly connected through an intermediate medium, and can be the communication inside two elements. For those of ordinary skill in the art, the specific meanings of the above terms in the present invention can be understood according to specific circumstances.

[0031] As Figures 1 to 7 shown, the embodiment of the present invention provides a bored pile self-cleaning slag and pouring coupling device, which includes a diversion steel cage and a grouting assembly. The diversion steel cage includes a steel cage 1 and a spiral diversion blade 2 welded to the outer periphery of the steel cage 1. The grouting assembly includes a grouting conduit 3, a threaded casing 4 and a connecting piece 5. The threaded casing 4 is rotatably connected to the outer periphery of the bottom of the grouting conduit 3 through the connecting piece 5. The specific structure and connection method of the device will be further described below with reference to the drawings.

[0032] As Figure 2As shown, the steel reinforcement cage 1 is cylindrical and is welded by a number of longitudinal stressed main steel bars, hoop stirrups and spiral stirrups. The spiral guide vane 2 is made of steel sheets and spirally extends along the height direction of the steel reinforcement cage 1. Preferably, the spiral guide vane 2 is provided throughout the height on the outer periphery of the steel reinforcement cage 1. The spiral guide vane 2 constructs a spiral surface with a concave center, that is, in any diameter direction, the spiral guide vane 2 extends outward at an upward horizontal inclination angle. In this embodiment: the thickness of the spiral guide vane 2 is set to 5 to 15 mm, and the width is 30 cm; the pitch, that is, the distance between adjacent two layers of spiral guide vanes 2 is set to 0.2 to 0.3 times the diameter of the pile hole; the guide angle, that is, the horizontal inclination angle of the spiral guide vane 2 is set to 30°.

[0033] As Figure 4 , Figure 5 shown, the connecting member 5 is generally in the shape of a flying chair facility and includes a rotating support 51 and a number of connecting rods 52. The rotating support 51 is constructed with a circular through cavity 511 penetrating in the thickness direction in the middle. A set of bearings 512 are fixedly connected in the circular through cavity 511, and the bearings 512 are sleeved on the outer periphery of the grouting conduit 3 and welded and fixed, so that the rotating support 51 can rotate around the grouting conduit 3. A number of card slots 513 are arranged at intervals along the circumferential direction on the outer periphery of the rotating support 51. The card slots 513 include a counterbore 5131 and a notch 5132 communicating with the counterbore 5131. Specifically, the rotating support 51 constructs the counterbore 5131 by concave downward from the top; at the position corresponding to the counterbore 5131, the rotating support 51 cuts out the vertical or inclined notch 5132 from the outer wall.

[0034] The plurality of connecting rods 52 are equivalent to the spokes of the flying chair facility. One end of the connecting rod 52 is configured with a spherical protrusion 521. The minimum width of the connecting rod 52 is less than the width of the notch 5132; the minimum width of the protrusion 521 is greater than the width of the notch 5132, and the maximum width is less than the inner diameter of the counterbore 5131. Preferably, the depth of the counterbore 5131 is not less than the height of the protrusion 521, that is, not less than the diameter of the protrusion 521 in this embodiment. Based on this structural relationship, during installation, the connecting rod 52 is laterally inserted into the notch 5132 and then pulled down, and the protrusion 521 is inserted into the counterbore 5131. The protrusion 521 is clamped in the card slot 513 through the limit fit with the notch 5132 in the vertical or horizontal direction, realizing the detachable connection between the connecting rod 52 and the rotating support 51. One end of the connecting rod 52 away from the rotating support 51 is welded to the top of the spiral casing. In this way, the spiral casing can rotate around the grouting conduit 3 under the action of an external force together with the rotating support 51. The threads formed on the outer surface of the threaded casing 4 match the spiral extension direction of the spiral guide vane 2 to strengthen the vortex effect of the concrete slurry 6 during rotation.

[0035] As Figure 7 shown, during grouting construction, the diversion steel reinforcement cage is centrally inserted into the pile hole 8. The grouting conduit 3 is connected to the threaded casing 4 and then inserted into the diversion steel reinforcement cage, parallel or coincident with the axis of the diversion steel reinforcement cage. Preferably, as Figure 6 shown, in this embodiment, the grouting conduit 3 is configured as a threaded structure near the slurry outlet, hereinafter referred to as the threaded grouting section.

[0036] As Figure 7As shown, in actual slag removal construction, in order to improve the fluidity of the pile bottom sediment, mud will be injected in advance to bond and entrain the pile bottom sediment. Hereinafter, this part of the mud mixed with sediment is referred to as sediment mud 7. During the grouting construction, the grouting conduit 3 is sprayed from a height of 2 to 15 cm from the bottom of the pile hole 8. The high-pressure sprayed concrete slurry 6 accelerates the tangential flow under the constraint of the threaded grouting section, and forms an initial vortex at the slurry outlet. The initial vortex flows at high speed around under the guidance of the pile bottom and rushes to the spiral guide vane 2 on the periphery. On the one hand, the spiral guide vane 2 with a certain inclination angle decomposes the dynamic pressure and drag force from the concrete slurry 6 into an upward lifting force. At the same time, the concrete slurry 6 forms a local vortex when it spirally climbs along the surface of the spiral guide vane 2, driving the inner threaded casing 4 to rotate. The threaded sleeve 4 is constructed with a thread on the outer surface that matches the spiral extension direction of the spiral guide vane 2, so that the threaded sleeve 4 further strengthens and gathers the local vortex when rotating, so that the concrete slurry 6 generates a stable vortex lift. Under the three-dimensional action of the lifting force and the vortex lift, the sediment slurry 7 is rolled up from the pile bottom to separate from the pile bottom. As the concrete is poured, the sediment slurry 7 with a smaller overall density continues to be lifted up under the buoyancy of the concrete slurry 6. A small part of the sediment slurry 7 and the concrete slurry 6 are centrifuged to the inner wall of the pile hole 8 under the action of the spiral guide vane, and most of the sediment slurry 7 is lifted to the orifice of the pile hole 8 as the grouting continues.

[0037] The following is an explanation of the working principle of the device when impacting the pile bottom and lifting the sediment slurry through mechanical analysis.

[0038] (1) Sediment slurry gravity

[0039] The diameter D of the bored pile bottom is equivalent to the area of ​​the sediment slurry, and the thickness of the sediment slurry is t and the density is ρ s , then the gravity of the sediment slurry is W s for:

[0040]

[0041] Where g is the acceleration due to gravity.

[0042] (2) Concrete lifting force

[0043] Assuming the density of concrete is ρ and the pouring speed is v, the dynamic pressure of concrete during pouring is P d for:

[0044]

[0045] Assume that the concrete ejection area from the grouting conduit 3 is A (take the cross-sectional area of ​​the grouting outlet of the grouting conduit 3), and the drag coefficient is C d , then the drag force F exerted by the concrete on the spiral guide vane 2drag is:

[0046] F drag = C d AP d ③

[0047] The drag force F drag is in the direction along the extension direction of the spiral guide vane 2. Since the spiral guide vane 2 is provided with a certain guide angle θ, the upward force F drag obtained by decomposing the drag force F up in the vertical direction is:

[0048] F up = F drag sinθ ④

[0049] (2) Concrete vortex lift

[0050] Let the central radius of the spiral guide vane 2 be r, and the rotational speed of the concrete vortex be n (unit: revolutions per second), then the tangential velocity v t (i.e., the linear velocity) is:

[0051] v t = 2πnr ⑤

[0052] Let the lift coefficient be C L , and the effective guide area be A eff (usually taking the vertical projection area of the spiral guide vane 2), then the vortex lift F lift generated by the flow of the concrete slurry on the spiral guide vane 2 is

[0053]

[0054] (3) Comprehensive concrete lifting force

[0055] The comprehensive lifting force F total of the sediment slurry during the concrete pouring process is the sum of the upward force F drag and the vortex lift F lift , that is

[0056] F total = F up + F lift ⑦

[0057] To achieve the purpose of removing the sediment slurry at the bottom of the pile, it must be satisfied that:

[0058] F total > W s ⑧

[0059] By combining equations ① - ⑧, we get

[0060]

[0061] Considering the influence of slurry wall protection in actual construction, a correction factor α is introduced to correct the rotation speed of the concrete slurry in the pile hole. Then, Equation ⑨ can be reorganized as

[0062]

[0063] In this embodiment, the specific coefficient values are: ρ = 2400 kg / m 3 , v = 2.0 m / s, C d = 1.2, α = 1, C L = 0.8, ρ s = 1800 kg / m 3 , g = 9.81 m / s 2 ,

[0064] The concrete ejection area A, the diversion angle θ of the spiral diversion blade 2, the central radius r, the effective diversion area A eff , the rotation speed n of the concrete vortex, the pile bottom diameter D, and the sediment slurry thickness t depend on the specific project. According to the specific dimensions of each component and the spraying speed of the concrete during construction, making Equation ⑩ hold can theoretically achieve the lifting of the sediment slurry at the pile bottom.

[0065] Based on the above device, the embodiment of the present invention also provides a combined construction method for self-cleaning sediment and pouring of cast-in-place piles, including the following steps:

[0066] Step 1: Apply slurry for wall protection and sediment slurry

[0067] Apply slurry for wall protection on the inner wall of the pile hole 8 to stabilize the hole wall, and inject an appropriate amount of slurry for wall protection into the pile bottom and mix it with the sediment to form sediment slurry 7. As a mature existing technology, the specific construction is not elaborated in this article.

[0068] Step 2: Install the device and position it

[0069] Assemble the steel reinforcement cage 1 and weld the spiral diversion blade 2 on the outer periphery to form the diversion steel reinforcement cage. At the same time, install the threaded sleeve at the bottom of the grouting conduit 3 through the connecting piece 5 to form the grouting assembly.

[0070] Lower the assembled diversion steel reinforcement cage and grouting assembly into the pile hole 8, and ensure that there is an appropriate gap between the spiral diversion blade 2 and the inner wall of the pile hole 8.

[0071] Step 3: Pour and clean the sediment

[0072] The slurry outlet of the grouting conduit 3 is located 2 to 15 cm from the bottom of the pile, and then the concrete pump is started. The concrete slurry 6 flows at high speed at the bottom of the pile. With the upward force and vortex lift formed by the spiral guide vane 2 and the threaded casing 4, the sediment slurry 7 at the bottom of the pile is flushed up.

[0073] Then, continuously lift the grouting conduit 3. By using the buoyancy provided by the lower concrete slurry 6 to the sediment slurry 7 and the vortex effect generated by the spiral guide vane 2, the sediment slurry 7 is lifted to the orifice of the pile hole 8.

[0074] Step 4: Disassemble the grouting assembly

[0075] After the pouring is completed, remove the protrusion 521 on the connecting rod 52 from the clamping groove 513 to disassemble the grouting conduit 3 and the threaded casing 4. Clean the disassembled grouting assembly for reuse in rotation.

[0076] In summary, the embodiment of the present invention combines the basic principles of fluid mechanics. By optimizing the structural configuration and connection cooperation of the self-cleaning slag and pouring device, the effective self-removal of the sediment at the bottom of the pile in the pile grouting process is realized. On the one hand, the multi-directional and three-dimensional upward force more effectively breaks the viscous action between the sediment slurry 7 and the bottom of the pile, thereby enhancing the slag cleaning effect and improving the construction quality of the pile foundation. On the other hand, thanks to the device, the construction personnel can organically combine the slag cleaning operation into the pouring process, avoiding the separation of the hole cleaning and grouting processes in the traditional process, which is of great significance for simplifying the construction process, reducing the construction input, and improving the construction efficiency. In addition, the detachable threaded casing 4 facilitates the disassembly, turnover, and maintenance of the equipment. Therefore, the device and the construction method synchronously solve the technical problems of incomplete slag cleaning and cumbersome processes in the traditional process by constructing an innovative self-cleaning slag system at the bottom of the pile, and have high engineering reference significance and broad engineering application prospects.

[0077] For those of ordinary skill in the art, although the above embodiments can well illustrate the technical solutions of the present invention, without departing from the basic idea of the present invention, various changes and improvements can still be made to the structures, parameters, and construction methods of each component, which should all be regarded as within the protection scope of the present invention.

Claims

1. A self-cleaning slag and pouring coupling device for cast-in-place piles, characterized in that: It includes a diversion steel reinforcement cage and a grouting assembly; the grouting assembly is arranged in the diversion steel reinforcement cage and is parallel or coincident with the axis of the diversion steel reinforcement cage; The diversion steel reinforcement cage includes a steel reinforcement cage and spiral diversion vanes welded to the outer periphery of the steel reinforcement cage; the spiral diversion vanes spirally extend along the height direction of the steel reinforcement cage and are used to provide an upward lifting force to the flowing concrete slurry and guide it to form a vortex; The grouting assembly includes a grouting conduit, a threaded casing and a connecting member; the threaded casing is rotatably connected to the outer periphery of the bottom of the grouting conduit through the connecting member so as to rotate around the axis of the grouting conduit under the drive of the vortex; the threads formed on the outer surface of the threaded casing match the spiral extension direction of the spiral diversion vanes.

2. The self-cleaning slag and pouring coupling device for cast-in-place piles according to claim 1, characterized in that: A section of threaded structure is configured at the grouting conduit near the slurry outlet.

3. The self-cleaning slag and pouring coupling device for cast-in-place piles according to claim 1, characterized in that: The spiral diversion vanes are arranged throughout the height on the outer periphery of the steel reinforcement cage.

4. The self-cleaning slag and pouring coupling device for cast-in-place piles according to claim 1, wherein: The spiral diversion vanes are configured to have a spiral surface with a concave center.

5. The self-cleaning slag and pouring coupling device for cast-in-place piles according to claim 1, characterized in that: The connecting member includes a rotating support and a plurality of connecting rods; the rotating support is axially rotatably connected to the grouting conduit; one ends of the plurality of connecting rods are detachably connected to the rotating support, and the other ends are connected to the top of the threaded casing.

6. The self-cleaning slag and pouring coupling device for cast-in-place piles according to claim 5, characterized in that: A plurality of card slots are arranged at intervals along the circumferential direction of the rotating support, and the card slots include a counterbore arranged at the top of the rotating support and a notch communicated with the counterbore; The connecting rod enters or exits the card slot through the notch; a protrusion is configured at the top end of the connecting rod, and the protrusion is placed in the counterbore and is in limit fit with the notch.

7. A self-cleaning slag and pouring coupling device for cast-in-place piles according to claim 5, characterized in that: A circular through cavity is configured to penetrate through the rotating support in the thickness direction in the middle; a group of bearings are fixedly connected in the circular through cavity; the inner ring of the bearing is fixed on the surface of the grouting conduit.

8. The self-cleaning slag and pouring coupling device for cast-in-place piles according to claim 1, wherein: The pitch of the spiral diversion vanes is 0.2 to 0.3 times the diameter of the pile hole.

9. The self-cleaning slag and pouring coupling device for cast-in-place piles according to claim 1, characterized in that: The spiral diversion vanes are made of steel sheets with a thickness of 5 to 15 millimeters.

10. A construction method for combined self-cleaning of sediment and pouring of cast-in-place piles, using a coupling device for self-cleaning of sediment and pouring of cast-in-place piles according to any one of claims 1 to 9, characterized in that: When pouring concrete, the vortex and upward lifting force formed by guiding the concrete slurry by the spiral diversion vanes are used to flush out the sediment slurry at the bottom of the pile hole, and the sediment slurry is lifted to the orifice of the pile hole by combining the buoyancy of the concrete slurry on the sediment slurry; the vortex drives the threaded casing to rotate to enhance the vortex lift force.

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